Rohde&Schwarz VSE-K10 User Manual

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R&S®VSE-K10 GSM Measurement Application User Manual

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1176894502 Version 09

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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)

The following firmware options are described:

●

R&S VSE-K10 (1320.7574.02)

●

R&S VSE-KT10 (1345.1705.02)

© 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. All other trademarks are the properties of their respective owners.

1176.8945.02 | Version 09 | R&S®VSE-K10

The following abbreviations are used throughout this manual: R&S®VSE is abbreviated as R&S VSE.

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R&S®VSE-K10

1.1 About this manual.........................................................................................................9

1.2 Typographical conventions..........................................................................................9

2.1 Starting the GSM application..................................................................................... 11

2.2 Understanding the display information.................................................................... 12

Contents

1 Preface.................................................................................................... 9

2 Welcome to the GSM application........................................................11

3 About the measurement......................................................................15

4 GSM I/Q measurement results............................................................16

5 Basics on GSM measurements...........................................................33

5.1 Relevant digital standards......................................................................................... 33

5.2 Short introduction to GSM (GMSK, EDGE and EDGE evolution)........................... 33

5.3 Short introduction to VAMOS.....................................................................................37

5.4 AQPSK modulation..................................................................................................... 38

5.5 Trigger settings........................................................................................................... 39

5.6 Defining the scope of the measurement...................................................................40

5.7 Overview of filters in the R&S VSE GSM application.............................................. 42

5.7.1 Power vs time filter........................................................................................................43

5.7.2 Multicarrier filter.............................................................................................................44

5.7.3 Measurement filter........................................................................................................ 45

5.8 Dependency of slot parameters.................................................................................46

5.9 Definition of the symbol period................................................................................. 46

5.9.1 GMSK modulation (normal symbol rate)....................................................................... 46

5.9.2 8PSK, 16QAM, 32QAM, AQPSK modulation (normal symbol rate)..............................47

5.9.3 QPSK, 16QAM and 32QAM modulation (higher symbol rate)...................................... 49

5.10 Synchronization.......................................................................................................... 50

5.11 Timeslot alignment......................................................................................................52

5.12 Delta to sync values....................................................................................................54

5.13 Limit checks................................................................................................................ 55

5.13.1 Limit check for modulation spectrum.............................................................................55

5.13.2 Limit check for transient spectrum................................................................................ 56

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5.13.3 Limit check for power vs time results............................................................................ 56

5.14 Impact of the "Statistic count"...................................................................................57

6.1 Configuration overview.............................................................................................. 58

6.2 Signal description....................................................................................................... 60

6.2.1 Device under test settings.............................................................................................60

6.2.2 Frame............................................................................................................................62

6.2.3 Slot settings...................................................................................................................63

6.2.4 Carrier settings..............................................................................................................67

6.3 Input, output and frontend settings...........................................................................69

6.3.1 Input source settings..................................................................................................... 69

6.3.1.1 Radio frequency input................................................................................................... 69

Contents

6 Modulation accuracy measurement configuration........................... 58

6.3.1.2 I/Q file input................................................................................................................... 75

6.3.2 Frequency settings........................................................................................................77

6.3.3 Amplitude settings.........................................................................................................80

6.4 Trigger settings........................................................................................................... 83

6.5 Data acquisition.......................................................................................................... 86

6.5.1 Data acquisition.............................................................................................................86

6.5.2 Capture......................................................................................................................... 88

6.6 Demodulation.............................................................................................................. 88

6.6.1 Slot scope..................................................................................................................... 88

6.6.2 Demodulation settings...................................................................................................90

6.7 Measurement settings................................................................................................ 93

6.7.1 Power vs time................................................................................................................93

6.7.2 Spectrum.......................................................................................................................95

6.7.3 Trigger to sync...............................................................................................................97

6.8 Adjusting settings automatically...............................................................................97

6.9 Result configuration................................................................................................... 98

6.9.1 Traces........................................................................................................................... 99

6.9.2 Trace / data export configuration.................................................................................101

6.9.3 Markers....................................................................................................................... 102

6.9.3.1 Individual marker settings........................................................................................... 102

6.9.3.2 General marker settings..............................................................................................105

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6.9.3.3 Marker positioning functions....................................................................................... 105

6.9.4 Y-Axis scaling..............................................................................................................106

7.1 How to perform a basic measurement on GSM signals........................................ 109

7.2 How to determine modulation accuracy parameters for GSM signals................ 110

7.3 How to analyze the power in GSM signals..............................................................111

7.4 How to analyze the spectrum of GSM signals........................................................113

8.1 Improving performance............................................................................................ 116

8.2 Improving EVM accuracy..........................................................................................116

8.3 Optimizing limit checks............................................................................................ 117

8.4 Error messages......................................................................................................... 118

Contents

7 How to perform measurements in the GSM application................ 109

8 Optimizing and troubleshooting the measurement........................ 116

9 Remote commands to perform GSM measurements......................119

9.1 Introduction............................................................................................................... 119

9.1.1 Conventions used in descriptions............................................................................... 120

9.1.2 Long and short form.................................................................................................... 121

9.1.3 Numeric suffixes..........................................................................................................121

9.1.4 Optional keywords.......................................................................................................121

9.1.5 Alternative keywords................................................................................................... 122

9.1.6 SCPI parameters.........................................................................................................122

9.1.6.1 Numeric values........................................................................................................... 122

9.1.6.2 Boolean....................................................................................................................... 123

9.1.6.3 Character data............................................................................................................ 124

9.1.6.4 Character strings.........................................................................................................124

9.1.6.5 Block data................................................................................................................... 124

9.2 Common suffixes...................................................................................................... 124

9.3 Activating GSM measurements............................................................................... 125

9.4 Restoring the default configuration (preset).......................................................... 125

9.5 Configuring and performing GSM I/Q measurements........................................... 125

9.5.1 Signal description........................................................................................................126

9.5.1.1 Device under test settings...........................................................................................126

9.5.1.2 Frame..........................................................................................................................130

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9.5.1.3 Slot.............................................................................................................................. 130

9.5.1.4 Carrier......................................................................................................................... 137

9.5.2 Configuring data input................................................................................................. 139

9.5.2.1 RF input.......................................................................................................................140

9.5.2.2 Using external mixers..................................................................................................151

9.5.2.3 Remote commands for external frontend control........................................................ 159

9.5.2.4 Working with power sensors....................................................................................... 168

Contents

Basic settings.............................................................................................................. 151

Mixer settings.............................................................................................................. 152

Programming example: working with an external mixer..............................................158

Commands for initial configuration..............................................................................159

Commands for alignment............................................................................................ 166

Configuring power sensors......................................................................................... 169

Configuring power sensor measurements.................................................................. 170

9.5.3 Frontend configuration................................................................................................ 176

9.5.3.1 Frequency................................................................................................................... 177

9.5.3.2 Amplitude settings.......................................................................................................178

9.5.3.3 Configuring the attenuation......................................................................................... 181

9.5.4 Triggering measurements........................................................................................... 183

9.5.4.1 Configuring the triggering conditions...........................................................................183

9.5.4.2 Configuring the trigger output......................................................................................189

9.5.5 Data acquisition...........................................................................................................191

9.5.6 Demodulation.............................................................................................................. 194

9.5.6.1 Slot scope................................................................................................................... 194

9.5.6.2 Demodulation.............................................................................................................. 195

9.5.7 Measurement.............................................................................................................. 198

9.5.7.1 Power vs time..............................................................................................................199

9.5.7.2 Spectrum.....................................................................................................................200

9.5.7.3 Trigger to sync.............................................................................................................204

9.5.8 Adjusting settings automatically.................................................................................. 204

9.6 Analyzing GSM measurements................................................................................205

9.6.1 Configuring the result display......................................................................................205

9.6.1.1 Global layout commands.............................................................................................205

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9.6.1.2 Working with windows in the display...........................................................................209

9.6.1.3 General window commands........................................................................................215

9.6.2 Result config............................................................................................................... 216

9.6.2.1 Traces......................................................................................................................... 216

9.6.2.2 Exporting trace results to an ASCII file....................................................................... 218

9.6.2.3 Marker......................................................................................................................... 220

9.6.2.4 Scaling........................................................................................................................ 224

9.6.3 Zooming into the display............................................................................................. 227

9.6.3.1 Using the single zoom.................................................................................................227

9.6.3.2 Using the multiple zoom..............................................................................................229

Contents

Individual marker settings........................................................................................... 220

General marker settings..............................................................................................222

Marker positioning settings......................................................................................... 223

9.7 Retrieving results......................................................................................................230

9.7.1 Graphical results......................................................................................................... 231

9.7.2 Measurement results for TRACe<n>[:DATA]? TRACE<n>.........................................237

9.7.2.1 EVM, phase error, magnitude error trace results........................................................ 237

9.7.2.2 Pvt full burst trace results............................................................................................238

9.7.2.3 Modulation spectrum and transient spectrum graph results....................................... 238

9.7.2.4 Magnitude capture results...........................................................................................238

9.7.2.5 Trigger to sync results.................................................................................................239

9.7.3 Magnitude capture results...........................................................................................239

9.7.4 Modulation accuracy results........................................................................................240

9.7.5 Modulation spectrum results....................................................................................... 252

9.7.6 Power vs slot results................................................................................................... 254

9.7.7 Transient spectrum results..........................................................................................262

9.7.8 Trigger to sync results.................................................................................................264

9.7.9 Limit check results.......................................................................................................265

9.7.10 Retrieving marker results............................................................................................ 268

9.8 Status reporting system........................................................................................... 270

9.8.1 STATus:QUEStionable:SYNC register........................................................................270

9.8.2 STATus:QUEStionable:LIMit register.......................................................................... 271

9.8.3 Querying the status registers...................................................................................... 272

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9.8.3.1 General status register commands............................................................................. 272

9.8.3.2 Reading out the EVENt part........................................................................................272

9.8.3.3 Reading out the CONDition part................................................................................. 273

9.8.3.4 Controlling the ENABle part........................................................................................ 273

9.8.3.5 Controlling the negative transition part........................................................................274

9.8.3.6 Controlling the positive transition part......................................................................... 274

9.9 Deprecated commands.............................................................................................274

9.10 Programming examples........................................................................................... 282

9.10.1 Programming example: determining the EVM............................................................ 283

9.10.2 Programming example: measuring an AQPSK signal................................................ 287

9.10.3 Programming example: measuring the power for access bursts................................ 289

9.10.4 Programming example: measuring statistics.............................................................. 292

Contents

Annex.................................................................................................. 293

A Annex: reference................................................................................293

A.1 List of abbreviations................................................................................................. 293

A.2 Menu reference..........................................................................................................294

A.2.1 Common R&S VSE menus......................................................................................... 294

A.2.1.1 File menu.................................................................................................................... 294

A.2.1.2 Window menu............................................................................................................. 296

A.2.1.3 Help menu...................................................................................................................296

A.2.2 GSM measurements menus....................................................................................... 296

A.2.2.1 Edit menu.................................................................................................................... 297

A.2.2.2 Input & output menu....................................................................................................297

A.2.2.3 Meas setup menu........................................................................................................297

A.2.2.4 Trace menu................................................................................................................. 298

A.2.2.5 Marker menu............................................................................................................... 298

A.2.2.6 Limits menu.................................................................................................................298

A.2.3 Reference of toolbar functions.................................................................................... 299

List of commands.............................................................................. 303

Index....................................................................................................312

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1 Preface

1.1 About this manual

Preface

Typographical conventions

This R&S VSE GSM User Manual provides all the information specific to the applica- tion. 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 GSM 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 GSM application

The basic procedure to perform each measurement and step-by-step instructions for more complex tasks or alternative methods

●

Optimizing and Troubleshooting the Measurement

Hints and tips on how to handle errors and optimize the measurement configuration

●

Remote Commands for GSM Measurements

Remote commands required to configure and perform GSM 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

1.2 Typographical conventions

The following text markers are used throughout this documentation:

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Preface

Typographical conventions

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 GSM application

Welcome to the GSM application

Starting the GSM application

The R&S VSE-K10 is a firmware application that adds functionality to perform GSM measurements to the R&S VSE.

The R&S VSE GSM application features:

●

Measurements on downlink or uplink signals according to the Third Generation Partnership Project (3GPP) standards for GSM/EDGE, EDGE Evolution (EGPRS2) and Voice services over Adaptive Multi-user Channels on One Slot (VAMOS)

●

Measurement in time, frequency or I/Q domains

●

Measurements of mobile devices (MS), single carrier and multicarrier base transceiver stations (BTS)

●

Measurement of signals with GMSK, AQPSK, QPSK, 8PSK, 16QAM and 32QAM modulation, normal or higher symbol rate

●

Measurement of signals using different Tx filters (e.g. narrow and wide pulse)

●

Measurements for Power vs Time, Modulation Accuracy and Modulation and Transient Spectrum as required in the standard

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 GSM application

The GSM measurement requires a special application on the R&S VSE. It is activated by creating a new measurement channel in GSM mode.

To activate the GSM application

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 GSM application

Understanding the display information

2. Select the "GSM" item.

The R&S VSE opens a new measurement channel for the GSM application.

2.2 Understanding the display information

The following figure shows a measurement diagram during analyzer operation. All different information areas are labeled. They are explained in more detail in the following sections.

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Welcome to the GSM application

Understanding the display information

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 the GSM application, the R&S VSE shows the following settings for the default I/Q measurement:

Table 2-1: Information displayed in the channel bar in the GSM application for the default I/Q mea-

Ref Level Reference level

(m.+el.) Att Mechanical and electronic RF attenuation

Offset Reference level offset (if available)

Freq / ARFCN Center frequency for the GSM signal / Absolute Radio Frequency Channel

Device / Band Device type and frequency band used by the DUT as defined in the Signal

surement

Number (if available)

description settings

Slot Scope Minimized visualization of the frame configuration and slots to be mea-

sured (see Chapter 5.6, "Defining the scope of the measurement", on page 40)

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Welcome to the GSM application

Understanding the display information

Count Number of frames already evaluated / Total number of frames required for

statistical evaluation (Statistic Count) (For Statistic Count > 1)

TRG Trigger source (if not "Free Run") and used trigger bandwidth (for IF, RF,

IP power triggers) or trigger offset (for external triggers)

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. This information is displayed only when applicable for the current application. For details see the R&S VSE Base Software User Manual.

Window title bar information

For each diagram, the header provides the following information:

1 3 5 6 7

2 4

Figure 2-1: Window title bar information in the R&S VSE GSM application

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 4, "GSM I/Q measurement results", on page 16).

Diagram footer information

The diagram footer (beneath the diagram) contains the start and stop values for the displayed time, frequency or symbol range.

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 About the measurement

About the measurement

A basic GSM measurement in the R&S VSE GSM application includes a power vs time and a spectrum measurement, as well as modulation accuracy (e.g. EVM, phase error) for a GSM signal as defined by the relevant 3GPP standards. The I/Q data from the GSM signal applied to the RF input of the R&S VSE is captured for a specified measurement time. This data is demodulated and synchronized with a reference signal to identify the individual frames and slots. The slots of interest are then analyzed in order to display the spectral and power results either graphically or numerically, and to calculate the modulation parameters.

The standard distinguishes between single-slot and multi-slot measurements. Singleslot measurements analyze one slot - referred to as the "Slot to measure" - within the GSM frame (which consists of 8 slots in total). Modulation-specific parameters such as the phase error, EVM, or spectrum due to modulation are determined on a per-slot basis. Multi-slot measurements, on the other hand, analyze a slot scope of up to 8 consecutive slots, each of which has different burst modulation characteristics. Power vs time limit checks and the transient spectrum measurements, for example, are determined for multiple slots.

Statistical evaluation of several measurements is also possible. Finally, the GSM measurement results can be exported to other applications.

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4 GSM I/Q measurement results

GSM I/Q measurement results

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 GSM channel, select the 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.

By default, the GSM measurement results for I/Q measurements are displayed in the following windows:

●

Magnitude Capture

●

PvT Full Burst

●

Modulation Accuracy

●

Power vs Slot

The following evaluation methods are available for GSM I/Q measurements:

Constellation................................................................................................................. 16

EVM.............................................................................................................................. 17

Magnitude Capture........................................................................................................17

Magnitude Error............................................................................................................ 18

Marker Table ................................................................................................................ 19

Modulation Accuracy.....................................................................................................19

Modulation Spectrum Graph......................................................................................... 21

Modulation Spectrum Table...........................................................................................22

Phase Error...................................................................................................................24

Power vs Slot................................................................................................................ 25

PvT Full Burst................................................................................................................26

Transient Spectrum Graph............................................................................................28

Transient Spectrum Table............................................................................................. 29

Trigger to Sync Graph...................................................................................................30

Trigger to Sync Table.................................................................................................... 32

"Add Window"

Constellation

The complex source signal is displayed as an X/Y diagram. The application analyzes the specified slot over the specified number of bursts.

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GSM I/Q measurement results

Remote command: LAY:ADD? '1',RIGH,CONS, see LAYout:ADD[:WINDow]? on page 209

EVM

Displays the error vector magnitude over time for the Slot to Measure.

Remote command: LAY:ADD:WIND '2',RIGH,ETIMe see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232

Magnitude Capture

Displays the power vs. time trace of the captured I/Q data. Pre-trigger samples are not displayed. The analyzed slot scopes (1 to 8 slots of a single GSM frame) are indicated by a green

bar, the Slot to Measure in each frame by a blue bar at the bottom of the diagram.

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GSM I/Q measurement results

For details see Chapter 5.6, "Defining the scope of the measurement", on page 40. For negative trigger offsets, the trigger is displayed as a vertical red line labeled "TRG".

Remote command: LAY:ADD:WIND '2',RIGH,MCAP see LAYout:ADD[:WINDow]? on page 209 Results:

FETCh:MCAPture:SLOTs:SCOPe? on page 240 FETCh:MCAPture:SLOTs:MEASure? on page 239 TRACe<n>[:DATA]? on page 232

Magnitude Error

Displays the magnitude error over time for the Slot to Measure.

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GSM I/Q measurement results

Remote command: LAY:ADD:WIND '2',RIGH,MERR see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232

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 105).

