Rohde&Schwarz R&S®VSE-K72 3GPP FDD User Manual
R&S®VSE-K72
3GPP FDD Measurements
Application
User Manual
(;ÚçÒ2)
1176896802
Version 08
This manual applies to the following software, version 2.10 and later:
●
R&S®VSE Enterprise Edition base software (1345.1105.06)
●
R&S®VSE Basic Edition base software (1345.1011.06)
The following firmware options are described:
●
R&S VSE-K72 (1320.7580.02)
© 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.
1176.8968.02 | Version 08 | R&S®VSE-K72
The following abbreviations are used throughout this manual: R&S®VSE is abbreviated as R&S VSE. "R&S VSE-K72" is abbreviated
as R&S VSE-K72.
R&S®VSE-K72
1.1 About this manual.........................................................................................................9
1.2 Typographical conventions........................................................................................10
2.1 Starting the 3GPP FDD application........................................................................... 11
2.2 Understanding the display information.................................................................... 12
3.1 Code domain analysis................................................................................................ 15
3.1.1 Code domain parameters..............................................................................................16
3.1.2 Evaluation methods for code domain analysis..............................................................18
Contents
Contents
1 Preface.................................................................................................... 9
2 Welcome to the 3GPP FDD applications............................................11
3 Measurements and result display...................................................... 15
3.2 Time alignment error measurements........................................................................ 33
4 Measurement basics............................................................................35
4.1 Channel detection....................................................................................................... 38
4.2 BTS channel types...................................................................................................... 38
4.3 UE channel types........................................................................................................ 42
4.4 3GPP FDD BTS test models....................................................................................... 43
4.5 Setup for base station tests....................................................................................... 44
4.6 3GPP FDD UE test models......................................................................................... 45
4.7 Setup for user equipment tests................................................................................. 46
4.8 Time alignment error measurements........................................................................ 47
4.8.1 Measurement setup for two antennas in a base station................................................48
4.8.2 Measurement setup for transmit signals from multiple base Stations...........................48
5 Configuration........................................................................................50
5.1 Code domain analysis................................................................................................ 50
5.1.1 Configuration overview..................................................................................................51
5.1.2 Signal description..........................................................................................................52
5.1.2.1 BTS signal description.................................................................................................. 53
5.1.2.2 BTS scrambling code.................................................................................................... 54
5.1.2.3 UE signal description (UE measurements)................................................................... 56
5.1.3 Input source settings..................................................................................................... 57
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5.1.3.1 Radio frequency input................................................................................................... 57
5.1.3.2 I/Q file input................................................................................................................... 63
5.1.4 Frontend settings.......................................................................................................... 65
5.1.4.1 Amplitude settings.........................................................................................................65
5.1.4.2 Y-axis scaling................................................................................................................ 69
5.1.4.3 Frequency settings........................................................................................................70
5.1.5 Trigger settings..............................................................................................................72
5.1.6 Signal capture (data acquisition)...................................................................................76
5.1.7 Synchronization (BTS measurements only)..................................................................78
5.1.8 Channel detection......................................................................................................... 80
5.1.8.1 General channel detection settings...............................................................................80
5.1.8.2 Channel table management.......................................................................................... 82
5.1.8.3 Channel table settings and functions............................................................................ 83
Contents
5.1.8.4 Channel details............................................................................................................. 84
5.1.9 Automatic settings.........................................................................................................87
5.2 Time alignment error measurements........................................................................ 89
5.2.1 Configuration overview..................................................................................................89
5.2.2 Carrier table configuration.............................................................................................91
5.2.2.1 Carrier table management............................................................................................ 91
5.2.2.2 Carrier table settings and functions...............................................................................92
5.2.2.3 Carrier details................................................................................................................93
6 Analysis................................................................................................ 96
6.1 Evaluation range......................................................................................................... 96
6.2 Code domain settings (BTS measurements)............................................................98
6.3 Code domain settings (UE measurements)............................................................100
6.4 Traces.........................................................................................................................101
6.5 Trace / data export configuration............................................................................ 102
6.6 Markers...................................................................................................................... 103
6.6.1 Individual marker settings........................................................................................... 104
6.6.2 General marker settings..............................................................................................106
6.6.3 Marker search settings................................................................................................107
6.6.4 Marker positioning functions....................................................................................... 107
7 How to perform measurements in 3GPP FDD applications........... 110
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8.1 Measurement 1: measuring the relative code domain power............................... 113
8.1.1 Synchronizing the reference frequencies.................................................................... 115
8.1.2 Behavior with deviating center frequency....................................................................116
8.1.3 Behavior with incorrect scrambling code.....................................................................116
8.2 Measurement 2: triggered measurement of relative code domain power........... 117
8.3 Measurement 3: measuring the composite EVM....................................................119
8.4 Measurement 4: determining the peak code domain error................................... 121
