Rohde&Schwarz R&S®VSE-K10x LTE UL User Manual
R&S®VSE-K10x (LTE Uplink)
LTE Uplink Measurements
User Manual
(;Úçï2)
1176899702
Version 11
This manual applies to the following software, version 2.20 and later:
●
R&S®VSE Enterprise Edition base software (1345.1105.06)
●
R&S®VSE Basic Edition base software (1345.1011.06)
This manual describes functionality of the following R&S®VSE options:
●
R&S®VSE-K100 (EUTRA/LTE FDD uplink and downlink measurement application) (1320.7545.02)
●
R&S®VSE-K102 (EUTRA/LTE Advanced and MIMO measurement application) (1320.7551.02)
●
R&S®VSE-K104 (EUTRA/LTE TDD uplink and downlink measurement application) (1320.7568.02)
●
R&S®VSE-K175 (O-RAN Measurements) (1350.7020.02)
●
R&S®VSE-KT100 (EUTRA/LTE FDD uplink and downlink measurement application) (1345.1786.02)
●
R&S®VSE-KT102 (EUTRA/LTE Advanced and MIMO measurement application) (1345.7770.02)
●
R&S®VSE-KT104 (EUTRA/LTE TDD uplink and downlink measurement application) (1345.1763.02)
●
R&S®VSE-KT175 (O-RAN measurements) (1345.2076.02)
© 2022 Rohde & Schwarz GmbH & Co. KG
Muehldorfstr. 15, 81671 Muenchen, 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.
1176.8997.02 | Version 11 | R&S®VSE-K10x (LTE Uplink)
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol , e.g. R&S®VSE is indicated as
R&S VSE.
R&S®VSE-K10x (LTE Uplink)
Contents
1 Preface.................................................................................................... 7
1.1 About this manual.........................................................................................................7
1.2 Documentation overview..............................................................................................7
1.3 Typographical conventions..........................................................................................8
2 Welcome to the LTE measurement application.................................10
2.1 LTE measurement application selection...................................................................10
2.2 Display information.....................................................................................................11
3 Measurements and result displays.................................................... 13
3.1 Selecting measurements............................................................................................13
3.2 Selecting result displays............................................................................................ 14
Contents
3.3 Performing measurements.........................................................................................14
3.4 I/Q measurements....................................................................................................... 15
3.5 Time alignment error measurements........................................................................ 29
3.6 3GPP test scenarios................................................................................................... 31
4 Measurement basics............................................................................33
4.1 Symbols and variables............................................................................................... 33
4.2 Overview...................................................................................................................... 34
4.3 The LTE uplink analysis measurement application................................................. 34
4.3.1 Synchronization.............................................................................................................35
4.3.2 Analysis.........................................................................................................................36
4.4 Performing time alignment measurements.............................................................. 38
4.5 O-RAN measurement guide....................................................................................... 39
4.6 SRS EVM calculation.................................................................................................. 39
5 Configuration........................................................................................42
5.1 Configuration overview.............................................................................................. 42
5.2 Configuring I/Q measurements..................................................................................44
5.2.1 Signal characteristics.................................................................................................... 45
5.2.2 Test scenarios............................................................................................................... 51
5.2.3 MIMO configuration.......................................................................................................52
5.2.4 Subframe configuration................................................................................................. 54
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5.2.5 Global signal characteristics......................................................................................... 59
5.2.6 Demodulation reference signal configuration................................................................60
5.2.7 Sounding reference signal configuration.......................................................................63
5.2.8 PUSCH structure...........................................................................................................66
5.2.9 PUCCH structure.......................................................................................................... 68
5.2.10 PRACH structure...........................................................................................................71
5.2.11 Selecting the input and output source...........................................................................73
5.2.12 Frequency configuration................................................................................................77
5.2.13 Amplitude configuration.................................................................................................78
5.2.14 Data capture..................................................................................................................81
5.2.15 Trigger configuration..................................................................................................... 83
5.2.16 Tracking configuration...................................................................................................85
5.2.17 Signal demodulation......................................................................................................86
Contents
5.2.18 Automatic configuration.................................................................................................88
5.3 Configuring time alignment error measurements....................................................88
6 Analysis................................................................................................ 90
6.1 General analysis tools................................................................................................ 90
6.1.1 Data export....................................................................................................................90
6.1.2 Microservice export....................................................................................................... 91
6.1.3 Diagram scale............................................................................................................... 91
6.1.4 Zoom............................................................................................................................. 92
6.1.5 Markers......................................................................................................................... 92