Remote command: LAY:ADD? '1',RIGH, MTAB, see LAYout:ADD[:WINDow]? on page 209 Results:

CALCulate<n>:MARKer<m>:X on page 269 CALCulate<n>:MARKer<m>:Y? on page 269

Modulation Accuracy

Displays the numeric values of the fundamental modulation characteristics of the signal to be analyzed in the vector (I/Q) domain: error vector magnitude ("EVM"), magnitude and phase error, IQ imbalance, etc.

The following modulation parameters are determined:

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Table 4-1: Modulation accuracy parameters

GSM I/Q measurement results

Parameter

"EVM" Error vector magnitude for the Slot to Measure

Mag Error Magnitude error for the Slot to Measure

"Phase Error"

Origin Offset Suppression

[dB]

I/Q Offset [%]

Description SCPI query for result value

RMS and peak error values for the current frame, in percent 95%ile: error value (in percent) below which 95% of all

"EVM" results for all frames in entire measurement fall

RMS and peak error values for the current frame, in percent 95%ile: error value (in percent) below which 95% of all

"Magnitude Error" results for all frames in entire measurement fall

Phase error for the Slot to Measure RMS and peak error values for the current frame, in percent 95%ile: error value (in percent) below which 95% of all

"Phase Error" results for all frames in entire measurement fall

Origin offset suppression for the demodulated signal in the

Slot to Measure; Indicates the suppression of the DC carrier;

the higher the suppression, the better the DUT

I/Q offset for the demodulated signal in the Slot to Measure

READ:BURSt[:MACCuracy][:EVM]:PEAK: <Resulttype>?

READ:BURSt[:MACCuracy][:EVM]:RMS: <Resulttype>?

READ:BURSt[:MACCuracy]PERCentile:EVM?

READ:BURSt[:MACCuracy]:MERRor:PEAK: <Resulttype>?

READ:BURSt[:MACCuracy]:MERRor:RMS: <Resulttype>?

READ:BURSt[:MACCuracy]PERCentile:MERRor?

READ:BURSt[:MACCuracy]:PERRor:PEAK: <Resulttype>?

READ:BURSt[:MACCuracy]:PERRor:RMS: <Resulttype>?

READ:BURSt[:MACCuracy]PERCentile:PERRor?

READ:BURSt[:MACCuracy]:OSUPpress: <Resulttype>?

READ:BURSt[:MACCuracy]:IQOFfset: <Resulttype>?

I/Q Imbalance

[%]

Frequency Error

[Hz]

Burst Power

[dBm]

Amplitude Droop

[dB]

A measure for gain imbalances and quadrature errors between the inphase and quadrature components of the signal.

Frequency error of the center frequency currently measured in the Slot to Measure

Average power measured in the slot

Indicates how much the amplitude decreases over a measured slot

The R&S VSE GSM application also performs statistical evaluation over a specified number of results (see "Statistic Count" on page 88). To do so, the same slot is evaluated in multiple frames, namely in the number specified by the "Statistic Count". The default value is 200 in accordance with the GSM standard.

For each parameter, the following results are displayed:

READ:BURSt[:MACCuracy]:IQIMbalance: <Resulttype>?

READ:BURSt[:MACCuracy]:FERRor: <Resulttype>?

READ:BURSt[:MACCuracy]:BPOWer: <Resulttype>?

READ:BURSt[:MACCuracy]:ADRoop: <Resulttype>?

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Table 4-2: Calculated summary results

GSM I/Q measurement results

Result type

Current Value for currently measured frame only

Average Linear average value of "Current" results from the specified

Peak Maximum value of "Current" results from specified number of

Std Dev Standard deviation of "Current" results for specified number

Description SCPI query for result value

number of frames Exception: The average of the "Origin Offset Suppression"

is the linear average of the power ratio, converted to dBm subsequently

frames Exception: The peak of the "Origin Offset Suppression" is

the minimum value, as this represents the worst case, which needs to be detected

of frames

Remote command: LAY:ADD:WIND '2',RIGH,MACC see LAYout:ADD[:WINDow]? on page 209 Results:

READ:BURSt[:MACCuracy]:ALL? on page 243

Chapter 9.7.4, "Modulation accuracy results", on page 240

READ:BURSt[:MACCuracy]:<Parameter>: CURRent?

READ:BURSt[:MACCuracy]:<Parameter>: AVERage?

READ:BURSt[:MACCuracy]:<Parameter>: MAXimum?

READ:BURSt[:MACCuracy]:<Parameter>: SDEViation?

Modulation Spectrum Graph

The modulation spectrum evaluates the power vs frequency trace of a certain part of the burst (50 to 90 % of the useful part, excluding the training sequence TSC) by measuring the average power in this part over several frames at certain fixed frequency offsets.

The "Modulation Spectrum Graph" displays the measured power levels as a trace against the frequencies.

The measured values can be checked against defined limits; the limit lines are indicated as red lines in the diagram. The result of the limit check ("PASS"/"FAIL") are shown at the top of the diagram.

Note: The GSM standards define both absolute and relative limits for the spectrum. The limit check is considered to fail if both limits are exceeded.

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Note: The graphical results only provide an overview of the spectrum. For a detailed

conformance check of the DUT to the GSM standard, use the "Modulation Spectrum Table" evaluation, which uses the 5-pole filter required by the 3GPP standard. The numeric results of the modulation spectrum evaluation are displayed in the "Modu-

lation Spectrum Table" on page 22.

The following default settings are used for a "Modulation Spectrum" evaluation.

Table 4-3: Default settings for a "Modulation Spectrum" evaluation

Setting Default

Measurement Scope The slot selected as Slot to Measure

Averaging Configuration Number of bursts as selected in Statistic Count

Limit Check According to standard: Limit check of average (Avg) trace

See Chapter 5.13.1, "Limit check for modulation spectrum", on page 55

Note: Modulation RBW at 1800 kHz. For the "Modulation Spectrum Graph" both the RBW and VBW are set to 30 kHz.

Remote command: LAY:ADD:WIND '2',RIGH,MSFD see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232 CALCulate<n>:LIMit<k>:FAIL? on page 266 CALCulate<n>:LIMit<li>:UPPer:DATA? on page 267 CALCulate<n>:LIMit<li>:CONTrol:DATA? on page 266

Modulation Spectrum Table

The "Modulation Spectrum Table" displays the measured power levels and their offset to the limits defined by the standard as numeric results.

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Note: The GSM standards define both absolute and relative limits for the spectrum.

The limit check is considered to fail if both limits are exceeded. Values that exceed both limits are indicated by red characters and an asterisk (*) next to the value, and a negative "Δ to Limit" value.

Note: The graphical results of the modulation spectrum evaluation are displayed in the

"Modulation Spectrum Graph" on page 21.

The following values are displayed:

Table 4-4: Modulation spectrum results

Result Description

Offset [kHz] Fixed frequency offsets (from the center frequency) at which power is measured

Power Negative Offsets

Power Positive Offsets

Table 4-5: Frequencies and filter bandwidths in modulation spectrum measurements

Offset Frequency (kHz) RBW (kHz) VBW (kHz)

± 100 30 30

± 200 30 30

± 250 30 30

± 400 30 30

Power at the frequency offset to the left of the center frequency Levels are provided as: [dB]: relative power level [dBm]: absolute power level Δ to Limit: power difference to limit defined in standard; negative values indicate the

power exceeds at least one of the limits

Power at the frequency offset to the right of the center frequency Levels are provided as: [dB]: relative power level [dBm]: absolute power level Δ to Limit: power difference to limit defined in standard; negative values indicate the

power exceeds at least one of the limits

± 600 30 30

± 800 30 30

± 1000 30 30

± 1200 30 30

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Offset Frequency (kHz) RBW (kHz) VBW (kHz)

± 1400 30 30

± 1600 30 30

± 1800 30 (single-carrier BTS);

100 (multi-carrier BTS);

30 (single-carrier BTS); 100 (multi-carrier BTS);

Note: "Normal" vs "Wide" Modulation Spectrum measurements. In previous Rohde & Schwarz signal and spectrum analyzers, both a "normal" and a "wide" modulation spectrum were available for GSM measurements. In the R&S VSE GSM application, only one evaluation is provided. The frequency range of the frequency list, however, can be configured to be "wider" or "narrower" (see "Modulation

Spectrum Table: Frequency List" on page 96). The RBW and VBW are then adapted

accordingly. Note: RBW at 1800 kHz.

As opposed to previous Rohde & Schwarz signal and spectrum analyzers, in which the RBW at 1800 kHz was configurable, the R&S VSE configures the RBW (and VBW) automatically according to the selected frequency list (see "Modulation Spectrum

Table: Frequency List" on page 96). For the "Modulation Spectrum Graph" both the

RBW and VBW are set to 30 kHz. For the "Modulation Spectrum Table", they are set according to Table 4-6, depending on the measured Device Type and the number of active carriers as defined in the "Signal Description" settings.

Table 4-6: RBW settings for Modulation Spectrum Table measurements according to standard

Offset Single-carrier BTS Multicarrier BTS

(N=1)

< 1.8 MHz

1.8 MHz

> 1.8 MHz

30 kHz

100 kHz

30 kHz

100 kHz

Multicarrier BTS (N>1)

30 kHz

100 kHz

MS mode

30 kHz

100 kHz

1) See 3GPP TS 51.021 § 6.5.1.2 c) d)

2) See 3GPP TS 51.021 § 6.12.2

3) See 3GPP TS 51.021 § 6.5.1.2 f)

4) See 3GPP TS 51.010-1 § 13.4.4.2 f) and 3GPP TS45.005 § 4.2.1.3, table a1-c4

5) See 3GPP TS 51.010-1 § 13.4.4.2 d) and 3GPP TS 45.005 § 4.2.1.3

Remote command: LAY:ADD:WIND '2',RIGH,MST see LAYout:ADD[:WINDow]? on page 209 Results:

READ:SPECtrum:MODulation[:ALL]? on page 252 READ:SPECtrum:MODulation:REFerence[:IMMediate]? on page 253

Phase Error

Displays the phase error over time.

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The following default settings are used for a "Phase Error vs Time" measurement.

Setting Default

Measurement Scope The slot selected as Slot to Measure

Averaging Configuration Number of frames as selected in Statistic Count

Limit Check None

Remote command: LAY:ADD:WIND '2',RIGH,PERR see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232

Power vs Slot

Displays the power per slot in the current frame and over all frames. The result of the (Power vs Time) limit check is also indicated.

Note: The power is measured for inactive slots, but not for slots outside the slot scope (see Chapter 5.6, "Defining the scope of the measurement", on page 40).

The following power values are determined:

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Table 4-7: Measured power values for Power vs Slot results

Value Description SCPI query for result value

GSM I/Q measurement results

Slot Analyzed slot number in frame(s)

[0..7]

PvT Limit Power vs Time limit for the power vs time

trace of the slot, defined by the standard

Delta to Sync

[NSP]

Power Avg

[dBm]

Power Peak

[dBm]

Crest [dB]

The distance between the mid of the TSC and the TSC of the Slot to Measure

NSP stands for Normal Symbol Period, i.e. the duration of one symbol using a normal symbol rate (approx. 3.69μs).

The measured "Delta to Sync" value has a resolution of 0.02 NSP.

For details see Chapter 5.12, "Delta to sync

values", on page 54.

Average power in slot in current or all frames READ:BURSt:SPOWer:SLOT<Slot>:CURRent:AVERage?

Maximum power in slot in current or all frames

Crest factor in slot in current or all frames, i.e. Power Peak / Power Avg

READ:BURSt:SPOWer:SLOT<Slot>:LIMit:FAIL? on page 261

READ:BURSt:SPOWer:SLOT<Slot>:DELTatosync? on page 260

on page 257

READ:BURSt:SPOWer:SLOT<Slot>:ALL:AVERage? on page 255

READ:BURSt:SPOWer:SLOT<Slot>:CURRent:MAXimum?

on page 259

READ:BURSt:SPOWer:SLOT<Slot>:ALL:MAXimum? on page 256

READ:BURSt:SPOWer:SLOT<Slot>:CURRent:CRESt?

on page 258

READ:BURSt:SPOWer:SLOT<Slot>:ALL:CRESt? on page 255

Remote command: LAY:ADD:WIND '2',RIGH,PST see LAYout:ADD[:WINDow]? on page 209 Results:

Chapter 9.7.6, "Power vs slot results", on page 254

PvT Full Burst

The Power vs Time evaluation determines the power of all slots (bursts) in the selected slot scope and performs a limit check of the power vs time trace against the specified PvT mask.

The "PvT Full Burst" result display shows the power vs time trace, where the time axis corresponds to the selected slot scope. The PvT mask is indicated by red lines, and the overall result of the limit check is shown at the top of the diagram.

Note: The result of the Power vs Time limit check for individual slots is indicated in the

"Power vs Slot" on page 25 evaluation.

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Note: Full burst refers to the fact that the entire burst is displayed, including the rising

and falling edges and the burst top. However, you can easily analyze the edges in more detail using the zoom functions (See the R&S VSE User Manual).

The following default settings are used for a "Power vs Time" evaluation.

Table 4-8: Default settings for a "Power vs Time" evaluation

Setting Default

Measurement Scope The slot scope defined by First Slot to measure and Number of Slots to mea-

sure

Averaging Configuration Number of bursts as selected in Statistic Count

Limit Check According to standard:

●

The maximum (Max) trace is checked against the upper limit.

●

The minimum (Min) trace is checked against the lower limit.

See Chapter 5.13.3, "Limit check for power vs time results", on page 56

Remote command: LAY:ADD:WIND '2',RIGH,PTF see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232 TRACe<n>[:DATA]:X? on page 233 CALCulate<n>:LIMit<k>:FAIL? on page 266 CALCulate<n>:LIMit<li>:UPPer:DATA? on page 267 CALCulate<n>:LIMit<li>:CONTrol:DATA? on page 266

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Transient Spectrum Graph

The transient spectrum is very similar to the modulation spectrum evaluation; it evaluates the power vs frequency trace by measuring the power over several frames. However, as opposed to the modulation spectrum evaluation, the entire slot scope (defined by the Number of Slots to measure and the First Slot to measure) is evaluated in each frame, including the rising and falling burst edges, not just the useful part in the Slot to

Measure.

Furthermore, the number of fixed frequency offsets is lower, and the peak power is evaluated rather than the average power, as this measurement is used to determine irregularities.

The "Transient Spectrum Graph" displays the measured power levels as a trace against the frequencies for the specified slots.

The measured values can be checked against defined limits; the limit lines are indicated as red lines in the diagram. The result of the limit check ("PASS"/"FAIL") is shown at the top of the diagram.

Note: The GSM standards define both absolute and relative limits for the spectrum. The limit check is considered to fail if both limits are exceeded.

Note: The graphical results only provide an overview of the spectrum. For a detailed conformance check of the DUT to the GSM standard, use the "Transient Spectrum Table" evaluation, which uses the 5-pole filter required by the 3GPP standard. The numeric results of the modulation spectrum evaluation are displayed in the "Modu-

lation Spectrum Table" on page 22.

The following default settings are used for "Transient Spectrum" measurements.

Setting Default

Measurement Scope The slot scope defined by Number of Slots to measure and the First Slot to

measure in the "Demodulation Settings" (see Chapter 6.6.1, "Slot scope",

on page 88).

Averaging Configuration Number of frames as selected in Statistic Count

Limit Check Limit check of maximum (Max) trace

See Chapter 5.13.2, "Limit check for transient spectrum", on page 56

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GSM I/Q measurement results

Remote command: LAY:ADD:WIND '2',RIGH,TSFD see LAYout:ADD[:WINDow]? on page 209 Results:

TRACe<n>[:DATA]? on page 232 CALCulate<n>:LIMit<k>:FAIL? on page 266

Transient Spectrum Table

The transient spectrum evaluates the power vs frequency trace of the slot scope by measuring the power in these slots over several frames.

For details see "Transient Spectrum Graph" on page 28. The "Transient Spectrum Table" displays the measured power levels and their offset to

the limits defined by the standard as numeric results. Note: The GSM standards define both absolute and relative limits for the spectrum.

To determine the relative limit values, a reference power is required (see "Transient

Spectrum: Reference Power" on page 96). In order to detect irregularities, it is useful

to define the peak power as a reference. However, the standard requires the reference power to be calculated from the RMS power.

To perform the measurement according to the 3GPP standard set the reference power to RMS and the Slot to Measure to the slot with the highest power.

See 3GPP TS 45.005, chapter "4 Transmitter characteristics ":

For GMSK modulation, the term output power refers to the measure of the power when averaged over the useful part of the burst (see annex B).

For QPSK, AQPSK, 8-PSK, 16-QAM and 32-QAM modulation, the term "output power" refers to a measure that, with sufficient accuracy, is equivalent to the long term average of the power when taken over the useful part of the burst as specified in 3GPP TS

45.002 with any fixed TSC and with random encrypted bits.

And 3GPP TS 51.021, chapter "6.5.2 Switching transients spectrum":

The reference power for relative measurements is the power measured in a bandwidth of at least 300 kHz for the TRX under test for the time slot in this test with the highest power.

Note: The graphical results of the transient spectrum evaluation are displayed in the

"Transient Spectrum Graph" on page 28.

The following values are displayed:

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Table 4-9: Transient spectrum results

Result Description

Offset [kHz]

Power Negative Offsets

Power Positive Offsets

Fixed frequency offsets (from the center frequency) at which power is measured

power exceeds at least one of the limits

Remote command: LAY:ADD:WIND '2',RIGH,TST see LAYout:ADD[:WINDow]? on page 209 Results:

READ:SPECtrum:SWITching[:ALL]? on page 262 READ:SPECtrum:SWITching:REFerence[:IMMediate]? on page 263

Trigger to Sync Graph

The Trigger to Sync measurement determines the time between an external trigger event and the start of the first symbol of the TSC. The start of the first symbol of the TSC corresponds to the time 0 of the symbol period (see Chapter 5.9, "Definition of the

symbol period", on page 46).

Only one result per data capture is provided. Therefore, it is useful to perform several data captures and average the results to obtain an accurate value (see "Statistic

Count" on page 88).

Both graphical and numeric (table) results are available. While the graphical results are mainly used to determine the required measurement settings, the numeric results provide the actual trigger to sync value, including statistical evaluation (see "Trigger to

Sync Table" on page 32).

