R&S®FPS-K10x (LTE Downlink)
LTE Downlink Measurement
Application
User Manual
(;ÚãÒ2)
1176856802
Version 09
This manual applies to the following R&S®FPS models with firmware version 1.70 and higher:
●
R&S®FPS4 (1319.2008K04)
●
R&S®FPS7 (1319.2008K07)
●
R&S®FPS13 (1319.2008K13)
●
R&S®FPS30 (1319.2008K30)
●
R&S®FPS40 (1319.2008K40)
The following firmware options are described:
●
R&S FPS-K100 (LTE FDD DL) (order no. 1321.4227.02)
●
R&S FPS-K102 (LTE MIMO DL) (order no. 1321.4233.02)
●
R&S FPS-K104 (LTE TDD DL) (order no. 1321.4233.02)
© 2021 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: +49 89 41 29 - 0
Email: info@rohde-schwarz.com
Internet: www.rohde-schwarz.com
Subject to change – data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of the owners.
1176.8568.02 | Version 09 | R&S®FPS-K10x (LTE Downlink)
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol , e.g. R&S®FPS is indicated as
R&S FPS.
R&S®FPS-K10x (LTE Downlink)
Contents
1 Preface.................................................................................................... 7
1.1 About this Manual......................................................................................................... 7
1.2 Typographical Conventions......................................................................................... 7
2 Welcome to the LTE Measurement Application.................................. 9
2.1 Overview of the LTE Applications............................................................................... 9
2.2 Installation................................................................................................................... 11
2.3 Starting the LTE Measurement Application.............................................................. 11
2.4 Understanding the Display Information....................................................................12
3 Measurements and Result Displays...................................................14
3.1 Selecting Measurements............................................................................................ 14
Contents
3.2 Selecting Result Displays.......................................................................................... 16
3.3 Performing Measurements.........................................................................................16
3.4 Selecting the Operating Mode................................................................................... 17
3.5 I/Q Measurements....................................................................................................... 18
3.6 Time Alignment Error Measurements....................................................................... 38
3.7 Transmit On / Off Power Measurement.....................................................................39
3.8 Frequency Sweep Measurements............................................................................. 43
3.9 3GPP Test Scenarios.................................................................................................. 52
4 Measurement Basics........................................................................... 54
4.1 Symbols and Variables...............................................................................................54
4.2 Overview...................................................................................................................... 55
4.3 The LTE Downlink Analysis Measurement Application...........................................55
4.3.1 Synchronization.............................................................................................................55
4.3.2 Channel Estimation and Equalization........................................................................... 57
4.3.3 Analysis.........................................................................................................................57
4.4 MIMO Measurement Guide......................................................................................... 58
4.4.1 MIMO Measurements with Signal Analyzers................................................................ 59
4.5 Performing Time Alignment Measurements.............................................................63
4.6 Performing Transmit On/Off Power Measurements.................................................64
5 Configuration........................................................................................67
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5.1 Configuration Overview..............................................................................................67
5.2 I/Q Measurements....................................................................................................... 69
5.2.1 Signal Characteristics................................................................................................... 70
5.2.2 Configuring MIMO Setups.............................................................................................78
5.2.3 PDSCH Demodulation.................................................................................................. 80
5.2.4 PDSCH Subframe Configuration...................................................................................81
5.2.5 Synchronization Signal Configuration........................................................................... 88
5.2.6 Reference Signal Configuration.................................................................................... 89
5.2.7 Positioning Reference Signal Configuration..................................................................90
5.2.8 Channel State Information Reference Signal Configuration......................................... 92
5.2.9 PDSCH Resource Block Symbol Offset........................................................................94
5.2.10 PBCH Configuration......................................................................................................95
5.2.11 PCFICH Configuration.................................................................................................. 96
Contents
5.2.12 PHICH Configuration.....................................................................................................97
5.2.13 PDCCH Configuration................................................................................................. 100
5.2.14 EPDCCH Configuration...............................................................................................101
5.2.15 Shared Channel Configuration....................................................................................103
5.2.16 MBSFN Characteristics...............................................................................................103
5.2.17 Input Source Configuration......................................................................................... 106
5.2.18 Frequency Configuration.............................................................................................106
5.2.19 Amplitude Configuration..............................................................................................107
5.2.20 Data Capture............................................................................................................... 111
5.2.21 Trigger Configuration...................................................................................................113
5.2.22 Parameter Estimation and Tracking............................................................................ 115
5.2.23 Measurement Error Compensation............................................................................. 116
5.2.24 Demodulation.............................................................................................................. 117
5.2.25 Automatic Configuration.............................................................................................. 119
5.3 Time Alignment Error Measurements..................................................................... 120
5.4 Power On/Off Measurements................................................................................... 120
5.5 Frequency Sweep Measurements........................................................................... 121
5.5.1 ACLR Signal Description.............................................................................................122
5.5.2 SEM and Multi-Carrier SEM Signal Description..........................................................122
5.5.3 Cumulative ACLR........................................................................................................124
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5.5.4 MC ACLR.................................................................................................................... 124
6 Analysis.............................................................................................. 126
6.1 General Analysis Tools.............................................................................................126
6.1.1 Data Export................................................................................................................. 126
6.1.2 Microservice Export.....................................................................................................127
6.1.3 Diagram Scale.............................................................................................................127
6.1.4 Zoom........................................................................................................................... 128
6.1.5 Markers....................................................................................................................... 128
6.2 Analysis Tools for I/Q Measurements..................................................................... 129
6.2.1 Layout of Numerical Results....................................................................................... 129
6.2.2 Evaluation Range........................................................................................................130
6.2.3 Result Settings............................................................................................................ 133
Contents
6.3 Analysis Tools for Frequency Sweep Measurements............................................134
7 Remote Control.................................................................................. 135
7.1 Common Suffixes......................................................................................................135
7.2 Introduction............................................................................................................... 136
7.2.1 Conventions used in Descriptions...............................................................................136
7.2.2 Long and Short Form.................................................................................................. 137
7.2.3 Numeric Suffixes......................................................................................................... 137
7.2.4 Optional Keywords...................................................................................................... 138
7.2.5 Alternative Keywords.................................................................................................. 138
7.2.6 SCPI Parameters........................................................................................................ 138
7.3 Remote Commands to Select the LTE Application................................................ 141
7.4 Screen Layout........................................................................................................... 144
7.4.1 General Layout............................................................................................................144
7.4.2 Layout of a Single Channel......................................................................................... 146
7.5 Measurement Control............................................................................................... 155
7.5.1 Measurements............................................................................................................ 155
7.5.2 Measurement Sequences........................................................................................... 157
7.6 Trace Data Readout...................................................................................................159
7.6.1 The TRACe[:DATA] Command....................................................................................159
7.6.2 Result Readout........................................................................................................... 176
7.7 Numeric Result Readout.......................................................................................... 178
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7.7.1 Frame Results.............................................................................................................178
7.7.2 Result for Selection..................................................................................................... 180
7.7.3 Time Alignment Error.................................................................................................. 186
7.7.4 Marker Table............................................................................................................... 187
7.7.5 CCDF Table.................................................................................................................191
7.8 Limit Check Result Readout.................................................................................... 192
7.8.1 Limits for Graphical Result Displays........................................................................... 192
7.8.2 Limits for Numerical Result Display............................................................................ 194
7.9 Configuration.............................................................................................................202
7.9.1 General Configuration................................................................................................. 202
7.9.2 I/Q Measurements.......................................................................................................204
7.9.3 Time Alignment Error Measurements..........................................................................257
7.9.4 Transmit On/Off Power Measurements.......................................................................258
Contents
7.9.5 Frequency Sweep Measurements.............................................................................. 260
7.10 Analysis..................................................................................................................... 264
7.10.1 Trace Export................................................................................................................264
7.10.2 Microservice Export.....................................................................................................265
7.10.3 Evaluation Range........................................................................................................266
7.10.4 Y-Axis Scale................................................................................................................ 270
7.10.5 Result Settings............................................................................................................ 271
List of commands.............................................................................. 274
Index....................................................................................................281
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1 Preface
1.1 About this Manual
This LTE User Manual provides all the information specific to the application. All
general instrument functions and settings common to all applications and operating
modes are described in the main R&S FPS User Manual.
The main focus in this manual is on the LTE measurement results and the tasks
required to obtain them. The following topics are included:
●
Welcome to the LTE application
Introduction to and getting familiar with the application
●
Measurements and result displays
Details on supported LTE measurements and their result types
●
Measurement basics
Background information on basic terms and principles in the context of LTE measurements
●
Configuration and analysis
A concise description of all functions and settings available to configure and analyze LTE measurements with their corresponding remote control command
●
Optimizing and troubleshooting the measurement
Hints and tips on how to handle errors and optimize the test setup
●
Remote commands for LTE measurements
Remote commands required to configure and perform LTE measurements in a
remote environment, sorted by tasks
(Commands required to set up the environment or to perform common tasks on the
instrument are provided in the main R&S FPS User Manual)
●
List of remote commands
Alpahabetical list of all remote commands described in the manual
●
Index
Preface
Typographical Conventions
1.2 Typographical Conventions
The following text markers are used throughout this documentation:
Convention Description
"Graphical user interface elements"
[Keys] Key and knob names are enclosed by square brackets.
Filenames, commands,
program code
All names of graphical user interface elements on the screen, such as
dialog boxes, menus, options, buttons, and softkeys are enclosed by
quotation marks.
Filenames, commands, coding samples and screen output are distinguished by their font.
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Convention Description
Input Input to be entered by the user is displayed in italics.
Links Links that you can click are displayed in blue font.
"References" References to other parts of the documentation are enclosed by quota-
Preface
Typographical Conventions
tion marks.
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2 Welcome to the LTE Measurement Applica-
tion
The R&S FPS-K100, -K102 and -K104 are firmware applications that add functionality
to measure LTE signals according to the 3GPP standard to the R&S FPS.
This user manual contains a description of the functionality that the application provides, including remote control operation. Functions that are not discussed in this manual are the same as in the Spectrum application and are described in the R&S FPS
User Manual. The latest versions of the manuals are available for download at the
product homepage.
https://www.rohde-schwarz.com/manual/fps.
● Overview of the LTE Applications............................................................................. 9
● Installation............................................................................................................... 11
● Starting the LTE Measurement Application............................................................. 11
● Understanding the Display Information...................................................................12
Welcome to the LTE Measurement Application
Overview of the LTE Applications
2.1 Overview of the LTE Applications
You can equip the R&S FPS with one or more LTE applications. Each of the applications provides functionality for specific measurement tasks.
R&S FPS-K100
The R&S FPS-K100 is designed to measure LTE FDD signals on the downlink.
The application has the following features:
●
Basic signal characteristics (like frequency, channel bandwidth or cyclic prefix).
●
Demodulation and configuration of the PDSCH transmitted over a single antenna
and without precoding functionality.
●
Characteristics of the Synchronization and Reference signals.
●
Consideration of various control channels in the measurement (for example the
PBCH or the PPDCH).
●
Analysis of individual antennas in a MIMO setup.
●
Tools to refine and filter the measurement results.
●
Various result displays that show the measured signal characteristics in a diagram
or a numeric result table.
●
Available measurements: EVM, ACLR and SEM.
R&S FPS-K101
The R&S FPS-K101 is designed to measure LTE FDD signals on the uplink.
The application has the following features:
●
Basic signal characteristics (like frequency, channel bandwidth or cyclic prefix).
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●
Demodulation and configuration of the subframes transmitted over a single
antenna.
●
Characteristics of the demodulation and sounding reference signals.
●
Consideration of the PUSCH, PUCCH and PRACH channels.
●
Analysis of individual antennas in a MIMO setup.
●
Tools to refine and filter the measurement results.
●
Various result displays that show the measured signal characteristics in a diagram
or a numeric result table.
●
Available measurements: EVM, ACLR and SEM.
R&S FPS-K102
The R&S FPS-K102 is designed to measure LTE Advanced systems and MIMO systems on the downlink.
Note that this application only works in combination with either R&S FPS-K100 or K104.
The application has the following features:
●
Support of 1024QAM modulation.
●
Consideration of the precoding schemes defined in the 3GPP standard.
●
Support of carrier aggregation.
●
Measurements on multimedia broadcast single frequency networks (MBSFNs).
●
Additional measurements: time alignment error, multi-carrier ACLR, cumulative
ACLR and multi-SEM.
Welcome to the LTE Measurement Application
Overview of the LTE Applications
R&S FPS-K103
The R&S FPS-K103 is designed to measure LTE Advanced systems on the uplink.
Note that this application only works in combination with either R&S FPS-K101 or K105.
The application has the following features:
●
Support of 256QAM modulation.
●
Consideration of the enhanced PUSCH and PUCCH characteristics.
●
Support of carrier aggregation.
●
Additional measurements: time alignment error, multi-carrier ACLR and multi SEM.
R&S FPS-K104
The R&S FPS-K104 is designed to measure LTE TDD signals on the downlink.
The features are basically the same as in the R&S FPS-K100 with additional features
that allow you to configure TDD subframes. It also provides tools to measure the
On/Off Power.
R&S FPS-K105
The R&S FPS-K105 is designed to measure LTE TDD signals on the uplink.
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The features are basically the same as in the R&S FPS-K101 with additional features
that allow you to configure TDD subframes.
2.2 Installation
Find detailed installing instructions in the Getting Started or the release notes of the
R&S FPS.
2.3 Starting the LTE Measurement Application
The LTE measurement application adds a new application to the R&S FPS.
Manual operation via an external monitor and mouse
Although the R&S FPS does not have a built-in display, it is possible to operate it interactively in manual mode using a graphical user interface with an external monitor and
a mouse connected.
It is recommended that you use the manual mode initially to get familiar with the instrument and its functions before using it in pure remote mode. Thus, this document
describes in detail how to operate the instrument manually using an external monitor
and mouse. The remote commands are described in the second part of the document.
For details on manual operation, see the R&S FPS Getting Started manual.
Welcome to the LTE Measurement Application
Starting the LTE Measurement Application
To activate the application
1. Press the [MODE] key on the front panel of the R&S FPS.
A dialog box opens that contains all operating modes and applications currently
available on your R&S FPS.
2. Select the "LTE" item.
The R&S FPS opens a new measurement channel for the LTE measurement application.
The measurement is started immediately with the default settings. It can be configured
in the "Overview" dialog box, which is displayed when you select the "Overview" softkey from any menu.
For more information, see Chapter 5, "Configuration", on page 67.
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2.4 Understanding the Display Information
The following figure shows a measurement diagram during analyzer operation. All different information areas are labeled. They are explained in more detail in the following
sections.
1 2 3 4 5 6
Welcome to the LTE Measurement Application
Understanding the Display Information
7 8
1 = Toolbar
2 = Channel bar
3 = Diagram header
4 = Result display
5 = Tabs to select displayed information for multiple data streams
6 = Subwindows (if more than one data stream is displayed at the same time)
7 = Status bar
8 = Softkeys
MSRA operating mode
In MSRA operating mode, additional tabs and elements are available. A colored background of the screen behind the measurement channel tabs indicates that you are in
MSRA operating mode. Frequency sweep measurements are not available in MSRA
operating mode.
For details on the MSRA operating mode, see the R&S FPS MSRA User Manual.
Channel bar information
In the LTE measurement application, the R&S FPS shows the following settings:
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Table 2-1: Information displayed in the channel bar in the LTE measurement application
Ref Level Reference level
Att Mechanical and electronic RF attenuation
Freq Frequency
Mode LTE standard
MIMO Number of Tx and Rx antennas in the measurement setup
Capture Time Signal length that has been captured
Frame Count Number of frames that have been captured
Selected Subframe Subframe considered in the signal analysis
In addition, the channel bar also displays information on instrument settings that affect
the measurement results even though this is not immediately apparent from the display
of the measured values (for example transducer or trigger settings). This information is
displayed only when applicable for the current measurement. For details, see the
R&S FPS Getting Started manual.
Welcome to the LTE Measurement Application
Understanding the Display Information
Window title bar information
The information in the window title bar depends on the result display.
The "Constellation Diagram", for example, shows the number of points that have been
measured.
Status bar information
Global instrument settings, the instrument status and any irregularities are indicated in
the status bar beneath the diagram. Furthermore, the progress of the current operation
is displayed in the status bar.
Regarding the synchronization state, the application shows the following labels.
●
Sync OK
The synchronization was successful. The status bar is green.
●
Sync Failed
The synchronization was not successful. The status bar is red.
There can be three different synchronization errors.
– Sync Failed (Cyclic Prefix): The cyclic prefix correlation failed.
– Sync Failed (P-SYNC): The P-SYNC correlation failed.
– Sync Failed (S-SYNC): The S-SYNC correlation failed.
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3 Measurements and Result Displays
The LTE measurement application measures and analyzes various aspects of an LTE
signal.
It features several measurements and result displays. Measurements represent different ways of processing the captured data during the digital signal processing. Result
displays are different representations of the measurement results. They may be diagrams that show the results as a graph or tables that show the results as numbers.