9.1 Error messages......................................................................................................... 124
10 Remote commands for 3GPP FDD measurements.........................125
10.1 Introduction............................................................................................................... 125
Contents
8 Measurement examples.....................................................................113
9 Optimizing and troubleshooting the measurement........................ 124
10.1.1 Conventions used in descriptions............................................................................... 126
10.1.2 Long and short form.................................................................................................... 127
10.1.3 Numeric suffixes..........................................................................................................127
10.1.4 Optional keywords.......................................................................................................127
10.1.5 Alternative keywords................................................................................................... 128
10.1.6 SCPI parameters.........................................................................................................128
10.1.6.1 Numeric values........................................................................................................... 128
10.1.6.2 Boolean....................................................................................................................... 129
10.1.6.3 Character data............................................................................................................ 130
10.1.6.4 Character strings.........................................................................................................130
10.1.6.5 Block data................................................................................................................... 130
10.2 Common suffixes...................................................................................................... 130
10.3 Activating 3GPP FDD measurements..................................................................... 131
10.4 Selecting a measurement.........................................................................................131
10.5 Restoring the default configuration (preset).......................................................... 132
10.6 Configuring code domain analysis and time alignment error measurements....132
10.6.1 Signal description........................................................................................................133
10.6.1.1 BTS signal description................................................................................................ 133
10.6.1.2 BTS scrambling code.................................................................................................. 136
10.6.1.3 UE signal description.................................................................................................. 137
10.6.2 Configuring data input................................................................................................. 138
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10.6.2.1 RF input.......................................................................................................................138
10.6.2.2 Using external mixers..................................................................................................149
10.6.2.3 Remote commands for external frontend control........................................................ 157
10.6.2.4 Working with power sensors....................................................................................... 166
10.6.3 Frontend configuration................................................................................................ 176
Contents
Basic settings.............................................................................................................. 149
Mixer settings.............................................................................................................. 151
Programming example: working with an external mixer..............................................156
Commands for initial configuration..............................................................................158
Commands for alignment............................................................................................ 163
Configuring power sensors......................................................................................... 166
Configuring power sensor measurements.................................................................. 168
Triggering with power sensors.................................................................................... 174
10.6.3.1 Frequency................................................................................................................... 177
10.6.3.2 Amplitude settings.......................................................................................................178
10.6.3.3 Configuring the attenuation......................................................................................... 181
10.6.4 Configuring triggered measurements..........................................................................184
10.6.4.1 Configuring the triggering conditions...........................................................................184
10.6.4.2 Configuring the trigger output......................................................................................189
10.6.5 Signal capturing.......................................................................................................... 191
10.6.6 Synchronization...........................................................................................................193
10.6.7 Channel detection....................................................................................................... 195
10.6.7.1 General channel detection.......................................................................................... 196
10.6.7.2 Managing channel tables............................................................................................ 197
10.6.7.3 Configuring channel tables..........................................................................................201
10.6.7.4 Configuring channel details (BTS measurements)......................................................203
10.6.7.5 Configuring channel details (UE measurements)........................................................205
10.6.8 Automatic settings.......................................................................................................207
10.6.9 Evaluation range......................................................................................................... 209
10.6.10 Code domain analysis settings (BTS measurements).................................................211
10.6.11 Code domain analysis settings (UE measurements).................................................. 213
10.6.12 Configuring carrier tables for time alignment measurements......................................214
10.7 Configuring the result display................................................................................. 219
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10.7.1 Global layout commands.............................................................................................219
10.7.2 Working with windows in the display...........................................................................223
10.7.3 General window commands........................................................................................229
10.8 Retrieving results......................................................................................................230
10.8.1 Retrieving calculated measurement results................................................................ 230
10.8.2 Measurement results for TRACe<n>[:DATA]? TRACE<n>.........................................235
10.8.2.1 Bitstream..................................................................................................................... 235
10.8.2.2 Channel table.............................................................................................................. 237
10.8.2.3 Code domain error power........................................................................................... 237
10.8.2.4 Code domain power.................................................................................................... 238
10.8.2.5 Composite constellation.............................................................................................. 238
10.8.2.6 Composite EVM (RMS)...............................................................................................238
10.8.2.7 EVM vs chip................................................................................................................ 238
Contents
10.8.2.8 Frequency error vs slot............................................................................................... 239