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The Trigger to Sync diagram shows two traces:

●

Trace1: a histogram shows the probability density function (PDF) of all measured Trigger to Sync values. Obviously, the histogram can only provide reasonable results if several I/Q captures are performed and considered. In an ideal case (assuming no noise), the histogram would be a rectangle over the trigger sampling time. The histogram is helpful to determine the number of Trigger to Sync values to be averaged (Statistic Count) in order to obtain the required time resolution of the averaged Trigger to Sync value. The higher the statistic count, the more the graph becomes rectangular, and the higher the resolution of the averaged Trigger to Sync value becomes.

●

Trace2: the second trace is superimposed on the histogram and visualizes the probability density function (PDF) of the average Trigger to Sync value and the standard deviation as provided in the Trigger to Sync table. This trace helps you judge the reliability of the averaged values in the table. The narrower this trace, the less the individual values deviate from the averaged result. if this trace is too wide, increase the Statistic Count.

Note: The x-axis of the histogram indicates the individual Trigger to Sync values. Thus, the scaling must be very small, in the range of ns. However, since the value range, in particular the start value, of the possible results is not known, the x-axis must be adapted to the actual values after a number of measurements have taken place. This is done using the adaptive data size setting (see "Adaptive Data Size" on page 97). This setting defines how many measurements are performed before the x-axis is adapted to the measured values, and then fixed to that range.

Remote command:

LAY:ADD? '1',RIGH,TGSG, see LAYout:ADD[:WINDow]? on page 209 DISPlay:WINDow:TRACe1:MODE WRITe (for Histogram, see DISPlay[:

WINDow<n>]:TRACe<t>:MODE on page 217 )

DISPlay:WINDow:TRACe2:MODE PDFavg (for PDF of average, see DISPlay[:

WINDow<n>]:TRACe<t>:MODE on page 217)

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Results:

TRACe<n>[:DATA]? on page 232 TRACe<n>[:DATA]:X? on page 233

Trigger to Sync Table

symbol period", on page 46).

Only one result per data capture is provided. Therefore, it is useful to perform several data captures and average the results to obtain an accurate value (see "Statistic

Count" on page 88).

Both graphical and numeric (table) results are available. While the graphical results are mainly used to determine the required measurement settings (see "Trigger to Sync

Graph" on page 30), the numeric results provide the actual trigger to sync value,

including statistical evaluation.

The Trigger to Sync table shows the following values:

Value Description

Current Trigger to Sync value for current measurement in μs

Average Trigger to Sync value averaged over the Statistic Count number of measurements

Min Minimum Trigger to Sync value in the previous Statistic Count number of measurements

Max Maximum Trigger to Sync value in the previous Statistic Count number of measurements

Std Dev Standard deviation of the individual Trigger to Sync values to the average value

Remote command: LAY:ADD? '1',RIGH,TGST, see LAYout:ADD[:WINDow]? on page 209 Results:

Chapter 9.7.8, "Trigger to sync results", on page 264

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5 Basics on GSM measurements

5.1 Relevant digital standards

Basics on GSM measurements

Short introduction to GSM (GMSK, EDGE and EDGE evolution)

Some background knowledge on basic terms and principles used in GSM measurements is provided here for a better understanding of the required configuration settings.

The measurements and the physical layer – the layer of the GSM network on which modulation, transmission of RF signals, reception of RF signals, and demodulation take place – is defined in the standards:

Table 5-1: GSM standards

3GPP TS 45.004 Details on Modulation

3GPP TS 45.005 General measurement specifications and limit values

3GPP TS 45.010 Details on Synchronization and Timing

3GPP TS 51.010 Detailed measurement specifications and limit values for mobile stations (MS)

3GPP TS 51.021 Detailed measurement specifications and limit values for base transceiver stations

(BTS)

5.2 Short introduction to GSM (GMSK, EDGE and EDGE evolution)

The GSM (Global System for Mobile Communication) standard describes the GSM mobile radio network that is in widespread use today. In a first step to enhance this network, 8PSK modulation has been defined in addition to the existing GMSK (Gaussian Minimum Shift Keying) modulation. With 8PSK, the mobile or base station operates in the EDGE mode. While the 8PSK modulation transmits 3 bits within a symbol, GMSK can only transmit 1 bit within a symbol.

In a second step to enhance this network, higher symbol rate (HSR), QPSK, 16QAM, and 32QAM modulation, narrow and wide pulse shapes for the Tx filter have been defined. Here, EDGE Evolution and EGPRS2 are synonyms for this second enhancement.

This means that GSM includes different modes: GMSK, EDGE and EDGE Evolution. The terms EDGE and EDGE Evolution are used here only when there are significant differences between the modes. In all other cases, the term GSM is used.

Time domain vs frequency domain

A TDMA (Time Division Multiple Access) and FDMA (Frequency Division Multiple Access) scheme is used to transfer data in the GSM network. This means that the digital information is transmitted discretely in the time domain (mainly used to distinguish

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Short introduction to GSM (GMSK, EDGE and EDGE evolution)

between different users) as well as in the frequency domain (mainly used to distinguish between BTS).

Slots and frames

The time domain is divided into slots with a duration of 576.923 µs (exactly: 3/5200 s). 8 slots (numbered 0 to 7) are combined into 1 frame with a duration of approximately

4.6154 ms (exactly: 3/650 s).

Multiframes and superframes

Frames can be grouped into a multiframe consisting of either 26 (for support traffic and associated control channels) or 51 (for all other purposes) frames. Multiframes can be grouped to superframes consisting of either 51 26-frame or 26 51-frame multiframes.

Multiframes and superframes are not of relevance for the physical measurements on the GSM system and thus not discussed in detail here.

A mobile phone, therefore, does not communicate continuously with the base station; instead, it communicates discretely in individual slots assigned by the base station during connection and call establishment. In the simplest case, 8 mobiles share the 8 slots of a frame (TDMA).

Frequency bands and channels

The frequency range assigned to GSM is divided into frequency bands, and each band, in turn, is subdivided into channels.

Each frequency channel is identified by its center frequency and a number, known as the ARFCN (Absolute Radio Frequency Channel Number), which identifies the frequency channel within the specific frequency band. The GSM channel spacing is 200 kHz.

Communication between a mobile and a base station can be either frequency-continuous or frequency-discrete – distributed across various frequency channels (FDMA). In the standard, the abbreviation "SFH" (slow frequency hopping) is used to designate the latter mode of communication.

Uplink and downlink

Base stations and mobiles communicate in different frequency ranges; the mobile sends in the "uplink" (UL), and the base station in the "downlink" (DL).

The frequencies specified in the standard plus their channel numbers (ARFCN) are shown in the figure and table below.

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Short introduction to GSM (GMSK, EDGE and EDGE evolution)

Figure 5-1: The frequencies specified in the GSM standard

Table 5-2: Frequencies and channel numbers (ARFCN) in the GSM standard

Band Class UL

[MHz]

Freq. DL

[MHz]

Freq. Freq.

Middle

Band UL-DL Shift ARFCN

Lower Upper Lower Upper UL DL Range 1 Range 2

T-GSM 380 380.2 389.8 390.2 399.8 385.0 395.0 10 MHz

T-GSM 410 410.2 419.8 420.2 429.8 415.0 425.0 10 MHz

0 … 48

–

GSM 450 450.4 457.6 460.4 467.6 454.0 464.0 10 MHz 259 … 293 –

GSM 480 478.8 486.0 488.8 496.0 482.4 492.4 10 MHz 306 … 340 –

GSM 710 698.0 716.0 728.0 746.0 707.0 737.0 30 MHz

0 … 90

–

GSM 750 747.0 762.0 777.0 792.0 754.5 784.5 30 MHz 438 … 511 –

T-GSM 810 806.0 821.0 851.0 866.0 813.5 858.5 45 MHz

0 … 75

–

GSM 850 824.0 849.0 869.0 894.0 836.5 881.5 45 MHz 128 … 251 –

P-GSM 900 890.0 915.0 935.0 960.0 902.5 947.5 45 MHz 1 … 124 –

E-GSM 900 880.0 915.0 925.0 960.0 897.5 942.5 45 MHz 0 … 124 975 … 1023

R-GSM 900 876.0 915.0 921.0 960.0 895.5 940.5 45 MHz 0 … 124 955 … 1023

T-GSM 900 870.4 876.0 915.4 921.0 873.2 918.2 45 MHz

0 … 28

–

DCS 1800 1710.0 1785.0 1805.0 1880.0 1747.5 1842.5 95 MHz 512 … 885 –

PCS 1900 1850.0 1910.0 1930.0 1990.0 1880.0 1960.0 80 MHz 512 … 810 –

For these frequency bands, there is no fixed ARFCN to frequency assignment, instead it is calculated with a formula taking an

OFFSET parameter which is signaled by a higher layer of the network. The given ARFCNs assume an OFFSET value of 0.

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Short introduction to GSM (GMSK, EDGE and EDGE evolution)

Modulation modes

Different modulation modes are used in the GSM mobile radio network. The original GSM modulation is GMSK, with the normal symbol rate (NSR) of approximately

270.833 ksymb/s (exactly: 1625/6 ksymb/s). This corresponds to a bit rate of 270.833 kbit/s. The details are specified in chapter 2 of "3GPP TS 45.004" (see Table 5-1).

The 8PSK (Phase Shift Keying) modulation, which is used within EDGE, was introduced to increase the data rate on the physical link. It uses the same symbol rate (the normal symbol rate) as GMSK (270.833 ksymb/s), but has a bit rate of 3 × 270.833 kbit/s (exactly: 812.5 kbit/s).

In this method, three bits represent a symbol. The details are specified in chapter 3 "3GPP TS 45.004" (see Table 5-1).

The 16QAM and 32QAM (Quadrature Amplitude Modulation) modulation, which are used in EDGE Evolution, were introduced to further increase the data rate on the physical link. They use the normal symbol rate (270.833 ksymb/s), but have bit rates of 4 ×

270.833 kbit/s or 5 × 270.833 kbit/s, respectively. The details are specified in chapter 4 "3GPP TS 45.004" (see Table 5-1).

The QPSK, 16QAM and 32QAM modulation with a higher symbol rate, which are used in EDGE Evolution, were introduced to further increase the data rate on the physical link. They use a higher symbol rate (325 ksymb/s), but have bit rates of 2 × 325 kbit/s, 4 × 325 kbit/s or 5 × 325 kbit/s, respectively. The details are specified in chapter 5 "3GPP TS 45.004" (see Table 5-1).

The figure below shows the modulation spectrum for both GMSK and 8PSK.

Figure 5-2: GMSK and 8PSK modulation spectrum

Increasing the bandwidth - multiple slots (GPRS, HSCSD)

The customers’ demand for higher telecommunication speeds increases the demand for bandwidth. Therefore, the GSM standard has to evolve constantly. An example of this development is the introduction of the EDGE/EDGE Evolution specification and the GPRS/EGPRS2 and HSCSD modes.

Until now, each mobile could use only one slot per frame, but the new HSCSD (High Speed Circuit Switched Data) and GPRS (General Packet Radio Service) methods will

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5.3 Short introduction to VAMOS

Basics on GSM measurements

Short introduction to VAMOS

allow permanent assignment of more than one slot per mobile, plus dynamic utilization of multiple slots.

The concept behind GPRS is dynamic assignment of up to 8 slots to each mobile for data transmission, depending on demand (and availability in the network).

HSCSD allows permanent assignment of up to 4 slots to a mobile.

Normal and higher symbol rates

The modulation modes GMSK, QPSK, 8PSK, 16QAM and 32QAM can be used with either normal or higher symbol rate and different Tx filters.

What is significant for the R&S VSE GSM application in this respect is that the mobile can send power on a frequency in more than one slot.

The "Voice services over Adaptive Multi-user Channels on One Slot" (VAMOS) extension to the GSM standard allows transmission of two GMSK users simultaneously within a single time slot.

Subchannels

The standard specifies the downlink signal using Adaptive QPSK (AQPSK) modulation (see 3GPP TS 45.004), where two "subchannel" binary sequences are multiplexed to form a single QPSK sequence. The ratio of powers for the subchannels is referred to as the "Subchannel Power Imbalance Ratio" (SCPIR). One of the subchannels is interpreted as interference. The value of SCPIR affects the shape of the AQPSK constellation. For an SCPIR of 0dB the constellation is square (as in "normal" QSPK), while for other values of the SCPIR the constellation becomes rectangular.

Training sequences (TSCs)

A new set of training sequences (TSCs) has also been proposed (see 3GPP TS

45.002) for GMSK signals. The previous TSCs for GMSK bursts are listed as "Set 1", while the new TSCs are listed as "Set 2". AQPSK signals can be formed using TSCs from Set 1 on the first subchannel and TSCs from either Set 1 or Set 2 on the second subchannel. In case a TSC from Set 2 is used, it should match the TSC from Set 1, i.e. TSC<n> from Set 1 on subchannel 1 should match TSC<n> from Set 2 on subchannel 2, for n = 0..7.

TSC vs "Midamble"

The terms TSC and Midamble are used synonymously in the standard. In this documentation, we use the term TSC to refer to the known symbol sequence in the middle of the slot.

The R&S VSE GSM application supports measurement of the following signals:

●

GMSK bursts using the TSCs from Set 1 or Set 2

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●

AQPSK bursts with combinations of TSCs from Set 1 and 2 on the subchannels

●

AQPSK bursts with a user-specified SCPIR

Basics on GSM measurements

The following measurements of the above signals are supported:

●

Power vs Time

●

Demod (Constellation, EVM vs time, Phase error vs time, magnitude error vs time, modulation accuracy)

●

Spectrum (modulation, transient) including limit check

●

Automatic trigger offset detection

Restriction for auto frame configuration

Auto Frame configuration only detects AQPSK normal bursts where the subchannels have a TSC according to Table 5-3. The SCPIR value is detected with a resolution of 1 dB. To obtain reliable measurement results on AQPSK normal bursts, compare the auto-detected slot settings with the settings of your device under test.

Table 5-3: Required subchannel - TSC assignment for AQPSK auto frame configuration

AQPSK modulation

AQPSK Subchannel 2

TSC j (Set 2)

0 1 2 3 4 5 6 7

Sub cha nnel 1

TSC i (Set

TSC j (Set 1)

0 1 2 3 4 5 6 7

2 x x

3 x x

7 x x

x x

5.4 AQPSK modulation

The AQPSK modulation scheme as proposed for use in GSM systems is illustrated in

Figure 5-3. First, the bits from two users (subchannels 1 and 2) are interleaved. The

combined bit sequence is then mapped to an AQPSK constellation which depends on the SCPIR value. The AQPSK symbols are then modulated using the linearized GMSK pulse (see 3GPP TS 45.004).

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Trigger settings

Figure 5-3: AQPSK modulation scheme for GSM systems

The proposed AQPSK mapping (as assumed in the R&S VSE GSM application) is given in Table 5-4 and illustrated in Figure 5-4, where the first (leftmost) bit corre- sponds to subchannel 1 and the second (rightmost) bit corresponds to subchannel 2.

Table 5-4: AQPSK symbol mappings [reproduced from 3GPP TS 45.004]

Modulating bits for

ai, b

(0,0)

(0,1)

(1,0)

(1,1)

AQPSK symbol in polar notation

jα

-jα

-e

jα

-e

The AQPSK modulation constellation diagram is shown in Figure 5-4, where the value α is an angle related to the SCPIR as follows:

SCPIRdB = 20*log10[tan(α) ] dB

Figure 5-4: AQPSK constellation [reproduced from 3GPP TS 45.004].

5.5 Trigger settings

The GSM measurements can be performed in "Free Run" (untriggered) mode; however, an external trigger or a power trigger can speed up measurements. To perform measurements the R&S VSE GSM application needs the frame start as a time reference. The R&S VSE GSM application searches for a frame start after every I/Q data acquisition. The required search effort depends on the trigger mode.

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Defining the scope of the measurement

Consider the following trigger mode settings:

●

In "Free Run" mode, i.e. without any trigger, the R&S VSE GSM application totally relies on the frame/slot configuration to find the frame start. The start of a measurement is not triggered. Once a measurement is completed, another is started immediately. For an unambiguous frame configuration, the GSM application searches for the frame start inside the captured I/Q data. This is the slowest frame search mode.

●

With a "Power Trigger", the measurement is triggered by the power ramp of the received GSM bursts. Nevertheless the R&S VSE GSM application still relies on the frame/slot configuration to find the frame start inside the captured I/Q data. Once a measurement is completed, the R&S VSE GSM application waits for the next trigger event to start the next measurement. The search for the frame start is as in "Free Run" mode, except that the I/Q data capture is triggered.

●

With the "External Trigger", the measurement is triggered by an external signal (connected to the "EXT TRIGGER" input of the connected instrument). The R&S VSE GSM application assumes that the frame start (i.e. the "active part" in slot 0) directly follows the trigger event. An external trigger requires a correct setting of the trigger offset. The search is faster compared to the free run and power trigger modes. Use an external trigger to maximize the measurement speed or if the frame configuration is ambiguous (i.e. if the slot properties are cyclic with a cycle less than the frame duration).

Refer to Chapter 6.4, "Trigger settings", on page 83 to learn more about appropriate trigger settings and to Chapter 6.2, "Signal description", on page 60 for information on the frame/slot configuration.

Refer to "Automatic Trigger Offset" on page 98 to learn more about setting the trigger offset automatically.

5.6 Defining the scope of the measurement

The R&S VSE GSM application is slot-based. It can measure up to 8 consecutive GSM slots (1 frame) and store the power results for all slots ("Power vs Time" and "Power vs Slot" measurements, see "PvT Full Burst" on page 26 and "Power vs Slot" on page 25).

In previous Rohde & Schwarz signal and spectrum analyzers, the term "burst" was used synonymously for "slot". In this documentation, we use the term "burst" when the signal behaves like a pulse, i.e. power is ramped up and down. The up ramp is referred to as the rising edge, the down ramp as the falling edge. A burst may occur within one or more slots, which is a measure of time in the captured signal. Thus, a burst may coincide with a slot, but it must not necessarily do so.

Usually only slots in which a burst is expected are of interest. Such slots are defined as active slots in the signal description.

Within this slot scope (defined by First Slot to measure and Number of Slots to mea-

sure), a single slot ( Slot to Measure) is selected for a more detailed analysis (e.g.