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 202
Result display selection: LAYout:ADD[:WINDow]? on page 146
● Selecting Measurements.........................................................................................14
● Selecting Result Displays........................................................................................16
● Performing Measurements......................................................................................16
● Selecting the Operating Mode.................................................................................17
● I/Q Measurements...................................................................................................18
● Time Alignment Error Measurements..................................................................... 38
● Transmit On / Off Power Measurement...................................................................39
● Frequency Sweep Measurements.......................................................................... 43
● 3GPP Test Scenarios..............................................................................................52
Measurements and Result Displays
Selecting Measurements
3.1 Selecting Measurements
Access: "Overview" > "Select Measurement"
The "Select Measurement" dialog box contains several buttons. Each button represents a measurement. A measurement in turn is a set of result displays that thematically belong together and that have a particular display configuration. If these predefined display configurations do not suit your requirements, you can add or remove
result displays as you like. For more information about selecting result displays, see
Chapter 3.2, "Selecting Result Displays", on page 16.
Depending on the measurement, the R&S FPS changes the way it captures and processes the raw signal data.
EVM
EVM measurements record, process and demodulate the signal's I/Q data. The result
displays available for EVM measurements show various aspects of the LTE signal
quality.
For EVM measurements, you can combine the result displays in any way.
For more information on the result displays, see Chapter 3.5, "I/Q Measurements",
on page 18.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
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Time alignment error
Time alignment error (TAE) measurements record, process and demodulate the signal's I/Q data. The result displays available for TAE measurements indicate how well
the antennas in a multi-antenna system are aligned.
For TAE measurements, you can combine the result displays in any way.
For more information on the result displays, see Chapter 3.6, "Time Alignment Error
Measurements", on page 38.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
Transmit on / off power
Transmit on / off power measurements record and process the signal's I/Q data without
demodulating the data. The result displays available for transmit on / off power measurements show various aspects of the transition from on to off power.
For transmit on / off power measurements, you can combine the result displays in any
way.
For more information on the result displays, see Chapter 3.7, "Transmit On / Off Power
Measurement", on page 39.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
Measurements and Result Displays
Selecting Measurements
Channel power ACLR
(inludes multi carrier ACLR and cumulative ACLR measurements)
ACLR measurements sweep the frequency spectrum instead of processing I/Q data.
The ACLR measurements evaluates the leakage ratio of neighboring channels and
evaluates if the signal is within the defined limits. The measurement provides several
result displays. You can combine the result displays in any way.
For more information on the result displays, see Chapter 3.8, "Frequency Sweep Mea-
surements", on page 43.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
SEM
(inlcudes multi carrier SEM measurements)
SEM measurements sweep the frequency spectrum instead of processing I/Q data.
The SEM measurements tests the signal against a spectrum emission mask and eval-
uates if the signal is within the defined limits. The measurement provides several result
displays. You can combine the result displays in any way.
For more information on the result displays, see Chapter 3.8, "Frequency Sweep Mea-
surements", on page 43.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
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3.2 Selecting Result Displays
Access:
The R&S FPS opens a menu (the SmartGrid) to select result displays. For more information on the SmartGrid functionality, see the R&S FPS Getting Started.
In the default state of the application, it shows several conventional result displays.
●
Capture Buffer
●
EVM vs Carrier
●
Power Spectrum
●
Result Summary
●
Constellation Diagram
From that predefined state, add and remove result displays as you like from the SmartGrid menu.
Remote command: LAYout:ADD[:WINDow]? on page 146
Measurements and Result Displays
Performing Measurements
Measuring several data streams
When you capture more than one data stream (for example component carriers), each
result display is made up out of several tabs.
The first tab shows the results for all data streams. The other tabs show the results for
each individual data stream. By default, the tabs are coupled to one another - if you
select a certain data stream in one display, the application also selects this data stream
in the other result displays (see Subwindow Coupling).
The number of tabs depends on the number of data streams.
3.3 Performing Measurements
By default, the application measures the signal continuously. In "Continuous Sweep"
mode, the R&S FPS captures and analyzes the data again and again.
●
For I/Q measurements, the amount of captured data depends on the capture time.
●
For frequency sweep measurement, the amount of captured data depends on the
sweep time.
In "Single Sweep" mode, the R&S FPS stops measuring after it has captured the data
once. The amount of data again depends on the capture time.
Refreshing captured data
You can also repeat a measurement based on the data that has already been captured
with the "Refresh" function. Repeating a measurement with the same data can be useful, for example, if you want to apply different modulation settings to the same I/Q data.
For more information, see the documentation of the R&S FPS.
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3.4 Selecting the Operating Mode
Access: [MODE] > "Multi-Standard Radio Analyzer Tab"
The LTE application is supported by the Multi Standard Radio Analyzer (MSRA).
The MSRA mode supports all I/Q measurements and result displays available with the
LTE application, except the frequency sweep measurements (SEM and ACLR).
In MSRA operating mode, only the MSRA master actually captures data. The application receives an extract of the captured data for analysis, referred to as the application
data. The application data range is defined by the same settings used to define the
signal capture in "Signal and Spectrum Analyzer" mode. In addition, a capture offset
can be defined, i.e. an offset from the start of the captured data to the start of the
analysis interval.
If a signal contains multiple data channels for multiple standards, separate applications
are used to analyze each data channel. Thus, it is of interest to know which application
is analyzing which data channel. The MSRA master display indicates the data covered
by each application by vertical blue lines labeled with the application name. The blue
lines correspond to the channel bandwidth.
Measurements and Result Displays
Selecting the Operating Mode
However, the individual result displays of the application need not analyze the complete data range. The data range that is actually analyzed by the individual result display is referred to as the analysis interval.
The analysis interval is automatically determined according to the Capture Time you
have defined. The analysis interval cannot be edited directly in the LTE application, but
is changed automatically when you change the evaluation range. The currently used
analysis interval (in seconds, related to capture buffer start) is indicated in the window
header for each result display.
A frequent question when analyzing multi-standard signals is how each data channel is
correlated (in time) to others. Thus, an analysis line has been introduced. The analysis
line is a common time marker for all MSRA client applications. It can be positioned in
any MSRA client application or the MSRA Master and is then adjusted in all other client
applications. Thus, you can easily analyze the results at a specific time in the measurement in all client applications and determine correlations.
If the marked point in time is contained in the analysis interval of the client application,
the line is indicated in all time-based result displays, such as time, symbol, slot or bit
diagrams. By default, the analysis line is displayed, however, it can be hidden from
view manually. In all result displays, the "AL" label in the window title bar indicates
whether the analysis line lies within the analysis interval or not:
●
orange "AL": the line lies within the interval
●
white "AL": the line lies within the interval, but is not displayed (hidden)
●
no "AL": the line lies outside the interval
For details on the MSRA operating mode, see the R&S FPS MSRA documentation.
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3.5 I/Q Measurements
Access: [MEAS] > "EVM/Frequency Err/Power"
You can select the result displays from the evaluation bar and arrange them as you like
with the SmartGrid functionality.
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 202
Result display selection: LAYout:ADD[:WINDow]? on page 146
Capture Buffer...............................................................................................................18
EVM vs Carrier..............................................................................................................19
EVM vs Symbol.............................................................................................................20
EVM vs RB....................................................................................................................21
EVM vs Subframe......................................................................................................... 21
Frequency Error vs Symbol...........................................................................................22
Power Spectrum............................................................................................................22
Power vs Resource Block PDSCH................................................................................23
Power vs Resource Block RS....................................................................................... 23
Channel Flatness.......................................................................................................... 24
Group Delay..................................................................................................................24
Channel Flatness Difference.........................................................................................25
Constellation Diagram...................................................................................................25
CCDF............................................................................................................................ 26
Allocation Summary...................................................................................................... 26
Bitstream.......................................................................................................................27
Channel Decoder Results............................................................................................. 28
EVM vs Symbol x Carrier..............................................................................................30
Power vs Symbol x Carrier............................................................................................30
Allocation ID vs Symbol x Carrier..................................................................................30
UE RS Magnitude......................................................................................................... 31
UE RS Phase................................................................................................................31
Cell RS Magnitude........................................................................................................ 32
Cell RS Phase...............................................................................................................32
CSI RS Magnitude........................................................................................................ 33
CSI RS Phase...............................................................................................................33
Beamform Allocation Summary.....................................................................................34
Result Summary............................................................................................................35
Marker Table ................................................................................................................ 37
Measurements and Result Displays
I/Q Measurements
Capture Buffer
The "Capture Buffer" shows the complete range of captured data for the last data capture.
The x-axis represents time. The maximum value of the x-axis is equal to the Capture
Time.
The y-axis represents the amplitude of the captured I/Q data in dBm (for RF input).
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Figure 3-1: Capture buffer without zoom
A colored bar at the bottom of the diagram represents the frame that is currently analyzed. Different colors indicate the OFDM symbol type.
●
Indicates the data stream.
●
Indicates the reference signal and data.
●
Indicates the P-Sync and data.
●
Indicates the S-Sync and data.
A green vertical line at the beginning of the green bar in the capture buffer represents
the subframe start. The diagram also contains the "Start Offset" value. This value is the
time difference between the subframe start and capture buffer start.
When you zoom into the diagram, you will see that the bar is interrupted at certain
positions. Each small bar indicates the useful parts of the OFDM symbol.
Measurements and Result Displays
I/Q Measurements
Figure 3-2: Capture buffer after a zoom has been applied
Remote command:
Selection: LAY:ADD ? '1',LEFT,CBUF
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Subframe start offset: FETCh[:CC<cc>]:SUMMary:TFRame? on page 186
EVM vs Carrier
The "EVM vs Carrier" result display shows the error vector magnitude (EVM) of the
subcarriers. With the help of a marker, you can use it as a debugging technique to
identify any subcarriers whose EVM is too high.
The results are based on an average EVM that is calculated over the resource elements for each subcarrier. This average subcarrier EVM is determined for each analyzed subframe in the capture buffer.
If you analyze all subframes, the result display contains three traces.
●
Average EVM
This trace shows the subcarrier EVM, averaged over all subframes.
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●
Minimum EVM
This trace shows the lowest (average) subcarrier EVM that has been found over
the analyzed subframes.
●
Maximum EVM
This trace shows the highest (average) subcarrier EVM that has been found over
the analyzed subframes.
If you select and analyze one subframe only, the result display contains one trace that
shows the subcarrier EVM for that subframe only. Average, minimum and maximum
values in that case are the same. For more information, see "Subframe Selection"
on page 131.
The x-axis represents the center frequencies of the subcarriers. The y-axis shows the
EVM in % or in dB, depending on the EVM Unit.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection LAY:ADD ? '1',LEFT,EVCA
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
EVM vs Symbol
The "EVM vs Symbol" result display shows the error vector magnitude (EVM) of the
OFDM symbols. You can use it as a debugging technique to identify any symbols
whose EVM is too high.
The results are based on an average EVM that is calculated over all subcarriers that
are part of a certain OFDM symbol. This average OFDM symbol EVM is determined for
all OFDM symbols in each analyzed subframe.
The x-axis represents the OFDM symbols, with each symbol represented by a dot on
the line. Any missing connections from one dot to another mean that the R&S FPS
could not determine the EVM for that symbol.
The number of displayed symbols depends on the subframe selection and the length of
the cyclic prefix.
For TDD signals, the result display does not show OFDM symbols that are not part of
the measured link direction.
On the y-axis, the EVM is plotted either in % or in dB, depending on the EVM Unit.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,EVSY
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
EVM vs RB
The "EVM vs RB" result display shows the Error Vector Magnitude (EVM) for all
resource blocks that can be occupied by the PDSCH.
The results are based on an average EVM that is calculated over all resource elements
in the resource block. This average resource block EVM is determined for each analyzed subframe. If you analyze all subframes, the result display contains three traces.
●
Average EVM
This trace shows the resource block EVM, averaged over all subframes.
●
Minimum EVM
This trace shows the lowest (average) resource block EVM that has been found
over the analyzed subframes.
●
Maximum EVM
This trace shows the highest (average) resource block EVM that has been found
over the analyzed subframes.
If you select and analyze one subframe only, the result display contains one trace that
shows the resource block EVM for that subframe only. Average, minimum and maximum values in that case are the same. For more information, see "Subframe Selec-
tion" on page 131.
The x-axis represents the PDSCH resource blocks. On the y-axis, the EVM is plotted
either in % or in dB, depending on the EVM Unit.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,EVRP
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
EVM vs Subframe
The "EVM vs Subframe" result display shows the Error Vector Magnitude (EVM) for
each subframe. You can use it as a debugging technique to identify a subframe whose
EVM is too high.
The result is an average over all subcarriers and symbols of a specific subframe.
The x-axis represents the subframes, with the number of displayed subframes being
10.
On the y-axis, the EVM is plotted either in % or in dB, depending on the EVM Unit.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,EVSU
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Frequency Error vs Symbol
Th e "Frequency Error vs Symbol" result display shows the frequency error of each
symbol. You can use it as a debugging technique to identify any frequency errors within
symbols.
The result is an average over all subcarriers in the symbol.
The x-axis represents the OFDM symbols, with each symbol represented by a dot on
the line. The number of displayed symbols depends on the subframe selection and the
length of the cyclic prefix. Any missing connections from one dot to another mean that
the R&S FPS could not determine the frequency error for that symbol.
Measurements and Result Displays
I/Q Measurements
On the y-axis, the frequency error is plotted in Hz.
Note that the variance of the measurement results in this result display can be much
higher compared to the frequency error display in the numerical result summary,
depending on the PDSCH and control channel configuration. The potential difference is
caused by the number of available resource elements for the measurement on symbol
level.
Remote command:
Selection: LAY:ADD ? '1',LEFT,FEVS
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Power Spectrum
The "Power Spectrum" shows the power density of the complete capture buffer in
dBm/Hz.
The displayed bandwidth depends on the selected channel bandwidth.
The x-axis represents the frequency. On the y-axis, the power level is plotted.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,PSPE
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Power vs Resource Block PDSCH
The "Power vs Resource Block PDSCH" result display shows the power of the physical
downlink shared channel per resource element averaged over one resource block.
By default, three traces are shown. One trace shows the average power. The second
and the third traces show the minimum and maximum powers respectively. You can
select to display the power for a specific subframe in the Subframe Selection dialog
box. In that case, the application shows the powers of that subframe only.
The x-axis represents the resource blocks. The displayed number of resource blocks
depends on the channel bandwidth or number of resource blocks you have set. On the
y-axis, the power is plotted in dBm.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,PCRP
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Power vs Resource Block RS
The "Power vs Resource Block RS" result display shows the power of the reference
signal per resource element averaged over one resource block.
By default, three traces are shown. One trace shows the average power. The second
and the third traces show the minimum and maximum powers respectively. You can
select to display the power for a specific subframe in the Subframe Selection dialog
box. In that case, the application shows the power of that subframe only.
The x-axis represents the resource blocks. The displayed number of resource blocks
depends on the channel bandwidth or number of resource blocks you have set. On the
y-axis, the power is plotted in dBm.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,PVRR
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Channel Flatness
The "Channel Flatness" shows the relative power offset caused by the transmit channel.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the channel flatness is plotted in
dB.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,FLAT
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Group Delay
This "Group Delay" shows the group delay of each subcarrier.
The measurement is evaluated over the currently selected slot in the currently selected
subframe.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the group delay is plotted in ns.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,GDEL
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Channel Flatness Difference
The "Channel Flatness Difference" shows the level difference in the spectrum flatness
result between two adjacent physical subcarriers.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the power is plotted in dB.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,FDIF
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 176
Constellation Diagram
The "Constellation Diagram" shows the in-phase and quadrature phase results and is
an indicator of the quality of the modulation of the signal.
In the default state, the result display evaluates the full range of the measured input
data.
Each color represents a modulation type.
●
●
●
●
●
●
●
●
●
You can filter the results by changing the evaluation range.
: BPSK
: RBPSK
: MIXTURE
: QPSK
: 16QAM
: 64QAM
: 256QAM
: 1024QAM
: PSK (CAZAC)
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The constellation diagram also contains information about the current evaluation
range, including the number of points that are displayed in the diagram.
Remote command:
Selection: LAY:ADD ? '1',LEFT,CONS
Query: TRACe:DATA?
CCDF
The "Complementary Cumulative Distribution Function (CCDF)" shows the probability
of an amplitude exceeding the mean power. For the measurement, the complete capture buffer is used.
The x-axis represents the power relative to the measured mean power. On the y-axis,
the probability is plotted in %.
Measurements and Result Displays
I/Q Measurements
In addition to the diagram, the results for the CCDF measurement are summarized in
the CCDF table.
Mean Mean power
Peak Peak power
Crest Crest factor (peak power – mean power)
10 % 10 % probability that the level exceeds mean power + [x] dB
1 % 1 % probability that the level exceeds mean power + [x] dB
0.1 % 0.1 % probability that the level exceeds mean power + [x] dB
0.01 % 0.01 % probability that the level exceeds mean power + [x] dB
Remote command:
Selection: LAY:ADD ? '1',LEFT,CCDF
Query (y-axis): TRACe:DATA?
Numerical results: CALCulate<n>:STATistics:CCDF:X<t>? on page 191
Numerical results: CALCulate<n>:STATistics:RESult<res>? on page 191
Allocation Summary
The "Allocation Summary" shows various parameters of the measured allocations in a
table.
Each row in the allocation table corresponds to an allocation. A set of several allocations make up a subframe. A horizontal line indicates the beginning of a new subframe.
Special allocations summarize the characteristics of all allocations in a subframe
("ALL") and the complete frame (allocation "ALL" at the end of the table).
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The columns of the table show the following properties for each allocation.
●
The location of the allocation (subframe number).
●
The ID of the allocation (channel type).
●
Number of resource blocks used by the allocation.
●
The relative power of the allocation in dB.
The R&S FPS does not calculate the PHICH power if you turn on boosting estima-
tion.