10.8.2.9 Mag error vs chip........................................................................................................ 239
10.8.2.10 Peak code domain error..............................................................................................239
10.8.2.11 Phase discontinuity vs slot.......................................................................................... 239
10.8.2.12 Phase error vs chip..................................................................................................... 239
10.8.2.13 Power vs slot...............................................................................................................239
10.8.2.14 Power vs symbol......................................................................................................... 239
10.8.2.15 Result summary.......................................................................................................... 240
10.8.2.16 Symbol constellation................................................................................................... 240
10.8.2.17 Symbol EVM............................................................................................................... 241
10.8.2.18 Symbol magnitude error..............................................................................................241
10.8.2.19 Symbol phase error.....................................................................................................241
10.8.3 Retrieving trace results............................................................................................... 242
10.8.4 Exporting trace results................................................................................................ 249
10.9 Analysis..................................................................................................................... 252
10.9.1 Traces......................................................................................................................... 252
10.9.2 Markers....................................................................................................................... 253
10.9.2.1 Individual marker settings........................................................................................... 253
10.9.2.2 General marker settings..............................................................................................257
10.9.2.3 Positioning the marker................................................................................................ 258
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10.10 Querying the status registers.................................................................................. 263
10.11 Deprecated commands.............................................................................................266
10.12 Programming examples (R&S VSE-K72)................................................................ 270
10.12.1 Measurement 1: measuring the relative code domain power..................................... 271
10.12.2 Measurement 2: triggered measurement of relative code domain power................... 273
10.12.3 Measurement 3: measuring the composite EVM........................................................ 274
10.12.4 Measurement 4: determining the peak code domain error......................................... 275
A Reference............................................................................................277
A.1 Menu reference..........................................................................................................277
Contents
Positioning normal markers.........................................................................................258
Positioning delta markers............................................................................................260
Annex.................................................................................................. 277
A.1.1 Common R&S VSE menus......................................................................................... 277
A.1.1.1 File menu.................................................................................................................... 277
A.1.1.2 Window menu............................................................................................................. 278
A.1.1.3 Help menu...................................................................................................................279
A.1.2 3GP FDD measurements menus................................................................................ 279
A.1.2.1 Edit menu.................................................................................................................... 280
A.1.2.2 Input & output menu....................................................................................................280
A.1.2.3 Meas setup menu........................................................................................................280
A.1.2.4 Trace menu................................................................................................................. 281
A.1.2.5 Marker menu............................................................................................................... 281
A.1.2.6 Limits menu.................................................................................................................282
A.2 Reference of toolbar functions................................................................................ 282
List of Remote Commands (3GPP FDD).......................................... 286
Index....................................................................................................292
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1 Preface
1.1 About this manual
Preface
About this manual
This R&S VSE 3GPP FDD User Manual provides all the information specific to the
application. All general software functions and settings common to all applications
and operating modes are described in the R&S VSE Base Software User Manual.
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 3GPP FDD Measurements application
Introduction to and getting familiar with the application
●
Measurements and Result Displays
Details on supported measurements and their result types
●
Measurement Basics
Background information on basic terms and principles in the context of the measurement
●
Configuration + Analysis
A concise description of all functions and settings available to configure measurements and analyze results with their corresponding remote control command
●
How to Perform Measurements in the R&S VSE 3GPP FDD Measurements
application
The basic procedure to perform each measurement and step-by-step instructions
for more complex tasks or alternative methods
●
Measurement Examples
Detailed measurement examples to guide you through typical measurement scenarios and allow you to try out the application immediately
●
Optimizing and Troubleshooting the Measurement
Hints and tips on how to handle errors and optimize the measurement configuration
●
Remote Commands for 3GPP FDD Measurements
Remote commands required to configure and perform 3GPP FDD measurements
in a remote environment, sorted by tasks
(Commands required to set up the environment or to perform common tasks in the
software are provided in the R&S VSE Base Software User Manual)
Programming examples demonstrate the use of many commands and can usually
be executed directly for test purposes
●
List of remote commands
Alphabetical list of all remote commands described in the manual
●
Index
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1.2 Typographical conventions
Preface
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
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 3GPP FDD applications
Welcome to the 3GPP FDD applications
Starting the 3GPP FDD application
The R&S VSE 3GPP FDD Measurements application applications add functionality to
the R&S VSE to perform code domain analysis or power measurements according to
the 3GPP standard (FDD mode). The application firmware is in line with the 3GPP
standard (Third Generation Partnership Project) with Release 5. Signals that meet the
conditions for channel configuration of test models 1 to 4 according to the 3GPP standard, e.g. W-CDMA signals using FDD, can be measured with the 3GPP FDD BTS
application.
R&S VSE-K72 performs Base Transceiver Station (BTS) measurements (for downlink
signals), as well as User Equipment (UE) measurements (for uplink signals).
In particular, the R&S VSE 3GPP FDD Measurements application features:
●
Code domain analysis, providing results like code domain power, EVM, peak code
domain error etc.
●
Time alignment error determination
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 I/Q Analyzer
application and are described in the R&S VSE Base Software User Manual. The latest
version is available for download at the product homepage (http://www.rohde-
schwarz.com/product/VSE.html).
2.1 Starting the 3GPP FDD application
The 3GPP FDD measurements require a special application on the R&S VSE. It is activated by creating a new measurement channel in 3GPP FDD mode.