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Defining the scope of the measurement

"Modulation Accuracy" measurement, see "Modulation Accuracy" on page 19). The

Slot to Measure is required for the following reasons:

●

To provide the reference power and time reference for the "Power vs Time" measurement (see "PvT Full Burst" on page 26). Typically, the masks for all slots are time-aligned according to the timing of the Slot to Measure (see "Limit Line Time

Alignment" on page 94).

●

All "Modulation Spectrum" results are based on the Slot to Measure (see "Modula-

tion Spectrum Graph" on page 21). (The results of all "Transient Spectrum" dia-

grams are based on the slot scope, i.e. on the interval defined by the First Slot to

measure and the Number of Slots to measure, see "Transient Spectrum Graph"

on page 28).

●

All results that require demodulation of one slot and statistical analysis (e.g. Modu-

lation Accuracy, Phase Error, and EVM) are based on the Slot to Measure.

The slot scope is defined in the "Demodulation Settings" (see Chapter 6.6.1, "Slot

scope", on page 88), and it is indicated by a filled green box in the "Frame Configura-

tion" (see Figure 5-6). The Slot to Measure is indicated by a filled blue box.

Frame configuration and slot scope in the channel bar

In the channel bar of the R&S VSE GSM application, as well as in the configuration "Overview", the current frame configuration and slot scope are visualized in a miniature graphic. Furthermore, the burst type and modulation of the Slot to Measure are indicated.

Figure 5-5: Frame configuration in GSM application channel bar

The graphic can be interpreted as follows:

Shape/Color Meaning

Each slot is represented by a small box

Active slots are indicated by polygonal symbols

Slots within the defined slot scope are highlighted green

The defined Slot to Measure is highlighted blue; the burst type and modulation defined for this slot are indicated to the right of the graphic

Frame configuration in the Frame and Slot Scope dialog boxes

The same graphic is displayed in the "Frame Configuration" of the "Frame" dialog box (see "Frame Configuration: Select Slot to Configure" on page 63) and in the "Slot Scope" tab of the "Demodulation" dialog box (see Chapter 6.6.1, "Slot scope", on page 88).

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Overview of filters in the R&S VSE GSM application

Figure 5-6: Frame configuration in "Slot Scope" settings

This graphic can be interpreted as follows:

●

Each slot is represented by its number (0 to 7).

●

Slot numbers within the defined slot scope are highlighted green.

●

The number of the defined Slot to Measure is highlighted blue.

●

Active slots are indicated by polygonal symbols above the number which contain the following information:

– The burst type, e.g. "Norm" for a normal burst – The modulation, e.g. GMSK – The training sequence TSC (and Set) or Sync (for access bursts)

5.7 Overview of filters in the R&S VSE GSM application

The R&S VSE GSM application requires a number of filters for different stages of signal processing. These include the "Multicarrier" filter (for multicarrier base station mea-

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Overview of filters in the R&S VSE GSM application

surements only), the "Power vs Time" filter and the "Measurement" filter. A signal flow diagram is shown in Figure 5-7 to illustrate where the different filters are used.

Figure 5-7: Signal flow diagram highlighting filtering operations

5.7.1 Power vs time filter

The "Power vs Time" filter is used to suppress out-of-band interference in the "Power vs Time" measurement (see "PvT Full Burst" on page 26).

The following filters are available:

Single-carrier filters:

●

1 MHz Gauss

●

500 kHz Gauss

●

600 kHz

Multicarrier filters:

●

400 kHz MC

●

300 kHz MC

The magnitude and step responses of the different "Power vs Time" filters are shown in

Figure 5-8 and Figure 5-9, respectively. In general, the smaller the filter bandwidth, the

worse the step response becomes (in terms of "ringing" effects) and the better the suppression of interference at higher frequencies. Gaussian type filters are especially useful for signals with "sharp" edges as the step response does not exhibit overshoot.

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Overview of filters in the R&S VSE GSM application

Figure 5-8: Magnitude response of the Power vs Time filters

Figure 5-9: Step response of the Power vs Time filters

5.7.2 Multicarrier filter

The "Multicarrier" filter is a special filter that is applied to the captured I/Q data if the device is defined as a multicarrier type (see "Device Type" on page 61). This filter is used to suppress neighboring channels which may disturb measurement of the channel of interest. The output from the "Multicarrier" filter is used to perform synchronization and demodulation. The frequency response of the "Multicarrier" filter is shown in

Figure 5-10.

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5.7.3 Measurement filter

Basics on GSM measurements

Overview of filters in the R&S VSE GSM application

Figure 5-10: Frequency response of the Multicarrier filter

The "Measurement" filter is used to limit the bandwidth of the demodulation measurements and is described in the 3GPP standard document TS 45.005 for QPSK, 8PSK, 16QAM and 32QAM as follows:

●

a raised-cosine filter with roll-off 0.25 and single side-band 6 dB bandwidth 90 kHz for normal symbol rate and for higher symbol-rate using narrow bandwidth pulseshaping filter

●

a raised-cosine filter with roll-off 0.25 and single side-band 6 dB bandwidth 108 kHz for higher symbol-rate using wide bandwidth pulse-shaping filter

In addition to these filters, a "Measurement" filter for GMSK is used in the R&S VSE GSM application to limit the effects of out-of-band interference due to the high sample rate of 6.5 MHz which is used. The magnitude responses of all the "Measurement" filters are shown in Figure 5-11.

Figure 5-11: Magnitude responses of Measurement filters for demodulation measurements

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









iTt

duught

)()'(



5.8 Dependency of slot parameters

Basics on GSM measurements

Definition of the symbol period

The parameters that define a slot used for a GSM measurement are dependent on each other, and only the following combinations of these parameters are available in the R&S VSE GSM application (see Chapter 6.2.3, "Slot settings", on page 63).

Table 5-5: Dependency of slot parameters

Burst Type Modulation Filter TSC

AB GMSK GMSK Pulse TS 0, TS 1, TS 2

User

HSR QPSK, 16QAM, 32QAM Narrow Pulse,

Wide Pulse

NB 8PSK, 16QAM, 32QAM Linearized GMSK Pulse TSC 0, …, TSC 7

AQPSK Linearized GMSK Pulse Subchannel 1:

GMSK GMSK Pulse TSC 0 (Set 1), …, TSC 7 (Set 1),

5.9 Definition of the symbol period

TSC 0, …, TSC 7

User

TSC 0 (Set 1), …, TSC 7 (Set 1) Subchannel 2: TSC 0 (Set 1), …, TSC 7 (Set 1), TSC 0 (Set 2), …, TSC 7 (Set 2)

Subchannel 1: User Subchannel 2: User

TSC 0 (Set 2), …, TSC 7 (Set 2)

User

The following sections define the symbol period for various modulation types.

5.9.1 GMSK modulation (normal symbol rate)

The GMSK frequency pulse is defined in the standard document "3GPP TS 45.004" as a Gaussian pulse convolved with a rectangular pulse, as illustrated at the top of Fig-

ure 5-12. The phase of a GMSK signal due to a sequence of symbols {α} is defined in

the standard as:

Equation 5-1: Phase of a GMSK signal due to a sequence of symbols

where:

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Definition of the symbol period

●

g(t): the frequency pulse

●

T: the normal symbol period

The modulating index is chosen such that the maximum phase change of π/2 radians per data interval is achieved.

Note that the standard 3GPP TS 45.004 specifies in chapter "2.5 Output phase" for Normal Burst GMSK:

"The time reference t' = 0 is the start of the active part of the burst as shown in figure 1.

This is also the start of the bit period of bit number 0 (the first tail bit) as defined in 3GPP TS 45.002."

The phase change due to the first tail symbol is illustrated at the bottom of Figure 5-12, where you can see that the "decision instant" corresponding to the center of the frequency pulse occurs at the beginning of the first symbol period, i.e. at t' = 0."

Figure 5-12: GMSK frequency pulse (top) and phase of the first tail symbol (bottom)

5.9.2 8PSK, 16QAM, 32QAM, AQPSK modulation (normal symbol rate)

The EDGE transmit pulse is defined in the standard document "3GPP TS 45.004" as a linearized GMSK pulse, as illustrated at the top of Figure 5-13. Note that according to the definition in the standard, the center of the pulse occurs at 2.5 T, where T is the normal symbol period (NSP). The baseband signal due to a sequence of symbols { } is defined in the standard as:

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



TiTtcsty )'(

)'( 2

Basics on GSM measurements

Definition of the symbol period

Equation 5-2: Baseband signal due to a sequence of symbols

where:

c0(t): the transmit pulse

Note that the standard 3GPP TS 45.004 specifies in chapter "3.5 Pulse shaping" for normal burst 8PSK, 16QAM and 32QAM:

"The time reference t' = 0 is the start of the active part of the burst as shown in figure 3.

This is also the start of the symbol period of symbol number 0 (containing the first tail bit) as defined in 3GPP TS 45.002."

For normal burst AQPSK, the standard 3GPP TS 45.004 specifies in chapter "6.5 Pulse shaping":

"The time reference t' = 0 is the start of the active part of the burst as shown in figure 6.

This is also the start of the symbol period of symbol number 0 (containing the first tail bit) as defined in 3GPP TS 45.002."

The transmitted pulse for the first tail symbol is illustrated in the lower part of Fig-

ure 5-13, where it can be seen that the "decision instant" corresponding to the center

of the transmit pulse occurs in the center of the first symbol period, i.e. at t'=0.5T.

Figure 5-13: EDGE transmit pulse (top) and the first transmitted symbol (bottom)

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

TiTtcsty ).'(

)'( 52

5.9.3 QPSK, 16QAM and 32QAM modulation (higher symbol rate)

Basics on GSM measurements

Definition of the symbol period

The description above also applies to the 16QAM and 32QAM modulations defined for EDGE Evolution, using the "normal" symbol rate.

For the newer "reduced" symbol period (higher symbol rate) the standard document "3GPP TS 45.004" defines two transmit pulse shapes; the so-called "narrow" and "wide" pulses. The narrow pulse is the same linearized GMSK pulse as described in

Chapter 5.9.2, "8PSK, 16QAM, 32QAM, AQPSK modulation (normal symbol rate)",

on page 47, while the wide pulse was designed based on a numerically optimized set of discrete filter coefficients. Both narrow and wide pulse shapes are illustrated at the top of Figure 5-14, where you can see that the center of the pulse occurs at 3T, with T being the reduced symbol period. For a sequence of symbols { nal is defined in the standard as:

}, the transmitted sig-

Equation 5-3: The transmitted signal for a sequence of symbols

where:

c(t): the transmit pulse(which may be either the narrow or wide pulse)

Note that the standard 3GPP TS 45.004 specifies in chapter "5.5 Pulse shaping" for higher symbol rate burst QPSK, 16QAM and 32QAM:

"The time reference t' = 0 is the start of the active part of the burst as shown in figure 3.

This is also the start of the symbol period of symbol number 0 (containing the first tail bit) as defined in 3GPP TS 45.002."

The transmitted pulse for the first tail symbol is illustrated at the bottom of Figure 5-14, where you can see that the "decision instant" corresponding to the center of the transmit pulse occurs in the center of the first symbol period, i.e. at t'=0.5T.

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Synchronization

Figure 5-14: EDGE Evolution transmit pulses (top) and the first transmitted symbols (bottom)

5.10 Synchronization

In order to detect and distinguish the individual slots and frames in the measured signal, the known signal sequence (Sync or TSC) must be found in each frame.

The synchronization process in the R&S VSE GSM application depends on how or if the measurement is triggered.

Synchronization process for power trigger or free run mode

If a power trigger or no trigger is used (free run mode), the synchronization process consists of the following steps:

1. Beginning at the start of a capture, the application searches for the synchronization

pattern (or TSC) of the Slot to Measure within one GSM frame length. This search must be performed over the entire area, as the time of occurrence of the TSC within the signal is not known. Thus, it is referred to as a "wide" search.

2. Once the synchronization point has been found, the application checks whether

enough samples remain in the capture buffer in order to analyze another frame. If so, the process continues with the next step. Otherwise, a new capture is started and the process begins with step 1 again.

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Synchronization

3. Assuming the signal is periodic, the synchronization point in the signal is moved by

exactly one GSM frame length. From there, a "narrow" search for the next TSC is performed within only a small search area. Thus, the remaining frames in the capture buffer can be synchronized quickly after the initial "wide" search. Steps 2 and 3 are repeated until all frames have been detected.

Figure 5-15: Synchronization using "wide" and "narrow" searches

Synchronization errors

The process described above assumes the GSM frame length in the signal is periodic (within a given tolerance: "frame length error"). If this is not the case, however, for example if a frame is too short, the application cannot synchronize to further frames after the initial search.

Frequency hopping can lead to the same problem, as successive frames may not be detected on the measured frequency channel.

Figure 5-16: Failed synchronization due to frame length error and resulting false search area

A special "Measure only on sync" option ensures that only those sections of the captured signal are processed further for which synchronization was possible, thus improving performance.

For frequency-hopping signals, it is recommended that you use a power trigger to ensure capture starts with an active frame.

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5.11 Timeslot alignment

Basics on GSM measurements

Timeslot alignment

External trigger

When using an external trigger source, the application assumes that the trigger offset is set such that the GSM frame start is aligned with the start of a capture. Therefore only "narrow" searches are performed from the beginning of the Synchronization proc-

ess for power trigger or free run mode.

Reference Time

The definition of a "reference time" is necessary for the following description of timeslot alignment. In the standard document "3GPP TS 45.010", in Section 5.7 it is stated that:

"Irrespective of the symbol duration used, the center of the training sequence shall occur at the same point in time. "

This is illustrated in Figure 5.7.3 of the standard document "3GPP TS 45.010" which is reproduced below for convenience (Figure 5-17). Due to this requirement, the "middle of TSC" or "center of Active Part" shall be used as the reference time when specifying timeslot alignment. Additionally, the "middle of TSC" is used for the alignment of the Power vs Time limit masks (see also "Limit Line Time Alignment" on page 94).

Figure 5-17: Timing alignment between normal symbol period and reduced symbol period bursts

As described in Chapter 5.9, "Definition of the symbol period", on page 46, the middle of TSC can be defined with respect to symbol periods and symbol decision instants. This is illustrated in Figure 5-18. You can see that for normal symbol period bursts (Normal bursts), the middle of TSC for GMSK occurs exactly at the decision instant of symbol 74. However, for EDGE it occurs between the decision instants of symbols 73 and 74, while for reduced symbol period bursts (Higher Symbol Rate bursts), it occurs exactly at the decision instant of symbol 88.

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Timeslot alignment

Figure 5-18: Middle of TSC for normal and reduced symbol period bursts.

Timeslot alignment within the frame

The standard document "3GPP TS 45.010" provides details on the alignment of slots within the GSM frame:

"Optionally, the BTS may use a timeslot length of 157 normal symbol periods on timeslots with TN = 0 and 4, and 156 normal symbol periods on timeslots with TN = 1, 2, 3, 5, 6, 7, rather than 156.25 normal symbol periods on all timeslots"

The alignment of slots therefore falls under the "Not Equal Timeslot Length" (Equal Timeslot Length = off) or the "Equal Timeslot Length" (Equal Timeslot Length = on) criterion (see also "Equal Timeslot Length" on page 63), which are illustrated in Fig-

ure 5-19.

Figure 5-19: "Not equal"(top) and "equal" (bottom) timeslot length criteria

Note that, since the reference point at the "middle of TSC" of each slot must coincide, the length of the guard interval between successive bursts will depend on both the

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Delta to sync values

timeslot length and the symbol rate of bursts in successive slots. As stated in the standard "3GPP TS 45.010", for the "Equal Timeslot Length" case:

"… if there is a pair of different symbol period bursts on adjacent timeslots, then the guard period between the two bursts shall be 8.5 normal symbol periods which equals

10.2 reduced symbol periods."

For the "Not Equal Timeslot Length" case, deriving the guard period length is somewhat more complicated, and the possible values are summarized in Table 5.7.2 of "3GPP TS 45.010", reproduced below as Guard period lengths between different time-

slots, for convenience:

Table 5-6: Guard period lengths between different timeslots

Burst Transition Guard Period Between Timeslots (In

terms of normal symbol periods)

normal symbol period to

normal symbol period

normal symbol period to

reduced symbol period

reduced symbol period to

normal symbol period

reduced symbol period to

reduced symbol period

TS0 and TS1 or

TS4 and TS5

9 8 10.8 9.6

9.25 8.25 11.1 9.9

9.5 8.5 11.4 10.2

Any other timeslot pair

Guard Period Between Timeslots (In terms of reduced symbol periods)

TS0 and TS1 or

TS4 and TS5

Any other timeslot pair

5.12 Delta to sync values

The "Delta to Sync" value is defined as the distance between the mid of the TSC and the TSC of the Slot to Measure.

The results are provided in the unit NSP, which stands for Normal Symbol Period, i.e. the duration of one symbol using a normal symbol rate (approx. 3.69μs). The measured "Delta to Sync" values have a resolution of 0.02 NSP.

These values are either assumed to be constant (according to the 3GPP standard) or measured, depending on the setting of the Limit Line Time Alignment parameter ("Slot to measure" or "Per Slot").

According to the standard (see "Timeslot length" in 3GPP TS 45.010), there are either eight slots of equal length (156.25 NSP), or slot 0 and slot 4 have a length of 157 NSP

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Limit checks

while all other slots have a length of 156 NSP. For details see Chapter 5.11, "Timeslot

alignment", on page 52.

The timeslot length is defined as the distance between the centers of the TSCs in successive slots. By setting the "Limit Time Alignment" parameter to "Per Slot", the "Delta to Sync" values can be measured and used in order to verify the timeslot lengths.

Setting the Limit Line Time Alignment to "Slot to measure" displays the expected values (according to the standard and depending on the value of Equal Timeslot Length). These values are summarized in Expected "Delta to Sync" values in normal symbol

periods (Slot to measure = 0, No. of slots = 8 and First slot to measure = 0).