●
The modulation of the allocation.
●
The power of each resource element in the allocation in dBm.
●
The EVM of the allocation.
The unit depends on the EVM unit
●
The EVM over all codewords in a layer. The layer EVM is calculated for all data
allocations, and not for the DMRS or other physical signals.
The unit depends on the EVM unit
For PDSCH allocations that use beamforming, the table contains two values. One for
the PDSCH, and one for the UE-specific reference signal (UE RS).
Click once on the header row to open a dialog box that allows you to add and remove
columns.
Remote command:
Selection: LAY:ADD ? '1',LEFT,ASUM
Query: TRACe:DATA?
Measurements and Result Displays
I/Q Measurements
Bitstream
The "Bitstream" shows the demodulated data stream for the data allocations.
Depending on the bitstream format, the numbers represent either bits (bit order) or
symbols (symbol order).
For the bit format, each number represents one raw bit. For the symbol format, the bits
that belong to one symbol are shown as hexadecimal numbers with two digits.
Resource elements that do not contain data or are not part of the transmission are rep-
resented by a "-".
If a symbol could not be decoded because the number of layers exceeds the number
of receive antennas, the application shows a "#" sign.
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The table contains the following information:
●
Subframe
Number of the subframe the bits belong to.
●
Allocation ID
Channel the bits belong to.
●
Codeword
Code word of the allocation.
●
Modulation
Modulation type of the channels.
●
Symbol Index or Bit Index
Indicates the position of the table row's first bit or symbol within the complete
stream.
●
Bit Stream
The actual bit stream.
Remote command:
Selection: LAY:ADD ? '1',LEFT,BSTR
Query: TRACe:DATA?
Measurements and Result Displays
I/Q Measurements
Channel Decoder Results
The "Channel Decoder" result display is a numerical result display that shows the characteristics of various channels for a specific subframe.
●
Protocol information of the PBCH, PCFICH and PHICH.
●
Information about the DCIs in the PDCCH.
●
Decoded bitstream for each PDCCH.
●
Decoded bitstream for each PDSCH.
The size of the table thus depends on the number of subframes in the signal.
Note that a complete set of results for the control channels is available only under cer-
tain circumstances.
●
The corresponding control channel (PBCH, PCFICH or PHICH) has to be present
and enabled.
●
Each channel must have a certain configuration (see list below).
For each channel, the table shows a different set of values.
●
PBCH
For the PBCH, the Channel Decoder provides the following results.
– The MIMO configuration of the DUT (1, 2 or 4 TX antennas)
– The Transmission bandwidth
– The Duration of the PHICH (normal or extended)
– The PHICH resource which is the same as PHICH Ng (1/6, 1/2, 1 or 2)
– System frame number
If the CRC is not valid, a corresponding message is shown instead of the results.
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Results for the PBCH can only be determined if the PHICH Duration or the PHICH
N_g are automatically determined ("Auto") or if automatic decoding of all control
channels is turned on.
●
PCFICH
For the PCFICH, the Channel Decoder provides the number of OFDM symbols that
are used for PDCCH at the beginning of a subframe.
●
PHICH
The PHICH carries the hybrid-ARQ ACK/NACK. Multiple PHICHs mapped to the
same set of resource elements are a PHICH group. The PHICHs within one group
are separated by different orthogonal sequences.
For the PHICH, the Channel Decoder provides the ACK/NACK pattern for the
PHICH group and the relative power for each PHICH in the PHICH group. Each
line in the result table represents one PHICH group. The columns on the left show
the ACK/NACK pattern of the PHICH group. The columns on the right show the relative powers for each PHICH.
If a PHICH is not transmitted, the table contains a "-" sign. Otherwise, the ACK/
NACK pattern is either a "1" (acknowledgement) or a "0" (not acknowledged). The
relative power is a numeric value in dB.
●
PDCCH
For each PDCCH that has been detected, the Channel Decoder shows several
results. Each line in the table represents one PDCCH.
– RNTI
– DCI Format
Shows the Downlink Control Information (DCI) format. The DCI contains information about the resource assignment for the UEs.
The following DCI formats are supported: 0, 1, 1A, 1B, 1C, 2, 2A, 2C, 2D, 3,
3A.
The DCI format is determined by the length of the DCI. Because they have the
same length, the Channel Decoder is not able to distinguish formats 0, 3 and
3A. Note that a DCI that consist of only zero bits cannot be decoded.
– PDCCH format used to transmit the DCI
– CCE Offset
The CCE Offset represents the position of the current DCI in the PDCCH bit
stream.
– Rel. Power
Relative power of the corresponding PDCCH.
Results for the PDCCH can only be determined if the PDSCH subframe configura-
tion is detected by the "PDCCH Protocol" or if automatic decoding of all control
channels is turned on.
●
PDSCH
For each decoded PDSCH allocation, there is a PDCCH DCI. The DCI contains
parameters that are required for the decoding process. If the channel could be
decoded successfully, the result display shows the bit stream for each codeword.
If the Cyclic Redundancy Check (CRC) fails, the result display shows an error message instead.
Results for the PDSCH can only be determined if the PDSCH subframe configura-
tion is detected by the "PDCCH Protocol" or if automatic decoding of all control
channels is turned on.
Measurements and Result Displays
I/Q Measurements
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Remote command:
Selection: LAY:ADD ? '1',LEFT,CDEC
Query: TRACe:DATA?
EVM vs Symbol x Carrier
The "EVM vs Symbol x Carrier" result display shows the EVM for each carrier in each
symbol.
The x-axis represents the symbols. The y-axis represents the subcarriers. Different colors in the diagram area represent the EVM. A color map in the diagram header indicates the corresponding power levels.
Remote command:
Selection: LAY:ADD ? '1',LEFT,EVSC
Query: TRACe:DATA?
Measurements and Result Displays
I/Q Measurements
Power vs Symbol x Carrier
The "Power vs Symbol x Carrier" result display shows the power for each carrier in
each symbol.
The x-axis represents the symbols. The y-axis represents the subcarriers. Different colors in the diagram area represent the power. A color map in the diagram header indicates the corresponding power levels.
Remote command:
Selection: LAY:ADD ? '1',LEFT,PVSC
Query: TRACe:DATA?
Allocation ID vs Symbol x Carrier
The "Allocation ID vs Symbol x Carrier" result display is a graphical representation of
the structure of the analyzed frame. It shows the allocation type of each subcarrier in
each symbol of the received signal.
The x-axis represents the OFDM symbols. The y-axis represents the subcarriers.
Each type of allocation is represented by a different color. The legend above the dia-
gram indicates the colors used for each allocation. You can also use a marker to get
more information about the type of allocation.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,AISC
Query: TRACe:DATA?
UE RS Magnitude
The "UE RS Weights Magnitude" result display shows the magnitude of the measured
weights of the UE-specific reference signal carriers. You can use it to calculate the
magnitude difference between different antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the amplitude of each reference signal in dB.
Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,URWM
Querying results: TRACe:DATA?
UE RS Phase
The "UE RS Weights Phase" result display shows the phase of the measured weights
of the UE specific reference signal carriers. You can use it to calculate the phase difference between different antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the phase of each reference signal in degree.
Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,URWP
Query: TRACe:DATA?
Cell RS Magnitude
The "Cell RS Weights Magnitude" result display shows the magnitude of the measured
weights of the reference signal (RS) carriers specific to the cell. This measurement
enables magnitude measurements on antenna port 0 using, for example, the enhanced
test models like E-TM 1.1.
You can use the result display to calculate the magnitude difference between different
antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the amplitude of each reference signal in dB.
Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,CRWM
Query: TRACe:DATA?
Cell RS Phase
The "Cell RS Weights Phase" result display shows the phase of the measured weights
of the reference signal (RS) carriers specific to the cell. This measurement enables
phase measurements on antenna port 0 using, for example, the enhanced test models
like E-TM 1.1.
You can use the result display to calculate the phase difference between different
antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the phase of each reference signal in degree.
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Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
Remote command:
Selection: LAY:ADD ? '1',LEFT,CRWP
Query: TRACe:DATA?
CSI RS Magnitude
The "CSI RS Weights Magnitude" result display shows the magnitude of the measured
weights of the CSI-specific reference signal carriers. You can use it to calculate the
magnitude difference between different antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the amplitude of each reference signal in dB.
Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
Measurements and Result Displays
I/Q Measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,IRWM
Query: TRACe:DATA?
CSI RS Phase
The "CSI RS Weights Phase" result display shows the phase of the measured weights
of the CSI-specific reference signal carriers. You can use it to calculate the phase difference between different antenna ports.
The x-axis represents the frequency, with the unit depending on your selection. The yaxis shows the phase of each reference signal in degree.
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Because the beamforming configuration can change between the subframes of one
frame, the contents of this result display for Subframe Selection = 'All' might be invalid.
Thus, it is recommended to select the precise subframe to be evaluated in order to get
valid results.
You can select the antenna port you want to show the information for from the corresponding beamforming selection dropdown menu.
Remote command:
Selection: LAY:ADD ? '1',LEFT,IRWP
Query: TRACe:DATA?
Beamform Allocation Summary
The "Beamform Allocation Summary" shows the phase characteristics for each
PDSCH and (if available) EPDCCH allocation used by the UE-specific reference signals in numerical form.
Measurements and Result Displays
I/Q Measurements
The rows in the table represent the allocations. A set of allocations form a subframe.
The subframes are separated by a dashed line. The columns of the table contain the
following information:
●
Subframe
Shows the subframe number.
●
Allocation ID
Shows the type / ID of the allocation.
●
Antenna Port
Shows the antenna port used by the allocation.
●
Phase
Shows the phase of the allocation.
●
Phase Diff(erence)
Shows the phase difference of the allocation relative to the first antenna.
Remote command:
Selection: LAY:ADD ? '1',LEFT,URWA
Query: TRACe:DATA?
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Result Summary
The Result Summary shows all relevant measurement results in numerical form, combined in one table.
Remote command:
LAY:ADD ? '1',LEFT,RSUM
Contents of the result summary
Measurements and Result Displays
I/Q Measurements
The table is split in two parts. The first part shows results that refer to the complete
frame. For each result, the minimum, mean and maximum values are displayed. It also
indicates limit check results where available. The font of 'Pass' results is green and that
of 'Fail' results is red.
In addition to the red font, the application also puts a red star ( ) in front of
failed results.
EVM PDSCH QPSK Shows the EVM for all QPSK-modulated resource elements of the PDSCH
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:DSQP[:AVERage]? on page 178
EVM PDSCH 16QAM Shows the EVM for all 16QAM-modulated resource elements of the PDSCH
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:DSST[:AVERage]? on page 179
EVM PDSCH 64QAM Shows the EVM for all 64QAM-modulated resource elements of the PDSCH
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:DSSF[:AVERage]? on page 179
EVM PDSCH 256QAM Shows the EVM for all 256QAM-modulated resource elements of the PDSCH
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:DSTS[:AVERage]? on page 179
EVM PDSCH 1024QAM Shows the EVM for all 1024QAM-modulated resource elements of the
PDSCH channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:DS1K[:AVERage]? on page 180
By default, all EVM results are in %. To view the EVM results in dB, change the EVM
Unit.
The second part of the table shows results that refer to a specific selection of the
frame.
The statistic is always evaluated over the subframes.
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The header row of the table contains information about the selection you have made
(like the subframe).
EVM All Shows the EVM for all resource elements in the analyzed frame.
EVM Phys Channel Shows the EVM for all physical channel resource elements in the analyzed
EVM Phys Signal Shows the EVM for all physical signal resource elements in the analyzed
Frequency Error Shows the difference in the measured center frequency and the reference
Measurements and Result Displays
I/Q Measurements
FETCh[:CC<cc>]:SUMMary:EVM[:ALL][:AVERage]? on page 181
frame.
A physical channel corresponds to a set of resource elements carrying infor-
mation from higher layers. PDSCH, PBCH or PDCCH, for example, are physical channels. For more information, see 3GPP 36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PCHannel[:AVERage]? on page 182
frame.
The reference signal, for example, is a physical signal. For more information,
see 3GPP 36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PSIGnal[:AVERage]? on page 182
center frequency.
FETCh[:CC<cc>]:SUMMary:FERRor[:AVERage]? on page 182
Sampling Error Shows the difference in measured symbol clock and reference symbol clock
relative to the system sampling rate.
FETCh[:CC<cc>]:SUMMary:SERRor[:AVERage]? on page 186
I/Q Offset Shows the power at spectral line 0 normalized to the total transmitted power.
FETCh[:CC<cc>]:SUMMary:IQOFfset[:AVERage]? on page 183
I/Q Gain Imbalance Shows the logarithm of the gain ratio of the Q-channel to the I-channel.
FETCh[:CC<cc>]:SUMMary:GIMBalance[:AVERage]? on page 183
I/Q Quadrature Error Shows the measure of the phase angle between Q-channel and I-channel
deviating from the ideal 90 degrees.
FETCh[:CC<cc>]:SUMMary:QUADerror[:AVERage]? on page 184
RSTP Shows the reference signal transmit power as defined in 3GPP TS 36.141. It
is required for the "DL RS Power" test.
It is an average power and accumulates the powers of the reference symbols
within a subframe divided by the number of reference symbols within a subframe.
FETCh[:CC<cc>]:SUMMary:RSTP[:AVERage]? on page 185
OSTP Shows the OFDM symbol transmit power as defined in 3GPP TS 36.141.
It accumulates all subcarrier powers of the 4th OFDM symbol. The 4th (out of
14 OFDM symbols within a subframe (for frame type 1, normal CP length))
contains exclusively PDSCH.
FETCh[:CC<cc>]:SUMMary:OSTP[:AVERage]? on page 184
RSSI Shows the Received Signal Strength Indicator. The RSSI is the complete sig-
nal power of the channel that has been measured, regardless of the origin of
the signal.
FETCh[:CC<cc>]:SUMMary:RSSI[:AVERage]? on page 185
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Power Shows the average time domain power of the analyzed signal.
Crest Factor Shows the peak-to-average power ratio of captured signal.
Marker Table
Displays a table with the current marker values for the active markers.
This table is displayed automatically if configured accordingly.
Wnd Shows the window the marker is in.
Type Shows the marker type and number ("M" for a nor-
Trc Shows the trace that the marker is positioned on.
Ref Shows the reference marker that a delta marker
X- / Y-Value Shows the marker coordinates (usually frequency
Measurements and Result Displays
I/Q Measurements
FETCh[:CC<cc>]:SUMMary:POWer[:AVERage]? on page 184
FETCh[:CC<cc>]:SUMMary:CRESt[:AVERage]? on page 181
mal marker, "D" for a delta marker).
refers to.
and level).
Z-EVM
Z-Power
Z-Alloc ID
Shows the EVM, power and allocation type at the
marker position.
Only in 3D result displays (for example "EVM vs
Symbol x Carrier").
Remote command:
LAY:ADD? '1',RIGH, MTAB, see LAYout:ADD[:WINDow]? on page 146
Results:
CALCulate<n>:MARKer<m>:X on page 188
CALCulate<n>:MARKer<m>:Y on page 189
CALCulate<n>:MARKer<m>:Z? on page 190
CALCulate<n>:MARKer<m>:Z:ALL? on page 190
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3.6 Time Alignment Error Measurements
Access: [MEAS] > "Time Alignment Error"
The Time Alignment Error measurement captures and analyzes new I/Q data when
you select it.
Note that the time alignment error measurement only work in a MIMO setup (2 or 4
antennas) or in a system with component carriers. Therefore, you have to mix the signal of the antennas into one cable that you can connect to the R&S FPS. For more
information on configuring and performing a time alignment error measurement see
Chapter 4.5, "Performing Time Alignment Measurements", on page 63.
In addition to the result displays mentioned in this section, the time alignment error
measurement also supports the following result displays described elsewhere.
●
"Capture Buffer" on page 18
●
"Power Spectrum" on page 22
●
" Marker Table " on page 37
Measurements and Result Displays
Time Alignment Error Measurements
You can select the result displays from the evaluation bar and arrange them as you like
with the SmartGrid functionality.
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 202
Result display selection: LAYout:ADD[:WINDow]? on page 146
Time Alignment Error.................................................................................................... 38
Time Alignment Error
The time alignment is an indicator of how well the transmission antennas in a MIMO
system and component carriers are synchronized. The time alignment error is either
the time delay between a reference antenna (for example antenna 1) and another
antenna or the time delay between a reference component carrier and other component carriers.
The application shows the results in a table.
Each row in the table represents one antenna. The reference antenna is not shown.
For each antenna, the maximum, minimum and average time delay that has been
measured is shown. The minimum and maximum results are calculated only if the
measurement covers more than one frame.
If you perform the measurement on a system with carrier aggregation, each row represents one antenna. The number of lines increases because of multiple carriers. The
reference antenna of the main component carrier (CC1) is not shown.
In any case, results are only displayed if the transmission power of both antennas is
within 15 dB of each other. Likewise, if only one antenna transmits a signal, results will
not be displayed (for example if the cabling on one antenna is faulty).
For more information on configuring this measurement, see Chapter 5.3, "Time Align-
ment Error Measurements", on page 120.
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The "Limit" value shown in the result display is the maximum time delay that may occur
for each antenna (only displayed for systems without carrier aggregation).
You can select the reference antenna from the dropdown menu in the result display.
You can also select the reference antenna in the MIMO Setup - if you change them in
one place, they are also changed in the other.