To activate the 3GPP FDD 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.
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Welcome to the 3GPP FDD applications
Understanding the display information
2. Select the 3GPP FDD BTS or 3GPP FDD UE item.
The R&S VSE opens a new measurement channel for the 3GPP FDD application.
2.2 Understanding the display information
The following figure shows a measurement diagram during a 3GPP FDD BTS measurement. All different information areas are labeled. They are explained in more detail
in the following sections.
(The basic screen elements are identical for 3GPP FDD UE measurements)
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Welcome to the 3GPP FDD applications
Understanding the display information
1
2
3
4
5
1 = Color coding for windows of same channel
2 = Channel bar with measurement settings
3 = Window title bar with diagram-specific (trace) information
4 = Diagram area
5 = Diagram footer with diagram-specific information, depending on result display
Channel bar information
In 3GPP FDD applications, when performing Code Domain Analysis, the R&S VSE
screen display shows the following settings:
Table 2-1: Hardware settings displayed in the channel bar in 3GPP FDD applications for Code
Ref Level Reference level
Att Mechanical and electronic RF attenuation
Freq Center frequency for the RF signal
Channel Channel number (code number and spreading factor)
CPICH Slot
/ Slot (UE)
Power Power result mode:
Domain Analysis
Slot of the (CPICH) channel
●
Absolute
●
Relative to CPICH (BTS application only)
●
Relative to total power
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Welcome to the 3GPP FDD applications
Understanding the display information
SymbRate Symbol rate of the current channel
Capture (UE application only): basis for analysis (slot or frame)
Window title bar information
For each diagram, the header provides the following information:
0
1 5 6 72 3 4
Figure 2-1: Window title bar information in 3GPP applications
0 = Color coding for windows of same channel
1 = Edit result display function
2 = Channel name
3 = Window number
4 = Window type
5 = Trace color, trace number, trace mode
6 = Dock/undock window function
7 = Close window function
Diagram area
The diagram area displays the results according to the selected result displays (see
Chapter 3.1.2, "Evaluation methods for code domain analysis", on page 18).
Diagram footer information
For most graphical evaluations the diagram footer (beneath the diagram) contains scaling information for the x-axis, where applicable:
●
Start channel/chip/frame/slot
●
Channel/chip/frame/slot per division
●
Stop channel/chip/frame/slot
For the Bitstream evaluation, the diagram footer indicates:
●
Channel format (type and modulation type (HS-PDSCH only))
●
Number of data bits
●
Number of TPC bits
●
Number of TFCI bits
●
Number of pilot bits
(The bit numbers are indicated in the order they occur.)
Status bar information
The software status, errors and warnings and any irregularities in the software are indicated in the status bar at the bottom of the R&S VSE window.
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3 Measurements and result display
Measurements and result display
Code domain analysis
The 3GPP FDD applications provide several different measurements for signals
according to the 3GPP FDD standard. The main and default measurement is Code
Domain Analysis. Furthermore, a Time Alignment Error measurement is provided.
Result display windows
For each measurement, a separate measurement channel is activated. Each measurement channel can provide multiple result displays, which are displayed in individual
windows. The measurement windows can be rearranged and configured in the
R&S VSE to meet your requirements. All windows that belong to the same measurement (including the channel bar) are indicated by a colored line at the top of the window title bar.
►
To add further result displays for the 3GPP FDD channel, select the
dow" icon from the toolbar, or select the "Window > New Window" menu item.
For details on working with channels and windows see the "Operating Basics"
chapter in the R&S VSE Base Software User Manual.
Evaluation range
You can restrict evaluation to a specific channel, frame or slot, depending on the evaluation method. See Chapter 6.1, "Evaluation range", on page 96.
● Code domain analysis.............................................................................................15
● Time alignment error measurements...................................................................... 33
3.1 Code domain analysis
Access: [MEAS] > "Code Domain Analyzer"
The Code Domain Analysis measurement provides various evaluation methods and
result diagrams.
The code domain power measurements are performed as specified by the 3GPP
standards. A signal section of approximately 20 ms is recorded for analysis and then
searched through to find the start of a 3GPP FDD frame. If a frame start is found in the
signal, the code domain power analysis is performed for a complete frame starting
from slot 0. The different evaluations are calculated from the captured I/Q data set.
Therefore it is not necessary to start a new measurement in order to change the evaluation.
"Add Win-
The 3GPP FDD applications provide the peak code domain error measurement and
composite EVM specified by the 3GPP standard, as well as the code domain power
measurement of assigned and unassigned codes. The power can be displayed either
for all channels in one slot, or for one channel in all slots. The composite constellation
diagram of the entire signal can also be displayed. In addition, the symbols demodulated in a slot, their power, and the determined bits or the symbol EVM can be displayed
for an active channel.