Table 5-7: Expected "Delta to Sync" values in normal symbol periods

Slot Number

Equal Timeslot Length = On

Equal Timeslot Length = Off

0 = Slot to measure

0 156.25 312.50 468.75 625.00 781.25 937.50 1093.75

0 157 313 469 625 782 938 1094

1 2 3 4 5 6 7

5.13 Limit checks

● Limit check for modulation spectrum.......................................................................55

● Limit check for transient spectrum.......................................................................... 56

● Limit check for power vs time results...................................................................... 56

5.13.1 Limit check for modulation spectrum

The determined "Modulation Spectrum" values in the average (Avg) trace can be checked against limits defined by the standard; the limit lines and the result of the limit check are indicated in the "Modulation Spectrum" diagram (see "Modulation Spectrum

Graph" on page 21).

The GSM standards define both absolute and relative limits for the spectrum. The limit check is considered to fail if both limits are exceeded.

The limits depend on the following parameters:

●

Frequency band

●

Device Type (only BTS type, not MS type)

●

Burst Type / Modulation / Filter - limits are different for Higher Symbol Rate and Wide Pulse Filter (case 2) and others (case 1), see 3GPP TS 45.005, chapter

4.2.1.3

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5.13.2 Limit check for transient spectrum

Basics on GSM measurements

Limit checks

●

The measured reference power (30 kHz bandwidth)

●

The measured burst power (power level)

●

Number of active carriers for multicarrier BTS. The limit is relaxed by 10*log10(N) dB for offset frequencies ≥1.8 MHz, see 3GPP TS 45.005 chapter 4.2.1.2

The determined "Transient Spectrum Accuracy" values can be checked against limits defined by the standard; the limit lines and the result of the limit check are indicated in the "Transient Spectrum" diagram (see "Transient Spectrum Graph" on page 28).

The limits depend on the following parameters:

●

Graph: Limit check of maximum (Max) trace

●

Table: Limit check of absolute and relative scalar values

●

The limit masks are generated adaptively from the measured signal.

●

The limits depend on the following parameters: – Frequency band (not for MS) – Burst Type / Modulation / Filter (not for MS) – The measured reference (slot) power

5.13.3 Limit check for power vs time results

The determined "Power vs Time" values can be checked against limits defined by the standard; the limit lines and the result of the limit check are indicated in the "Power vs Time" diagram (see "PvT Full Burst" on page 26) and in the "Power vs Slot" table (see

"Power vs Slot" on page 25).

The limits depend on the following parameters:

●

The maximum (Max) trace is checked against the upper limit.

●

The minimum (Min) trace is checked against the lower limit.

●

The limit masks are generated adaptively from the measured signal according to the following parameters:

– Frequency band (special masks for PCS1900 and DCS1800 BTS with GMSK) – Burst type – Modulation – Filter – The reference burst power is measured and the "0 dB line" of the limit mask is

assigned to it.

– For MS, the "-6 dB line" of the limit mask depends on the PCL. The PCL is

derived from the measured burst power.

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5.14 Impact of the "Statistic count"

Basics on GSM measurements

Impact of the "Statistic count"

Generally, the "Statistic Count" defines how many measurements (or: analysis steps) are performed - equivalent to the "Sweep Count" in applications that perform sweeps.

In particular, the "Statistic Count" defines the number of frames to be included in statistical evaluations. For measurements on the Slot to Measure, the same slot is evaluated in multiple frames, namely in the number specified by the "Statistic Count", for statistical evaluations.

For Trigger to Sync measurements, where only one result is calculated per data acquisition, the "Statistic Count" determines how many values are considered for averaging.

Statistic count for Trigger to Sync vs other measurements

As mentioned above, the "Statistic Count" for Trigger to Sync measurements refers to the number of data acquisitions, whereas for all other measurements, the value refers to the number of frames. Since usually more than one frame is captured per data acquisition, the number of data acquisitions required to obtain the required number of results (the "Statistic Count") may vary considerably. If both Trigger to Sync and other result types are active at the same time, the latter are finished first and the traces (in particular the current measurement trace) remains unchanged until the Trigger to Sync measurement has also finished. The counter in the channel bar counts the "slower" of the two events, i.e. the number of measurements if a Trigger to Sync result display is active.

Tip: You can query the current value of the counter for both Trigger to Sync and other measurements in remote control, as well. See [SENSe:]SWEep:COUNt:TRGS:

CURRent? on page 192.

Obviously, the "Statistic Count" has an impact on all results and values that are re-calculated after each measurement. The higher the count, the more values are taken into consideration, and the more likely the result of the calculation will converge to a stable value. On the other hand, the fewer measurements are considered, the higher the variance of the individual results, and the less reliable the calculation result will be.

For instance, if the "Statistic Count" is set to values smaller than 5, the measured reference power for "Modulation Spectrum Table" (see "Modulation Spectrum Table" on page 22) and "Transient Spectrum Table" (see "Transient Spectrum Table" on page 29) measurements increases. This leads to a higher variance of the measured relative powers at the offset frequencies, and thus to a reduced measurement dynamic.

For the Power vs Time (see "PvT Full Burst" on page 26) and "Power vs Slot" (see

"Power vs Slot" on page 25) measurements, a small "Statistic Count" increases the

variance of the measured slot powers. The slot power is required to calculate the PVT limit lines.

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6 Modulation accuracy measurement configu-

Modulation accuracy measurement configuration

Configuration overview

ration

GSM measurements require a special application on the R&S VSE.

Multiple access paths to functionality

The easiest way to configure a measurement channel is via the "Overview" dialog box, which is displayed when you select the "Overview" icon from the main toolbar or the "Meas Setup" > "Overview" menu item.

Alternatively, you can access the individual dialog boxes from the corresponding menu items, or via tools in the toolbars, if available.

In this documentation, only the most convenient method of accessing the dialog boxes is indicated - usually via the "Overview". For an overview of all available menu items and toolbar icons see Chapter A, "Annex: reference", on page 293.

General R&S VSE functions

The application-independent functions for general tasks on the R&S VSE are also available for GSM measurements and are described in the R&S VSE Base Software User Manual. In particular, this comprises the following functionality:

●

Controlling Instruments and Capturing I/Q Data

●

Data Management

●

General Software Preferences and Information

● Configuration overview............................................................................................58

● Signal description....................................................................................................60

● Input, output and frontend settings..........................................................................69

● Trigger settings....................................................................................................... 83

● Data acquisition.......................................................................................................86

● Demodulation..........................................................................................................88

● Measurement settings.............................................................................................93

● Adjusting settings automatically.............................................................................. 97

● Result configuration................................................................................................ 98

6.1 Configuration overview

Access: "Meas Setup" > "Overview"

Throughout the measurement channel configuration, an overview of the most important currently defined settings is provided in the "Overview".

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Configuration overview

Figure 6-1: Configuration "Overview" for Modulation Accuracy measurement

In addition to the main measurement settings, the "Overview" provides quick access to the main settings dialog boxes. The individual configuration steps are displayed in the order of the data flow. Thus, you can easily configure an entire measurement channel from input over processing to output and analysis by stepping through the dialog boxes as indicated in the "Overview".

In particular, the "Overview" provides quick access to the following configuration dialog boxes (listed in the recommended order of processing):

1. Signal Description

See Chapter 6.2, "Signal description", on page 60

2. Input and Frontend Settings

See Chapter 6.3, "Input, output and frontend settings", on page 69

3. Triggering

See Chapter 6.4, "Trigger settings", on page 83

4. Data Acquisition

See Chapter 6.5, "Data acquisition", on page 86

5. Demodulation Settings

See Chapter 6.6, "Demodulation", on page 88

6. Measurement Settings

See Chapter 6.7, "Measurement settings", on page 93

7. Result Configuration

See Chapter 6.9, "Result configuration", on page 98

8. Display Configuration

See "Result display windows" on page 16

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Modulation accuracy measurement configuration

Signal description

To configure settings

► Select any button to open the corresponding dialog box. The corresponding dialog

box is opened with the focus on the selected setting.

For step-by-step instructions on configuring GSM measurements, see Chapter 7, "How

to perform measurements in the GSM application", on page 109.

Preset Channel

Select the "Preset Channel" button in the lower left-hand corner of the "Overview" to restore all measurement settings in the current channel to their default values.

Remote command:

SYSTem:PRESet:CHANnel[:EXEC] on page 125

Select Measurement

Selects a measurement to be performed.

Specifics for

The channel can contain several windows for different results. Thus, the settings indicated in the "Overview" and configured in the dialog boxes vary depending on the selected window.

Select an active window from the "Specifics for" selection list that is displayed in the "Overview" and in all window-specific configuration dialog boxes.

The "Overview" and dialog boxes are updated to indicate the settings for the selected window.

6.2 Signal description

Access: "Overview" > "Signal Description"

The signal description provides information on the expected input signal, which optimizes frame detection and measurement.

● Device under test settings.......................................................................................60

● Frame......................................................................................................................62

● Slot settings.............................................................................................................63

● Carrier settings........................................................................................................67

6.2.1 Device under test settings

Access: "Overview" > "Signal Description" > "Device"

The type of device to be tested provides additional information on the signal to be expected.

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Signal description

Device Type.................................................................................................................. 61

Frequency Band............................................................................................................61

Power Class..................................................................................................................62

Maximum Output Power per Carrier (multicarrier measurements only)........................62

Device Type

Defines the type of device under test (DUT). The following types are available:

●

BTS Normal

●

BTS Micro

●

BTS Pico

●

MS Normal

●

MS Small

●

Multicarrier BTS Wide Area

●

Multicarrier BTS Medium Range

●

Multicarrier BTS Local Area The default device type is "BTS Normal". Remote command:

CONFigure[:MS]:DEVice:TYPE on page 126

Frequency Band

The frequency band defines the frequency range used to transmit the signal. For details see "Frequency bands and channels" on page 34. The following frequency bands are supported:

●

DCS 1800

●

E-GSM 900

●

GSM 450

●

GSM 480

●

GSM 710

●

GSM 750

●

GSM 850

●

PCS 1900

●

P-GSM 900

●

R-GSM 900

●

T-GSM 380

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●

T-GSM 410

●

T-GSM 810

●

T-GSM 900 The default frequency band is "E-GSM 900". Remote command:

CONFigure[:MS]:NETWork[:TYPE] on page 127 CONFigure[:MS]:NETWork:FREQuency:BAND on page 127

Power Class

The following power classes are supported:

●

1, …, 8 (BTS)

●

1, …,5 (MS: GMSK)

●

E1, E2, E3 (MS: all except GMSK)

●

M1, M2, M3 (Micro BTS)

●

P1 (Pico BTS) The default power class is 2. Remote command:

CONFigure[:MS]:POWer:CLASs on page 128

Signal description

Maximum Output Power per Carrier (multicarrier measurements only)

Defines the maximum output power per carrier, which determines the limit lines for the modulation spectrum.

In "Auto" mode, the maximum measured power level for the carriers is used. This setting is only available for multicarrier measurements. Remote command:

CONFigure[:MS]:POWer:PCARrier:AUTO on page 129 CONFigure[:MS]:POWer:PCARrier on page 129

6.2.2 Frame

Access: "Overview" > "Signal Description" > "Frames"

Frame settings determine the frame configuration used by the device under test.

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Equal Timeslot Length

This parameter is only taken into account if "Limit Time Alignment" is set to "Slot to measure" (see "Limit Line Time Alignment" on page 94).

If activated, all slots of a frame are considered to have the same length (8 x 156.26 normal symbol periods).

In this case, the limit line for each slot (required for the "Power vs Time" spectrum masks) is aligned by measuring the TSC of the Slot to Measure only, and using this value to align the limit line for all slots in the frame (see also "PvT Full Burst" on page 26).

If deactivated, slots number 0 and 4 of a frame have a longer duration, all others have a shorter duration compared to the "Equal Timeslot Length" (157, 156, 156, 156, 157, 156, 156, 156 normal symbol periods).

See GPP TS 51.021 and 3GPP TS 45.010 chapter "6.7 Timeslot length" for further details.

Remote command:

CONFigure[:MS]:CHANnel:FRAMe:EQUal on page 130

Frame Configuration: Select Slot to Configure

This area shows a graphical representation of the configuration of each slot. Select a slot to display its "Slot" dialog box (see Chapter 6.2.3, "Slot settings", on page 63).

For active slots the following information is shown:

●

The burst type, e.g. "Normal (NB)" for a normal burst.

●

The modulation, e.g. GMSK.

●

The training sequence TSC (and Set) For details on how to interpret the graphic, see "Frame configuration and slot scope in

the channel bar" on page 41.

6.2.3 Slot settings

Access: "Overview" > "Signal Description" > "Slot"> "Slot1"/.../"Slot7"

The individual slots are configured on separate tabs. The dialog box for the selected slot is displayed directly when you select a slot in the "Frame Configuration" graphic on the "Frame" tab (see "Frame Configuration: Select Slot to Configure" on page 63).

Slot structure display

The basic slot structure according to the selected Frequency Band and Power Class is displayed graphically for reference.

White fields indicate unknown data; colored fields indicate known symbol sequences.

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Signal description

The slot settings vary slightly for different burst types.

Figure 6-2: Slot configuration for normal and higher symbol rate bursts

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Figure 6-3: Slot configuration for access burst

The "Slot" settings are dependant on each other, and only specific combinations of these parameters are available in this dialog box (see Chapter 5.8, "Dependency of

slot parameters", on page 46).

Slot State (On/Off)

Activates or deactivates the selected slot. The R&S VSE GSM application expects an input signal within the active slots only.

At least the Slot to Measure must be active in order to evaluate it. Remote command:

CONFigure[:MS]:CHANnel:SLOT<Number>[:STATe] on page 131

Burst Type

Assigns a burst type to the selected slot. The following burst types are supported:

●

Normal (NB)

●

Higher Symbol Rate (HB)

●

Access (AB) The graphical slot structure is adapted according to the selected burst type. Note: The "Slot" settings are dependant on each other, and only specific combinations

of these parameters are available in this dialog box (see Chapter 5.8, "Dependency of

slot parameters", on page 46).

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Remote command:

CONFigure[:MS]:CHANnel:SLOT<Number>:TYPE on page 136

Modulation

Defines the modulation used in the slot. The possible modulations depend on the set burst type (see Chapter 5.8, "Dependency

of slot parameters", on page 46).

The graphical slot structure is adapted according to the selected modulation. Remote command:

CONFigure[:MS]:CHANnel:SLOT<Number>:MTYPe on page 131

SCPIR

This parameter is only available for AQPSK modulation. It specifies the Subchannel Power Imbalance Ratio (SCPIR). The value of SCPIR

affects the shape of the AQPSK constellation (see Chapter 5.4, "AQPSK modulation", on page 38). For an SCPIR of 0 dB the constellation is square (as in "normal" QPSK), while for other values of SCPIR the constellation becomes rectangular.

Remote command:

CONFigure[:MS]:CHANnel:SLOT<s>:SCPir on page 132

Filter

Specifies the pulse shape of the modulator on the DUT and thus the measurement filter in the R&S VSE GSM application.

(For details see Chapter 5.7.3, "Measurement filter", on page 45). The following filter types are supported for normal and higher symbol rate bursts:

●

GMSK Pulse

●

Linearized GMSK Pulse

●

Narrow Pulse

●

Wide Pulse For access bursts, only a GMSK Pulse filter is supported. Remote command:

CONFigure[:MS]:CHANnel:SLOT<Number>:FILTer on page 130

Timing Advance (Access Burst only)

Specifies the position of an access burst within a single slot as an offset in symbols from the slot start.

Remote command:

CONFigure[:MS]:CHANnel:SLOT<Number>:TADVance on page 134

Training Sequence TSC[/]Sync

(Note: for Access bursts, this setting is labeled "Sync", but the functionality is the same.)

The "Training Sequence TSC" or "Sync" values are known symbol sequences used to synchronize the measured signal with the expected input signal in a single slot.

The available values depend on the modulation as indicated in the table below.

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Signal description

For user-defined TSCs, select "User" and define the training sequence in the User

TSC[/]User Sync table.

For more information on TSCs see "Training sequences (TSCs)" on page 37. Remote command:

CONFigure[:MS]:CHANnel:SLOT<s>:TSC on page 134

AQPSK:

CONFigure[:MS]:CHANnel:SLOT<s>:SUBChannel<ch>:TSC on page 133

User TSC[/]User Sync

(Note: for Access bursts, this setting is labeled "User Sync", but the functionality is the same.)

Defines the bits of the user-defined TSC or Sync. The number of bits depend on the burst type and the modulation and is indicated in Table 6-1.

For AQPSK modulation, the training sequence is defined for each subchannel, see

Chapter 5.4, "AQPSK modulation", on page 38.

Note:

As the "User TSC" table in the dialog box only displays 25 bits at a time, a scrollbar beneath the table allows you to display the remaining bits. The currently selected bit number is indicated in the center of the scrollbar.

Table 6-1: Number of TSC bits depending on burst type and modulation

Burst Type Modulation Number of Bits

Normal GMSK 26

Normal 8PSK 78

Normal 16QAM 104

Normal 32QAM 130

Higher Symbol Rate QPSK 62

Higher Symbol Rate 16QAM 124

Higher Symbol Rate 32QAM 155

Access GMSK 41

Remote command:

CONFigure[:MS]:CHANnel:SLOT<s>:TSC:USER on page 136

AQPSK:

CONFigure[:MS]:CHANnel:SLOT<s>:SUBChannel<ch>:TSC:USER on page 133

6.2.4 Carrier settings

Access: "Overview" > "Signal Description" > "Carriers"

The "Carrier" settings define whether the expected signal contains a single or multiple carriers. Multiple carriers can only be defined if a multicarrier Device Type is selected (see Chapter 6.2.1, "Device under test settings", on page 60.

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Signal description

Carrier Allocation...........................................................................................................68

Gap start after carrier (Non-contiguous carriers only)...................................................68

Active carriers............................................................................................................... 68

Frequency..................................................................................................................... 69

Modulation.....................................................................................................................69

Carrier Allocation

Defines whether a multicarrier measurement setup contains one subblock of regularly spaced carriers only (contiguous), or two subblocks of carriers with a gap in-between (non-contiguous).

Remote command:

CONFigure[:MS]:MCARrier:FALLocation[:MODE] on page 139

Gap start after carrier (Non-contiguous carriers only)

For non-contiguous setups (see Carrier Allocation) the position of the gap must be defined as the number of the active carrier after which the gap starts.