In the default layout, the application also shows the "Capture Buffer" and "Power Spectrum" result displays for each component carrier.
Remote command:
Selection: LAY:ADD ? '1',LEFT,TAL
Query: FETCh:TAERror[:CC<cc>]:ANTenna<ant>[:AVERage]? on page 187
Reference antenna: CONFigure[:LTE]:DL[:CC<cc>]:MIMO:ASELection
on page 213
Measurements and Result Displays
Transmit On / Off Power Measurement
3.7 Transmit On / Off Power Measurement
Access: [MEAS] > "Transmit On/Off Power"
The transmit on / off power measurement captures and analyzes new I/Q data when
you select it.
The transmit on / off power measurement consists of several result displays that you
can select from the evaluation bar. You can arrange them as you like with the SmartGrid functionality.
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 202
Result display selection: LAYout:ADD[:WINDow]? on page 146
Transmit On / Off Power................................................................................................39
└ Numerical results............................................................................................ 40
└ Transmit power on / off diagram..................................................................... 41
└ Transition diagram.......................................................................................... 42
└ Adjust Timing.................................................................................................. 42
└ Noise Cancellation..........................................................................................42
Transmit On / Off Power
The transmit on / off power measurement analyzes the transition from transmission
("on" periods) to reception ("off" periods) of an LTE TDD signal over time. Because this
transition must happen very fast to use resources efficiently, it can be an issue in TDD
systems.
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During the transmit power on / off measurement, the R&S FPS verifies if the "off" periods (= no signal transmission) comply to the limits defined by 3GPP. Note that you
have to apply a signal to the RF input for this measurement, because the R&S FPS
has to capture new I/Q data instead of using the data other I/Q measurements are
based on.
For more information on setting up the measurement, see Chapter 4.6, "Performing
Transmit On/Off Power Measurements", on page 64.
The results for the transmit on / off power measurement are available in the following
displays.
●
"Numerical results" on page 40
●
"Transmit power on / off diagram" on page 41
●
"Transition diagram" on page 42
Remote command:
Selection: CONF:MEAS TPOO
Query: TRACe:DATA?
Unit: UNIT:OPOWer on page 259
Numerical results ← Transmit On / Off Power
The result summary shows the measurement results in a table. Each line in the table
corresponds to one "off" period.
The result summary shows the following information for each "off" period.
●
"Start Off Period Limit"
Shows the beginning of the "off" period relative to the frame start (0 seconds).
●
"Stop Off Period Limit"
Shows the end of the "off" period relative to the frame start (0 seconds).
The time from the start to the stop of the "off" period is the period over which the
limits are checked. It corresponds to the yellow trace in the diagram.
●
"Time at Δ to Limit"
Shows the trace point at which the lowest distance between trace and limit line has
been detected. The result is a time relative to the frame start.
●
"OFF Power"
Shows the absolute power of the signal at the trace point with the lowest distance
to the limit line.
You can display the "OFF Power" either as an absolute value in dBm or a relative
value in dBm/MHz. To select the unit, use the "Power Unit (dBm/MHz)" softkey
available in the "Meas Config" menu.
●
"OFF Power Δ to Limit"
Shows the distance between the trace and the limit line of the trace point with the
lowest distance to the limit line in dB.
●
"Falling Transition Period"
Shows the length of the falling transient.
●
"Rising Transition Period"
Shows the length of the rising transient.
Results that comply with the limits are displayed in green. Any results that violate the
limits defined by 3GPP are displayed in red.
Measurements and Result Displays
Transmit On / Off Power Measurement
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Note that the beginning and end of a transition period is determined based on the "Off
Power Density Limit". This limit is defined in 3GPP 36.141 as the maximum allowed
mean power spectral density. The length of the transient from "on" to "off" period is, for
example, the distance from the detected end of the subframe to the last time that the
signal power is above the measured mean power spectral density.
Measurements and Result Displays
Transmit On / Off Power Measurement
Figure 3-3: Power profile of a TD-LTE On-to-Off transition. The transition lasts from the end of the ON
1 = subframe ("on" power period)
2 = transient (transition length)
3 = "off" power density limit
4 = "off" power period
period until the signal is completely below the off power density limit.
Transmit power on / off diagram ← Transmit On / Off Power
The diagram shows all TDD frames that were captured and analyzed and contains
several elements.
●
Yellow trace
The yellow trace represents the signal power during the "off" periods. The calculation of the trace also accounts for filtering as defined in 3GPP 36.141.
●
Blue trace
The blue trace represents the transition periods (falling and rising).
Note that the blue trace might not be visible in the diagram because of its steep
flank and small horizontal dimensions. You can see the falling and rising transitions
in separate diagrams.
●
Blue rectangles
The blue rectangles represent the "on" periods. Because of the overload during the
"on" periods, the actual signal power is only hinted at, not shown.
●
Red lines
Limits as defined by 3GPP.
●
Other information
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In addition to these elements, the diagram also shows the overall limit check, the
average count and the limit for the mean power spectral density ("Off Power Density Limit").
The overall limit check only passes if all "off" periods (including the transients) comply with the limits.
Transition diagram ← Transmit On / Off Power
The transition diagrams show the rising and falling periods for each TDD frame in more
detail.
You can display the transitions for up to two TDD frames.
The diagrams contain the following elements.
●
Blue trace
The blue trace represents the transition periods (falling and rising).
●
Red lines
Limits as defined by 3GPP.
Measurements and Result Displays
Transmit On / Off Power Measurement
Adjust Timing ← Transmit On / Off Power
Access: [Sweep] > "Adjust Timing"
If you are using an external trigger for the on / off power measurement, you have to
determine the offset of the trigger time to the time the LTE frame starts. You can do this
with the "Adjust Timing" function. When the application has determined the offset, it
corrects the results of the on / off power measurement accordingly.
Adjust timing also captures data with a reference level optimized for the "on" period to
increase the probability for successful synchronization.
Remote command:
[SENSe:][LTE:]OOPower:ATIMing on page 156
Noise Cancellation ← Transmit On / Off Power
Access: [Meas Config] > "Noise Cancellation"
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Noise cancellation corrects the results by removing the inherent noise of the analyzer,
which increases the dynamic range. To do this, the R&S FPS measures its inherent
noise and subtracts the measured noise power from the power in the channel that is
being analyzed.
Noise cancellation is valid for the current measurement configuration. If you change
the measurement configuration in any way, you have to repeat noise cancellation.
Remote command:
[SENSe:][LTE:]OOPower:NCORrection on page 259
3.8 Frequency Sweep Measurements
Access (ACLR): [MEAS] > "Channel Power ACLR"
Access (MC ACLR): [MEAS] > "Multi Carrier ACLR"
Access (Cumulative ACLR): [MEAS] > "Cumulative ACLR"
Access (SEM): [MEAS] > "Spectrum Emission Mask"
Measurements and Result Displays
Frequency Sweep Measurements
Access (Multi Carrier SEM): [MEAS] > "Multi Carrier SEM"
The LTE aplication supports the following frequency sweep measurements.
●
Adjacent channel leakage ratio (ACLR)
●
Spectrum emission mask (SEM)
Instead of using I/Q data, the frequency sweep measurements sweep the spectrum
every time you run a new measurement. Therefore, it is mandatory to feed a signal into
the RF input for these measurements. Using previously acquired I/Q data for the frequency sweep measurements is not possible (and vice-versa).
Because each of the frequency sweep measurements uses different settings to obtain
signal data it is also not possible to run a frequency sweep measurement and view the
results in another frequency sweep measurement.
Make sure to have sufficient bandwidth to be able to capture the whole signal, including neighboring channels.
In addition to the specific diagrams and table (see description below), frequency sweep
measurements support the following result displays.
●
" Marker Table " on page 37
●
Marker peak list
Both result displays have the same contents as the spectrum application.
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 202
Result display selection: LAYout:ADD[:WINDow]? on page 146
Adjacent Channel Leakage Ratio (ACLR).....................................................................44
└ Result diagram................................................................................................44
└ Result summary..............................................................................................45
Cumulative ACLR..........................................................................................................46
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└ Result diagram................................................................................................46
└ Result summary..............................................................................................47
Multi Carrier ACLR (MC ACLR).................................................................................... 47
└ Result diagram................................................................................................48
└ Result summary..............................................................................................49
Spectrum Emission Mask (SEM).................................................................................. 49
└ Result diagram................................................................................................50
└ Result summary..............................................................................................50
Marker Peak List .......................................................................................................... 51
Adjacent Channel Leakage Ratio (ACLR)
The adjacent channel leakage ratio (ACLR) measurement is designed to analyze signals that contain multiple signals for different radio standards. Using the ACLR measurement, you can determine the power of the transmit (Tx) channel and the power of
the neighboring (adjacent) channels to the left and right of the Tx channel. Thus, the
ACLR measurement provides information about the power in the adjacent channels as
well as the leakage into these adjacent channels.
When you measure the ACLR in the LTE application, the R&S FPS automatically
selects appropriate ACLR settings based on the selected channel bandwidth.
For a comprehensive description of the ACLR measurement, refer to the user manual
of the R&S FPS.
Measurements and Result Displays
Frequency Sweep Measurements
Remote command:
Selection: CONF:MEAS ACLR
Result diagram ← Adjacent Channel Leakage Ratio (ACLR)
The result diagram is a graphic representation of the signals with a trace that shows
the measured signal. Individual channels (Tx and adjacent channels) are indicated by
vertical lines and corresponding labels.
In addition, the R&S FPS highlights the channels (blue: Tx channel, green: adjacent
channels).
The x-axis represents the frequency with a frequency span that relates to the specified
LTE channel and adjacent channel bandwidths. On the y-axis, the power is plotted in
dBm.
The power for the Tx channel is an absolute value in dBm. The power of the adjacent
channels is relative to the power of the Tx channel.
In addition, the R&S FPS tests the ACLR measurement results against the limits
defined by 3GPP.
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Remote command:
Result query: TRACe:DATA?
Measurements and Result Displays
Frequency Sweep Measurements
Result summary ← Adjacent Channel Leakage Ratio (ACLR)
The result summary shows the signal characteristics in numerical form. Each row in
the table corresponds to a certain channel type (Tx, adjacent channel). The columns
contain the channel characteristics.
●
Channel
Shows the channel type (Tx, adjacent or alternate channel).
●
Bandwidth
Shows the channel bandwidth.
●
Offset
Shows the channel spacing.
●
Power
Shows the power of the Tx channel.
●
Lower / Upper
Shows the relative power of the lower and upper adjacent and alternate channels.
The values turn red if the power violates the limits.
●
Limit
Shows the limit of that channel, if one is defined.
Remote command:
Result query: CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult[:
CURRent]?
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Cumulative ACLR
The cumulative ACLR measurement is designed to measure the cumulative ACLR test
requirement for non-contiguous spectrum in 36.141. It calculates the cumulative ACLR
of the gaps as defined in 3GPP 36.141. Note that this measurement is only useful for
two non-contiguous carriers.
The gap channels are labeled "Gap<x>U" or "Gap<x>L", with <x> representing the
number of the gap channels and "U" and "L" standing for "Upper" and "Lower". The
number of analyzed gap channels depends on the channel spacing between the carriers as defined in the test specification.
Remote command:
Selection: CONF:MEAS CCAC
Result diagram ← Cumulative ACLR
The result diagram is a graphic representation of the signals with a trace that shows
the measured signal. Individual channels (Tx and adjacent channels) are indicated by
vertical lines and corresponding labels.
In addition, the R&S FPS highlights the channels (blue: Tx channel, green: adjacent
channels).
The x-axis represents the frequency. Note that the application automatically determines the center frequency and span of the measurement according to the frequencies
of the carriers.
On the y-axis, the power is plotted in dBm. The power for the Tx channels is an absolute value in dBm. The power of the gap channels is an absolute value relative to the
cumulative power of the Tx channels. The power of the channels is automatically tested against the limits defined by 3GPP.
The result display contains several additional elements.
●
Blue and green lines:
Represent the bandwidths of the carriers (blue lines) and those of the gap channels (green lines). Note that the channels can overlap each other.
●
Blue and green bars:
Represent the integrated power of the transmission channels (blue bars) and gap
channels (green bars).
Measurements and Result Displays
Frequency Sweep Measurements
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Remote command:
TRACe:DATA?
Result summary ← Cumulative ACLR
The result summary shows the signal characteristics in numerical form. Each row in
the table corresponds to a certain channel type (Tx, adjacent channel). The columns
contain the channel characteristics.
A table in the result display contains information about the measurement in numerical
form:
●
Channel
Shows the type of channel.
Channel "A" and "B" represent the component carriers. For each of the channels,
the application also shows the "Total", which should be the same as that for the
channel.
The other rows ("AB:Gap") represent the gap channels.
●
Bandwidth
Shows the bandwidth of the channel.
The bandwidth of the carrier is the sum of the two component carriers.
●
Frequency
Shows the frequency of the carrier.
Available for the aggregated carriers.
●
Offset
Frequency offset relative to the center frequency of the aggregated carrier.
Available for the gap channels.
●
Power / Lower / Upper
Shows the power of the carrier and the power of the lower and upper gap channels
relative to the power of the aggregated carrier.
Measurements and Result Displays
Frequency Sweep Measurements
Remote command:
Result query: CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult[:
CURRent]? on page 176
Limit check adjacent: CALCulate<n>:LIMit<li>:ACPower:ACHannel:RESult?
on page 192
Limit check alternate: CALCulate<n>:LIMit<li>:ACPower:ALTernate<alt>:
RESult? on page 193
Multi Carrier ACLR (MC ACLR)
The MC ACLR measurement is basically the same as the Adjacent Channel Leakage
Ratio (ACLR) measurement: it measures the power of the transmission channels and
neighboring channels and their effect on each other. Instead of measuring a single carrier, the MC ACLR measures several component carriers and the gaps in between.
The component carriers do not necessarily have to be next to each other.
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In its default state, the MC ACLR measurement measures one neighboring channel
above and below the carrier. You can select the type and bandwidth of the neighboring
channel (it is either an UTRA or E-UTRA channel) in the Carrier Aggregation panel.
Note that you can configure a different neighboring channel setup with the tools provided by the measurement. These tools are the same as those in the spectrum application. For more information, refer to the documentation of the R&S FPS.
The configuration in its default state complies with the test specifications defined in
36.141.
Remote command:
Selection: CONF:MEAS MCAC
Result diagram ← Multi Carrier ACLR (MC ACLR)
The result diagram is a graphic representation of the signals with a trace that shows
the measured signal. Individual channels (Tx and adjacent channels) are indicated by
vertical lines and corresponding labels.
In addition, the R&S FPS highlights the channels (blue: Tx channel, green: adjacent
channels).
The x-axis represents the frequency with a frequency span that relates to the LTE
channel characteristics and adjacent channel bandwidths. Note that the application
automatically determines the center frequency of the measurement according to the
frequencies of the carriers.
On the y-axis, the power is plotted in dBm. The power for the TX channels is an absolute value in dBm. The powers of the adjacent channels are values relative to the
power of the TX channel. The power of the channels is automatically tested against the
limits defined by 3GPP.
The result display contains several additional elements.
●
Blue and green lines:
Represent the bandwidths of the carriers (blue lines) and those of the neighboring
channels (green lines). Note that the channels can overlap each other.
●
Blue and green bars:
Represent the integrated power of the transmission channels (blue bars) and
neighboring channels (green bars).
Measurements and Result Displays
Frequency Sweep Measurements
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Remote command:
TRACe:DATA?
Result summary ← Multi Carrier ACLR (MC ACLR)
The result summary shows the signal characteristics in numerical form. Each row in
the table corresponds to a certain channel type (Tx, adjacent channel). The columns
contain the channel characteristics.
A table above the result display contains information about the measurement in numerical form:
●
Channel
Shows the type of channel.
The first rows represent the characteristics of the component carriers. The label
also indicates their respective bandwidths (for example: LTE_10M1 means the first
LTE channel ("_10M1) with a 10 MHz bandwidth ("_10M1")). The information also
includes the total power of all component carriers.
The other rows represent the neighboring channels (Adj Lower / Upper and Alt1
Lower / Upper).
●
Bandwidth
Shows the bandwidth of the channel.
The bandwidth of the carrier is the sum of the two component carriers.
●
Frequency
Shows the center frequency of the component carriers.
●
Offset
Frequency offset relative to the center frequency of the aggregated carrier.
●
Power / Lower / Upper / Gap
Shows the power of the carrier and the power of the lower and upper neighboring
channels relative to the power of the aggregated carrier.
Measurements and Result Displays
Frequency Sweep Measurements
Note that the font of the results turns red if the signal violates the limits defined by
3GPP.
Remote command:
Result query: CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult[:
CURRent]? on page 176
Limit check adjacent: CALCulate<n>:LIMit<li>:ACPower:ACHannel:RESult?
on page 192
Limit check alternate: CALCulate<n>:LIMit<li>:ACPower:ALTernate<alt>:
RESult? on page 193
Spectrum Emission Mask (SEM)
Note: The application also provides multi-SEM measurements as a separate measure-
ment. This measurement is basically the same as the SEM measurement, with the dif-
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ference that it analyzes several sub blocks, each with its own power class definition.
The multi-SEM measurement also supports Carrier Aggregation.
The "Spectrum Emission Mask" (SEM) measurement shows the quality of the measured signal by comparing the power values in the frequency range near the carrier
against a spectral mask that is defined by the 3GPP specifications. In this way, you can
test the performance of the DUT and identify the emissions and their distance to the
limit.
