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Rohde&Schwarz ESW8, ESW26, ESW44 User Manual

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R&S®ESW Spectrum Application User Manual
1177630002 Version 10
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This manual describes the following R&S®ESW models:
●
R&S®ESW8 (1328.4100K08)
●
R&S®ESW8 (1328.4100K09)
●
R&S®ESW26 (1328.4100K26)
●
R&S®ESW26 (1328.4100K27)
●
R&S®ESW44 (1328.4100K44)
●
R&S®ESW44 (1328.4100K45)
The contents of this manual correspond to firmware version 2.20 and higher. The Spectrum application is integral part of the R&S®ESW.
© 2022 Rohde & Schwarz GmbH & Co. KG Muehldorfstr. 15, 81671 Muenchen, Germany Phone: +49 89 41 29 - 0 Email: info@rohde-schwarz.com Internet: www.rohde-schwarz.com Subject to change – data without tolerance limits is not binding. R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarks of the owners.
1177.6300.02 | Version 10 | R&S®ESW
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol , e.g. R&S®ESW is indicated as R&S ESW.
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Contents

Contents
1 Preface.................................................................................................. 11
1.1 About this manual....................................................................................................... 11
1.2 Documentation overview............................................................................................11
1.2.1 Getting started manual..................................................................................................12
1.2.2 User manuals and help................................................................................................. 12
1.2.3 Service manual............................................................................................................. 12
1.2.4 Instrument security procedures.....................................................................................12
1.2.5 Basic safety instructions................................................................................................13
1.2.6 Data sheets and brochures........................................................................................... 13
1.2.7 Release notes and open source acknowledgment (OSA)............................................ 13
1.2.8 Application notes, application cards, white papers, etc.................................................13
1.3 Conventions used in the documentation..................................................................13
1.3.1 Typographical conventions............................................................................................13
1.3.2 Conventions for procedure descriptions........................................................................14
1.3.3 Notes on screenshots................................................................................................... 14
2 Welcome to the spectrum application............................................... 15
2.1 Starting the application.............................................................................................. 15
2.2 Understanding the display information.................................................................... 16
2.3 R&S multiview............................................................................................................. 17
3 Measurements and results..................................................................19
3.1 Basic measurements.................................................................................................. 20
3.1.1 Basic measurement types.............................................................................................20
3.1.2 How to perform a basic sweep measurement...............................................................21
3.1.3 Measurement examples - measuring a sinusoidal signal............................................. 22
3.1.4 Measurement example – measuring levels at low S/N ratios....................................... 25
3.1.5 Measurement examples - measuring signal spectra with multiple signals....................28
3.1.6 Measurement examples in zero span........................................................................... 34
3.2 Channel power and adjacent-channel power (ACLR) measurement..................... 40
3.2.1 About channel power measurements............................................................................40
3.2.2 Channel power results.................................................................................................. 41
3.2.3 Channel power basics...................................................................................................43
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3.2.10 Reference: predefined ACLR user standard XML files................................................. 89
Contents
3.2.4 Channel power configuration........................................................................................ 56
3.2.5 MSR ACLR configuration.............................................................................................. 64
3.2.6 How to perform channel power measurements............................................................ 79
3.2.7 Measurement examples................................................................................................84
3.2.8 Optimizing and troubleshooting the measurement........................................................87
3.2.9 Reference: predefined CP/ACLR standards................................................................. 88
3.3 Carrier-to-noise measurements.................................................................................90
3.3.1 About the measurement................................................................................................91
3.3.2 Carrier-to-noise results..................................................................................................92
3.3.3 Carrier-to-noise configuration........................................................................................92
3.3.4 How to determine the carrier-to-noise ratio...................................................................94
3.4 Occupied bandwidth measurement (OBW).............................................................. 94
3.4.1 About the measurement................................................................................................95
3.4.2 OBW results.................................................................................................................. 97
3.4.3 OBW configuration........................................................................................................ 97
3.4.4 How to determine the occupied bandwidth................................................................... 99
3.4.5 Measurement example................................................................................................101
3.5 Spectrum emission mask (SEM) measurement..................................................... 101
3.5.1 About the measurement..............................................................................................102
3.5.2 Typical applications.....................................................................................................102
3.5.3 SEM results.................................................................................................................102
3.5.4 SEM basics................................................................................................................. 105
3.5.5 SEM configuration....................................................................................................... 116
3.5.6 How to perform a spectrum emission mask measurement......................................... 133
3.5.7 Measurement example: multi-sem measurement....................................................... 138
3.5.8 Reference: SEM file descriptions................................................................................ 139
3.6 Spurious emissions measurement..........................................................................146
3.6.1 About the measurement..............................................................................................146
3.6.2 Spurious emissions measurement results.................................................................. 147
3.6.3 Spurious emissions basics..........................................................................................148
3.6.4 Spurious emissions measurement configuration........................................................ 150
3.6.5 How to perform a spurious emissions measurement.................................................. 156
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Contents
3.6.6 Reference: ASCII export file format (spurious)........................................................... 158
3.7 Statistical measurements (APD, CCDF)..................................................................159
3.7.1 About the measurements............................................................................................ 159
3.7.2 Typical applications.....................................................................................................160
3.7.3 APD and CCDF results............................................................................................... 160
3.7.4 APD and CCDF basics - gated triggering................................................................... 162
3.7.5 APD and CCDF configuration..................................................................................... 163
3.7.6 How to perform an APD or CCDF measurement........................................................ 169
3.7.7 Examples.................................................................................................................... 170
3.7.8 Optimizing and troubleshooting the measurement......................................................173
3.8 Time domain power measurement.......................................................................... 173
3.8.1 About the measurement..............................................................................................174
3.8.2 Time domain power results......................................................................................... 174
3.8.3 Time domain power basics - range definition using limit lines.................................... 175
3.8.4 Time domain power configuration............................................................................... 175
3.8.5 How to measure powers in the time domain............................................................... 177
3.8.6 Measurement example................................................................................................178
3.9 Harmonic distortion measurement..........................................................................179
3.9.1 About the measurement..............................................................................................179
3.9.2 Harmonic distortion basics.......................................................................................... 180
3.9.3 Harmonic distortion results..........................................................................................182
3.9.4 Harmonic distortion configuration................................................................................183
3.9.5 How to determine the harmonic distortion...................................................................185
3.10 Third order intercept (TOI) measurement............................................................... 185
3.10.1 About the TOI measurement.......................................................................................186
3.10.2 TOI basics................................................................................................................... 186
3.10.3 TOI results...................................................................................................................190
3.10.4 TOI configuration.........................................................................................................191
3.10.5 How to determine the third order intercept..................................................................192
3.10.6 Measurement example – measuring the R&S ESW's intrinsic intermodulation..........193
3.11 AM modulation depth measurement.......................................................................195
3.11.1 About the measurement..............................................................................................195
3.11.2 AM modulation depth results.......................................................................................195
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3.11.3 AM modulation depth configuration.............................................................................196
3.11.4 Optimizing and troubleshooting the measurement......................................................197
3.11.5 How to determine the AM modulation depth............................................................... 198
3.12.1 About the EMI measurement...................................................................................... 199
3.12.2 EMI measurement results........................................................................................... 199
3.12.3 EMI measurement basics............................................................................................200