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Measurements and result display
Code domain analysis
The power of a code channel is always measured in relation to its symbol rate within
the code domain. It can be displayed either as absolute values or relative to the total
signal or the CPICH channel. By default, the power relative to the CPICH channel is
displayed. The total power may vary depending on the slot, since the power can be
controlled on a per-slot-basis. The power in the CPICH channel, on the other hand, is
constant in all slots.
For all measurements performed in a slot of a selected channel (bits, symbols, symbol
power, EVM), the actual slot spacing of the channel is taken as a basis, rather than the
CPICH slots. The time reference for the start of a slot is the CPICH slot. If code channels contain a timing offset, the start of a specific slot of the channel differs from the
start of the reference channel (CPICH). Thus, the power-per-channel display may not
be correct. If channels with a timing offset contain a power control circuit, the channelpower-versus-time display may provide better results.
The composite EVM, peak code domain error and composite constellation measurements are always referenced to the total signal.
Remote command:
CONF:WCDP:MEAS WCDP, see CONFigure:WCDPower[:BTS]:MEASurement
on page 131
3.1.1 Code domain parameters
Two different types of measurement results are determined and displayed in the Result
Summary: global results and channel results (for the selected channel).
The number of the CPICH slot at which the measurement is performed is indicated
globally for the measurement in the channel bar.
The spreading code of the selected channel is indicated with the channel number in
the channel bar and above the channel-specific results in the Result Summary.
In the Channel Table, the analysis results for all active channels are displayed.
Table 3-1: General code domain power results for a specific frame and slot
Parameter Description
Total Power: The total signal power (average power of total evaluated slot).
Carrier Freq Error: The frequency error relative to the center frequency of the analyzer. The absolute
frequency error is the sum of the analyzer and DUT frequency error. The specified
value is averaged for one (CPICH) slot. See also the note on "Carrier Frequency
Error" on page 17.
Chip Rate Error: The chip rate error in the frame to analyze in ppm. As a result of a high chip rate
error, symbol errors arise and the CDP measurement is possibly not synchronized
to the 3GPP FDD BTS signal. The result is valid even if synchronization of the analyzer and signal failed.
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Measurements and result display
Code domain analysis
Parameter Description
Trigger to Frame: The time difference between the beginning of the recorded signal section to the
start of the analyzed frame. In case of triggered data collection, this difference is
identical with the time difference of frame trigger (+ trigger offset) – frame start. If
synchronization of the analyzer and input signal fails, the value of "Trigger to
Frame" is not significant.
IQ Offset: DC offset of the signal in the selected slot in %
IQ Imbalance: I/Q imbalance of signals in the selected slot in %
Avg Power Inact
Chan
Composite EVM: The composite EVM is the difference between the test signal and the ideal refer-
Pk CDE (15 ksps): The Peak Code Domain Error projects the difference between the test signal and
RHO Quality parameter RHO for each slot.
No of Active Chan: The number of active channels detected in the signal in the selected slot. Both the
Avg. RCDE Average Relative Code Domain Error over all channels detected with 64 QAM (UE:
Average power of the inactive channels
ence signal in the selected slot in %.
See also "Composite EVM" on page 23
the ideal reference signal onto the selected spreading factor in the selected slot
(see "Peak Code Domain Error" on page 27). The spreading factor onto which
projection is performed can be derived from the symbol rate indicated in brackets.
detected data channels and the control channels are considered active channels.
4PAM) modulation in the selected frame.
Carrier Frequency Error
The maximum frequency error that can be compensated is specified in Table 3-2 as a
function of the synchronization mode. Transmitter and receiver should be synchronized
as far as possible.
Table 3-2: Maximum frequency error that can be compensated
SYNC mode ANTENNA DIV Max. Freq. Offset
CPICH X 5.0 kHz
SCH OFF 1.6 kHz
SCH ANT 1 330 Hz
SCH ANT 2 330 Hz
Table 3-3: Channel-specific code domain power results
Symbol Rate: Symbol rate at which the channel is transmitted
Channel Slot No: (BTS measurements only):
Channel slot number; determined by combining the value of the selected CPICH and
the channel's timing offset
Channel Mapping (UE measurements only):
Branch onto which the channel is mapped (I or Q, specified by the standard)
Chan Power Abs: Channel power, absolute
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3.1.2 Evaluation methods for code domain analysis
Measurements and result display
Code domain analysis
Chan Power Rel: Channel power, relative (referenced to CPICH or total signal power)
Timing Offset: Offset between the start of the first slot in the channel and the start of the analyzed
3GPP FDD BTS frame
RCDE Relative Code Domain Error for the complete frame of the selected channel
Symbol EVM: Peak and average of the results of the error vector magnitude evaluation
No of Pilot Bits: Number of pilot bits of the selected channel
Modulation Type: BTS measurements:
Modulation type of an HSDPA channel. High speed physical data channels can be
modulated with QPSK, 16 QAM or 64 QAM modulation.