For a comprehensive description of the SEM measurement, refer to the user manual of
the R&S FPS.
Remote command:
Selection (SEM): CONF:MEAS ESP
Selection (Multi-SEM): CONF:MEAS MCES
Result diagram ← Spectrum Emission Mask (SEM)
The result diagram is a graphic representation of the signal with a trace that shows the
measured signal. The SEM is represented by a red line.
If any measured power levels are above that limit line, the test fails. If all power levels
are inside the specified limits, the test passes. The application labels the limit line to
indicate whether the limit check has passed or failed.
The x-axis represents the frequency with a frequency span that relates to the specified
LTE channel bandwidths. The y-axis shows the signal power in dBm.
Measurements and Result Displays
Frequency Sweep Measurements
Remote command:
Result query: TRACe:DATA?
Result summary ← Spectrum Emission Mask (SEM)
The result summary shows the signal characteristics in numerical form. Each row in
the table corresponds to a certain SEM range. The columns contain the range characteristics. If a limit fails, the range characteristics turn red.
●
Start / Stop Freq Rel
Shows the start and stop frequency of each section of the spectrum emission mask
relative to the center frequency.
●
RBW
Shows the resolution bandwidth of each section of the spectrum emission mask.
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●
Freq at Δ to Limit
Shows the absolute frequency whose power measurement being closest to the
limit line for the corresponding frequency segment.
●
Power Abs
Shows the absolute measured power of the frequency whose power is closest to
the limit. The application evaluates this value for each frequency segment.
●
Power Rel
Shows the distance from the measured power to the limit line at the frequency
whose power is closest to the limit. The application evaluates this value for each
frequency segment.
●
Δ to Limit
Shows the minimal distance of the tolerance limit to the SEM trace for the corresponding frequency segment. Negative distances indicate that the trace is below
the tolerance limit, positive distances indicate that the trace is above the tolerance
limit.
Note that when you perform a multi-SEM measurement, the table is expanded to show
information about the subblocks.
Measurements and Result Displays
Frequency Sweep Measurements
Marker Peak List
The marker peak list determines the frequencies and levels of peaks in the spectrum or
time domain. How many peaks are displayed can be defined, as well as the sort order.
In addition, the detected peaks can be indicated in the diagram. The peak list can also
be exported to a file for analysis in an external application.
Remote command:
LAY:ADD? '1',RIGH, PEAK, see LAYout:ADD[:WINDow]? on page 146
Results:
CALCulate<n>:MARKer<m>:X on page 188
CALCulate<n>:MARKer<m>:Y on page 189
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3.9 3GPP Test Scenarios
3GPP defines several test scenarios for measuring base stations. These test scenarios
are described in detail in 3GPP TS 36.141.
The following table provides an overview which measurements available in the LTE
application are suited to use for the test scenarios in the 3GPP documents.
Table 3-1: Test scenarios for E-TMs as defined by 3GPP (3GPP TS 36.141)
Test Model Test scenario Test described in Measurement
E-TM1.1 Base station output power chapter 6.2 Power (➙ "Result Sum-
Measurements and Result Displays
3GPP Test Scenarios
mary")
E-TM1.2 ACLR chapter 6.6.2 ACLR
E-TM2 RE power control dynamic
Transmit on/off power chapter 6.4 On/Off Power
DL RS power chapter 6.5.4 RSTP (➙ "Result Summary")
Time alignment chapter 6.5.3 Time alignment error
Transmitter intermodulation chapter 6.7 ACLR
Occupied bandwidth chapter 6.6.1
ACLR chapter 6.6.2 ACLR
Operating band unwanted
emissions
Transmitter spurious emissions
Operating band unwanted
emissions
range
Frequency error chapter 6.5.1 Frequency Error (➙ "Result
Total power dynamic range chapter 6.3.2 OSTP (➙ "Result Summary")
chapter 6.6.3 Spectrum emission mask
chapter 6.6.4
chapter 6.6.2 Spectrum emission mask
chapter 6.3.1 Power results
Occupied bandwidth
Spurious emissions
Summary")
1
1
E-TM2a Total power dynamic range chapter 6.3.2 OSTP (➙ "Result Summary")
E-TM3.1 RE power control dynamic
Error vector magnitude chapter 6.5.2 EVM results
Error vector magnitude chapter 6.5.2 EVM results
Frequency error chapter 6.5.1 Frequency error (➙ "Result
Summary")
chapter 6.3.1 Power results
range
Total power dynamic range chapter 6.3.2 OSTP (➙ "Result Summary")
Frequency error chapter 6.5.1 Frequency error (➙ "Result
Summary")
Error vector magnitude chapter 6.5.2 EVM results
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Test Model Test scenario Test described in Measurement
E-TM3.1a Total power dynamic range chapter 6.3.2 OSTP (➙ "Result Summary")
Measurements and Result Displays
3GPP Test Scenarios
E-TM3.2 RE power control dynamic
E-TM3.3 RE power control dynamic
1
these measurements are available in the spectrum application of the Rohde & Schwarz signal and spec-
trum analyzers (for example the R&S FSW)
Error vector magnitude chapter 6.5.2 EVM results
Frequency error chapter 6.5.1 Frequency error (➙ "Result
Summary")
chapter 6.3.1 Power results
range
Frequency error chapter 6.5.1 Frequency error (➙ "Result
Summary")
Error vector magnitude chapter 6.5.2 EVM results
chapter 6.3.1 Power results
range
Frequency error chapter 6.5.1 Frequency error (➙ "Result
Summary")
Error vector magnitude chapter 6.5.2 EVM results
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4 Measurement Basics
● Symbols and Variables............................................................................................54
● Overview................................................................................................................. 55
● The LTE Downlink Analysis Measurement Application...........................................55
● MIMO Measurement Guide.....................................................................................58
● Performing Time Alignment Measurements............................................................63
● Performing Transmit On/Off Power Measurements................................................64
4.1 Symbols and Variables
The following chapters use various symbols and variables in the equations that the
measurements are based on. The table below explains these symbols for a better
understanding of the measurement principles.
Measurement Basics
Symbols and Variables
a
l,kâl,k
b
l,k
Δf, Δ
coarse
Δf
res
ζ
H
l,k, l,k
i time index
î
, î
coarse
fine
k subcarrier index
l OFDM symbol index
N
FFT
N
g
N
s
N
RE
n subchannel index, subframe index
data symbol (actual, decided)
boosting factor
carrier frequency offset between transmitter and
receiver (actual, coarse estimate)
residual carrier frequency offset
relative sampling frequency offset
channel transfer function (actual, estimate)
timing estimate (coarse, fine)
length of FFT
number of samples in cyclic prefix (guard interval)
number of Nyquist samples
number of resource elements
n
l,k
Φ
l
r(i) received sample in the time domain
r
, r'
, r''
l,k
l,k
l,k
T useful symbol time
noise sample
common phase error
received sample (uncompensated, partially compensated, equalized) in the frequency domain
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Measurement Basics
The LTE Downlink Analysis Measurement Application
T
g
T
s
guard time
symbol time
4.2 Overview
The digital signal processing (DSP) involves several stages until the software can present results like the EVM.
The contents of this chapter are structured like the DSP.
4.3 The LTE Downlink Analysis Measurement Application
The block diagram in Figure 4-1 shows the EUTRA/LTE downlink measurement application from the capture buffer containing the I/Q data to the actual analysis block. The
outcome of the fully compensated reference path (orange) is the estimate â
transmitted data symbols a
received samples r''
of the measurement path (blue) still contain the transmitted sig-
l,k
. Depending on the user-defined compensation, the
l,k
nal impairments of interest. The analysis block reveals these impairments by comparing the reference and the measurement path. Prior to the analysis, diverse synchronization and channel estimation tasks have to be accomplished.
of the
l,k
4.3.1 Synchronization
The first of the synchronization tasks is to estimate the OFDM symbol timing, which
coarsely estimates both timing and carrier frequency offset. The frame synchronization
block determines the position of the P-/S-Sync symbols in time and frequency by using
the coarse fractional frequency offset compensated capture buffer and the timing estimate î
the reference signal is used for synchronization. The fine timing block prior to the FFT
allows a timing improvement and makes sure that the EVM window is centered on the
measured cyclic prefix of the considered OFDM symbol. For the 3GPP EVM calculation according to 3GPP TS 36.211 (v8.9.0), the block “window” produces three signals
taken at the timing offsets , and . For the reference path, only the signal taken at
the timing offset is used.
to position the window of the FFT. If no P-/S-Sync is available in the signal,
coarse
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kl
lTfNNjlkNNjj
klklkl
NeeeHAR
CFOres
resFFTS
SFO
FFTS
CPE
l
,
22
,,,
.
Measurement Basics
The LTE Downlink Analysis Measurement Application
Figure 4-1: Block diagram for the LTE DL measurement application
After the time to frequency transformation by an FFT of length N
, the phase syn-
FFT
chronization block is used to estimate the following:
●
The relative sampling frequency offset ζ (SFO)
●
The residual carrier frequency offset Δf
●
The common phase error Φl (CPE)
(CFO)
res
According to 3GPP TS 25.913 and 3GPP TR 25.892, the uncompensated samples can
be expressed as
Equation 4-1:
where
●
The data symbol is a
●
The channel transfer function is H
●
The number of Nyquist samples is Ns within the symbol time T
●
The useful symbol time T=Ts-T
●
The independent and Gaussian distributed noise sample is n
, on subcarrier k at OFDM symbol l
l,k
l,k
g
s
l,k
Within one OFDM symbol, both the CPE and the residual CFO cause the same phase
rotation for each subcarrier, while the rotation due to the SFO depends linearly on the
subcarrier index. A linear phase increase in symbol direction can be observed for the
residual CFO as well as for the SFO.
The results of the tracking estimation block are used to compensate the samples r
l,k
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2
,
,
,
,
''
,
,
ˆ
kl
kl
kl
klkl
kl
b
a
Eb
ar
EVM
kl
kl
kl
ln
b
ar
EVM
,
,
''
,
,
ˆ
Whereas a full compensation is performed in the reference path, the signal impairments that are of interest to the user are left uncompensated in the measurement path.
After having decided the data symbols in the reference path, an additional phase tracking can be utilized to refine the CPE estimation.
4.3.2 Channel Estimation and Equalization
As shown in Figure 4-1, there is one coarse and one fine channel estimation block.
The reference signal-based coarse estimation is tapped behind the CFO compensation
block (SFO compensation can optionally be enabled) of the reference path. The coarse
estimation block uses the reference signal symbols to determine estimates of the channel transfer function by interpolation in both time and frequency direction. A special
channel estimation (
coarse estimation results are used to equalize the samples of the reference path prior
to symbol decision. Based on the decided data symbols, a fine channel estimation is
optimally performed and then used to equalize the partially compensated samples of
the measurement path.
Measurement Basics
The LTE Downlink Analysis Measurement Application
) as defined in 3GPP TS 36.211 is additionally generated. The
4.3.3 Analysis
The analysis block of the EUTRA/LTE downlink measurement application allows to
compute a variety of measurement variables.
EVM
The error vector magnitude (EVM) measurement results 'EVM PDSCH QPSK/16QAM/64-QAM' are calculated according to the specification in 3GPP TS 36.211.
All other EVM measurement results are calculated according to
Equation 4-2:
on subcarrier k at OFDM symbol l, where b
power of all possible constellations is 1 when no boosting is applied, the equation can
be rewritten as
is the boosting factor. Since the average
l,k
Equation 4-3:
The average EVM of all data subcarriers is then
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l k
kl
REdata
data
data
data
EVM
N
EVM
2
,
1
tsjQtsItr
|1|balancegain modulator Q
}1arg{mismatch quadrature Q
Equation 4-4:
Measurement Basics
MIMO Measurement Guide
The number of resource elements taken into account is denoted by N
RE data
.
I/Q imbalance
The I/Q imbalance can be written as
Equation 4-5:
where s(t) is the transmit signal, r(t) is the received signal, and I and Q are the weighting factors. We define that I:=1 and Q:=1+ΔQ.
The I/Q imbalance estimation makes it possible to evaluate the
Equation 4-6:
and the
Equation 4-7:
based on the complex-valued estimate .
Other measurement variables
Without going into detail, the EUTRA/LTE downlink measurement application additionally provides the following results.
●
Total power
●
Constellation diagram
●
Group delay
●
I/Q offset
●
Crest factor
●
Spectral flatness
4.4 MIMO Measurement Guide
Performing MIMO measurements requires additional equipment that allows you to capture multiple data streams.
●
Several signal analyzers, the number depending on the number of data streams
you have to capture.
True MIMO measurements are useful to verifiy MIMO precoding implementations for
setups where it is not possible to decode the transmit data using only one antenna
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(e.g. applying spatial multiplexing MIMO precoding with more than 1 layer) and to measure the hardware performance of the MIMO transmitter hardware in a true MIMO
measurement setup.
4.4.1 MIMO Measurements with Signal Analyzers
MIMO measurements require multiple signal analyzers. The number depends on the
number of data streams you have to capture.
For valid measurement results, the frequencies of the analyzers in the test setup have
to be synchronized. It is also necessary to configure the trigger system properly to capture the data simultaneously.
Synchronizing the frequency
The frequency of the analyzers in the test setup have to be synchronized. Thus, one of
the analyzers (master) controls the other analyzers (slaves) in the test setup. The master analyzer has to be equipped with the LTE MIMO application and provides the reference oscillator source for the slave analyzers.
Measurement Basics
MIMO Measurement Guide
► Connect the REF OUT of the master to the REF IN connector of the slaves. Make
sure to configure the slaves to use an external reference (➙ General Setup menu).
If you are using a measurement setup with several R&S signal generators (for example
R&S SMW), the situation is similar. One of the generators controls the other via the
external reference.
► Connect the REF OUT of the master to the REF IN of the slaves. Make sure to
configure the slaves to use an external reference (➙ Reference Oscillator settings).
Triggering MIMO measurements
For valid MIMO measurements, it is crucial to capture all data streams simultaneously.
To do so, you need a trigger signal provided by the DUT or the signal generator. The
trigger signal has to be connected to all analyzers. If you have several signal generators in the setup, the master generator has to trigger the slave as well.
The 4-2 shows a MIMO setup with two (or optional four) analyzers and one (or optional
two) signal generators with two channels.
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Measurement Basics
MIMO Measurement Guide
Figure 4-2: MIMO Hardware Setup
You can use several trigger configurations, with or without additional hardware.
Measurements with a delayed trigger signal
Simultaneous capture of the I/Q data requires the trigger inputs of all instruments in the
setup to be armed.
Arming a trigger does not happen immediately when you start a measurement, but is
delayed slightly for a number of reasons, for example:
●
Connecting several instruments with a LAN or GPIB connection usually causes a
certain network delay.
●
Tasks like the auto leveling function require some time to finish.
Because of these factors, you have to make sure that the trigger event does not occur
during this time frame. You can do so, for example, by configuring an appropriate delay
time on the DUT.
The exact delay depends on the GPIB or network condition and the input settings.
A typical delay to arm the trigger is 2 seconds per instrument.
The minimum delay of the trigger signal must now be greater than the measured time
multiplied with the number of measured antennas (the number of analyzers), because
the spectrum analyzers are initialized sequentially.
The usage of an LTE frame trigger is not possible for this measurement setup.
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Measurements with a frame trigger signal
You can use a frame trigger if all transmitted LTE frames use the same frame configuration and contain the same data. In this case, the analyzers in the test setup capture
data from different LTE frames but with the same content.
This method to analyze data, however, raises one issue. The phase variations of the
reference oscillators of the different signals that are transmitted are not the same,
because the data is not captured simultaneously.
The result is a phase error which degrades the EVM (see the figures below).
An application for this measurement method is, for example, the test of the MIMO precoding implementation. Because of the bad EVM values, it is not recommended to use
this test setup to measure hardware performance.
Measurement Basics
MIMO Measurement Guide
Figure 4-3: Constellation diagram
Figure 4-4: EVM vs OFDM symbol number
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Measurements with the R&S FS-Z11 trigger unit
The trigger unit R&S FS-Z11 is a device that makes sure that the measurement starts
on all analyzers (master and slaves) at the same time.
Connecting the trigger unit
► Connect the NOISE SOURCE output of the master analyzer to the NOISE
SOURCE CONTROL input of the trigger unit.
► Connect the EXT TRIG inputs of all analyzers (master and slaves) to the TRIG
OUT 1 to 4 (or 1 and 2 in case of measurements on two antennas) of the trigger
unit. The order is irrelevant, that means it would be no problem if you connect the
master analyzer to the TRIG OUT 2 of the trigger unit.
With this setup, all analyzers (including the master analyzer) are triggered by the
trigger unit.
The trigger unit also has a TRIG INPUT connector that you can connect an external
trigger to. If you are using an external trigger, the external trigger supplies the trigger
event. If not, the analyzer noise source control supplies the trigger event. Note that if
you do not use an external trigger, the TRIG INPUT must remain open.
Measurement Basics
MIMO Measurement Guide
To use the R&S FS-Z11 as the trigger source, you have to turn it on in the "Trigger"
dialog box of the LTE measurement application. For more information see Chap-
ter 5.2.21, "Trigger Configuration", on page 113.