3.12.4 EMI measurement configuration................................................................................. 209
3.12.5 EMI result analysis...................................................................................................... 218
3.12.6 How to perform EMI measurements........................................................................... 218
3.12.7 Measurement example: measuring radio frequency interference............................... 221
3.12.8 Optimizing and troubleshooting EMI measurements.................................................. 223
Contents
3.12 Electromagnetic interference (EMI) measurement................................................ 198
4 Common measurement settings...................................................... 224
4.1 Measurement basics.................................................................................................224
4.1.1 IF and video signal output........................................................................................... 224
4.2 Configuration overview............................................................................................ 224
4.3 Data input and output............................................................................................... 226
4.3.1 Receiving data input and providing data output.......................................................... 226
4.3.2 Input source settings................................................................................................... 230
4.3.3 Configuring the preselector......................................................................................... 232
4.3.4 Optional external generator control.............................................................................232
4.3.5 Optional external mixers............................................................................................. 260
4.3.6 Output settings............................................................................................................ 283
4.4 Frequency and span configuration......................................................................... 286
4.4.1 Impact of the frequency and span settings................................................................. 287
4.4.2 Frequency and span settings...................................................................................... 288
4.4.3 Keeping the center frequency stable - signal tracking................................................ 292
4.4.4 How to define the frequency range............................................................................. 293
4.4.5 How to move the center frequency through the frequency range............................... 294
4.5 Amplitude and vertical axis configuration..............................................................294
4.5.1 Impact of the vertical axis settings.............................................................................. 295
4.5.2 Amplitude settings.......................................................................................................297
4.5.3 Scaling the Y-Axis....................................................................................................... 300
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Contents
4.5.4 How to optimize the amplitude display........................................................................302
4.6 Bandwidth, filter and sweep configuration.............................................................302
4.6.1 Impact of the bandwidth, filter and sweep settings..................................................... 303
4.6.2 Bandwidth, filter and sweep settings...........................................................................309
4.6.3 Reference: list of available RRC and Channel filters.................................................. 317
4.7 Trigger and gate configuration................................................................................ 319
4.7.1 Triggering.................................................................................................................... 319
4.7.2 Gating..........................................................................................................................329
4.8 Adjusting settings automatically.............................................................................334
5 Common analysis and display functions........................................ 337
5.1 Result display configuration....................................................................................337
5.1.1 Basic evaluation methods........................................................................................... 337
5.1.2 Laying out the result display with the smartgrid.......................................................... 340
5.2 Zoomed displays.......................................................................................................344
5.2.1 Single zoom versus multiple zoom..............................................................................345
5.2.2 Zoom functions............................................................................................................346
5.2.3 How to zoom into a diagram....................................................................................... 348
5.3 Configuring traces.................................................................................................... 351
5.3.1 Basic information about traces....................................................................................351
5.3.2 Trace configuration......................................................................................................367
5.3.3 How to configure traces.............................................................................................. 383
5.3.4 References..................................................................................................................389
5.4 Marker usage............................................................................................................. 392
5.4.1 Basics on markers.......................................................................................................393
5.4.2 Marker settings............................................................................................................396
5.4.3 Marker search settings and positioning functions....................................................... 401
5.4.4 Marker (measurement) functions................................................................................ 407
5.4.5 How to work with markers........................................................................................... 429
5.4.6 Measurement example: measuring harmonics using marker functions...................... 431
5.5 Display and limit lines.............................................................................................. 433
5.5.1 Display lines................................................................................................................ 433
5.5.2 Limit lines.................................................................................................................... 436
6 Remote commands in the spectrum application............................ 453
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Contents
6.1 Introduction............................................................................................................... 453
6.1.1 Conventions used in descriptions............................................................................... 453
6.1.2 Long and short form.................................................................................................... 454
6.1.3 Numeric suffixes..........................................................................................................454
6.1.4 Optional keywords.......................................................................................................455
6.1.5 Alternative keywords................................................................................................... 455
6.1.6 SCPI parameters.........................................................................................................455
6.2 Common suffixes...................................................................................................... 458
6.3 Application selection................................................................................................ 458
6.4 General window commands.....................................................................................461
6.5 Screen layout.............................................................................................................463
6.6 Preset......................................................................................................................... 470
6.7 Measurement configuration..................................................................................... 470
6.7.1 Measurement control.................................................................................................. 470
6.7.2 Power measurements................................................................................................. 473
6.7.3 Channel power and ACLR.......................................................................................... 478
6.7.4 Carrier-to-noise ratio................................................................................................... 519
6.7.5 Occupied bandwidth....................................................................................................520
6.7.6 Spectrum emission mask (SEM).................................................................................522
6.7.7 Spurious emissions..................................................................................................... 558
6.7.8 Statistics......................................................................................................................571
6.7.9 Time domain power.....................................................................................................581
6.7.10 Harmonic distortion..................................................................................................... 591
6.7.11 Third order intercept point (TOI)..................................................................................594
6.7.12 AM modulation depth.................................................................................................. 597
6.7.13 List evaluations........................................................................................................... 600
6.7.14 Measuring the pulse power......................................................................................... 604
6.7.15 EMI measurements..................................................................................................... 608
6.7.16 Programming example: EMI measurement.................................................................616
6.7.17 Programming example: carrier-to-noise ratio..............................................................618
6.7.18 Programming example: performing a basic frequency sweep.................................... 619
6.8 Configuration.............................................................................................................622
6.8.1 Inputs and output configuration...................................................................................622
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Contents
6.8.2 Frequency configuration..............................................................................................655
6.8.3 Amplitude configuration...............................................................................................661
6.8.4 Y-Axis scaling..............................................................................................................665
6.8.5 Bandwidth configuration..............................................................................................668
6.8.6 Sweep configuration....................................................................................................671
6.8.7 Trigger configuration................................................................................................... 677
6.8.8 Automatic configuration...............................................................................................684
6.9 Analysis..................................................................................................................... 687
6.9.1 Zoom........................................................................................................................... 688
6.9.2 Trace configuration......................................................................................................691
6.9.3 Marker configuration................................................................................................... 714
6.9.4 Lines............................................................................................................................771
List of commands.............................................................................. 789
Index....................................................................................................802
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Contents
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1 Preface