6.2 Analysis tools for I/Q measurements........................................................................93
6.2.1 Layout of numerical results........................................................................................... 93
6.2.2 Evaluation range........................................................................................................... 94
6.2.3 Result settings...............................................................................................................97
7 Remote control.....................................................................................99
7.1 Common suffixes........................................................................................................ 99
7.2 Introduction............................................................................................................... 100
7.2.1 Conventions used in descriptions............................................................................... 100
7.2.2 Long and short form.................................................................................................... 101
7.2.3 Numeric suffixes..........................................................................................................101
7.2.4 Optional keywords.......................................................................................................102
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7.2.5 Alternative keywords................................................................................................... 102
7.2.6 SCPI parameters.........................................................................................................102
7.3 LTE application selection......................................................................................... 105
7.4 Screen layout.............................................................................................................105
7.4.1 General layout.............................................................................................................105
7.4.2 Layout over all channels............................................................................................. 106
7.4.3 Layout of a single channel...........................................................................................110
7.5 Trace data readout.................................................................................................... 116
7.5.1 Using the TRACe[:DATA] command............................................................................116
7.6 Numeric result readout.............................................................................................127
7.6.1 Frame results.............................................................................................................. 127
7.6.2 Result for selection......................................................................................................131
7.6.3 Time alignment error................................................................................................... 136
Contents
7.6.4 Marker table................................................................................................................ 137
7.6.5 CCDF table................................................................................................................. 140
7.7 Limit check result readout....................................................................................... 142
7.7.1 Limits for numerical result display............................................................................... 142
7.8 Remote commands to configure the application...................................................152
7.8.1 General configuration..................................................................................................152
7.8.2 Configuring I/Q measurements................................................................................... 153
7.8.3 Configuring time alignment measurements.................................................................208
7.9 Analysis..................................................................................................................... 209
7.9.1 Trace export................................................................................................................ 209
7.9.2 Microservice export..................................................................................................... 210
7.9.3 Evaluation range..........................................................................................................211
7.9.4 Y-axis scale................................................................................................................. 214
7.9.5 Result settings.............................................................................................................215
Annex.................................................................................................. 218
A Annex: reference................................................................................218
A.1 Menu reference..........................................................................................................218
A.1.1 Common R&S VSE menus......................................................................................... 218
A.1.2 LTE measurement menus........................................................................................... 220
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A.2 Reference of toolbar functions................................................................................ 222
List of commands.............................................................................. 226
Index....................................................................................................232
Contents
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1 Preface
1.1 About this manual
This User Manual describes information specific to measurements in the LTE measurement application. All other applications are described in the corresponding appli-
cation manuals.
The main focus in this manual is on the measurement results and the tasks required to
obtain them. The following topics are included:
●
Welcome to the R&S VSE
Introduction to and getting familiar with the software
●
Measurements and Results
Descriptions of the measurement types available in the R&S VSE software
●
Controlling Instruments and Capturing I/Q Data
Methods of data acquisition and description of basic instrument control functions
●
LTE Measurements
Description of the settings and functions provided to analyze results with the software and the corresponding remote control commands
●
Remote Commands for LTE Measurements
Remote commands required to configure and perform measurements in a remote
environment, sorted by tasks
Remote commands required to set up the environment and to perform common
tasks in the software, sorted by tasks
Programming examples demonstrate the use of many commands and can usually
be executed directly for test purposes
●
List of Commands
Alphabetical list of all remote commands described in the manual
●
Index
Preface
Documentation overview
1.2 Documentation overview
The user documentation for the R&S VSE consists of the following parts:
●
"Getting Started" printed manual
●
Online Help system in the software
●
CD-ROM including the following documentation:
– Getting Started
– User Manuals for base software and options
– Service Manual
– Release Notes
– Data sheet and product brochures
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Online Help
The Online Help is embedded in the software. It offers quick, context-sensitive access
to the complete information needed for operation and programming. Online help is
available using the icon on the toolbar of the R&S VSE.