Trigger cable
Optional trigger cable (DUT w/ trigger output)
RF cable
Master Analyzer
RF
DUT
RF Output 1
RF Output 2
RF Output 3
RF Output 4
Trigger Out
FS-Z11 Trigger Unit
Trigger In
Trigger Manual
Noise Source
Trigger Out 1
Trigger Out 2
Trigger Out 3
Trigger Out 4
Trigger InNoise
RF
Trigger
In
RF
Trigger
In
RF
Trigger
In
Source
Analyzer 2
Analyzer 3
Analyzer 4
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4.5 Performing Time Alignment Measurements
The measurement application allows you to perform time alignment measurements
between different antennas.
The measurement supports setups of up to four Tx antennas.
The result of the measurement is the time alignment error. The time alignment error is
the time offset between a reference antenna (for example antenna 1) and another
antenna.
The time alignment error results are summarized in the corresponding result display.
A schematic description of the results is provided in Figure 4-5.
Measurement Basics
Performing Time Alignment Measurements
Tx Antenna 1 (Reference)
Time
Tx Antenna 2
Time Alignment Error
Time Alignment Error
LTE Frame Start Indicator
Time Alignment Error
Figure 4-5: Time Alignment Error (4 Tx antennas)
Δ2,1
Time
Tx Antenna 3
Δ3,1
Time
Tx Antenna 4
Δ4,1
Time
Test setup
Successful Time Alignment measurements require a correct test setup.
A typical hardware test setup is shown in Figure 4-6. Note that the dashed connections
are only required for MIMO measurements on 4 Tx antennas.
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Tx Ant 1
Tx Ant 2
DUT
Tx Ant 3
Tx Ant 4
Figure 4-6: Hardware setup
For best measurement result accuracy, it is recommended to use cables of the same
length and identical combiners as adders.
In the application, make sure to correctly apply the following settings.
●
Select a reference antenna in the MIMO Configuration dialog box (not "All")
●
Set the Subframe Selection to "All"
●
Turn on Compensate Crosstalk in the "Demodulation Settings"
●
Note that the Time Alignment measurement only evaluates the reference signal
and therefore ignores any PDSCH settings - for example, it does not have an influence on this measurement if the PDSCH MIMO scheme is set to transmit diversity
or spatial multiplexing.
Measurement Basics
Performing Transmit On/Off Power Measurements
+
FSx
+
+
4.6 Performing Transmit On/Off Power Measurements
The technical specification in 3GPP TS 36.141 describes the measurement of the
transmitter "Off" power and the transmitter transient period of an EUTRA/LTE TDD
base transceiver station (BTS) operating at its specified maximum output power.
A special hardware setup is required for this measurement. During the transmitter "Off"
periods (the interesting parts of the signal for this measurement), the signal power is
very low - measuring such low powers requires a low attenuation at the RF input. On
the other hand, the signal power is very high during the transmitter "On" periods - in
fact the signal power is usually higher than the maximum allowed RF input level. Measuring high signal levels requires an appropriate test setup as described below.
Risk of instrument damage
The signal power during the "On" transmitter periods in this test scenario is usually
higher than the maximum power allowed at the RF input of a spectrum analyzer.
Make sure to set up the measurement appropriately. Not doing so can cause severe
damage to the spectrum analyzer.
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Test setup
Ext. reference signal
Measurement Basics
Performing Transmit On/Off Power Measurements
R&S FSx with R&S
FSx-B25
Frame Trigger
Ext Trigger
RF Input
BTS
Tx signal
10 dB
Attenuator
Figure 4-7: Test setup for transmit on / off power measurement
●
Connect an RF limiter to the RF input to protect the RF input from damage (see
RF Limiter
Figure 4-7).
Table 4-1 shows the specifications that the limiter has to fulfill.
●
Insert an additional 10 dB attenuator in front of the RF limiter to absorb possible
reflected waves (because of the high VSWR of the limiter). The maximum allowed
CW input power of the attenuator must be lower than the maximum output power
of the BTS.
Table 4-1: Specifications of the RF limiter in the test setup
Min. acceptable CW input power BTS output power minus 10 dB
Min. acceptable peak input power BTS peak output power minus 10 dB
Max. output leakage 20 dBm
Max. response time 1 µs
Max. recovery time 1 µs
Measuring the on / off power
●
Use test model E-TM1.1 for transmit on / off power measurements according to
36.141, 6.4.
For more information about loading test model settings, see "Test Scenarios"
on page 71.
●
If you are using an external trigger, you have to adjust the timing before you can
start the actual measurement.
The status message in the diagram header shows if timing adjustment is required
or not. After timing was successfully adjusted, you can start the measurement.
Note that relevant changes of settings might require another timing adjustment.
If timing adjustment fails for any reason, the application shows a corresponding
message in the diagram header. To find out what causes the synchronization failure, you should perform a regular EVM measurement (i.e. leave the ON/OFF
Power measurement). Then you can use all the measurement results like "EVM vs
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Carrier" to get more detailed information about the failure. The timing adjustment
will succeed if the synchronization state in the header is OK.
●
If you are using an R&S FSQ or R&S FSG for the measurement, it is recommended to use the external trigger mode, because for high power signals a successful
synchronization is not guaranteed under certain circumstances.
When you start the measurement ("Run Single"), the R&S FPS starts the measurement. The number of measurements that trace averaging is based on depends on the
number of frames you have defined. When all measurements are done, the R&S FPS
indicates in the numerical result table if the measurement has failed or passed.
Measurement Basics
Performing Transmit On/Off Power Measurements
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5 Configuration
LTE measurements require a special application on the R&S FPS, which you activate
using the [MODE] key on the front panel.
When you start the LTE application, the R&S FPS starts to measure the input signal
with the default configuration or the configuration of the last measurement (when you
haven't performed a preset since then).
Automatic refresh of preview and visualization in dialog boxes after configuration changes
The R&S FPS supports you in finding the correct measurement settings quickly and
easily - after each change in settings in dialog boxes, the preview and visualization
areas are updated immediately and automatically to reflect the changes. Thus, you can
see if the setting is appropriate or not before accepting the changes.
Unavailable menus
Note that the [SPAN], [BW], [TRACE], [LINES] and [MKR FUNC] menus have no function in the LTE application.
Configuration
Configuration Overview
● Configuration Overview...........................................................................................67
● I/Q Measurements...................................................................................................69
● Time Alignment Error Measurements................................................................... 120
● Power On/Off Measurements................................................................................120
● Frequency Sweep Measurements........................................................................ 121
5.1 Configuration Overview
Throughout the measurement channel configuration, an overview of the most important
currently defined settings is provided in the "Overview". The "Overview" is displayed
when you select the "Overview" icon, which is available at the bottom of all softkey
menus.
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In addition to the main measurement settings, the "Overview" provides quick access to
the main settings dialog boxes. The individual configuration steps are displayed in the
order of the data flow. Thus, you can easily configure an entire measurement channel
from input over processing to output and analysis by stepping through the dialog boxes
as indicated in the "Overview".
Configuration
Configuration Overview
In particular, the "Overview" provides quick access to the following configuration dialog
boxes (listed in the recommended order of processing):
1. Signal Description
See Chapter 5.2.1, "Signal Characteristics", on page 70.
2. Input / Frontend
See Chapter 5.2.17, "Input Source Configuration", on page 106.
3. Trigger / Signal Capture
See Chapter 5.2.21, "Trigger Configuration", on page 113.
See Chapter 5.2.20, "Data Capture", on page 111
4. Estimation / Tracking
See Chapter 5.2.23, "Measurement Error Compensation", on page 116.
5. Demodulation
See Chapter 5.2.24, "Demodulation", on page 117.
6. Evaluation Range
See Chapter 6.2.2, "Evaluation Range", on page 130.
7. Analysis
See Chapter 6, "Analysis", on page 126.
8. Display Configuration
See Chapter 3, "Measurements and Result Displays", on page 14.
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In addition, the dialog box provides the "Select Measurement" button that serves as a
shortcut to select the measurement type.
Note that the "Overview" dialog box for frequency sweep measurement is similar to
that of the Spectrum mode.
For more information refer to the documentation of the R&S FPS.
To configure settings
► Select any button in the "Overview" to open the corresponding dialog box.
Select a setting in the channel bar (at the top of the measurement channel tab) to
change a specific setting.
Preset Channel
Select the "Preset Channel" button in the lower left-hand corner of the "Overview" to
restore all measurement settings in the current channel to their default values.
Do not confuse the "Preset Channel" button with the [Preset] key, which restores the
entire instrument to its default values and thus closes all channels on the R&S FPS
(except for the default channel)!
Remote command:
SYSTem:PRESet:CHANnel[:EXEC] on page 204
Configuration
I/Q Measurements
Select Measurement
Opens a dialog box to select the type of measurement.
For more information about selecting measurements, see Chapter 3.1, "Selecting Mea-
surements", on page 14.
Remote command:
CONFigure[:LTE]:MEASurement on page 202
Specific Settings for
The channel may contain several windows for different results. Thus, the settings indicated in the "Overview" and configured in the dialog boxes vary depending on the
selected window.
Select an active window from the "Specific Settings for" selection list that is displayed
in the "Overview" and in all window-specific configuration dialog boxes.
The "Overview" and dialog boxes are updated to indicate the settings for the selected
window.
5.2 I/Q Measurements
● Signal Characteristics............................................................................................. 70
● Configuring MIMO Setups.......................................................................................78
● PDSCH Demodulation............................................................................................ 80
● PDSCH Subframe Configuration.............................................................................81
● Synchronization Signal Configuration..................................................................... 88
● Reference Signal Configuration.............................................................................. 89
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● Positioning Reference Signal Configuration............................................................90
● Channel State Information Reference Signal Configuration................................... 92
● PDSCH Resource Block Symbol Offset..................................................................94
● PBCH Configuration................................................................................................95
● PCFICH Configuration............................................................................................ 96
● PHICH Configuration...............................................................................................97
● PDCCH Configuration...........................................................................................100
● EPDCCH Configuration.........................................................................................101
● Shared Channel Configuration..............................................................................103
● MBSFN Characteristics.........................................................................................103
● Input Source Configuration................................................................................... 106
● Frequency Configuration.......................................................................................106
● Amplitude Configuration........................................................................................107
● Data Capture......................................................................................................... 111
● Trigger Configuration.............................................................................................113
● Parameter Estimation and Tracking......................................................................115
● Measurement Error Compensation....................................................................... 116
● Demodulation........................................................................................................ 117
● Automatic Configuration........................................................................................119
Configuration
I/Q Measurements
5.2.1 Signal Characteristics
Access: "Overview" > "Signal Description" > "Signal Description"
The general signal characteristics contain settings to describe the general physical
attributes of the signal.
Selecting the LTE mode................................................................................................ 71
Test Scenarios...............................................................................................................71
└ Test models.....................................................................................................72
└ User defined test scenarios............................................................................ 72
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Carrier Aggregation.......................................................................................................72
└ Basic component carrier configuration............................................................73
└ Features of the I/Q measurements................................................................. 74
└ Features of the time alignment error measurement........................................74
└ Features of the transmit power on/off measurement...................................... 74
└ Features of the cumulative and MC ACLR measurement.............................. 74
└ Remote commands to configure carrier aggregation......................................75
Channel Bandwidth / Number of Resource Blocks....................................................... 75
Cyclic Prefix.................................................................................................................. 76
Configuring TDD Frames.............................................................................................. 76
└ TDD UL/DL Allocations...................................................................................76
└ Conf. of Special Subframe..............................................................................77
Configuring the Physical Layer Cell Identity..................................................................77
Exclude Inband NB-IoT.................................................................................................78
Selecting the LTE mode
The "Mode" selects the LTE standard you are testing.
The choices you have depend on the set of options you have installed.
●
Option xxx-K100 enables testing of 3GPP LTE FDD signals on the downlink
●
Option xxx-K101 enables testing of 3GPP LTE FDD signals on the uplink
●
Option xxx-K102 enables testing of 3GPP LTE MIMO signals on the downlink
●
Option xxx-K103 enables testing of 3GPP MIMO signals on the uplink
●
Option xxx-K104 enables testing of 3GPP LTE TDD signals on the downlink
●
Option xxx-K105 enables testing of 3GPP LTE TDD signals on the uplink
●
Option xxx-K106 enables testing of 3GPP LTE NB-IoT TDD signals on the downlink
FDD and TDD are duplexing methods.
●
FDD mode uses different frequencies for the uplink and the downlink.
●
TDD mode uses the same frequency for the uplink and the downlink.
Downlink (DL) and Uplink (UL) describe the transmission path.
●
Downlink is the transmission path from the base station to the user equipment.
The physical layer mode for the downlink is always OFDMA.
●
Uplink is the transmission path from the user equipment to the base station.
The physical layer mode for the uplink is always SC-FDMA.
The application shows the currently selected LTE mode (including the bandwidth) in
the channel bar.
Configuration
I/Q Measurements
Remote command:
Link direction: CONFigure[:LTE]:LDIRection on page 209
Duplexing mode: CONFigure[:LTE]:DUPLexing on page 205
Test Scenarios
Test scenarios are descriptions of specific LTE signals.
Test scenarios are stored in .allocation files. You can select, manage and create
test scenarios in the "Test Models" dialog box.
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Test models ← Test Scenarios
Access: "Overview" > "Signal Description" > "Test Models / User Defined Sets" >
"Specification"
Test models are certain signal descriptions defined by 3GPP for certain test scenarios.
3GPP calls them E-TM. All test models are available in the firmware.
3GPP already defines several test models (E-TM) for various test scenarios in 3GPP
36.141. There are three main test model groups (E-TM1, E-TM2 and E-TM3) and are
defined by the following characteristics.
●
Single antenna port, single code word, single layer and no precoding
●
Duration of one frame
●
Normal cyclic prefix
●
Localized virtual resource blocks, no intra-subframe hopping for PDSCH
●
UE-specific reference signal not used
For an overview of the test scenarios, see Chapter 3.9, "3GPP Test Scenarios",
on page 52.
The data content of the physical channels and signals is defined by 3GPP. Each E-TM
is defined for all bandwidths defined in the standard (1.4 MHz / 3 MHz / 5 MHz /
10 MHz / 15 MHz / 20 MHz).
Configuration
I/Q Measurements
More information.
Remote command:
MMEMory:LOAD[:CC<cc>]:TMOD:DL on page 211
User defined test scenarios ← Test Scenarios
Access: "Overview" > "Signal Desription" > "Test Models / User Defined Sets" > "User
Defined"
User defined test scenarios are custom signal descriptions that you can save and
restore as you like.
To create a custom test scenario, describe a signal as required and then save it with
the corresponding button. The R&S FPS stores custom scenarios in .allocation
files.
If you do not need test scenarios any longer, you can also delete them.
Remote command:
Save: MMEMory:STORe<n>[:CC<cc>]:DEModsetting on page 211
Restore: MMEMory:LOAD[:CC<cc>]:DEModsetting on page 210
Carrier Aggregation
Carrier aggregation has been introduced in the LTE standard to increase the bandwidth. In those systems, several carriers can be used to transmit a signal.
Each carrier usually has one of the channel bandwidths defined by 3GPP.
The R&S FPS features several measurements that support contiguous and non-contig-
uous intra-band carrier aggregation (the carriers are in the same frequency band).
●
I/Q based measurements (EVM, frequency error, etc.) (downlink)
●
I/Q based measurements (EVM, frequency error, etc.) (uplink)
●
Time alignment error (downlink)
●
Time alignment error (uplink)
●
Transmit on/off power (downlink)
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●
Cumulative ACLR (downlink, non-contiguous intra-band carrier aggregation)
●
Multi carrier ACLR (downlink, non-contiguous intra-band carrier aggregation)
●
Multi carrier ACLR (uplink, contiguous intra-band carrier aggregation)
●
SEM (downlink, non-contiguous intra-band carrier aggregation)
●
SEM (uplink, contiguous intra-band carrier aggregation)
The way to configure these measurements is similar (but not identical, the differences
are indicated below).
●
"Basic component carrier configuration" on page 73
●
"Features of the I/Q measurements" on page 74
●
"Features of the time alignment error measurement" on page 74
●
"Features of the transmit power on/off measurement" on page 74
●
"Features of the cumulative and MC ACLR measurement" on page 74
●
"Remote commands to configure carrier aggregation" on page 75
Basic component carrier configuration ← Carrier Aggregation
The number of component carriers (CCs) you can select depends on the measurement.
●
I/Q based measurements (EVM etc.): up to 5 CCs
●
Time alignment error: up to 2 CCs
●
Transmit on/off power: up to 5 CCs
●
Multi-carrier ACLR: up to 5 CCs
●
Cumulative ACLR: up to 5 CCs
●
Multi-carrier SEM: up to 5 CCs
You can define the characteristics of the CCs in the table in the "Carrier Configuration"
panel (in the "Signal Characteristics" dialog box). Depending on the "Number of Component Carriers", the application adjusts the size of the table. Each line corresponds to
a component carrier.
●
The "Center Frequency" defines the carrier frequency of the carriers.
●
For each carrier, you can select the "Bandwidth" from the corresponding dropdown
menu.
●
For all component carriers, the R&S FPS also shows the "Frequency Offset" relative to the center frequency of the first carrier.
If you define a different frequency offset, the application adjusts the center frequency accordingly.
Note that the actual measurement frequency differs from the carrier frequencies: the
application calculates that frequency based on the carrier frequencies. It is somewhere
in between the carrier frequencies.
The measurement frequency is displayed in the channel bar.
For each component carrier, you can select one of the channel bandwidths defined
by 3GPP from the "Bandwidth" dropdown menus. The combination of bandwidths is
arbitrary.