UE measurements: the modulation type of the selected channel. Valid entries are:
●
BPSK I for channels on I-branch
●
BPSK Q for channels on Q-branch
●
NONE for inactive channels
Access: "Overview" > "Display Config"
The captured I/Q data can be evaluated using various different methods without having
to start a new measurement.
The selected evaluation also affects the results of the trace data query (see Chap-
ter 10.8.2, "Measurement results for TRACe<n>[:DATA]? TRACE<n>", on page 235).
Bitstream.......................................................................................................................19
Channel Table............................................................................................................... 19
└ Table Configuration.........................................................................................20
Code Domain Power.....................................................................................................21
Code Domain Error Power............................................................................................22
Composite Constellation............................................................................................... 22
Composite EVM............................................................................................................ 23
EVM vs Chip................................................................................................................. 24
Frequency Error vs Slot................................................................................................ 25
Mag Error vs Chip......................................................................................................... 26
Marker Table................................................................................................................. 26
Peak Code Domain Error..............................................................................................27
Phase Discontinuity vs Slot...........................................................................................27
Phase Error vs Chip......................................................................................................28
Power vs Slot................................................................................................................ 29
Power vs Symbol.......................................................................................................... 30
Result Summary............................................................................................................30
Symbol Constellation.................................................................................................... 31
Symbol EVM................................................................................................................. 31
Symbol Magnitude Error............................................................................................... 32
Symbol Phase Error......................................................................................................33
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Measurements and result display
Code domain analysis
Bitstream
The Bitstream evaluation displays the demodulated bits of a selected channel for a
given slot. Depending on the symbol rate the number of symbols within a slot can vary
from 12 (min) to 384 (max). For QPSK modulation a symbol consists of 2 bits (I and
Q). For BPSK modulation a symbol consists of 1 bit (only I used).
Figure 3-1: Bitstream display for 3GPP FDD BTS measurements
TIP: Select a specific symbol using a marker for the display. Enter the symbol number
as the x-value. The marker is moved to the selected symbol, which is highlighted by a
blue circle.
The diagram footer indicates:
●
Channel format (type and modulation type (HS-PDSCH only))
●
Number of data bits (D1 / D2)
●
Number of TPC bits (TPC)
●
Number of TFCI bits (TFCI)
●
Number of pilot bits (Pil)
Remote command:
LAY:ADD? '1',RIGH, BITS, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? ABITstream
Channel Table
The Channel Table evaluation displays the detected channels and the results of the
code domain power measurement. The channel table can contain a maximum of 512
entries.
In BTS measurements, this corresponds to the 512 codes that can be assigned within
the class of spreading factor 512.
In UE measurements, this corresponds to the 256 codes that can be assigned within
the class of spreading factor 256, with both I and Q branches.
The first entries of the table indicate the channels that must be available in the signal to
be analyzed and any other control channels (see Chapter 4.2, "BTS channel types",
on page 38 and Chapter 4.3, "UE channel types", on page 42).
The lower part of the table indicates the data channels that are contained in the signal.
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Code domain analysis
If the type of a channel can be fully recognized, based on pilot sequences or modulation type, the type is indicated in the table. In BTS measurements, all other channels
are of type CHAN.
The channels are in descending order according to symbol rates and, within a symbol
rate, in ascending order according to the channel numbers. Therefore, the unassigned
codes are always displayed at the end of the table.
Figure 3-2: Channel Table display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, CTABle, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? CTABle
TRACe<n>[:DATA]? PWCDp
TRACe<n>[:DATA]? CWCDp
Table Configuration ← Channel Table
You can configure which parameters are displayed in the Channel Table by clicking
(not double-clicking!) a column header.
A "Table Configuration" dialog box is displayed in which you can select the columns to
be displayed.
By default, only active channels are displayed. In order to display all channels, including the inactive ones, enable the "Show Inactive Channels" option.
The following parameters of the detected channels are determined by the CDP measurement and can be displayed in the Channel Table evaluation. (For details see
Chapter 3.1.1, "Code domain parameters", on page 16.)
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Code domain analysis
Table 3-4: Code domain power results in the channel table
Label Description
Chan Type Type of channel (active channels only)
Ch. SF Number of channel spreading code (0 to [spreading factor-1])
Symbol Rate [ksps] Symbol rate at which the channel is transmitted
In BTS measurements: always
State Active: channel is active and all pilot symbols are correct
Inactive: channel is not active
Pilotf: channel is active, but pilot symbols incomplete or missing
TFCI (BTS measurements only):
Data channel uses TFCI symbols
Mapping (UE measurements only):
Branch the channel is mapped to (I or Q)
PilotL [Bits] Number of pilot bits in the channel
(UE measurements: only for control channel DPCCH)
Pwr Abs [dBm]/Pwr Rel [dBm] Absolute and relative channel power (referred to the CPICH or the
total power of the signal)
T Offs [Chips] (BTS measurements only):
Timing offset
Code Domain Power
Figure 3-3: Code Domain Power Display for 3GPP FDD BTS measurements
The Code Domain Power evaluation shows the power of all possible code channels in
the selected channel slot. The x-axis shows the possible code channels from 0 to the
highest spreading factor. Due to the circumstance that the power is regulated from slot
to slot, the result power may differ between different slots. Detected channels are displayed yellow. The selected code channel is highlighted red. The codes where no
channel could be detected are displayed green.