Remote command:

CONFigure[:MS]:MCARrier:FALLocation:NCONtiguous:GSACarrier

on page 139

Active carriers

Defines which of the defined carriers are active for the current measurement. Remote command:

CONFigure[:MS]:MCARrier:CARRier<c>[:STATe]? on page 137

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6.3 Input, output and frontend settings

Modulation accuracy measurement configuration

Input, output and frontend settings

Frequency

Defines the absolute frequency of each (active) carrier. Remote command:

CONFigure[:MS]:MCARrier:CARRier<c>:FREQuency on page 137

Modulation

Defines the burst type, modulation and pulse shape filter of each (active) carrier. For possible combinations see Chapter 5.8, "Dependency of slot parameters",

on page 46. Note: This setting determines the appropriate limits from the 3GPP standard. Remote command:

CONFigure[:MS]:MCARrier:CARRier<c>:MTYPe on page 138

Access: "Overview" > "Input/Frontend"

The R&S VSE can evaluate signals from different input sources and provide various types of output (such as noise or trigger signals).

Output settings are described in the R&S VSE Base Software User Manual.

● Input source settings...............................................................................................69

● Frequency settings..................................................................................................77

● Amplitude settings...................................................................................................80

6.3.1 Input source settings

Access: "Overview" > "Input/Frontend" > "Input Source"

Or: "Input & Output" > "Input Source"

The R&S VSE can control the input sources of the connected instruments.

● Radio frequency input............................................................................................. 69

● I/Q file input.............................................................................................................75

6.3.1.1 Radio frequency input

Access: "Overview" > "Input/Frontend" > "Input Source" > "Radio Frequency"

Or: "Input & Output" > "Input Source" > "Radio Frequency"

The default input source for the connected instrument is "Radio Frequency". Depending on the connected instrument, different input parameters are available.

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Input, output and frontend settings

Figure 6-4: RF input source settings for an R&S FSW with B2000 option

If the Frequency Response Correction option (R&S VSE-K544) is installed, the R&S VSE GSM application also supports frequency response correction using Touchstone (.snp) files or .fres files.

For details on user-defined frequency response correction, see the R&S VSE Base Software User Manual.

Input Type (Instrument / File)........................................................................................70

Instrument..................................................................................................................... 71

Input 1 / Input 2............................................................................................................. 71

Input Coupling ..............................................................................................................71

Impedance ................................................................................................................... 71

Direct Path ................................................................................................................... 72

High Pass Filter 1 to 3 GHz ..........................................................................................72

YIG-Preselector ............................................................................................................72

Capture Mode............................................................................................................... 73

B2000 State.................................................................................................................. 73

Oscilloscope Sample Rate............................................................................................73

Oscilloscope Splitter Mode............................................................................................74

Oscilloscope IP Address............................................................................................... 74

Preselector State...........................................................................................................74

Preselector Mode..........................................................................................................75

10 dB Minimum Attenuation..........................................................................................75

Input Type (Instrument / File)

Selects an instrument or a file as the type of input provided to the channel.

Note: External mixers are only available for input from a connected instrument.

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Input, output and frontend settings

Note: If the R&S VSE software is installed directly on an instrument, or integrated in Cadence®AWR®VSS, some restrictions apply on the available input type.

Remote command:

INSTrument:BLOCk:CHANnel[:SETTings]:SOURce<si> on page 147 INPut<ip>:SELect on page 146

Instrument

Specifies a configured instrument to be used for input.

Input 1 / Input 2

For instruments with two input connectors, you must define which input source is used for each measurement channel.

Note that you cannot use both RF inputs simultaneously. "Input 1"

R&S FSW85: 1.00 mm RF input connector for frequencies up to 85 GHz (90 GHz with option R&S FSW-B90G)

"Input2"

Remote command:

INPut<ip>:TYPE on page 147

Input Coupling

The RF input of the R&S VSE can be coupled by alternating current (AC) or direct current (DC).

The RF input of the connected instrument can be coupled by alternating current (AC) or direct current (DC).

AC coupling blocks any DC voltage from the input signal. AC coupling is activated by default to prevent damage to the instrument. Very low frequencies in the input signal can be distorted.

However, some specifications require DC coupling. In this case, you must protect the instrument from damaging DC input voltages manually. For details, refer to the data sheet.

Remote command:

INPut<ip>:COUPling<ant> on page 141

Impedance

For some measurements, the reference impedance for the measured levels of the connected instrument can be set to 50 Ω or 75 Ω.

R&S FSW85: 1.85 mm RF input connector for frequencies up to 67 GHz

For GSM and Avionics measurements, the impedance is always 50 Ω and cannot be changed.

Select 75 Ω if the 50 Ω input impedance is transformed to a higher impedance using a 75 Ω adapter of the RAZ type. (That corresponds to 25Ω in series to the input impedance of the instrument.) The correction value in this case is 1.76 dB = 10 log (75Ω/ 50Ω).

Remote command:

INPut<ip>:IMPedance<ant> on page 143

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Input, output and frontend settings

Direct Path

Enables or disables the use of the direct path for small frequencies. In spectrum analyzers, passive analog mixers are used for the first conversion of the

input signal. In such mixers, the LO signal is coupled into the IF path due to its limited isolation. The coupled LO signal becomes visible at the RF frequency 0 Hz. This effect is referred to as LO feedthrough.

To avoid the LO feedthrough the spectrum analyzer provides an alternative signal path to the A/D converter, referred to as the direct path. By default, the direct path is selected automatically for RF frequencies close to zero. However, this behavior can be disabled. If "Direct Path" is set to "Off" , the spectrum analyzer always uses the analog mixer path.

"Auto"

"Off" Remote command:

INPut<ip>:DPATh on page 141

(Default) The direct path is used automatically for frequencies close to zero.

The analog mixer path is always used.

High Pass Filter 1 to 3 GHz

Activates an additional internal highpass filter for RF input signals from 1 GHz to 3 GHz. This filter is used to remove the harmonics of the analyzer to measure the harmonics for a DUT, for example.

For some connected instruments, this function requires an additional hardware option on the instrument.

Note: For RF input signals outside the specified range, the high-pass filter has no effect. For signals with a frequency of approximately 4 GHz upwards, the harmonics are suppressed sufficiently by the YIG-preselector, if available.)

Remote command:

INPut<ip>:FILTer:HPASs[:STATe] on page 142

YIG-Preselector

Enables or disables the YIG-preselector. This setting requires an additional option on the connected instrument. An internal YIG-preselector at the input of the connected instrument ensures that

image frequencies are rejected. However, image rejection is only possible for a restricted bandwidth. To use the maximum bandwidth for signal analysis you can disable the YIG-preselector at the input of the connected instrument, which can lead to image-frequency display.

Note: Note that the YIG-preselector is active only higher frequencies, depending on the connected instrument. Therefore, switching the YIG-preselector on or off has no effect if the frequency is below that value.

To use the optional 90 GHz frequency extension (R&S FSW-B90G), the YIG-preselector must be disabled.

To use the optional 54 GHz frequency extension (R&S FSV3-B54G), the YIG-preselector must be disabled.

Note:

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For the following measurements, the YIG-"Preselector" is off by default (if available).

●

I/Q Analyzer

●

GSM

●

VSA

●

OFDM VSA Remote command:

INPut<ip>:FILTer:YIG[:STATe] on page 143

Capture Mode

Determines how data from an oscilloscope is input to the R&S VSE software. This function is only available for a connected R&S oscilloscope with a firmware ver-

sion 3.0.1.1 or higher (for other versions and instruments the input is always I/Q data). "I/Q"

"Waveform"

"Auto"

Remote command:

INPut<ip>:RF:CAPMode on page 144

The measured waveform is converted to I/Q data directly on the R&S oscilloscope (requires option K11), and input to the R&S VSE software as I/Q data. For data imports with small bandwidths, importing data in this format is quicker. However, the maximum record length is restricted by the R&S oscilloscope. (Memory options on the R&S oscilloscope are not available for I/Q data.)

The data is input in its original waveform format and converted to I/Q data in the R&S VSE software. No additional options are required on the R&S oscilloscope. For data imports with large bandwidths, this format is more convenient as it allows for longer record lengths if appropriate memory options are available on the R&S oscilloscope.

Uses "I/Q" mode when possible, and "Waveform" only when required by the application (e.g. Pulse measurement, oscilloscope baseband input).

B2000 State

Activates the optional 2 GHz bandwidth extension (R&S FSW-B2000). Note: The R&S VSE software supports input from a connected R&S FSW with a

B2000 option installed. However, the R&S FSW interface to the oscilloscope must be set up and aligned directly on the instrument before the R&S VSE software can start analyzing the input. The analysis bandwidth is defined in the data acquisition settings of the application as usual. Note that the maximum bandwidth cannot be restricted manually as for other bandwidth extension options.

Manual operation on the connected oscilloscope, or remote operation other than by the R&S VSE, is not possible while the B2000 option is active.

Remote command:

SYSTem:COMMunicate:RDEVice:OSCilloscope[:STATe] on page 149

Oscilloscope Sample Rate

Determines the sample rate used by the connected oscilloscope.

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This setting is only available if an R&S oscilloscope is used to obtain the input data, either directly or via the R&S FSW.

"10 GHz"

"20 GHz"

Default for waveform Capture Mode (not available for I/Q Capture

Mode); provides maximum record length

Achieves a higher decimation gain, but reduces the record length by half. Only available for R&S oscilloscope models that support a sample rate of 20 GHz (see data sheet). For R&S oscilloscopes with an analysis bandwidth of 4 GHz or larger, a sample rate of 20 GHZ is always used in waveform Capture Mode

"40 GHz"

Remote command: Input source R&S FSW via oscilloscope:

SYSTem:COMMunicate:RDEVice:OSCilloscope:SRATe on page 150

Input source oscilloscope waveform mode:

INPut<ip>:RF:CAPMode:WAVeform:SRATe on page 145

Input source oscilloscope I/Q mode:

INPut<ip>:RF:CAPMode:IQ:SRATe on page 145

Oscilloscope Splitter Mode

Activates the use of the power splitter inserted between the [IF 2 GHZ OUT] connector of the R&S FSW and the [CH1] and [CH3] input connectors of the oscilloscope. Note that this mode requires an additional alignment with the power splitter.

For details see the R&S FSW I/Q Analyzer and I/Q Input User Manual. Remote command:

SYSTem:COMMunicate:RDEVice:OSCilloscope:PSMode[:STATe] on page 149

Oscilloscope IP Address

When using the optional 2 GHz bandwidth extension (R&S FSW-B2000) with an R&S FSW as the connected instrument, the entire measurement, as well as both instruments, are controlled by the R&S VSE software. Thus, the instruments must be connected via LAN, and the TCPIP address of the oscilloscope must be defined in the R&S VSE software.

Provides a maximum sample rate. Only available for I/Q Capture Mode, and only for R&S RTP13/RTP16 models that support a sample rate of 40 GHz (see data sheet)

For tips on how to determine the computer name or TCPIP address, see the oscilloscope's user documentation.

Remote command:

SYSTem:COMMunicate:RDEVice:OSCilloscope:TCPip on page 149

Preselector State

Turns the preselector on and off. When you turn on the preselector, you can configure the characteristics of the prese-

lector and add the preamplifier into the signal path. When you turn off the preselector, the signal bypasses the preselector and the pream-

plifier, and is fed into the input mixer directly.

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Remote command:

INPut<ip>:PRESelection[:STATe] on page 144

Preselector Mode

Selects the preselection filters to be applied to the measurement. "Auto"

"Auto Wide"

"Auto Narrow"

"Manual" Remote command:

INPut<ip>:PRESelection:SET on page 144

Automatically applies all available bandpass filters in a measurement. Available with the optional preamplifier.

Automatically applies the wideband filters consecutively:

●

Lowpass 40 MHz

●

Bandpass 30 MHz to 2250 MHz

●

Bandpass 2 GHz to 8 GHz

●

Bandpass 8 GHz to 26.5 GHz Available with the optional preselector. Automatically applies the most suitable narrowband preselection fil-

ters in a measurement, depending on the bandwidth you have selected. For measurement frequencies up to 30 MHz, the connected instrument uses combinations of lowpass and highpass filters. For higher frequencies, the connected instrument uses bandpass filters. Available with the optional preselector.

Applies the filter settings you have defined manually.

10 dB Minimum Attenuation

Turns the availability of attenuation levels of less than 10 dB on and off. When you turn on this feature, the attenuation is always at least 10 dB. This minimum

attenuation protects the input mixer and avoids accidental setting of 0 dB, especially if you measure EUTs with high RFI voltage.

When you turn it off, you can also select attenuation levels of less than 10 dB. The setting applies to a manual selection of the attenuation as well as the automatic

selection of the attenuation. Remote command:

INPut<ip>:ATTenuation:PROTection:RESet on page 141

6.3.1.2 I/Q file input

Access: "Overview" > "Input/Frontend" > "Input Source" > "I/Q File"

Or: "Input & Output" > "Input Source" > "I/Q File"

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Loading a file via drag&drop

You can load a file simply by selecting it in a file explorer and dragging it to the R&S VSE software. Drop it into the "Measurement Group Setup" window or the channel bar for any channel. The channel is automatically configured for file input, if necessary. If the file contains all essential information, the file input is immediately displayed in the channel. Otherwise, the "Recall I/Q Recording" dialog box is opened for the selected file so you can enter the missing information.

If the file contains data from multiple channels (e.g. from LTE measurements), it can be loaded to individual input sources, if the application supports them.

For details see the R&S VSE Base Software User Manual.

The "Input Source" settings defined in the "Input" dialog box are identical to those configured for a specific channel in the "Measurement Group Setup" window.

If the Frequency Response Correction option (R&S VSE-K544) is installed, the R&S VSE GSM application also supports frequency response correction using Touchstone (.snp) files or .fres files.

For details on user-defined frequency response correction, see the R&S VSE Base Software User Manual.

Encrypted .wv files can also be imported. Note, however, that traces resulting from encrypted file input cannot be exported or stored in a saveset.

Input Type (Instrument / File)........................................................................................77

Input File....................................................................................................................... 77

Zero Padding.................................................................................................................77

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Input Type (Instrument / File)

Selects an instrument or a file as the type of input provided to the channel.

Note: External mixers are only available for input from a connected instrument. Note: If the R&S VSE software is installed directly on an instrument, or integrated in

Cadence®AWR®VSS, some restrictions apply on the available input type. Remote command:

INSTrument:BLOCk:CHANnel[:SETTings]:SOURce<si> on page 147 INPut<ip>:SELect on page 146

Input File

Specifies the I/Q data file to be used for input. Select "Select File" to open the "Load I/Q File" dialog box.

Zero Padding

Enables or disables zero padding for input from an I/Q data file that requires resampling. For resampling, a number of samples are required due to filter settling. These samples can either be taken from the provided I/Q data, or the software can add the required number of samples (zeros) at the beginning and end of the file.

If enabled, the required number of samples are inserted as zeros at the beginning and end of the file. The entire input data is analyzed. However, the additional zeros can effect the determined spectrum of the I/Q data. If zero padding is enabled, a status message is displayed.

If disabled (default), no zeros are added. The required samples for filter settling are taken from the provided I/Q data in the file. The start time in the R&S VSE Player is adapted to the actual start (after filter settling).

Note: You can activate zero padding directly when you load the file, or afterwards in the "Input Source" settings.

Remote command:

INPut<ip>:FILE:ZPADing on page 142

6.3.2 Frequency settings

Access: "Overview" > "Input/Frontend" > "Frequency"

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Frequency Band............................................................................................................78

Center Frequency......................................................................................................... 78

ARFCN..........................................................................................................................79

Center Frequency Stepsize ..........................................................................................79

Frequency Offset ..........................................................................................................79

Frequency Band

The frequency band defines the frequency range used to transmit the signal. For details see "Frequency bands and channels" on page 34. The following frequency bands are supported:

●

DCS 1800

●

E-GSM 900

●

GSM 450

●

GSM 480

●

GSM 710

●

GSM 750

●

GSM 850

●

PCS 1900

●

P-GSM 900

●

R-GSM 900

●

T-GSM 380

●

T-GSM 410

●

T-GSM 810

●

T-GSM 900 The default frequency band is "E-GSM 900". Remote command:

CONFigure[:MS]:NETWork[:TYPE] on page 127 CONFigure[:MS]:NETWork:FREQuency:BAND on page 127

Center Frequency

Specifies the center frequency of the signal to be measured (typically the center of the Tx band).

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If the frequency is modified, the "ARFCN" is updated accordingly (for I/Q measurements, see ARFCN).

Remote command:

[SENSe:]FREQuency:CENTer on page 177

ARFCN

Defines the Absolute Radio Frequency Channel Number (ARFCN). The "Center Fre-

quency" on page 78 is adapted accordingly.

Possible values are in the range from 0 to 1023; however, some values may not be allowed depending on the selected Frequency Band.

Remote command:

CONFigure[:MS]:ARFCn on page 177

Center Frequency Stepsize

Defines the step size by which the center frequency is increased or decreased using the arrow keys.

When you use the mouse wheel, the center frequency changes in steps of only 1/10 of the span.

The step size can be coupled to another value or it can be manually set to a fixed value.

"X * Span"

Sets the step size for the center frequency to a defined factor of the span. The "X-Factor" defines the percentage of the span. Values between 1 % and 100 % in steps of 1 % are allowed. The default setting is 10 %.

"= Center"

"Manual"

Remote command:

[SENSe:]FREQuency:CENTer:STEP on page 177

Frequency Offset

Shifts the displayed frequency range along the x-axis by the defined offset. This parameter has no effect on the instrument's hardware, on the captured data, or on

data processing. It is simply a manipulation of the final results in which absolute frequency values are displayed. Thus, the x-axis of a spectrum display is shifted by a constant offset if it shows absolute frequencies. However, if it shows frequencies relative to the signal's center frequency, it is not shifted.

A frequency offset can be used to correct the display of a signal that is slightly distorted by the measurement setup, for example.

The allowed values range from -1 THz to 1 THz. The default setting is 0 Hz. Remote command:

[SENSe:]FREQuency:OFFSet on page 178

Sets the step size to the value of the center frequency. The used value is indicated in the "Value" field.

Defines a fixed step size for the center frequency. Enter the step size in the "Value" field.