When the defined carrier configuration is not supported by the application, a corresponding error message is displayed. This can be the case, for example, if the carriers
occupy a bandwidth that is too large.
Configuration
I/Q Measurements
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Features of the I/Q measurements ← Carrier Aggregation
For measurements on component carriers, results are shown for each component carrier separately. The layout of the diagrams is adjusted like this:
●
The first tab ("All") shows the results for all component carriers.
●
The other tabs ("CC <x>") show the results for each component carrier individually.
The application also shows the "Occupied Bandwidth" of the aggregated carriers and
the "Sample Rate" in a read-only field below the carrier configuration.
Configuration
I/Q Measurements
Features of the time alignment error measurement ← Carrier Aggregation
When you perform a TAE measurement, you can capture the data of the component
carriers either on one R&S FPS ("wideband capture") or on two R&S FPS. When you
capture the data with only one R&S FPS, make sure that it has a bandwidth wide
enough to capture all component carriers in a single measurement.
You can define the number of devices to measure in the corresponding input field.
You can configure additional signal characteristics of the first and second carrier in the
"CC1" and "CC2" tabs.
In case you are testing a MIMO DUT, you can also select the number of antennas the
DUT supports. When you select "1 Tx Antenna", the application measures the timing
difference between two SISO carriers, when you select more than one antenna, it
measures the timing difference between the antennas. In that case, you can select the
reference antenna from the dropdown menu in the time alignment error result display.
Note that the application shows measurement results for the second component carrier
even if only one antenna of the second component carrier is attached (i.e. no combiner
is used).
Features of the transmit power on/off measurement ← Carrier Aggregation
The "Frequency Lower Edge" and "Frequency Higher Edge" field displayed below
the component carrier table represent the bandwidth required by the aggregated carriers.
Features of the cumulative and MC ACLR measurement ← Carrier Aggregation
The diagram at the bottom of the dialog box represents the current configuration.
When you change the bandwidth of a carrier (represented by blue bars), the application adjusts the bandwidth of the carriers in the diagram accordingly.
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In the MC ACLR measurement, you can also define the bandwidth characteristics of
the upper and lower neighboring channels (not represented in the diagram).
Remote commands to configure carrier aggregation ← Carrier Aggregation
Configuration
I/Q Measurements
Remote command:
Number of carriers: CONFigure[:LTE]:NOCC on page 258
Carrier frequency: [SENSe:]FREQuency:CENTer[:CC<cc>] on page 239
Measurement frequency: SENSe:FREQuency:CENTer?
Offset: [SENSe:]FREQuency:CENTer[:CC<cc>]:OFFSet on page 239
Channel bandwidth: CONFigure[:LTE]:DL[:CC<cc>]:BW on page 205
Number of devices: CONFigure[:LTE]:NDEVices on page 260
Lower adjacent channel BW: [SENSe:]POWer:ACHannel:AACHannel on page 260
Upper adjacent channel BW: [SENSe:]POWer:ACHannel:UAAChannel
on page 261
Channel Bandwidth / Number of Resource Blocks
Specifies the channel bandwidth and number of resource blocks (RB).
The channel bandwidth and number of resource blocks (RB) are interdependent. Cur-
rently, the LTE standard recommends six bandwidths (see table below).
Tip: The "Auto LTE Config" feature (available in the "Auto Set" menu) automatically
detects the channel bandwidth.
The application also calculates the FFT size, sampling rate, occupied bandwidth and
occupied carriers from the channel bandwidth. Those are read only.
Channel Bandwidth [MHz] 1.4 20151053
Number of Resource Blocks 6 10075502515
Sample Rate [MHz] 1.92 30.7230.7215.367.683.84
FFT Size 128 204820481024512256
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For more information about configuring aggregated carriers, see "Carrier Aggregation"
on page 72.
The application shows the currently selected LTE mode (including the bandwidth) in
the channel bar.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:BW on page 205
Cyclic Prefix
The cyclic prefix serves as a guard interval between OFDM symbols to avoid interferences. The standard specifies two cyclic prefix modes with a different length each.
The cyclic prefix mode defines the number of OFDM symbols in a slot.
●
Normal
A slot contains 7 OFDM symbols.
●
Extended
A slot contains 6 OFDM symbols.
The extended cyclic prefix is able to cover larger cell sizes with higher delay
spread of the radio channel.
●
Auto
The application automatically detects the cyclic prefix mode in use.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CYCPrefix on page 206
Configuration
I/Q Measurements
Configuring TDD Frames
TDD frames contain both uplink and downlink information separated in time with every
subframe being responsible for either uplink or downlink transmission. The standard
specifies several subframe configurations or resource allocations for TDD systems.
TDD UL/DL Allocations ← Configuring TDD Frames
Selects the configuration of the subframes in a radio frame in TDD systems.
The UL/DL configuration (or allocation) defines the way each subframe is used: for
uplink, downlink or if it is a special subframe. The standard specifies seven different
configurations.
Configuration
0
1
2
3
4
5
6
0 987654321
D
D
D
D
D
D
D
S
S
S
S
S
S
S
Subframe Number and Usage
U
U
U
U
U
D
U
D
D
U
U
U
U
U
D
U
D
D
U
U
U
D
S
U
U
U
D
S
U
U
D
D
S
U
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
S
U
U
D
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)2()1(
3
IDID
cell
ID
NNN
U = uplink
D = downlink
S = special subframe
Remote command:
Subframe: CONFigure[:LTE]:DL[:CC<cc>]:TDD:UDConf on page 208
Conf. of Special Subframe ← Configuring TDD Frames
In combination with the cyclic prefix, the special subframes serve as guard periods for
switches from uplink to downlink. They contain three parts or fields.
●
DwPTS
The DwPTS is the downlink part of the special subframe. It is used to transmit
downlink data.
●
GP
The guard period makes sure that there are no overlaps of up- and downlink signals during a switch.
●
UpPTS
The UpPTS is the uplink part of the special subframe. It is used to transmit uplink
data.
The length of the three fields is variable. This results in several possible configurations
of the special subframe. The LTE standard defines 10 different configurations for the
special subframe. However, configurations 8 and 9 only work for a normal cyclic prefix.
If you select configurations 8 or 9 using an extended cyclic prefix or automatic detection of the cyclic prefix, the application will show an error message.
Remote command:
Special subframe: CONFigure[:LTE]:DL[:CC<cc>]:TDD:SPSC on page 208
Configuration
I/Q Measurements
Configuring the Physical Layer Cell Identity
The "Cell ID", "Cell Identity Group" and physical layer "Identity" are interdependent
parameters. In combination, they are responsible for synchronization between network
and user equipment.
The physical layer cell ID identifies a particular radio cell in the LTE network. The cell
identities are divided into 168 unique cell identity groups. Each group consists of 3
physical layer identities. According to:
(1)
= cell identity group, {0...167}
N
(2)
= physical layer identity, {0...2}
N
there is a total of 504 different cell IDs.
If you change one of these three parameters, the application automatically updates the
other two.
For automatic detection of the cell ID, turn on the "Auto" function.
Before it can establish a connection, the user equipment must synchronize to the radio
cell it is in. For this purpose, two synchronization signals are transmitted on the downlink. These two signals are reference signals whose content is defined by the "Physical
Layer Identity" and the "Cell Identity Group".
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The first signal is one of 3 possible Zadoff-Chu sequences. The sequence that is used
is defined by the physical layer identity. It is part of the P-Sync.
The second signal is one of 168 unique sequences. The sequence is defined by the
cell identity group. This sequence is part of the S-Sync.
In addition to the synchronization information, the cell ID also determines:
●
The cyclic shifts for PCFICH, PHICH and PDCCH mapping,
●
The frequency shifts of the reference signal.
Remote command:
Cell ID: CONFigure[:LTE]:DL[:CC<cc>]:PLC:CID on page 207
Cell Identity Group (setting): CONFigure[:LTE]:DL[:CC<cc>]:PLC:CIDGroup
on page 207
Cell Identity Group (query): FETCh[:CC<cc>]:PLC:CIDGroup? on page 210
Identity (setting): CONFigure[:LTE]:DL[:CC<cc>]:PLC:PLID on page 208
Identity (query): FETCh[:CC<cc>]:PLC:PLID? on page 210
Exclude Inband NB-IoT
The 3GPP standard specifies several operating modes, or deployments, for NB-IoT
transmission. The deployment specifies where the NB-IoT signal is located in the frequency spectrum.
One of these deployments is the inband deployment. In that case, the The NB-IoT signal uses resource blocks within an LTE carrier.
You can exclude the resource blocks used by the NB-IoT signal from the measurement
results when you turn on "Exclude Inband NBIoT". When you turn on this feature, you
can also define the location of the NB-IoT signal within the LTE carrier as an resource
block offset. The resource block offset is a value relative to resource block 0.
Remote command:
State: CONFigure[:LTE]:DL[:CC<cc>]:EINBiot[:STATe] on page 206
Offset: CONFigure[:LTE]:DL[:CC<cc>]:NRBoffset on page 206
Configuration
I/Q Measurements
5.2.2 Configuring MIMO Setups
Access: "Overview" > "Signal Description" > "MIMO / CA Setup"
MIMO measurements need a special setup that you can configure with the settings
available in the MIMO configuration dialog box.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Configuration
I/Q Measurements
Functions in the "MIMO Setup" dialog box described elsewhere:
●
"Number Of Component Carrier", see "Carrier Aggregation" on page 72.
DUT MIMO Configuration..............................................................................................79
Tx Antenna Selection....................................................................................................79
DUT MIMO Configuration
The "DUT MIMO Configuration" selects the number of antennas in the system you are
analyzing.
The number of antennas corresponds to the number of cell-specific reference signals.
The R&S FPS supports measurements on one, two or four antennas.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:MIMO:CONFig on page 213
Tx Antenna Selection
The "Tx Antenna Selection" selects the antenna(s) you want to analyze. The number of
menu items depends on the number of antennas in the system.
Each antenna corresponds to a cell-specific reference signal.
For automatic detection, the R&S FPS analyzes the reference signal to select the
antenna. It also determines the order in which the antennas are tested.
Antenna 1 Tests antenna 1 only.
Antenna 2 Tests antenna 2 only.
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Antenna 3 Tests antenna 3 only.
Antenna 4 Tests antenna 4 only.
Auto Analyzes the reference signal to select the correct antenna.
The antenna you have selected is also the reference antenna for time alignment measurements.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:MIMO:ASELection on page 213
5.2.3 PDSCH Demodulation
Access: "Overview" > "Signal Description" > "PDSCH Settings"
The Physical Layer Shared Channel (PDSCH) carries user data, broadcast system
information and paging messages. It is always present in a downlink transmission.
The application allows you to automatically demodulate the PDSCH and detect the
subframe configuration of the signal you are testing.
Configuration
I/Q Measurements
For more information on manual PDSCH configuration, see Chapter 5.2.4, "PDSCH
Subframe Configuration", on page 81.
PDSCH Subframe Configuration Detection.................................................................. 80
Auto PDSCH Demodulation..........................................................................................81
PDSCH Subframe Configuration Detection
Selects the method of identifying the PDSCH resource allocation.
●
Off
Uses the user configuration to demodulate the PDSCH subframe. If the user configuration does not match the frame that was measured, a bad EVM will result.
●
PDCCH protocol
Sets the PDSCH configuration according to the data in the protocol of the PDCCH
DCIs.
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When you use this method, the application measures the boosting for each
PDCCH it has detected. The result is displayed in the Channel Decoder Results.
●
Physical detection
The physical detection is based on power and modulation detection.
Physical detection makes measurements on TDD E-TMs without a 20 ms trigger
signal possible.
More information.
Remote command:
[SENSe:][LTE:]DL:FORMat:PSCD on page 214
Auto PDSCH Demodulation
Turns automatic demodulation of the PDSCH on and off.
When you turn on this feature, the application automatically detects the PDSCH
resource allocation. This is possible by analyzing the protocol information in the
PDCCH or by analyzing the physical signal. The application then writes the results into
the PDSCH Configuration Table.
You can set the way the application identifies the PDSCH resource allocation with
PDSCH Subframe Configuration Detection.
When you turn off automatic demodulation of the PDSCH, you have to configure the
PDSCH manually. In that case, the application compares the demodulated LTE frame
to the customized configuration. If the "PDSCH Subframe Configuration Detection" is
not turned off, the application analyzes the frame only if both configurations are the
same.
Remote command:
[SENSe:][LTE:]DL:DEMod:AUTO on page 214
Configuration
I/Q Measurements
5.2.4 PDSCH Subframe Configuration
Access: "Overview" > "Signal Description" > "PDSCH Settings"
The application allows you to configure individual subframes that are used to carry the
information of the PDSCH. The PDSCH (Physical Downlink Shared Channel) primarily
carries all general user data. It therefore takes up most of the space in a radio frame.
When you turn on "Auto Demodulation", the application automatically determines the
subframe configuration for the PDSCH. In the default state, automatic configuration is
on (➙ More information).
Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
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Every LTE frame (FDD and TDD) contains 10 subframes. (In TDD systems, some subframes are used by the uplink, however.) Each downlink subframe consists of one or
more (resource) allocations. The application shows the contents for each subframe in
the configuration table. In the configuration table, each row corresponds to one allocation.
If there are any errors or conflicts between allocations in one or more subframes, the
application shows the corrupt subframe in the "Error in Subframes" field, which
appears below the table and is highlighted red if an error occurs. In addition, it shows
the conflicting rows of the configuration table. It does not show the kind of error.
Configuration
I/Q Measurements
Before you start to work on the contents of each subframe, you should define the number of subframes you want to customize with the "Configurable Subframes" parameter.
The application supports the configuration of up to 40 subframes.
Then you can select a particular subframe that you want to customize in the "Selected
Subframe" field. Enter the number of the subframe (starting with 0). The application
updates the contents of the configuration table to the selected subframe.
Remote command:
Number of subframes: CONFigure[:LTE]:DL[:CC<cc>]:CSUBframes
on page 215
Number of allocations: CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:
ALCount on page 215
● PDSCH Allocations................................................................................................. 82
● Enhanced Settings..................................................................................................85
5.2.4.1 PDSCH Allocations
In the default state, each subframe contains one allocation. Add allocations with the
"Used Allocations" parameter. The application expands the configuration table accordingly with one row representing one allocation. You can define a different number of
allocations for each subframe you want to configure and configure up to 110 allocations in every subframe.
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The configuration table contains the settings to configure the allocations.
ID/N_RNTI.....................................................................................................................83
Code Word....................................................................................................................83
Modulation.....................................................................................................................83
Enhanced Settings........................................................................................................84
VRB Gap.......................................................................................................................84
Number of RB............................................................................................................... 84
Offset RB.......................................................................................................................84
Power............................................................................................................................85
Conflict.......................................................................................................................... 85
ID/N_RNTI
Selects the allocation's ID. The ID corresponds to the N_RNTI.
By default, the application assigns consecutive numbers starting with 0.
The ID, or N_RNTI, is the user equipment identifier for the corresponding allocation
and is a number in the range from 0 to 65535. The order of the numbers is irrelevant.
You can combine allocations by assigning the same number more than once. Combining allocations assigns those allocations to the same user.
Allocations with the same N_RNTI have the same modulation scheme and power settings.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:UEID
on page 220
Configuration
I/Q Measurements
Code Word
Shows the code word of the allocation.
The code word is made up out of two numbers. The first number is the number of the
code word in the allocation. The second number is the total number of code words that
the allocation contains. Thus, a table entry of "1/2" would mean that the row corresponds to code word 1 out of 2 code words in the allocation.
Usually one allocation corresponds to one code word. In case of measurements on a
MIMO system (2 or 4 antennas) in combination with the "Spatial Multiplexing" precoding value, however, you can change the number of layers. Selecting 2 or more layers
assigns two code words to the allocation. This results in an expansion of the configuration table. The allocation with the spatial multiplexing then comprises two rows instead
of only one. Except for the modulation of the code word, which can be different, the
contents of the second code word (row) are the same as the contents of the first code
word.
Modulation
Selects the modulation scheme for the corresponding allocation.
The modulation scheme for the PDSCH is either QPSK, 16QAM, 64QAM, 256QAM or
1024QAM.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>[:CW<cw>]:
MODulation on page 220
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Enhanced Settings
Opens a dialog box to configure MIMO functionality.
For more information see Chapter 5.2.4.2, "Enhanced Settings", on page 85.
VRB Gap
Turns the use of virtual resource blocks (VRB) on and off.
The standard defines two types of VRBs. Localized VRBs and distributed VRBs. While
localized VRBs have a direct mapping to the PRBs, distributed VRBs result in a better
frequency diversity.
Three values of VRB gap are allowed.
●
0 = Localized VRBs are used.
●
1 = Distributed VRBs are used and the first gap is applied.
●
2 = Distributed VRBs are used and the second gap is applied (for channel bandwidths > 50 resource blocks).
The second gap has a smaller size compared to the first gap.
If on, the VRB Gap determines the distribution and mapping of the VRB pairs to the
physical resource blocks (PRB) pairs.
The distribution of the VRBs is performed in a way that consecutive VRBs are
spread over the frequencies and are not mapped to PRBs whose frequencies are
next to each other. Each VRB pair is split into two parts which results in a frequency gap between the two VRB parts. This method corresponds to frequency
hopping on a slot basis.