Note: Effects of missing or incomplete pilot symbols. In "Autosearch" channel detection
mode, the application expects specific pilot symbols for DPCH channels. If these sym-
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Code domain analysis
bols are missing or incomplete, the channel power in the Code Domain Power evaluation is displayed green at the points of the diagram the channel should appear due to
its spreading code, and a message ("INCORRECT PILOT") is displayed in the status
bar. In this case, check the pilot symbols for those channels using the Power vs Slot or
the Bitstream evaluations.
Optionally, all QPSK-modulated channels can also be recognized without pilot symbols
(see "HSDPA/UPA" on page 53).
Remote command:
LAY:ADD? '1',RIGH, CDPower, see LAYout:ADD[:WINDow]? on page 223
CALC:MARK:FUNC:WCDP:RES? CDP, seeCALCulate<n>:MARKer<m>:FUNCtion:
WCDPower[:BTS]:RESult on page 233
CALC:MARK:FUNC:WCDP:MS:RES? CDP, see CALCulate<n>:MARKer<m>:
FUNCtion:WCDPower:MS:RESult? on page 232
TRACe<n>[:DATA]? CTABle
TRACe<n>[:DATA]? PWCDp
TRACe<n>[:DATA]? CWCDp
Code Domain Error Power
Code Domain Error Power is the difference in power between the measured and the
ideal signal. The unit is dB. There are no other units for the y-axis.
Figure 3-4: Code Domain Error Power Display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, CDEPower, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Composite Constellation
The Composite Constellation evaluation analyzes the entire signal for one single slot. If
a large number of channels is to be analyzed, the results are superimposed. In that
case the benefit of this evaluation is limited (senseless).
In Composite Constellation evaluation the constellation points of the 1536 chips are
displayed for the specified slot. This data is determined inside the DSP even before the
channel search. Thus, it is not possible to assign constellation points to channels. The
constellation points are displayed normalized with respect to the total power.
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2560|%100*
²
²
1
0
0
N
x
xs
EVM
N
n
n
N
n
nn
RMS
Measurements and result display
Code domain analysis
Figure 3-5: Composite Constellation display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, CCONst, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Composite EVM
The Composite EVM evaluation displays the root mean square composite EVM (modulation accuracy) according to the 3GPP specification. The square root is determined of
the mean squared errors between the real and imaginary components of the received
signal and an ideal reference signal (EVM referenced to the total signal). The error is
averaged over all channels for individual slots. The Composite EVM evaluation covers
the entire signal during the entire observation time.
where:
EVM
RMS
s
n
x
n
n index number for mean power calculation of received and reference signal.
N number of chips at each CPICH slot
root mean square of the vector error of the composite signal
complex chip value of received signal
complex chip value of reference signal
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Figure 3-6: Composite EVM display for 3GPP FDD BTS measurements
The measurement result consists of one composite EVM measurement value per slot.
In this case, the measurement interval is the slot spacing of the CPICH (timing offset of
0 chips referenced to the beginning of the frame). Only the channels recognized as
active are used to generate the ideal reference signal. If an assigned channel is not
recognized as active since pilot symbols are missing or incomplete, the difference
between the measurement and reference signal and the composite EVM is very high.
Remote command:
LAY:ADD? '1',RIGH, CEVM, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
EVM vs Chip
EVM vs Chip activates the Error Vector Magnitude (EVM) versus chip display. The
EVM is displayed for all chips of the selected slot.
Note: In UE measurements, if the measurement interval "Halfslot" is selected for evaluation, 30 slots are displayed instead of the usual 15 (see "Measurement Interval"
on page 100).
The EVM is calculated by the root of the square difference of received signal and reference signal. The reference signal is estimated from the channel configuration of all
active channels. The EVM is related to the square root of the mean power of reference
signal and given in percent.
where:
EVM
s
k
x
k
k
vector error of the chip EVM of chip number k
complex chip value of received signal
complex chip value of reference signal
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Code domain analysis
k index number of the evaluated chip
N number of chips at each CPICH slot
n index number for mean power calculation of reference signal
Figure 3-7: EVM vs Chip display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, EVMChip, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Frequency Error vs Slot
For each value to be displayed, the difference between the frequency error of the corresponding slot to the frequency error of the first (zero) slot is calculated (based on
CPICH slots). This helps eliminate a static frequency offset of the whole signal to achieve a better display of the actual time-dependant frequency diagram.