1.1 About this manual

This User Manual provides all the information specific to RF measurements in the Spectrum application. All other operating modes and applications are described in
the specific application manuals.
The main focus in this manual is on the measurement results and the tasks required to obtain them. The following topics are included:
●
Welcome to the R&S ESW
Introduction to and getting familiar with the instrument
●
Measurements
Descriptions of the individual measurements in the Spectrum application, including result types and configuration settings.
●
Common Measurement Settings
Description of the measurement settings common to all measurement types with their corresponding remote control commands
●
Common Measurement Analysis and Display Functions
Description of the settings and functions provided to analyze results independently of the measurement type with their corresponding remote control commands
●
Remote Commands
Remote commands required to configure and perform measurements in a remote environment, sorted by tasks Remote commands required to set up the environment and to perform common tasks on the instrument, sorted by tasks Programming examples demonstrate the use of many commands and can usually be executed directly for test purposes
●
List of Commands
Alphabetical list of all remote commands described in the manual
●
Index
Preface
Documentation overview

1.2 Documentation overview

This section provides an overview of the R&S ESW user documentation. You find it on the product page at:
www.rohde-schwarz.com/manual/esw
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1.2.1 Getting started manual

1.2.2 User manuals and help

Preface
Documentation overview
Introduces the R&S ESW and describes how to set up and start working with the prod­uct. Includes basic operations, typical measurement examples, and general informa­tion, e.g. safety instructions, etc.
A printed version is delivered with the instrument. A PDF version is available for down­load on the Internet.
Separate user manuals are provided for the base unit and the firmware applications:
●
Base unit manual Contains the description of all instrument modes and functions. It also provides an introduction to remote control, a complete description of the remote control com­mands with programming examples, and information on maintenance, instrument interfaces and error messages. Includes the contents of the getting started manual.
●
Manuals for (optional) firmware applications Contains the description of the specific functions of a firmware application, includ­ing remote control commands. Basic information on operating the R&S ESW is not included.
The contents of the user manuals are available as help in the R&S ESW. The help offers quick, context-sensitive access to the complete information for the base unit and the firmware applications.
All user manuals are also available for download or for immediate display on the Inter­net.