The information whether localized or distributed VRBs are applied is carried in the
PDCCH. The DCI formats 1A, 1B and 1D provide a special 1-bit flag for this purpose ("Localized / Distributed VRB Assignment"). Another bit in the DCI formats
controls whether the first or second bit is applied.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:GAP on page 215
Configuration
I/Q Measurements
Number of RB
Defines the number of resource blocks the allocation covers. The number of resource
blocks defines the size or bandwidth of the allocation.
If you allocate too many resource blocks compared to the bandwidth you have set, the
application shows an error message in the "Conflicts" column and the "Error in Subframes" field.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:RBCount
on page 219
Offset RB
Sets the resource block at which the allocation begins.
A wrong offset for any allocation would lead to an overlap of allocations. In that case,
the application shows an error message.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:RBOFfset
on page 219
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Power
Sets the boosting of the allocation.
Boosting is the allocation's power relative to the reference signal power.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:POWer
on page 216
Conflict
In case of a conflict, the application shows the type of conflict and the ID of the allocations that are affected. Possible conflicts are:
●
bandwidth error (">BW")
A bandwidth error occurs when the number of resource blocks in the subframe
exceeds the bandwidth you have set.
Number of
Allocations = 6
●
RB overlap errors
An RB overlap error occurs if one or more allocations overlap. In that case, check if
the length and offset values of the allocations are correct.
Configuration
I/Q Measurements
ID=5
ID 4
ID 3
ID 2
ID 1
ID 0
Subframe Bandwidth = 3 MHz or 15 Resource Blocks
Number of
Allocations = 6
Subframe Bandwidth = 3 MHz or 15 Resource Blocks
5.2.4.2 Enhanced Settings
The "Enhanced Settings" contain mostly functionality to configure the precoding
scheme of a physical channel. The application supports several precoding schemes
that you can select from a dropdown menu.
In addition, you can configure PDSCH allocations that use carrier aggregation.
5
ID 4
ID 3
ID 2
ID 1
ID 0
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None..............................................................................................................................86
Transmit Diversity..........................................................................................................86
Spatial Multiplexing....................................................................................................... 86
Beamforming (UE Spec RS)......................................................................................... 87
Carrier Aggregation.......................................................................................................87
Configuration
I/Q Measurements
None
Turns off precoding.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding[:
SCHeme] on page 218
Transmit Diversity
Turns on precoding for transmit diversity according to 3GPP TS 36.211.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding[:
SCHeme] on page 218
Spatial Multiplexing
Turns on precoding for spatial multiplexing according to 3GPP TS 36.211.
If you are using spatial multiplexing, you can also define the number of layers for any
allocation and the codebook index.
The number of layers of an allocation in combination with the number of code words
determines the layer mapping. The available number of layers depends on the number
of transmission antennas. Thus, the maximum number of layers you can select is
eight.
The codebook index determines the precoding matrix. The available number of indices
depends on the number of transmission antennas in use. The range is from 0 to 15.
The application automatically selects the codebook index if you turn on the "Cyclic
Delay Diversity" (CDD).
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Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding[:
SCHeme] on page 218
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:
CLMapping on page 217
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:
CBINdex on page 216
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:CDD
on page 217
Beamforming (UE Spec RS)
Turns on the precoding for beamforming.
If you are using beamforming, you can also define the number of layers and code-
words (see Spatial Multiplexing), the scrambling identity and the single layer antenna
port.
The mapping of antenna port to the physical antenna is fixed:
●
Port 5 and 7: Antenna 1
●
Port 8: Antenna 2
●
Port 9: Antenna 3
●
Port 10: Antenna 4
The scrambling identity (n
alize the sequence that generates UE specific reference signals according to 36.211
(section 6.10.3.1).
The single layer antenna port selects the preconfigured antenna port in single layer
beamforming scenarios. Available if the codeword to layer mapping is "1/1".
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding[:
SCHeme] on page 218
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:
CLMapping on page 217
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:
SCID on page 218
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PRECoding:AP
on page 216
Configuration
I/Q Measurements
) is available for antenna ports 7 and 8. It is used to initi-
SCID
Carrier Aggregation
Defines the PDSCH start offset for the selected PDSCH allocation in a system that
uses carrier aggregation.
For cross-scheduled UEs, the PDSCH start offset for the secondary carrier is usually
not defined for each subframe individually but is constant over several subframes. In
case the control channel region of the secondary component carrier is longer than the
PDSCH start offset you have defined for the primary carrier, PDSCH resource elements might be overwritten by the resource elements of the control channel. Note that
the bit stream result displays labels these resource elements with a "#" sign.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SUBFrame<sf>:ALLoc<al>:PSOFfset
on page 219
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5.2.5 Synchronization Signal Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Synchronization
Signal"
The synchronization signal settings contain settings to describe the physical attributes
and structure of the synchronization signal.
Configuration
I/Q Measurements
Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
P-/S-SYNC Tx Antenna.................................................................................................88
P-Sync Relative Power................................................................................................. 88
S-Sync Relative Power................................................................................................. 89
Custom Sync Weight.....................................................................................................89
P-/S-SYNC Tx Antenna
Selects the antenna that transmits the synchronization signal (P-SYNC or S-SYNC).
When selecting the antenna, you implicitly select the synchronization method. If the
selected antenna transmits no synchronization signal, the application uses the reference signal to synchronize. Note that automatic cell ID detection is not available if synchronization is based on the reference signal.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SYNC:ANTenna on page 221
P-Sync Relative Power
Defines the power of the primary synchronization signal (P-Sync) relative to the reference signal.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SYNC:PPOWer on page 223
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S-Sync Relative Power
Defines the power of the secondary synchronization signal (S-Sync) relative to the reference signal.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SYNC:SPOWer on page 224
Custom Sync Weight
Turns custom weighting of the (primary and secondary) synchronization signals on and
off (for example for beamforming scenarios).
If you turn on custom weights, you can define the weights applied to the first and second half frames. The signal weights are a complex number and are therefore defined
by the real and imaginary parts of the signal.
Remote command:
State: CONFigure[:LTE]:DL[:CC<cc>]:SYNC:CSWeight[:STATe] on page 223
1st 1/2 frame real: CONFigure[:LTE]:DL[:CC<cc>]:SYNC:CSWeight:FHFRame:
REAL on page 222
1st 1/2 frame imaginary: CONFigure[:LTE]:DL[:CC<cc>]:SYNC:CSWeight:
FHFRame:IMAGinary on page 221
2nd 1/2 frame real: CONFigure[:LTE]:DL[:CC<cc>]:SYNC:CSWeight:
SHFRame:REAL on page 223
2nd 1/2 frame imaginary: CONFigure[:LTE]:DL[:CC<cc>]:SYNC:CSWeight:
SHFRame:IMAGinary on page 222
Configuration
I/Q Measurements
5.2.6 Reference Signal Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Reference Sig-
nal"
The reference signal settings contain settings to describe the physical attributes and
structure of the reference signal.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Rel Power (Reference Signal).......................................................................................90
Rel Power (Reference Signal)
Defines the relative power of the reference signal compared to all the other physical
signals and physical channels.
Note that this setting gives you an offset to all other relative power settings.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:REFSig:POWer on page 224
Configuration
I/Q Measurements
5.2.7 Positioning Reference Signal Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Reference Sig-
nal"
The positioning reference signal settings contain settings to describe the physical
attributes and structure of the positioning reference signal.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Present..........................................................................................................................91
Bandwidth..................................................................................................................... 91
Configuration Index.......................................................................................................91
Num. Subframes (N_PRS)............................................................................................91
Relative Power (Positioning Reference Signal)............................................................ 91
Frame Number Offset....................................................................................................91
Present
Turns the positioning reference signal on and off.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PRSS:STATe on page 226
Configuration
I/Q Measurements
Bandwidth
Defines the bandwidth and thus the number of resource blocks the positioning reference signal occupies.
Note that the PRS bandwidth has to be smaller than the channel bandwidth.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PRSS:BW on page 224
Configuration Index
Defines the PRS Configuration Index I
as defined in 3GPP TS 36.211, table
PRS
6.10.4.3-1.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PRSS:CI on page 225
Num. Subframes (N_PRS)
Defines the number of consecutive DL subframes in that PRS are transmitted.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PRSS:NPRS on page 225
Relative Power (Positioning Reference Signal)
Defines the power of a PRS resource element in relation to the power of a common
reference signal resource element.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PRSS:POWer on page 225
Frame Number Offset
Defines the system frame number of the current frame that you want to analyze.
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Because the positioning reference signal and the CSI reference signal usually have a
periodicity of several frames, for some reference signal configurations it is necessary to
change the expected system frame number of the frame to be analyzed.
Note that if you define the frame number offset for either reference signal, it is automatically defined for both reference signals.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SFNO on page 226
5.2.8 Channel State Information Reference Signal Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Reference Sig-
nal"
The channel state information reference signal (CSI-RS) settings contain settings to
describe the physical attributes and structure of the Channel State Information Reference Signal (CSI-RS).
CSI-RS are used to estimate the channel properties of the signal propagation channel
from the base station to the user equipment. This information is quantized and fed
back to the base station. The base station makes use of this information for example to
adjust the beamforming parameters.
Configuration
I/Q Measurements
The mapping of up to four antenna ports to the physical antenna is as follows:
●
Port 15: antenna 1
●
Port 16: antenna 2
●
Port 17: antenna 3
●
Port 18: antenna 4
Resource elements used by CSI-RS are shown in yellow color in the Allocation ID versus Symbol X Carrier measurement.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Present..........................................................................................................................93
Antenna Ports............................................................................................................... 93
Configuration Index.......................................................................................................93
Overwrite PDSCH......................................................................................................... 93
Relative Power (CSI Reference Signal)........................................................................94
Subframe Configuration................................................................................................ 94
Frame Number Offset....................................................................................................94
Present
Turns the CSI reference signal on and off.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:STATe on page 228
Configuration
I/Q Measurements
Antenna Ports
Defines the number of antenna ports that transmit the CSI reference signal.
The CSI reference signals are transmitted on one, two, four or eight antenna ports
using
●
p = 15
●
p = 15 to 16
●
p = 15 to 18
●
p = 15 to 22
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:NAP on page 227
Configuration Index
Defines the CSI reference signal configuration as defined in 3GPP TS 36.211, table
6.10.5.2-1/2
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:CI on page 226
Overwrite PDSCH
Turns overwriting of PDSCH resource elements for UEs that do not consider the CSI
reference signal on and off.
If on, the application assumes that the UE is not configured to consider CSI reference
signals. Thus, resource elements of the CSI reference signal overwrite the PDSCH
resource elements. Note that the bit stream result displays labels these resource elements with a "#" sign.
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Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:OPDSch on page 227
Relative Power (CSI Reference Signal)
Defines the power of a CSI reference signal resource element in relation to the power
of a common reference signal resource element.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:POWer on page 227
Subframe Configuration
Defines the CSI reference signal subframe configuration index (I_CSI-RS) as defined
in 3GPP TS 36.211, table 6.10.5.3-1.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:CSIRs:SCI on page 228
Frame Number Offset
Defines the system frame number of the current frame that you want to analyze.
Because the positioning reference signal and the CSI reference signal usually have a
periodicity of several frames, for some reference signal configurations it is necessary to
change the expected system frame number of the frame to be analyzed.
Note that if you define the frame number offset for either reference signal, it is automatically defined for both reference signals.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:SFNO on page 226
Configuration
I/Q Measurements
5.2.9 PDSCH Resource Block Symbol Offset
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Control Channel"
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
PRB Symbol Offset....................................................................................................... 95
PRB Symbol Offset
PRB Symbol Offset specifies the symbol offset of the PDSCH allocations relative to the
subframe start. This setting applies to all subframes in a frame.
With this setting, the number of OFDM symbols used for control channels is defined,
too. For example, if this parameter is set to "2" and the PDCCH is enabled, the number
of OFDM symbols actually used by the PDCCH is "2".
Special control channels like the PCFICH or PHICH require a minimum number of control channel OFDM symbols at the beginning of each subframe. If PRB Symbol Offset
is lower than the required value, the control channel data overwrites some resource
elements of the PDSCH.
If Auto is selected, the Control Region for PDCCH (PRB Symbol Offset) value is detected from the PCFICH. For correct demodulation of a PCFICH signal conforming to
3GPP, the Scrambling of Coded Bits has to be enabled.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PSOFfset on page 234
Configuration
I/Q Measurements
5.2.10 PBCH Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Control Channel"
The physical broadcast channel (PBCH) carries system information for the user equipment. You can include or exclude the PBCH in the test setup and define the relative
power of this channel.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Configuration
I/Q Measurements
PBCH Present...............................................................................................................96
PBCH Relative Power...................................................................................................96
PBCH Present
Includes or excludes the PBCH from the test setup.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PBCH:STAT on page 231
PBCH Relative Power
Defines the power of the PBCH relative to the reference signal.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PBCH:POWer on page 230
5.2.11 PCFICH Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Control Channel"
The physical control format indicator channel (PCFICH) carries information about the
format of the PDCCH. You can include or exclude the PCFICH in the test setup and
define the relative power of this channel.
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Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
Configuration
I/Q Measurements
PCFICH Present........................................................................................................... 97
PCFICH Relative Power................................................................................................97
PCFICH Present
Includes or excludes the PCFICH from the test setup.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PCFich:STAT on page 231
PCFICH Relative Power
Defines the power of the PCFICH relative to the reference signal.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PCFich:POWer on page 231
5.2.12 PHICH Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Control Channel"
The physical hybrid ARQ indicator channel (PHICH) contains the hybrid ARQ indicator.
The hybrid ARQ indicator contains the acknowledgement / negative acknowledgments
for uplink blocks.
You can set several specific parameters for the PHICH.
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Turning off the PHICH
If you set the value of the PHICH Ng to "Custom" and at the same time define "0"
PHICH groups, the PHICH is excluded from the signal.
Configuration
I/Q Measurements
Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
PHICH Duration............................................................................................................ 98
PHICH TDD m_i=1 (E-TM)............................................................................................99
PHICH N_g................................................................................................................... 99
PHICH Number of Groups............................................................................................ 99
PHICH Rel Power......................................................................................................... 99
PHICH Duration
Selects the duration of the PHICH. Normal and extended durations are supported.
With a normal duration, all resource element groups of the PHICH are allocated on the
first OFDM symbol.
With an extended duration, the resource element groups of the PHICH are distributed
over three OFDM symbols for a normal subframe or over two symbols within a special
subframe.
If you select Auto, the duration of PHICH is automatically determined and based on the
PBCH decoding results.
Note that you have to turn on the PBCH for an automatic determination of the PHICH
duration.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PHICh:DURation on page 232
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PHICH TDD m_i=1 (E-TM)
Turns the special setting of the PHICH for the enhanced test models on and off.
The special setting is defined in 36.141 V9.0.0, 6.1.2.6: "For frame structure type 2 the
factor m_i shall not be set as per TS36.211, Table 6.9-1, but instead shall be set to
m_i=1 for all transmitted subframes".
The parameter is available if you have selected TDD.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PHICh:MITM on page 233
PHICH N_g
Defines the variable Ng.
Ng in combination with the number of resource blocks defines the number of PHICH
groups in a downlink subframe. The standard specifies several values for Ng that you
can select from the dropdown menu.
If you need a customized configuration, you can set the number of PHICH groups in a
subframe by selecting the "Custom" menu item and define the number of PHICH
groups directly with PHICH Number of Groups.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PHICh:NGParameter on page 233
Configuration
I/Q Measurements
PHICH Number of Groups
Defines the number of PHICH groups in a subframe.
To select the number of groups, you have to set the PHICH N_g to "Custom".
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PHICh:NOGRoups on page 234
PHICH Rel Power
Defines the power of all PHICHs in a PHICH group relative to the reference signal.
The application measures a separate relative power for each PHICH if Boosting Esti-
mation is on. In that case, the "Rel. Power / dB" result in the Allocation Summary stays
empty, because it refers to the common relative power for all PHICHs. The relative
powers for each PHICH in the group are displayed in the Channel Decoder Results.
Note that the PHICH power results are quantized to 1 dB steps based on the PHICH
relative power, because only a few PHICH symbols are available for boosting estimation.
Example:
The "PHICH Rel Power" is -3.01 dB.
In that case, possible PHICH boostings are -4.01 dB, -3.01 dB, -2.01 dB, etc.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PHICh:POWer on page 234
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5.2.13 PDCCH Configuration
Access: "Overview" > "Signal Description" > "Advanced Settings" > "Control Channel"
The physical downlink control channel (PDCCH) carries the downlink control information (for example the information about the PDSCH resource allocation).
You can define several specific parameters for the PDCCH.
Configuration
I/Q Measurements
Configuring component carriers
When you are doing measurements on aggregated carriers, you can configure each
carrier separately.
When available, each carrier in the dialog boxes is represented by an additional tab
labeled "CC<x>", with <x> indicating the number of the component carrier.
Note that the additional tabs are only added to the user interface after you have
selected more than "1" component carrier.
PDCCH Format...........................................................................................................100
Number of PDCCHs....................................................................................................100
PDCCH Rel Power......................................................................................................101
PDCCH Format
Defines the format of the PDCCH (physical downlink control channel).
Note that PDCCH format "-1" is not defined in the standard. This format corresponds to
the transmission of one PDCCH on all available resource element groups. As a special
case for this PDCCH format, the center of the constellation diagram is treated as a
valid constellation point.
Remote command:
CONFigure[:LTE]:DL[:CC<cc>]:PDCCh:FORMat on page 232
Number of PDCCHs
Sets the number of physical downlink control channels.
This parameter is available if the PDCCH format is -1.
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