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6.3.3 Amplitude settings

Modulation accuracy measurement configuration

Input, output and frontend settings

Access: "Overview" > "Input/Frontend" > "Amplitude"

Amplitude settings affect the y-axis values.

Power Class..................................................................................................................80

Reference Level ...........................................................................................................81

└ Shifting the Display ( Offset ).......................................................................... 81

Mechanical Attenuation.................................................................................................81

└ Attenuation Mode / Value ...............................................................................81

Using Electronic Attenuation ........................................................................................82

Input Settings................................................................................................................ 82

└ Preamplifier ....................................................................................................82

Power Class

The following power classes are supported:

●

1, …, 8 (BTS)

●

1, …,5 (MS: GMSK)

●

E1, E2, E3 (MS: all except GMSK)

●

M1, M2, M3 (Micro BTS)

●

P1 (Pico BTS) The default power class is 2. Remote command:

CONFigure[:MS]:POWer:CLASs on page 128

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Reference Level

Defines the expected maximum input signal level. Signal levels above this value are possibly not measured correctly, which is indicated by the "IF Overload" status display.

Defines the expected maximum reference level. Signal levels above this value are possibly not measured correctly. Signals above the reference level are indicated by an "IF Overload" status display.

The reference level can also be used to scale power diagrams; the reference level is then used for the calculation of the maximum on the y-axis.

Since the hardware of the connected instrument is adapted according to this value, it is recommended that you set the reference level close above the expected maximum signal level. Thus you ensure an optimal measurement (no compression, good signal-tonoise ratio).

Remote command:

DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]: RLEVel<ant> on page 179

Shifting the Display ( Offset ) ← Reference Level

Defines an arithmetic level offset. This offset is added to the measured level. In some result displays, the scaling of the y-axis is changed accordingly.

Define an offset if the signal is attenuated or amplified before it is fed into the R&S VSE so the application shows correct power results. All displayed power level results are shifted by this value.

The setting range is ±200 dB in 0.01 dB steps. Note, however, that the internal reference level (used to adjust the hardware settings to

the expected signal) ignores any "Reference Level Offset" . Thus, it is important to keep in mind the actual power level the R&S VSE must handle. Do not rely on the displayed reference level (internal reference level = displayed reference level - offset).

Remote command:

DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]: RLEVel<ant>:OFFSet on page 179

Mechanical Attenuation

Defines the mechanical attenuation for RF input.

Attenuation Mode / Value ← Mechanical Attenuation

The RF attenuation can be set automatically as a function of the selected reference level (Auto mode). Automatic attenuation ensures that no overload occurs at the RF Input connector for the current reference level. It is the default setting.

In "Manual" mode, you can set the RF attenuation in 1 dB steps (down to 0 dB). Other entries are rounded to the next integer value. The range is specified in the data sheet. If the defined reference level cannot be set for the defined RF attenuation, the reference level is adjusted accordingly and the warning "limit reached" is displayed.

NOTICE! Risk of hardware damage due to high power levels. When decreasing the attenuation manually, ensure that the power level does not exceed the maximum level allowed at the RF input, as an overload can lead to hardware damage.

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Remote command:

INPut<ip>:ATTenuation on page 181 INPut<ip>:ATTenuation:AUTO on page 182

Using Electronic Attenuation

If the (optional) Electronic Attenuation hardware is installed on the connected instrument, you can also activate an electronic attenuator.

In "Auto" mode, the settings are defined automatically; in "Manual" mode, you can define the mechanical and electronic attenuation separately.

Note: Note that restrictions can apply concerning which frequencies electronic attenuation is available for, depending on which instrument is connected to the R&S VSE software. Check your instrument documentation for details. In "Auto" mode, RF attenuation is provided by the electronic attenuator as much as possible to reduce the amount of mechanical switching required. Mechanical attenuation can provide a better signal-to-noise ratio, however.

When you switch off electronic attenuation, the RF attenuation is automatically set to the same mode (auto/manual) as the electronic attenuation was set to. Thus, the RF attenuation can be set to automatic mode, and the full attenuation is provided by the mechanical attenuator, if possible.

If the defined reference level cannot be set for the given attenuation, the reference level is adjusted accordingly and the warning "limit reached" is displayed in the status bar.

Remote command:

INPut<ip>:EATT:STATe on page 183 INPut<ip>:EATT:AUTO on page 182 INPut<ip>:EATT on page 182

Input Settings

Some input settings affect the measured amplitude of the signal, as well. See Chapter 6.3.1.1, "Radio frequency input", on page 69.

Preamplifier ← Input Settings

If the (optional) internal preamplifier hardware is installed on the connected instrument, a preamplifier can be activated for the RF input signal.

You can use a preamplifier to analyze signals from DUTs with low output power. Note: If an optional external preamplifier is activated, the internal preamplifier is auto-

matically disabled, and vice versa. "Off" "15 dB" "30 dB" Depending on the connected instrument, different settings are available. See the

instrument's documentation for details. Remote command:

INPut<ip>:GAIN<ant>:STATe on page 180 INPut<ip>:GAIN<ant>[:VALue] on page 180

Deactivates the preamplifier. The RF input signal is amplified by about 15 dB. The RF input signal is amplified by about 30 dB.

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6.4 Trigger settings

Modulation accuracy measurement configuration

Trigger settings

Access: "Overview" > "Trigger"

or: "Input & Output" > "Trigger"

Trigger settings determine when the input signal is measured. Which settings are available depends on the connected instrument.

External triggers from one of the [TRIGGER INPUT/OUTPUT] connectors on the connected instrument are also available.

See the R&S VSE Base Software User Manual.

Trigger Source ..............................................................................................................83

└ Free Run ........................................................................................................83

└ External Trigger / Trigger Channel X.............................................................. 84

└ I/Q Power .......................................................................................................84

└ RF Power .......................................................................................................84

└ Magnitude (Offline) ........................................................................................ 84

└ Manual............................................................................................................ 84

Trigger Level ................................................................................................................ 85

Drop-Out Time ..............................................................................................................85

Trigger Offset ............................................................................................................... 85

Hysteresis .................................................................................................................... 85

Trigger Holdoff ..............................................................................................................86

Slope ............................................................................................................................86

Trigger Source

Selects the trigger source. If a trigger source other than "Free Run" is set, "TRG" is displayed in the channel bar and the trigger source is indicated.

Note that the availability of trigger sources depends on the connected instrument. Remote command:

TRIGger[:SEQuence]:SOURce on page 188

Free Run ← Trigger Source

No trigger source is considered. Data acquisition is started manually or automatically and continues until stopped explicitly.

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Trigger settings

Remote command: TRIG:SOUR IMM, see TRIGger[:SEQuence]:SOURce on page 188

External Trigger / Trigger Channel X ← Trigger Source

Data acquisition starts when the signal fed into the specified input connector or input channel of the connected instrument meets or exceeds the specified trigger level.

Note: Which input and output connectors are available depends on the connected instrument. For details, see the instrument's documentation. For a connected R&S oscilloscope, the following signals are used as trigger input:

●

"External Trigger": EXT TRIGGER INPUT connector on rear panel of instrument

●

"Trigger Channel 2"/"Trigger Channel 3"/"Trigger Channel 4": Input at channel connectors CH 2/3/4 on front panel of instrument - if not used as an input source

Remote command: TRIG:SOUR EXT, TRIG:SOUR EXT2, TRIG:SOUR EXT3, TRIG:SOUR EXT4 See TRIGger[:SEQuence]:SOURce on page 188

I/Q Power ← Trigger Source

Triggers the measurement when the magnitude of the sampled I/Q data exceeds the trigger threshold.

Remote command: TRIG:SOUR IQP, see TRIGger[:SEQuence]:SOURce on page 188

RF Power ← Trigger Source

Defines triggering of the measurement via signals which are outside the displayed measurement range.

For this purpose, the software uses a level detector at the first intermediate frequency. The resulting trigger level at the RF input depends on the RF attenuation and preampli-

fication. For details on available trigger levels, see the instrument's data sheet. Note: If the input signal contains frequencies outside of this range (e.g. for fullspan

measurements), the measurement can be aborted. A message indicating the allowed input frequencies is displayed in the status bar.

A "Trigger Offset" , "Trigger Polarity" and "Trigger Holdoff" (to improve the trigger stability) can be defined for the RF trigger, but no "Hysteresis" .

Remote command: TRIG:SOUR RFP, see TRIGger[:SEQuence]:SOURce on page 188

Magnitude (Offline) ← Trigger Source

For (offline) input from a file, rather than an instrument. Triggers on a specified signal level.

Remote command: TRIG:SOUR MAGN, see TRIGger[:SEQuence]:SOURce on page 188

Manual ← Trigger Source

Only available for a connected R&S RTP:

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Trigger settings

Any trigger settings in the R&S VSE software are ignored; only trigger settings defined on the connected instrument are considered. Thus, you can make use of the more complex trigger settings available on an R&S RTP.

Remote command: TRIG:SOUR MAN, see TRIGger[:SEQuence]:SOURce on page 188

Trigger Level

Defines the trigger level for the specified trigger source. For details on supported trigger levels, see the instrument data sheet. Remote command:

TRIGger[:SEQuence]:LEVel:IFPower on page 185 TRIGger[:SEQuence]:LEVel:IQPower on page 186 TRIGger[:SEQuence]:LEVel[:EXTernal<port>] on page 185 TRIGger[:SEQuence]:LEVel:RFPower on page 186

Drop-Out Time

Defines the time that the input signal must stay below the trigger level before triggering again.

Remote command:

TRIGger[:SEQuence]:DTIMe on page 184

Trigger Offset

Defines the time offset between the trigger event and the start of the measurement. Note: When using an external trigger, the trigger offset is particularly important to

detect the frame start correctly! (See Chapter 5.5, "Trigger settings", on page 39.) The R&S VSE GSM application expects the trigger event to be the start of the "active part" in slot 0.

Offset > 0: Start of the measurement is delayed

Offset < 0: Measurement starts earlier (pretrigger)

(If supported by the connected instrument.) Remote command:

TRIGger[:SEQuence]:HOLDoff[:TIME] on page 184

Hysteresis

Defines the distance in dB to the trigger level that the trigger source must exceed before a trigger event occurs. Setting a hysteresis avoids unwanted trigger events caused by noise oscillation around the trigger level.

This setting is only available for "IF Power" or "Magnitude (Offline)" trigger sources. The range of the value depends on the connected instrument. Remote command:

TRIGger[:SEQuence]:IFPower:HYSTeresis on page 185 TRIGger[:SEQuence]:MAPower:HYSTeresis on page 187

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6.5 Data acquisition

Modulation accuracy measurement configuration

Data acquisition

Trigger Holdoff

Defines the minimum time (in seconds) that must pass between two trigger events. Trigger events that occur during the holdoff time are ignored.

Remote command:

TRIGger[:SEQuence]:IFPower:HOLDoff on page 184 TRIGger[:SEQuence]:MAPower:HOLDoff on page 187

Slope

For all trigger sources except time, you can define whether triggering occurs when the signal rises to the trigger level or falls down to it.

Remote command:

TRIGger[:SEQuence]:SLOPe on page 188

Access: "Overview" > "Data Acquisition"

You must define how much and how often data is captured from the input signal.

● Data acquisition.......................................................................................................86

● Capture................................................................................................................... 88

6.5.1 Data acquisition

Access: "Overview" > "Data Acquisition" > "Data Acquisition"

The "Data Acquisition" settings define how long data is captured from the input signal by the R&S VSE GSM application.

Sample rate...................................................................................................................87

Analysis Bandwidth.......................................................................................................87

Capture Time.................................................................................................................87

Swap I/Q ...................................................................................................................... 87

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Sample rate

The sample rate for I/Q data acquisition is indicated for reference only. It is a fixed value, depending on the frequency range to be measured (see also Chapter 6.7.2,

"Spectrum", on page 95).

Remote command:

TRACe<t>:IQ:SRATe? on page 193

Analysis Bandwidth

The analysis bandwidth is indicated for reference only. It defines the flat, usable bandwidth of the final I/Q data. This value is dependent on the Frequency list and the defined signal source.

The following rule applies:

analysis bandwidth = 0.8 * sample rate

Remote command:

TRACe:IQ:BWIDth on page 193

Capture Time

Specifies the duration (and therefore the amount of data) to be captured in the capture buffer.

Be sure to define a sufficiently long capture time. If the capture time is too short, demodulation will fail.

Note: The duration of one GSM slot equals 15/26 ms = 0.576923 ms. The duration of one GSM frame (8 slots) equals 60/13 ms = 4.615384 ms.

Tip: In order to improve the measurement speed further by using short capture times, consider the following:

●

Use an external trigger which indicates the frame start. In this case, the minimum allowed capture time is reduced from 10 ms to 866 us (see Chapter 5.5, "Trigger

settings", on page 39)

●

Measure only slots at the beginning of the frame, directly after the trigger (see

Chapter 6.6.1, "Slot scope", on page 88)

●

Use a small statistic count (see "Statistic Count" on page 88)

Remote command:

[SENSe:]SWEep:TIME on page 193

Swap I/Q

Activates or deactivates the inverted I/Q modulation. If the I and Q parts of the signal from the DUT are interchanged, the R&S VSE can do the same to compensate for it.

Tip: Try this function if the TSC cannot be found.

On I and Q signals are interchanged

Inverted sideband, Q+j*I

Off I and Q signals are not interchanged

Normal sideband, I+j*Q

Remote command:

[SENSe:]SWAPiq on page 192

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6.5.2 Capture

Modulation accuracy measurement configuration

Demodulation

Access: "Overview" > "Data Acquisition" > "Capture"

The "Capture" settings define how often data is captured from the input signal by the R&S VSE GSM application.

Statistic Count...............................................................................................................88

Statistic Count

Defines the number of frames to be included in statistical evaluations. For measurements on the Slot to Measure, the same slot is evaluated in multiple frames, namely in the number specified by the "Statistic Count", for statistical evaluations.

The default value is 200 in accordance with the GSM standard. For details on the impact of this value, see Chapter 5.14, "Impact of the "Statistic

count"", on page 57.

Remote command:

[SENSe:]SWEep:COUNt on page 191

6.6 Demodulation

Access: "Overview" > "Demodulation"

Demodulation settings determine how frames and slots are detected in the input signal and which slots are to be evaluated.

The "Frame" and "Slot" settings are identical to those in the "Signal Description" dialog box, see Chapter 6.2.2, "Frame", on page 62 and Chapter 6.2.3, "Slot settings", on page 63.

● Slot scope............................................................................................................... 88

● Demodulation settings.............................................................................................90

6.6.1 Slot scope

Access: "Overview" > "Demodulation" > "Slot Scope"

The slot scope defines which slots are to be evaluated (see also Chapter 5.6, "Defining

the scope of the measurement", on page 40).

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Demodulation

Slot to Measure.............................................................................................................89

Number of Slots to measure......................................................................................... 90

First Slot to measure.....................................................................................................90

Frame Configuration: Select Slot to Configure..............................................................90

Slot to Measure

This parameter specifies the slot to be measured in single-slot measurements relative to the GSM frame boundary. The following rule applies:

0 ≤ Slot to Measure ≤ 7 The "Slot to Measure" is used as the (only) slot to measure in the following measure-

ments: (see "First Slot to measure" on page 90)

●

Modulation Accuracy

●

EVM

●

Phase Error

●

Magnitude Error

●

Modulation Spectrum

●

Constellation

Furthermore, the "Slot to Measure" is used to measure the reference power for the following measurements:

●

Power vs Time

●

Modulation Spectrum

●

Transient Spectrum

Finally, the "Slot to Measure" is used to measure the position of its TSC, which represents the timing reference for the Power vs Time mask (limit lines) of all slots.

See also Chapter 5.6, "Defining the scope of the measurement", on page 40. For details on the measurement types see Chapter 4, "GSM I/Q measurement results", on page 16.

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Demodulation

Remote command:

CONFigure[:MS]:CHANnel:MSLots:MEASure on page 194

Number of Slots to measure

This parameter specifies the "Number of Slots to measure" for the measurement interval of multi-slot measurements, i.e. the Power vs Time and Transient Spectrum mea- surements. Between 1 and 8 consecutive slots can be measured.

See also Chapter 5.6, "Defining the scope of the measurement", on page 40. Remote command:

CONFigure[:MS]:CHANnel:MSLots:NOFSlots on page 194

First Slot to measure

This parameter specifies the start of the measurement interval for multi-slot measurements, i.e. Power vs Time and Transient Spectrum measurements, relative to the GSM frame boundary. The following conditions apply:

●

First Slot to measure ≤ Slot to Measure

●

Slot to Measure ≤ First Slot to measure + Number of Slots to measure -1

See also Chapter 5.6, "Defining the scope of the measurement", on page 40. Remote command:

CONFigure[:MS]:CHANnel:MSLots:OFFSet on page 195

Frame Configuration: Select Slot to Configure

This area shows a graphical representation of the configuration of each slot. Select a slot to display its "Slot" dialog box (see Chapter 6.2.3, "Slot settings", on page 63).

For active slots the following information is shown:

●

The burst type, e.g. "Normal (NB)" for a normal burst.

●

The modulation, e.g. GMSK.

●

The training sequence TSC (and Set) For details on how to interpret the graphic, see "Frame configuration and slot scope in

the channel bar" on page 41.

6.6.2 Demodulation settings

Access: "Overview" > "Demodulation" > "Demodulation"

The demodulation settings provide additional information to optimize frame, slot and symbol detection.

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Demodulation

Synchronization.............................................................................................................91

Measure only on Sync...................................................................................................92

I/Q Correlation Threshold..............................................................................................92

Symbol Decision........................................................................................................... 92

Tail & TSC Bits.............................................................................................................. 93

Synchronization

Sets the synchronization mode of the R&S VSE GSM application. "Burst+TSC"

"TSC"

"Burst"

"None"

Remote command:

CONFigure[:MS]:SYNC:MODE on page 195

First search for the power profile (burst search) according to the frame configuration in the capture buffer. Second, inside the found bursts search for the TSC of the Slot to Measure as given in the frame configuration. "Burst +TSC" is usually faster than "TSC" for bursted signals.

Search the capture buffer for the TSC of the Slot to Measure as given in the frame configuration. This mode corresponds to a correlation with the given TSC. This mode can be used for continuous (but framed) signals or bursted signals.