1.2.3 Service manual

Describes the performance test for checking the rated specifications, module replace­ment and repair, firmware update, troubleshooting and fault elimination, and contains mechanical drawings and spare part lists.
The service manual is available for download for registered users on the global Rohde & Schwarz information system (GLORIS):
https://gloris.rohde-schwarz.com

1.2.4 Instrument security procedures

Deals with security issues when working with the R&S ESW in secure areas. It is avail­able for download on the Internet.
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1.2.5 Basic safety instructions

1.2.6 Data sheets and brochures

1.2.7 Release notes and open source acknowledgment (OSA)

Preface
Conventions used in the documentation
Contains safety instructions, operating conditions and further important information. The printed document is delivered with the instrument.
The data sheet contains the technical specifications of the R&S ESW. It also lists the options and their order numbers, and optional accessories.
The brochure provides an overview of the instrument and deals with the specific char­acteristics.
See www.rohde-schwarz.com/brochure-datasheet/esw
The release notes list new features, improvements and known issues of the current firmware version, and describe the firmware installation.
The open source acknowledgment document provides verbatim license texts of the used open source software.
See www.rohde-schwarz.com/firmware/esw

1.2.8 Application notes, application cards, white papers, etc.

These documents deal with special applications or background information on particu­lar topics.
See www.rohde-schwarz.com/application/esw

1.3 Conventions used in the documentation

1.3.1 Typographical conventions

The following text markers are used throughout this documentation:
Convention Description
"Graphical user interface ele­ments"
[Keys] Key and knob names are enclosed by square brackets.
All names of graphical user interface elements on the screen, such as dialog boxes, menus, options, buttons, and softkeys are enclosed by quotation marks.
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Preface
Conventions used in the documentation
Convention Description
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-
Filenames, commands, coding samples and screen output are distin­guished by their font.
tion marks.

1.3.2 Conventions for procedure descriptions

When operating the instrument, several alternative methods may be available to per­form the same task. In this case, the procedure using the touchscreen is described. Any elements that can be activated by touching can also be clicked using an addition­ally connected mouse. The alternative procedure using the keys on the instrument or the on-screen keyboard is only described if it deviates from the standard operating pro­cedures.
The term "select" may refer to any of the described methods, i.e. using a finger on the touchscreen, a mouse pointer in the display, or a key on the instrument or on a key­board.

1.3.3 Notes on screenshots

When describing the functions of the product, we use sample screenshots. These screenshots are meant to illustrate as many as possible of the provided functions and possible interdependencies between parameters. The shown values may not represent realistic usage scenarios.
The screenshots usually show a fully equipped product, that is: with all options instal­led. Thus, some functions shown in the screenshots may not be available in your par­ticular product configuration.
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Welcome to the spectrum application
Starting the application

2 Welcome to the spectrum application

The Spectrum application is a firmware application that adds functionality to perform signal and spectrum analysis to the R&S ESW. The application is part of the R&S ESW firmware.
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 Receiver appli­cation and are described in the R&S ESW User Manual. The latest versions of the manuals are available for download at the product homepage.
http://www2.rohde-schwarz.com/product/ESW.html.
Installation
Find detailed installing instructions in the Getting Started or the release notes of the R&S ESW.
● Starting the application............................................................................................15
● Understanding the display information....................................................................16
● R&S multiview.........................................................................................................17

2.1 Starting the application

Access: [MODE] > "Spectrum"
Multiple Measurement Channels and Sequencer Function
When you enter an application, a new measurement channel is created which deter­mines the measurement settings for that application. The same application can be acti­vated with different measurement settings by creating several channels for the same application.
The number of channels that can be configured at the same time depends on the avail­able memory on the instrument.
Only one measurement can be performed at any time, namely the one in the currently active channel. However, in order to perform the configured measurements consecu­tively, a Sequencer function is provided.
If activated, the measurements configured in the currently active channels are per­formed one after the other in the order of the tabs. The currently active measurement is indicated by a are updated in the tabs (as well as the "MultiView") as the measurements are per­formed. Sequential operation itself is independent of the currently displayed tab.
symbol in the tab label. The result displays of the individual channels
For details on the Sequencer function see the R&S ESW User Manual.
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Welcome to the spectrum application
Understanding the display information

2.2 Understanding the display information

The following figure shows the display as it looks for measurements in spectrum mode. All different information areas are labeled. They are explained in more detail in the fol­lowing sections.
1
Figure 2-1: Screen layout of the noise figure measurement application
42 3 5 6
1 = Toolbar 2 = Channel bar 3 = Diagram header 4 = Result display 5 = Status bar 6 = Softkey bar
Channel bar information
The channel bar contains information about the current measurement setup, progress and results.
Figure 2-2: Channel bar of the Spectrum application
Ref Level Reference level of the R&S ESW.
Att Attenuation of the R&S ESW.
Input Input and input coupling
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Welcome to the spectrum application
R&S multiview
SWT Sweep time
PS Preselector state
RBW Resolution bandwidth
VBW Video bandwidth
Mode Currently selected measurement mode, including the sweep count.
Frequency Center frequency
Window title bar information
For each diagram, the header provides the following information:
1 2 3 4
Figure 2-3: Window title bar information for the Noise Figure application
1 = Window number 2 = Window type 3 = Trace color and number 4 = Trace mode and detector
Status bar information
Global instrument settings, the instrument status and any irregularities are indicated in the status bar beneath the diagram. Furthermore, the progress of the current operation is displayed in the status bar.