Getting Started
This manual is delivered with the software in printed form and in PDF format on the
CD. It provides the information needed to set up and start working with the software.
Basic operations and handling are described. Safety information is also included.
User Manuals
User manuals are provided for the base software and each additional (software)
option.
The user manuals are available in PDF format - in printable form - on the CD-ROM
delivered with the software. In the user manuals, all software functions are described in
detail. Furthermore, they provide a complete description of the remote control commands with programming examples.
Preface
Typographical conventions
The user manual for the base software provides basic information on operating the
R&S VSE in general, and the I/Q Analyzer application in particular. Furthermore, the
software functions that enhance the basic functionality for various applications are
described here. An introduction to remote control is provided, as well as information on
troubleshooting.
In the individual application manuals, the specific software functions of the application
are described in detail. For additional information on default settings and parameters,
refer to the data sheets. Basic information on operating the R&S VSE is not included in
the application manuals.
Release Notes
The release notes describe the installation of the software, new and modified functions,
eliminated problems, and last minute changes to the documentation. The corresponding software version is indicated on the title page of the release notes.
Application Notes
Application notes, application cards, white papers and educational notes are further
publications that provide more comprehensive descriptions and background information. The latest versions are available for download from the Rohde & Schwarz website, at www.rohde-schwarz.com/appnote/.
1.3 Typographical conventions
The following text markers are used throughout this documentation:
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Convention Description
Preface
Typographical conventions
"Graphical user interface elements"
[Keys] Key and knob names are enclosed by square brackets.
Filenames, commands,
program code
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-
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.
tion marks.
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2 Welcome to the LTE measurement applica-
tion
The LTE measurement application is a firmware application that adds functionality to
perform measurements on LTE signals according to the 3GPP standard to the
R&S VSE.
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 VSE
User Manual. The latest versions of the manuals are available for download at the
product homepage.
https://www.rohde-schwarz.com/manual/vse.
● LTE measurement application selection................................................................. 10
● Display information..................................................................................................11
Welcome to the LTE measurement application
LTE measurement application selection
2.1 LTE measurement application selection
The LTE measurement application adds a new application to the R&S VSE.
Starting the application
1.
Select the "Add Channel" function in the "Sequence" tool window.
A dialog box opens that contains all operating modes and applications currently
available in your R&S VSE.
2. Select the "LTE" item.
The R&S VSE opens a new measurement channel for the LTE application.
The application starts with the default settings. You can configure measurements with
the items in the "Meas Setup" menu.
For more information see Chapter 5, "Configuration", on page 42.
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2.2 Display information
The following figure shows a typical measurement diagram of the LTE application. All
different information areas are labeled. They are explained in more detail in the following sections.
1 2 3 4 5
Welcome to the LTE measurement application
Display information
1 = Window title bar with information about the diagram and its traces
2 = Channel bar with measurement settings
3 = Diagram area
4 = Diagram footer with information about the contents of the diagram
5 = Color code for windows of the same channel (here: red)
Channel bar information
In the LTE measurement application, the R&S VSE shows the following settings:
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 Slot Slot considered in the signal analysis
Selected Subframe Subframe considered in the signal analysis
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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 (e.g. transducer or trigger settings). This information is displayed only when applicable for the current measurement. For a comprhensive
description, refer to the user manual of the R&S VSE.
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.
Welcome to the LTE measurement application
Display information
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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 152
Result display selection: LAYout:ADD[:WINDow]? on page 110
● Selecting measurements.........................................................................................13
● Selecting result displays..........................................................................................14
● Performing measurements......................................................................................14
● I/Q measurements...................................................................................................15
● Time alignment error measurements...................................................................... 29
● 3GPP test scenarios............................................................................................... 31
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 14.
Depending on the measurement, the R&S VSE 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, "Time alignment error
measurements", on page 29.
Remote command:
CONFigure[:LTE]:MEASurement on page 152
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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 3.5, "Time alignment error
measurements", on page 29.