Figure 3-8: Frequency Error vs Slot display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, FESLot, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? ATRACE
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Code domain analysis
Mag Error vs Chip
The Magnitude Error versus chip display shows the magnitude error for all chips of the
selected slot.
The magnitude error is calculated as the difference of the magnitude of the received
signal to the magnitude of the reference signal. The reference signal is estimated from
the channel configuration of all active channels. The magnitude error is related to the
square root of the mean power of reference signal and given in percent.
Where:
MAG
k
s
k
x
k
k Index number of the evaluated chip
N Number of chips at each CPICH slot
n Index number for mean power calculation of reference signal
Magnitude error of chip number k
Complex chip value of received signal
Complex chip value of reference signal
Figure 3-9: Magnitude Error vs Chip display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, MECHip, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Marker Table
Displays a table with the current marker values for the active markers.
This table is displayed automatically if configured accordingly.
(See "Marker Table Display" on page 106).
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Code domain analysis
Remote command:
LAY:ADD? '1',RIGH, MTAB, see LAYout:ADD[:WINDow]? on page 223
Results:
CALCulate<n>:MARKer<m>:X on page 254
CALCulate<n>:MARKer<m>:Y? on page 255
Peak Code Domain Error
In line with the 3GPP specifications, the error between the measurement signal and
the ideal reference signal for a given slot and for all codes is projected onto the various
spreading factors. The result consists of the peak code domain error value per slot.
The measurement interval is the slot spacing of the CPICH (timing offset of 0 chips referenced to the beginning of the frame). Only the channels recognized as active are
used to generate the ideal reference signal for the peak code domain error. If an
assigned channel is not recognized as active since pilot symbols are missing or incomplete, the difference between the measurement and reference signal is very high. This
display is a bar diagram over slots. The unit is dB. The Peak Code Domain Error evaluation covers the entire signal and the entire observation time.
Figure 3-10: Peak Code Domain Error display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, PCDerror, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Phase Discontinuity vs Slot
The Phase Discontinuity vs Slot is calculated according to 3GPP specifications. The
phase calculated for each slot is interpolated to both ends of the slot using the frequency shift of that slot. The difference between the phase interpolated for the beginning of one slot and the end of the preceding slot is displayed as the phase discontinuity of that slot.
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Code domain analysis
Figure 3-11: Phase Discontinuity vs Slot display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, PDSLot, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Phase Error vs Chip
Phase Error vs Chip activates the phase error versus chip display. The phase error is
displayed for all chips of the selected slot.
The phase error is calculated by the difference of the phase of received signal and
phase of reference signal. The reference signal is estimated from the channel configuration of all active channels. The phase error is given in degrees in a range of +180° to
-180°.
Figure 3-12: Calculating the magnitude, phase and vector error per chip
Where:
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Code domain analysis
PHI
k
s
k
x
k
k Index number of the evaluated chip
N Number of chips at each CPICH slot
φ(x) Phase calculation of a complex value
Phase error of chip number k
Complex chip value of received signal
Complex chip value of reference signal
Remote command:
LAY:ADD? '1',RIGH, PECHip, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Power vs Slot
The Power vs Slot evaluation displays the power of the selected channel for each slot.
The power is displayed either absolute or relative to the total power of the signal or to
the CPICH channel.
Figure 3-13: Power vs Slot Display for 3GPP FDD BTS measurements
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Code domain analysis
If a timing offset of the selected channel in relation to the CPICH channel occurs, the
power is calculated and displayed per channel slot (as opposed to the Code Domain
Power evaluation). However, for reference purposes, the grid in the Power vs Slot diagram indicates the CPICH slots. The first CPICH slot is always slot 0, the grid and
labels of the grid lines do not change. Thus, the channel slots may be shifted in the
diagram grid. The channel slot numbers are indicated within the power bars. The
selected slot is highlighted in the diagram.
Remote command:
LAY:ADD? '1',RIGH, PSLot, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TPVSlot
Power vs Symbol
The Power vs. Symbol evaluation shows the power over the symbol number for the
selected channel and the selected slot. The power is not averaged here. The trace is
drawn using a histogram line algorithm, i.e. only vertical and horizontal lines, no diagonal, linear Interpolation (polygon interpolation). Surfaces are NOT filled.
Figure 3-14: Power vs Symbol display for 3GPP FDD BTS measurements
Remote command:
LAY:ADD? '1',RIGH, PSYMbol, see LAYout:ADD[:WINDow]? on page 223
TRACe<n>[:DATA]? TRACE<1...4>
Result Summary
The Result Summary evaluation displays a list of measurement results on the screen.
For details see Chapter 3.1.1, "Code domain parameters", on page 16.
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