2.3 R&S multiview

Each application is displayed in a separate tab. An additional tab ("MultiView") provides an overview of all currently active channels at a glance. In the "MultiView" tab, each individual window contains its own channel bar with an additional button. Select this button to switch to the corresponding channel display quickly.
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Welcome to the spectrum application
R&S multiview
Remote command:
DISPlay:FORMat on page 462
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Measurements and results

3 Measurements and results

Access: "Overview" > "Select Measurement"
Or: [MEAS]
In the Spectrum application, the R&S ESW provides a variety of different measurement functions.
●
Basic measurements - measure the spectrum of your signal or watch your signal in time domain
●
Power measurements - calculate the powers involved in modulated carrier signals
●
Emission measurements - detect unwanted signal emission
●
Statistic measurements - evaluate the spectral distribution of the signal
●
Special measurements - provide characteristic values of the signal
●
EMI measurements - detect electromagnetic interference in the signal
The individual functions are described in detail in the following chapters.
The measurement function determines which settings, functions and evaluation meth­ods are available in the R&S ESW. The various measurement functions are described in detail here.
When you select a measurement function, the measurement is started with its default settings immediately and the corresponding measurement configuration menu is dis­played. The measurement configuration menu can be displayed at any time by press­ing the [MEAS CONFIG] key.
The easiest way to configure measurements is using the configuration "Overview", see
Chapter 4.2, "Configuration overview", on page 224.
In addition to the measurement-specific parameters, the general parameters can be configured as usual, see Chapter 4, "Common measurement settings", on page 224. Many measurement functions provide special result displays or evaluation methods; however, in most cases the general evaluation methods are also available, see Chap-
ter 5, "Common analysis and display functions", on page 337.
The remote commands required to retrieve measurement results are described in
Chapter 6.9.2.1, "Trace data retrieval", on page 691.
● Basic measurements...............................................................................................20
● Channel power and adjacent-channel power (ACLR) measurement......................40
● Carrier-to-noise measurements.............................................................................. 90
● Occupied bandwidth measurement (OBW).............................................................94
● Spectrum emission mask (SEM) measurement....................................................101
● Spurious emissions measurement........................................................................146
● Statistical measurements (APD, CCDF)............................................................... 159
● Time domain power measurement........................................................................173
● Harmonic distortion measurement........................................................................ 179
● Third order intercept (TOI) measurement............................................................. 185
● AM modulation depth measurement..................................................................... 195
● Electromagnetic interference (EMI) measurement................................................198
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3.1.1 Basic measurement types

Measurements and results
Basic measurements

3.1 Basic measurements

Basic measurements are common sweeps in the time or frequency domain which pro­vide an overview of the basic input signal characteristics.
If no other measurement function is selected, or if all measurement functions are switched off, the R&S ESW performs a basic frequency or time sweep.
Use the general measurement settings to configure the measurement, e.g. via the "Overview" (see Chapter 4, "Common measurement settings", on page 224).
Frequency Sweep......................................................................................................... 20
Zero Span..................................................................................................................... 20
All Functions Off............................................................................................................21
Frequency Sweep
A common frequency sweep of the input signal over a specified span. Can be used for general purposes to obtain basic measurement results such as peak levels and spec­trum traces. The "Frequency" menu is displayed. This is the default measurement if no other function is selected.
Use the general measurement settings to configure the measurement, e.g. via the "Overview" (see Chapter 4, "Common measurement settings", on page 224).
Remote command:
[SENSe:]FREQuency:STARt on page 658, [SENSe:]FREQuency:STOP
on page 658
INITiate<mt>[:IMMediate] on page 471 INITiate<n>:CONTinuous on page 472
Zero Span
A sweep in the time domain at the specified (center) frequency, i.e. the frequency span is set to zero. The display shows the time on the x-axis and the signal level on the y­axis, as on an oscilloscope. On the time axis, the grid lines correspond to 1/10 of the current sweep time.
Use the general measurement settings to configure the measurement, e.g. via the "Overview" (see Chapter 4, "Common measurement settings", on page 224).
Most result evaluations can also be used for zero span measurements, although some functions (e.g. markers) may work slightly differently and some may not be available. If so, this will be indicated in the function descriptions (see Chapter 5, "Common analysis
and display functions", on page 337).
Remote command:
[SENSe:]FREQuency:SPAN on page 658 INITiate<mt>[:IMMediate] on page 471 INITiate<n>:CONTinuous on page 472
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3.1.2 How to perform a basic sweep measurement