Search for the power profile (burst search) according to the frame configuration in the capture buffer. Note: For "Burst" no demodulation measurements (e.g. "Modulation Accuracy") are supported. Only "Power vs Time", "Modulation Spectrum", "Transient Spectrum" measurements are supported.

Do not synchronize at all. If an external or power trigger is chosen, the trigger instant corresponds to the frame start. Tip: Manually adjust the trigger offset to move the burst to be analyzed under the mask in the "Power vs Time" measurement. Note: For "None" no demodulation measurements (e.g. "Modulation Accuracy") are supported. Only "Power vs Time", "Modulation Spectrum", "Transient Spectrum" measurements are supported.

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Demodulation

Measure only on Sync

If activated (default), only results from frames (slots) where the Slot to Measure was found are displayed and taken into account in the averaging of the results. The behavior of this option depends on the value of the Synchronization parameter.

Remote command:

CONFigure[:MS]:SYNC:ONLY on page 196

I/Q Correlation Threshold

This threshold determines whether a burst is accepted if Measure only on Sync is activated. If the correlation value between the ideal I/Q signal of the given TSC and the measured TSC is below the I/Q correlation threshold, then the application reports "Sync not found" in the status bar. Additionally, such bursts are ignored if "Measure only on Sync" is activated.

Note: If the R&S VSE GSM application is configured to measure GMSK normal bursts, a threshold below 97% will also accept 8PSK normal bursts (with the same TSC) for analysis. In this case, activate Measure only on Sync and set the "I/Q Correlation Threshold" to 97%. This will exclude the 8PSK normal bursts from the analysis.

Remote command:

CONFigure[:MS]:SYNC:IQCThreshold on page 196

Symbol Decision

The symbol decision determines how the symbols are detected in the demodulator. Setting this parameter does not affect the demodulation of normal bursts with GMSK modulator. For normal bursts with 8PSK, 16QAM, 32QAM or AQPSK modulation, or higher symbol rate bursts with QPSK, 16QAM or 32QAM modulation, use this parameter to get a trade-off between performance (symbol error rate of the R&S VSE GSM application) and measurement speed.

"Auto" "Linear"

"Sequence"

Remote command:

CONFigure[:MS]:DEMod:DECision on page 197

Automatically selects the symbol decision method. Linear symbol decision: Uses inverse filtering (a kind of zero-forcing

filter) and a symbol-wise decision method. This method is recommended for high symbol to noise ratios, but not for higher symbol rate bursts with a narrow pulse. The inverse filter colors the noise inside the signal bandwidth and therefore is not recommended for narrowband signals or signals with a low signal to noise ratio. Peaks in the "EVM vs Time" measurement (see "EVM" on page 17) may occur if the "Linear" symbol decision algorithm fails. In that case use the "Sequence" method. Linear is the fastest option.

Symbol decision via sequence estimation. This method uses an algorithm that minimizes the symbol errors of the entire burst. It requires that the tail bits in the analyzed signal are correct. It has a better performance (lower symbol error rate) compared to the "Linear" method, especially at low signal to noise ratios, but with a loss of measurement speed. This method is recommended for normal bursts with 16QAM or 32QAM modulation and for Higher Symbol Rate bursts with a narrow pulse. Tip: Use this setting if it reduces the "EVM RMS" measurement result.

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Measurement settings

Tail & TSC Bits

The demodulator in the R&S VSE GSM application requires the bits of the burst (tail, data, TSC, data, tail) to provide an ideal version of the measured signal. The "data" bits can be random and are typically not known inside the demodulator of the R&S VSE GSM application. "tail" and "TSC" bits are specified in the "Slot" dialog box (see

"Training Sequence TSC[/]Sync" on page 66).

"Detected" "Standard"

Remote command:

CONFigure[:MS]:DEMod:STDBits on page 198

The detected Tail and TSC bits are used to construct the ideal signal. The standard tail and TSC bits (as set in the "Slot" dialog box) are

used to construct the ideal signal. Using the standard bits can be advantageous to verify whether the device under test sends the correct tail and TSC bits. Incorrect bits would lead to peaks in the "EVM vs Time" trace (see "EVM" on page 17) at the positions of the incorrect bits.

6.7 Measurement settings

Access: "Overview" > "Measurement"

Measurement settings define how power or spectrum measurements are performed.

6.7.1 Power vs time

Access: "Overview" > "Measurement" > "Power vs Time"

The "Power vs Time" filter is used to suppress out-of-band interference in the Power vs Time measurement (see Chapter 5.7.1, "Power vs time filter", on page 43). A limit line is available to determine if the power exceeds the limits defined by the standard in each slot.

Power vs Time Filter

The PvT filter controls the filter used to reduced the measurement bandwidth in "Power vs Time" measurements.

Note: The PvT filter is optimized to get smooth edges after filtering burst signals and to suppress adjacent, active channels.

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Measurement settings

Depending on the Device Type (single carrier or multicarrier), different PvT filters are supported:

" 1 MHz Gauss"

default for single carrier device

"600 kHz"

(single carrier only) for backwards compatibility to FS-K5

"500 kHz Gauss"

(single carrier only) for backwards compatibility to FS-K5

"400 kHz (multicarrier)"

(default for multicarrier device) Recommended for measurements with multi channels of equal power.

"300 kHz (multicarrier)"

Recommended for multicarrier measurement scenarios where a total of six channels is active and the channel to be measured has a reduced power (e.g. 30 dB) compared to its adjacent channels.

Remote command:

CONFigure:BURSt:PTEMplate:FILTer on page 199

Limit Line Time Alignment

Controls how the limit lines are aligned in a "Power vs Time" measurement graph (see

"PvT Full Burst" on page 26). Limit lines are defined for each slot. The limit lines are

time-aligned in each slot, based on the position of the TSC (the center of the TSC is the reference point). This parameter affects how the center of the TSC is determined for each slot:

●

Slot to measure (default): For each slot the center of the TSC is derived from the

measured center of the TSC of the Slot to Measure and the timeslot lengths speci-

fied in the standard (see "Timeslot length" in 3GPP TS 45.010 and "Equal Timeslot

Length" on page 63).

●

Per Slot: For each slot the center of the TSC is measured. This provides reasona-

ble time-alignment if the slot lengths are not according to standard. Note that in this

case the "Power vs Time" limit check may show "pass" even if the timeslot lengths

are not correct according to the standard. Note: The "Limit Time Alignment" also decides whether the "Delta to sync" values of

the "Power vs Time" list result are measured (for "Limit Time Alignment" = "Per Slot") or if they are constant as defined by the 3PP standard (for "Limit Time Alignment" = "Slot to measure").

The R&S VSE GSM application offers a strictly standard-conformant, multiple-slot PvT limit line check. This is based on time alignment to a single specified slot (the "Slot to Measure") and allows the user to check for correct BTS timeslot alignment in the DUT, according to the GSM standard. In addition, a less stringent test which performs PvT limit line alignment on a per-slot basis ("Per Slot") is also available.

Note:

When measuring access bursts the parameter "Limit Time Alignment" should be set to "Per Slot", since the position of an access burst within a slot depends on the set timing advance of the DUT.

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6.7.2 Spectrum

Modulation accuracy measurement configuration

Measurement settings

Remote command:

CONFigure:BURSt:PTEMplate:TALign on page 199

Access: "Overview" > "Measurement" > "Spectrum"

The modulation and transient spectrum measurements allow for further configuration.

Enable Left Limit/ Enable Right Limit............................................................................ 95

Filter Type..................................................................................................................... 95

Modulation Spectrum Table: Frequency List................................................................. 96

Transient Spectrum: Reference Power.........................................................................96

Enable Left Limit/ Enable Right Limit

Controls whether the results for the frequencies to the left or to the right of the center frequency, or both, are considered in the limit check of the spectrum trace (spectrum graph measurement). This parameter affects the "Modulation Spectrum Graph" on page 21 and "Transient Spectrum Graph" on page 28 measurements.

Note: For measurements on multicarrier signals, using either the check on the left or right side only allows you to measure the spectrum of the left or right-most channel while ignoring the side where adjacent channels are located.

Remote command:

CONFigure:SPECtrum:LIMit:LEFT on page 200 CONFigure:SPECtrum:LIMit:RIGHt on page 201

Filter Type

Defines the filter type for the resolution filter for the "Modulation Spectrum" and "Transient Spectrum" measurements.

"Normal" "5-pole"

3 dB Gauss filter according to the GSM standard

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Measurement settings

Remote command:

[SENSe:]BANDwidth[:RESolution]:TYPE on page 203

Modulation Spectrum Table: Frequency List

This setting is only required by the "Modulation Spectrum Table" evaluation (see "Mod-

ulation Spectrum Table" on page 22). In this evaluation, the spectrum of the signal at

fixed frequency offsets is determined. The list of frequencies to be measured is defined by the standard. Additionally, sparse versions of the specified frequency lists with fewer intermediate frequencies are provided for quicker preliminary tests.

Note: Modulation RBW at 1800 kHz. As opposed to previous R&S signal and spectrum analyzers, in which the modulation RBW at 1800 kHz was configurable, the R&S VSE configures the RBW (and VBW) internally according to the selected frequency list (see "Modulation Spectrum Table:

Frequency List" on page 96). For the "Modulation Spectrum Graph" both the RBW and

VBW are set to 30 kHz. For the "Modulation Spectrum Table", they are set according to

Table 4-6.

The frequency list also determines the used sample rate, see "Sample rate" on page 87).

"1.8 MHz"

"1.8 MHz (sparse)"

"6 MHz"

"6 MHz (sparse)"

Remote command:

CONFigure:WSPectrum:MODulation:LIST:SELect on page 202

The frequency list comprises offset frequencies up to 1.8 MHz from the carrier. The sample rate is 6.5 MHz. In previous R&S signal and spectrum analyzers, this setting was referred to as "narrow".

More compact version of "1.8 MHz". The sample rate is 6.5 MHz.

The frequency list comprises offset frequencies up to 6 MHz from the carrier. The sample rate is 19.5 MHz. In previous R&S signal and spectrum analyzers, this setting was referred to as "wide".

More compact version of "6 MHz". The sample rate is 19.5 MHz.

Transient Spectrum: Reference Power

This setting is only required by the "Transient Spectrum" evaluation (see Transient

Spectrum Graph).

In this evaluation, the power vs spectrum for all slots in the slot scope is evaluated and checked against a spectrum mask. To determine the relative limit values, a reference power is required. In order to detect irregularities, it is useful to define the peak power as a reference. However, the standard requires the reference power to be calculated from the RMS power.

To perform the measurement according to the 3GPP standard set the reference power to RMS and the Slot to Measure to the slot with the highest power (see also "Transient

Spectrum Table" on page 29).

"RMS"

(Default:) The reference power is the RMS power level measured over the useful part of the Slot to Measure and averaged according to the defined Statistic Count.

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Adjusting settings automatically

"Peak"

Remote command:

CONFigure:SPECtrum:SWITching:TYPE on page 201

The reference power is the peak power level measured over the selected slot scope (see Chapter 6.6.1, "Slot scope", on page 88) and its peak taken over Statistic Count measurements (GSM frames).

6.7.3 Trigger to sync

Access: "Overview" > "Measurement" > "Trigger to Sync"

The Trigger to Sync measurement allows for further configuration.

No. of Bins

Specifies the number of bins for the histogram of the "Trigger to Sync" measurement. For details see "Trigger to Sync Graph" on page 30. Remote command:

CONFigure:TRGS:NOFBins on page 204

Adaptive Data Size

Specifies the number of measurements (I/Q captures) after which the x-axis of the "Trigger to Sync" histogram is adapted to the measured values and fixed for subsequent measurements.

Up to the defined number of measurements, the Trigger to Sync value is stored. When enough measurements have been performed, the x-axis is adapted to the value range of the stored results. For subsequent measurements, the result is no longer stored and the x-axis (and thus the dimensions of the bins) is maintained at the set range.

The higher the "Adaptive Data Size", the more precise the x-axis scaling. For details see "Trigger to Sync Graph" on page 30. Remote command:

CONFigure:TRGS:ADPSize on page 204

6.8 Adjusting settings automatically

Access: "Auto Set" toolbar

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Result configuration

Some settings can be adjusted by the R&S VSE automatically according to the current measurement settings.

Setting the Reference Level Automatically (Auto Level)...............................................98

Automatic Frame Configuration.................................................................................... 98

Automatic Trigger Offset............................................................................................... 98

Setting the Reference Level Automatically (Auto Level)

Automatically determines the optimal reference level for the current input data. At the same time, the internal attenuators and the preamplifier are adjusted so the signal-tonoise ratio is optimized, while signal compression, clipping and overload conditions are minimized.

In order to do so, a level measurement is performed to determine the optimal reference level.

Remote command:

CONFigure[:MS]:AUTO:LEVel ONCE on page 205

Automatic Frame Configuration

When activated, a single auto frame configuration measurement is performed. The auto frame configuration measurement may take a long time, therefore it is deacti-

vated by default. The following parameters are detected and automatically measured:

●

Active slots

●

Slot configuration (burst type, modulation, filter, TSC)

●

Equal time slot length

●

For VAMOS normal burst and GMSK: TSCs of set 1 and set 2

●

For VAMOS normal burst and AQPSK: TSCs of both subchannels (restrictions see

"Restriction for auto frame configuration" on page 38) and SCPIR

Remote command: CONF:AUTO:FRAM ONCE, see CONFigure[:MS]:AUTO:FRAMe ONCE on page 204

Automatic Trigger Offset

If activated, the trigger offset (for external and IF power triggers) are detected and automatically measured.

For details on the trigger offset refer to " Trigger Offset " on page 85. Remote command:

CONF:AUTO:TRIG ONCE, see CONFigure[:MS]:AUTO:TRIGger ONCE on page 205

6.9 Result configuration

Access: "Overview" > "Result Config"

or: "Meas Setup" > "Result"

Some evaluation methods require or allow for additional settings to configure the result display. Note that the available settings depend on the selected window (see " Specif-

ics for " on page 60).

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6.9.1 Traces

Modulation accuracy measurement configuration

Result configuration

● Traces..................................................................................................................... 99

● Trace / data export configuration.......................................................................... 101

● Markers................................................................................................................. 102

● Y-Axis scaling........................................................................................................106

Access: "Overview" > "Result Config" > "Traces"

or: "Trace"

The number of available traces depends on the selected window (see " Specifics for " on page 60). Only graphical evaluations have trace settings.

The following traces are activated directly after a GSM measurement channel has been opened, or after a Preset Channel:

Table 6-2: Default traces depending on result display

Result display Trace 1 Trace 2 Trace 3 Trace 4

"Magnitude Capture" Clear Write - - -

"Power vs Time" "EVM vs Time" "Phase Error vs Time" "Magnitude Error vs Time"

"Constellation": Graph Clear Write - - -

"Modulation Spectrum " Graph Average Clear Write - -

"Transient Spectrum " Graph Max Hold Clear Write - -

"Trigger to Sync": Graph Histogram PDF of Average - -

Average Max Hold Min Hold Clear Write

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Result configuration

Trace 1/Trace 2/Trace 3/Trace 4.................................................................................100

Trace Mode.................................................................................................................100

Preset All Traces.........................................................................................................101

Trace 1/Trace 2/Trace 3/Trace 4

Selects the corresponding trace for configuration. The currently selected trace is highlighted orange.

Remote command:

DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>[:STATe] on page 216

Selected via numeric suffix of TRACe<t> commands

Trace Mode

Defines the update mode for subsequent traces. The available trace modes depend on the selected result display. Not all evaluations

support all trace modes. "Clear Write" "Max Hold"

"Min Hold"

"Average"

"PDFAvg" "Blank"

Overwrite mode: the trace is overwritten by each capture. The maximum value is determined over several captures and dis-

played. The R&S VSE saves the capture result in the trace memory only if the new value is greater than the previous one.

The minimum value is determined from several captures and displayed. The R&S VSE saves the capture result in the trace memory only if the new value is lower than the previous one.

The average is formed over several captures. The Statistic Count determines the number of averaging procedures.

Displays the probability density function (PDF) of the average value. Removes the selected trace from the display.

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Rohde&Schwarz VSE-K10 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

1 Preface

1.1 About this manual

1.2 Typographical conventions

2 Welcome to the GSM application

2.1 Starting the GSM application

2.2 Understanding the display information

3 About the measurement

4 GSM I/Q measurement results

5 Basics on GSM measurements

5.1 Relevant digital standards

5.2 Short introduction to GSM (GMSK, EDGE and EDGE evolution)

5.3 Short introduction to VAMOS

5.4 AQPSK modulation

5.5 Trigger settings

5.6 Defining the scope of the measurement

5.7 Overview of filters in the R&S VSE GSM application

5.7.1 Power vs time filter

5.7.2 Multicarrier filter

5.7.3 Measurement filter

5.8 Dependency of slot parameters

5.9 Definition of the symbol period

5.9.1 GMSK modulation (normal symbol rate)

5.9.2 8PSK, 16QAM, 32QAM, AQPSK modulation (normal symbol rate)

5.9.3 QPSK, 16QAM and 32QAM modulation (higher symbol rate)

5.10 Synchronization

5.11 Timeslot alignment

5.12 Delta to sync values

5.13 Limit checks

5.13.1 Limit check for modulation spectrum

5.13.2 Limit check for transient spectrum

5.13.3 Limit check for power vs time results

5.14 Impact of the "Statistic count"

Modulation accuracy measurement configuration

6.1 Configuration overview

6.2 Signal description

6.2.1 Device under test settings

6.2.2 Frame

6.2.3 Slot settings

6.2.4 Carrier settings

6.3 Input, output and frontend settings

6.3.1 Input source settings

6.3.1.1 Radio frequency input

6.3.1.2 I/Q file input

6.3.2 Frequency settings

6.3.3 Amplitude settings

6.4 Trigger settings

6.5 Data acquisition

6.5.1 Data acquisition

6.5.2 Capture

6.6 Demodulation

6.6.1 Slot scope

6.6.2 Demodulation settings

6.7 Measurement settings

6.7.1 Power vs time

6.7.2 Spectrum

6.7.3 Trigger to sync

6.8 Adjusting settings automatically

6.9 Result configuration

6.9.1 Traces