Remote command:
CONFigure[:LTE]:MEASurement on page 152
3.2 Selecting result displays
Access: or "Window" > "New Window"
The R&S VSE opens a menu to select result displays. Depending on the number of
LTE channels you are currently using, there is a submenu that contains all available
result displays for each LTE channel.
Measurements and result displays
Performing measurements
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 to the channels as you like
from the "Window" menu.
Remote command: LAYout:ADD[:WINDow]? on page 110
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 VSE captures and analyzes the data again and again.
●
For I/Q measurements, the amount of captured data depends on the capture time.
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●
For frequency sweep measurement, the amount of captured data depends on the
sweep time.
In "Single Sweep" mode, the R&S VSE 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 VSE.
3.4 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.
Measurements and result displays
I/Q measurements
Remote command:
Measurement selection: CONFigure[:LTE]:MEASurement on page 152
Result display selection: LAYout:ADD[:WINDow]? on page 110
Capture Buffer...............................................................................................................15
EVM vs Carrier..............................................................................................................16
EVM vs Symbol.............................................................................................................17
EVM vs Subframe......................................................................................................... 18
Power Spectrum............................................................................................................18
Inband Emission............................................................................................................19
Spectrum Flatness........................................................................................................ 20
Spectrum Flatness SRS................................................................................................20
Group Delay..................................................................................................................21
Spectrum Flatness Difference.......................................................................................21
Constellation Diagram...................................................................................................22
CCDF............................................................................................................................ 22
Allocation Summary...................................................................................................... 23
Bitstream.......................................................................................................................23
EVM vs Symbol x Carrier..............................................................................................24
Power vs Symbol x Carrier............................................................................................25
Result Summary............................................................................................................25
Marker Table................................................................................................................. 28
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.
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The y-axis represents the amplitude of the captured I/Q data in dBm (for RF input).
The capture buffer uses the auto peak detector to evaluate the measurement data. The
auto peak detector determines the maximum and the minimum value of the measured
levels for each measurement point and combines both values in one sample point.
Figure 3-1: Capture buffer without zoom
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 127
Subframe start offset: FETCh[:CC<cc>]:SUMMary:TFRame? on page 135
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 slot in the capture buffer.
If you analyze all slots, the result display contains three traces.
●
Average EVM
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This trace shows the subcarrier EVM, averaged over all slots.
●
Minimum EVM
This trace shows the lowest (average) subcarrier EVM that has been found over
the analyzed slots.
●
Maximum EVM
This trace shows the highest (average) subcarrier EVM that has been found over
the analyzed slots.
If you select and analyze one slot only, the result display contains one trace that shows
the subcarrier EVM for that slot only. Average, minimum and maximum values in that
case are the same. For more information, see "Slot Selection" on page 95.
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 127
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 slot.
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 VSE
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 127
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.
Measurements and result displays
I/Q measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,EVSU
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 127
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 127
Inband Emission
The "Inband Emission" result display shows the power of the unused resource blocks
relative to the allocated resource blocks (yellow trace). The diagram also shows the
inband emission limit lines (red trace). The allocated resource blocks are not evaluated.
The x-axis represents the resource blocks. The numbering of the resource blocks is
based on 3GPP 38.521 as a function of the resource block offset from the edge of the
allocated uplink transmission bandwidth.
The y-axis shows the measured power for each resource block.
Because the measurement is evaluated over a single slot in the currently selected sub-
frame, you have to select a specific slot and subframe to get valid measurement
results.
Limits for the inband emission are specified in 3GPP 36.101.
Measurements and result displays
I/Q measurements
You can also display the inband emissions for the allocated resource block in addition
to the unused resource blocks when you select the "Inband Emissions All" result display.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,IE
Selection: LAY:ADD ? '1',LEFT,IEA
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 127
Spectrum Flatness
The "Spectrum Flatness" result display shows the relative power offset caused by the
transmit channel.
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 channel flatness is plotted in
dB.
Measurements and result displays
I/Q measurements
Note that the limit lines are only displayed if you match the Operating Band to the center frequency. Limits are defined for each operating band in the standard.
The shape of the limit line is different when "Extreme Conditions" on page 51 are on.