Measurements and results
Basic measurements
All Functions Off
Switches off all measurement functions and returns to a basic frequency sweep. Selecting "Frequency Sweep" has the same effect.
The following step-by-step instructions demonstrate how to perform basic sweep mea­surements.
For remote operation, see Chapter 6.7.18, "Programming example: performing a basic
frequency sweep", on page 619.
To perform one or more single sweeps
1. Configure the frequency and span to be measured ("Frequency" dialog box, see
Chapter 4.4, "Frequency and span configuration", on page 286).
2. Configure the number of sweeps to be performed in a single measurement ("Sweep Config" dialog box, see "Sweep/Average Count" on page 313).
3. If necessary, configure how the signal is processed internally ("Bandwidth" dialog box, see "Sweep Type" on page 315).
4. If necessary, configure a trigger for the measurement ("Trigger/ Gate Config" dialog box, see Chapter 4.7, "Trigger and gate configuration", on page 319).
5. Define how the results are evaluated for display ("Trace" dialog box, see Chap-
ter 5.3.2.1, "Trace settings", on page 367).
6. If necessary, configure the vertical axis of the display ("Amplitude" dialog box, see
Chapter 4.5.3, "Scaling the Y-Axis", on page 300).
7. To start the measurement, select one of the following:
● [RUN SINGLE] key
● "Single Sweep" softkey in the "Sweep" menu The defined number of sweeps are performed, then the measurement is stopped.
While the measurement is running, the [RUN SINGLE] key is highlighted. To abort the measurement, press the [RUN SINGLE] key again. The key is no longer high­lighted. The results are not deleted until a new measurement is started.
8. To repeat the same number of sweeps without deleting the last trace, select the "Continue Single Sweep" softkey in the "Sweep" menu.
To start continuous sweeping
1. If you want to average the trace or search for a maximum over more (or less) than 10 sweeps, configure the "Sweep/Average Count" ("Sweep Config" dialog box, see
"Sweep/Average Count" on page 313).
2. To start the measurement, select one of the following:
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3.1.3 Measurement examples - measuring a sinusoidal signal

Measurements and results
Basic measurements
● [RUN CONT] key
● "Continuous Sweep" softkey in the "Sweep" menu After each sweep is completed, a new one is started automatically. While the mea-
surement is running, the [RUN CONT] key is highlighted. To stop the measure­ment, press the [RUN CONT] key again. The key is no longer highlighted. The results are not deleted until a new measurement is started.
One of the most common measurement tasks that can be handled using a signal ana­lyzer is determining the level and frequency of a signal. When measuring an unknown signal, you can usually start with the presettings.
Test setup
1. Configure the signal generator (e.g. R&S SMW):
● Frequency: 128 MHz
● Level: -30 dBm
NOTICE! Signal levels exceeding 30 dBm can damage the RF attenuator or the
2. input mixer. When calculating the expected power level, consider the total power of all occuring signals.
If you measure signals higher than +30 dBm (=1 W), insert a power attenuator before the RF input of the analyzer.
3. Connect the RF output of the signal generator to the RF input of the R&S ESW.
● Measuring the level and frequency using markers..................................................22
● Measuring the signal frequency using the signal counter....................................... 24
3.1.3.1 Measuring the level and frequency using markers
The level and frequency of a sinusoidal signal can be measured easily using the marker function. The R&S ESW always displays its amplitude and frequency at the marker position. The frequency measurement uncertainty is determined by the refer­ence frequency of the R&S ESW, the resolution of the marker frequency display and the number of sweep points.
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Connect the signal to be measured to the "RF INPUT" connector on the R&S ESW.
4. Set the center frequency to 128
5. Reduce the frequency span to 1 MHz.
MHz.
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Note: Coupled settings. When the frequency span is defined, the resolution band­width, the video bandwidth and the sweep time are automatically adjusted, because these functions are defined as coupled functions in the presettings.
6. Select [MKR] to activate marker 1 and automatically set it to the maximum of the trace.
The level and frequency values measured by the marker are displayed in the marker information at the top of the display.
Note: Performing a peak search. When a marker is initially activated, it automati­cally performs the peak search function (as shown in the example). If a marker was already active, select the [Peak Search] key or the "Peak" softkey in the [MKR >] menu in order to set the currently active marker to the maximum of the displayed signal.
Increasing the frequency resolution
The frequency resolution of the marker is determined by the resolution of the trace. A trace consists of 1001 trace points, i.e. if the frequency span is 1 MHz, each trace point represents a span of approximately 1 kHz. This corresponds to a maximum uncertainty of +/- 0.5 kHz.
You can increase the resolution of the trace by reducing the frequency span.
Reducing the frequency span to 10 kHz
► Reduce the frequency span to 10 kHz.
The resolution of the trace is now approximately 10 Hz (10 kHz span / 1001 trace points), thus, the precision of the marker frequency display increases to approxi­mately ±5 Hz.
Setting the reference level
The reference level is the level at the upper limit of the diagram. To achieve the widest dynamic range possible for a spectrum measurement, use the entire level span of the R&S ESW. In other words, the highest level that occurs in the signal should be located at the top edge of the diagram ( = reference level) or immediately below it.
Low Reference Levels
If the selected reference level is lower than the highest signal that occurs in the spec­trum, the signal path in the R&S ESW is overloaded.
In this case, the message "IFOVL" is displayed in the error message field.
In the presettings, the value of the reference level is 0 dBm. If the input signal is
-30 dBm, the reference level can be reduced by 30 dB without causing the signal path
to be overloaded.
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3.1.3.2 Measuring the signal frequency using the signal counter
Measurements and results
Basic measurements
Reducing the reference level by 30 dB
► Set the reference level to -30 dBm.
The maximum of the trace is near the maximum of the measurement diagram. The increase in the displayed noise is not substantial. Thus, the distance between the signal maximum and the noise display (=dynamic range) has increased.
Setting the reference level with the help of a marker
You can also use a marker to shift the maximum value of the trace directly to the top edge of the diagram. If the marker is located at the maximum level of the trace (as in this example), the reference level can be moved to the marker level as follows:
1. Press the [MKR ->] key.
2. Select "Ref Lvl = Mkr Lvl".
The reference level is set to the current marker level.
The built-in signal counter allows you to measure the frequency more accurately than measuring it with the marker. The frequency sweep is stopped at the marker, and the R&S ESW measures the frequency of the signal at the marker position (see also Chap-
ter 5.4.4.1, "Precise frequency (signal count) marker", on page 408).
In the following example, the frequency of the generator at 128 MHz is shown using the marker.
Prerequisite
Precise frequency measurements require a precise reference frequency. Therefore, an external reference frequency from the signal generator is used. Connect the signal generator's "Ref OUT" connector to the analyzer's "Ref IN" connector.
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 128 MHz.
4. Set the frequency span to 1 MHz.
5. Select "Setup" > "Reference" > "External Reference 10 MHz" to activate the exter­nal reference frequency.
6. Select [MKR] to activate marker 1 and automatically set it to the maximum of the trace.
The level and the frequency of the marker are displayed in the marker results in the diagram or the marker table.
7. Select [MKR FUNC] > "Signal Count" to activate the signal counter. The result of the signal counter is displayed in the marker results.
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3.1.4 Measurement example – measuring levels at low S/N ratios

Measurements and results
Basic measurements
8. If necessary, increase the resolution of the signal counter by selecting "Signal Count Resolution" (in the "Signal Count" menu).
Prerequisites for using the internal signal counter
In order to obtain a correct result when measuring the frequency with the internal sig­nal counter, an RF sinusoidal signal or a spectral line must be available. The marker must be located more than 25 dB above the noise level to ensure that the specified measurement accuracy is adhered to.
The minimum signal level a signal analyzer can measure is limited by its intrinsic noise. Small signals can be swamped by noise and therefore cannot be measured. For sig­nals that are just above the intrinsic noise, the accuracy of the level measurement is influenced by the intrinsic noise of the R&S ESW.
The displayed noise level of a signal analyzer depends on its noise figure, the selected RF attenuation, the selected reference level, the selected resolution and video band­width and the detector.
For details see:
●
"Attenuation" on page 299
●
Chapter 4.5.1.1, "Reference level", on page 295
●
Chapter 4.6.1.1, "Separating signals by selecting an appropriate resolution band­width", on page 303
●
Chapter 4.6.1.2, "Smoothing the trace using the video bandwidth", on page 304
●
Chapter 5.3.1.1, "Mapping samples to sweep points with the trace detector",
on page 351
This measurement example shows the different factors influencing the S/N ratio.
Table 3-1: Signal generator settings (e.g. R&S SMW)
Frequency 128 MHz
Level -95 dBm
1. Preset the R&S ESW.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 128 MHz.
4. Set the span to 100 MHz.
5. Set the reference level to -30
dBm.
The signal is measured with the auto peak detector and is completely hidden in the intrinsic noise of the R&S ESW.
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Figure 3-1: Sine wave signal with low S/N ratio
6. To suppress noise spikes, average the trace. In the "Traces" configuration dialog, set the "Trace Mode" to "Average" (see "Trace Mode" on page 368).
The traces of consecutive sweeps are averaged. To perform averaging, the R&S ESW automatically switches on the sample detector. The RF signal, therefore, can be more clearly distinguished from noise.
Figure 3-2: RF sine wave signal with low S/N ratio with an averaged trace
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7. Instead of trace averaging, you can select a video filter that is narrower than the resolution bandwidth. Set the trace mode back to "Clear/ Write", then set the VBW to 10 kHz manually in the "Bandwidth" configuration dialog.
The RF signal can be distinguished from noise more clearly.
Figure 3-3: RF sine wave signal with low S/N ratio with a smaller video bandwidth
8. By reducing the resolution bandwidth by a factor of 10, the noise is reduced by 10 dB. Set the RBW to 100 kHz.
The displayed noise is reduced by approximately 10 dB. The signal, therefore, emerges from noise by about 10 dB. Compared to the previous setting, the video bandwidth has remained the same, i.e. it has increased relative to the smaller reso­lution bandwidth. The averaging effect of the video bandwidth is therefore reduced. The trace will be noisier.
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Figure 3-4: Reference signal at a smaller resolution bandwidth