Remote command:
Selecting the result display: LAY:ADD ? '1',LEFT,SFL
Querying results:
TRACe:DATA?
TRACe<n>[:DATA]:X? on page 127
Spectrum Flatness SRS
The "Spectrum Flatness SRS" display shows the amplitude of the channel transfer
function based on the sounding reference signal.
The measurement is evaluated over the currently selected slot in the currently selected
subframe. The slot and subframe selection may be changed in the general settings.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,SFSR
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 127
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.
Measurements and result displays
I/Q measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,GDEL
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 127
Spectrum Flatness Difference
The "Spectrum Flatness Difference" result display shows the level difference in the
spectrum flatness result between two adjacent physical subcarriers.
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 power is plotted in dB.
Remote command:
Selection: LAY:ADD ? '1',LEFT,SFD
Query (y-axis): TRACe:DATA?
Query (x-axis): TRACe<n>[:DATA]:X? on page 127
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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.
: RBPSK
: MIXTURE
: QPSK
: 16QAM
: 64QAM
: 256QAM
: PSK (CAZAC)
Measurements and result displays
I/Q measurements
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 %.
In addition to the diagram, the results for the CCDF measurement are summarized in
the CCDF table.
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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 141
Numerical results: CALCulate<n>:STATistics:RESult<res>? on page 141
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.
Measurements and result displays
I/Q measurements
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 resource block offset of the allocation.
●
The modulation of the allocation.
●
The power of the allocation in dBm.
●
The EVM of the allocation.
The unit depends on the EVM unit
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?
Bitstream
The "Bitstream" shows the demodulated data stream for the data allocations.
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At the end of the table is a summary of all total number of bits, total number of coded
bits, total number of bit errors and bit error rate in %. The totals are calculated over all
PUSCH allocations that contribute to the bitstream. The results are shown when you
select an ORAN test case.
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 represented 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.
Measurements and result displays
I/Q measurements
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?
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.
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Remote command:
Selection: LAY:ADD ? '1',LEFT,EVSC
Query: TRACe:DATA?
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.
Measurements and result displays
I/Q measurements
Remote command:
Selection: LAY:ADD ? '1',LEFT,PVSC
Query: TRACe:DATA?
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
The contents of the result summary depend on the analysis mode you have selected.
The first screenshot shows the results for "PUSCH/PUCCH" analysis mode, the second one those for "PRACH" analysis mode.
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Measurements and result displays
I/Q measurements
Figure 3-3: Result summary in PUSCH/PUCCH analysis mode
Figure 3-4: Result summary in PRACH analysis mode
The table is split in two parts. The first part shows results that refer to the complete
frame. 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.
The second part of the table shows results that refer to a specific selection of the
frame. The statistic is always evaluated over the slots. The header row of the table
contains information about the selection you have made (like the subframe).
Note: The EVM results on a frame level (first part of the table) are calculated as
defined by 3GPP at the edges of the cyclic prefix.
The other EVM results (lower part of the table) are calculated at the optimal timing
position in the middle of the cyclic prefix.
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Because of inter-symbol interference, the EVM calculated at the edges of the cyclic
prefix is higher than the EVM calculated in the middle of the cyclic prefix.
By default, all EVM results are in %. To view the EVM results in dB, change the EVM
Unit.
Table 3-1: Result summary: part containing results as defined by 3GPP (PUSCH/PUCCH analysis)
EVM PUSCH QPSK Shows the EVM for all QPSK-modulated resource elements of the PUSCH
EVM PUSCH 16QAM Shows the EVM for all 16QAM-modulated resource elements of the PUSCH
EVM PUSCH 64QAM Shows the EVM for all 64QAM-modulated resource elements of the PUSCH
EVM PUSCH 256QAM Shows the EVM for all 256QAM-modulated resource elements of the PUSCH
Measurements and result displays
I/Q measurements
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:USQP[:AVERage]? on page 130
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:USST[:AVERage]? on page 130
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:USSF[:AVERage]? on page 130
channel in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:USTS[:AVERage]? on page 131
EVM DMRS PUSCH QPSK Shows the EVM of all DMRS resource elements with QPSK modulation of the
PUSCH in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:SDQP[:AVERage]? on page 128
EVM DMRS PUSCH 16QAM Shows the EVM of all DMRS resource elements with 16QAM modulation of
the PUSCH in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:SDST[:AVERage]? on page 128
EVM DMRS PUSCH 64QAM Shows the EVM of all DMRS resource elements with 64QAM modulation of
the PUSCH in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:SDSF[:AVERage]? on page 128
EVM DMRS PUSCH
256QAM
EVM PUCCH Shows the EVM of all resource elements of the PUCCH channel in the ana-
EVM DMRS PUCCH Shows the EVM of all DMRS resource elements of the PUCCH channel in the
Table 3-2: Result summary: part containing results as defined by 3GPP (PRACH analysis)
EVM PRACH Shows the EVM of all resource elements of the PRACH channel in the ana-
Shows the EVM of all DMRS resource elements with 256QAM modulation of
the PUSCH in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:SDTS[:AVERage]? on page 129
lyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:UCCH[:AVERage]? on page 129
analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:UCCD[:AVERage]? on page 129
lyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM:UPRA[:AVERage]? on page 130
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Table 3-3: Result summary: part containing results for a specific selection
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 132
frame.
A physical channel corresponds to a set of resource elements carrying infor-
mation from higher layers. PUSCH, PUCCH and PRACH are physical channels. For more information, see 3GPP 36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PCHannel[:AVERage]? on page 132
("PUSCH/PUCCH" analysis mode only.)
frame.
The reference signal is a physical signal. For more information, see 3GPP
36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PSIGnal[:AVERage]? on page 133
("PUSCH/PUCCH" analysis mode only.)
center frequency.
FETCh[:CC<cc>]:SUMMary:FERRor[:AVERage]? on page 133
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 135
I/Q Offset Shows the power at spectral line 0 normalized to the total transmitted power.
FETCh[:CC<cc>]:SUMMary:IQOFfset[:AVERage]? on page 134
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 133
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 135
Power Shows the average time domain power of the allocated resource blocks of the
analyzed signal.
FETCh[:CC<cc>]:SUMMary:POWer[:AVERage]? on page 134
Crest Factor Shows the peak-to-average power ratio of captured signal.
FETCh[:CC<cc>]:SUMMary:CRESt[:AVERage]? on page 132
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-
mal marker, "D" for a delta marker).
Trc Shows the trace that the marker is positioned on.
Ref Shows the reference marker that a delta marker
refers to.
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X- / Y-Value Shows the marker coordinates (usually frequency
Measurements and result displays
Time alignment error measurements
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 110
Results:
CALCulate<n>:MARKer<m>:X on page 138
CALCulate<n>:MARKer<m>:Y on page 139
CALCulate<n>:MARKer<m>:Z? on page 139
CALCulate<n>:MARKer<m>:Z:ALL? on page 140
3.5 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 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 VSE. For more information on configuring and performing a time alignment error measurement see Chap-
ter 4.4, "Performing time alignment measurements", on page 38.
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 15
●
"Power Spectrum" on page 18
●
"Marker Table" on page 28
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 152
Result display selection: LAYout:ADD[:WINDow]? on page 110
Time Alignment Error.................................................................................................... 30
Carrier Frequency Error................................................................................................ 30
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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 subframe.
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 case of carrier aggregation, the time alignment error measurement also evaluates
the "Carrier Frequency Error" on page 30 of the component carrier (CC2) relative to
the main component carrier (CC1).
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, "Configuring
time alignment error measurements", on page 88.
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 137
Measurements and result displays
Time alignment error measurements
Carrier Frequency Error
The "Carrier Frequency Error" shows the frequency deviation between a reference carrier (usually component carrier 1) and another component carrier. It is an indicator of
how well the component carriers in a system with carrier aggregation are synchronized.
The application shows the results in a table.
For each component carrier, the application adds two rows to the table.
●
The first row shows the lowest, average and highest frequency error that has been
measured in Hz. In addition, the limit defined by 3GPP for that scenario is displayed. Note that the application always tests against the highest measured value;
if the limit has been violated, the font color of the maximum value turns red.
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