3.1.5 Measurement examples - measuring signal spectra with multiple signals

● Separating signals by selecting the resolution bandwidth...................................... 28
● Measuring the modulation depth of an AM-modulated carrier in the frequency
domain.................................................................................................................... 31
● Measuring AM-modulated signals...........................................................................32
3.1.5.1 Separating signals by selecting the resolution bandwidth
A basic feature of a Signal and Spectrum Analyzer is the ability to separate the spec­tral components of a mixture of signals. The resolution at which the individual compo­nents can be separated is determined by the resolution bandwidth. Selecting a resolu­tion bandwidth that is too large may make it impossible to distinguish between spectral components, i.e. they are displayed as a single component (see also Chapter 4.6.1.1,
"Separating signals by selecting an appropriate resolution bandwidth", on page 303).
Two signals with the same amplitude can be resolved if the resolution bandwidth is smaller than or equal to the frequency spacing of the signal. If the resolution bandwidth is equal to the frequency spacing, the spectrum display shows a level drop of 3 dB pre­cisely in the center of the two signals. Decreasing the resolution bandwidth makes the level drop larger, which thus makes the individual signals clearer.
In this measurement example we will analyze two signals with a level of -30 dBm each and a frequency spacing of 30 kHz.
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Signal
Generator 1
Coupler
[-6 dB]
R&S ESW
Signal
Generator 2
Figure 3-5: Test setup
Table 3-2: Signal generator settings (e.g. R&S SMW)
Measurements and results
Basic measurements
Signal generator 1 -30 dBm 128,00 MHz
Signal generator 2 -30 dBm 128,03 MHz
Level Frequency
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 128.015
MHz.
4. Set the frequency span to 300 kHz.
5. Set the resolution bandwidth to 30 kHz and the video bandwidth to 1 kHz.
Note: Larger video bandwidths. The video bandwidth is set to 1 kHz in order to make the level drop in the center of the two signals clearly visible. At larger video bandwidths, the video voltage that results from envelope detection is not suffi­ciently suppressed. This produces additional voltages, which are visible in the trace, in the transition area between the two signals.
Figure 3-6: Measurement of two equally-leveled RF sinusoidal signals with the resolution band-
width which corresponds to the frequency spacing of the signals
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Matching generator and R&S ESW frequencies
The level drop is located exactly in the center of the display only if the generator frequencies match the frequency display of the R&S ESW exactly. To achieve exact matching, the frequencies of the generators and the R&S ESW must be synchronized.
6. Set the resolution bandwidth to 100 kHz.
It is no longer possible to clearly distinguish the two generator signals.
Figure 3-7: Measurement of two equally-leveled RF sinusoidal signals with a resolution band-
width which is larger than their frequency spacing
7. Set the resolution bandwidth to 1 kHz.
The two generator signals are shown with high resolution. However, the sweep time becomes longer. At smaller bandwidths, the noise display decreases simulta­neously (10 dB decrease in noise floor for a decrease in bandwidth by a factor of
10).
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Figure 3-8: Measurement of two equally-leveled RF sinusoidal signals with a resolution band-
width (1 kHz) which is significantly smaller than their frequency spacing
3.1.5.2 Measuring the modulation depth of an AM-modulated carrier in the frequency domain
In the frequency range display, the AM side bands can be resolved with a narrow bandwidth and measured separately. The modulation depth of a carrier modulated with a sinusoidal signal can then be measured. Since the dynamic range of a signal ana­lyzer is very large, extremely small modulation depths can also be measured precisely. For this purpose, the R&S ESW provides measurement routines that output the modu­lation depth numerically in percent directly.
Signal
Generator
Figure 3-9: Test setup
Table 3-3: Signal generator settings (e.g. R&S SMW)
Frequency 128 MHz
Level -30 dBm
R&S ESW
Modulation 50 % AM, 10 kHz AF
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 128 MHz.
4. Set the frequency span to 50 kHz.
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5. Select [MEAS] > "AM Modulation Depth" to activate the modulation depth mea-
surement. The R&S ESW automatically sets a marker to the carrier signal in the center of the
diagram and one delta marker each to the upper and lower AM sidebands. The R&S ESW calculates the AM modulation depth from the level differences of the delta markers to the main marker and outputs the numeric value in the marker information.
Figure 3-10: Measurement of the AM modulation depth
The modulation depth is displayed as "MDepth". The frequency of the AF signal can be obtained from the frequency display of the delta marker.
3.1.5.3 Measuring AM-modulated signals
The R&S ESW rectifies the RF input signal (that is, removes the negative parts) and displays it as a magnitude spectrum. The rectification also demodulates AM-modulated signals. The AF voltage can be displayed in zero span if the modulation sidebands fall within the resolution bandwidth.
Displaying the AF of an AM-modulated signal (Zero Span)
Signal
Generator
Figure 3-11: Test setup
R&S ESW
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Table 3-4: Signal generator settings (e.g. R&S SMW)
Frequency 128 MHz
Level -30 dBm
Modulation 50 % AM, 1 kHz AF
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 128
4. Set the frequency span to 0
MHz.
Hz or select "Zero Span".
5. Set the sweep time to 2.5 ms.
6. Set the RBW to 3 MHz.
7. Set the reference level to -24 dBm and the display range to linear ([AMPT] > "Scale
Config" > "Scaling": "Linear Percent").
8. Set the scaling unit to Volt ([AMPT] > "Amplitude Config" > "Unit": "V").
9. Define triggering in response to the AF signal using the video trigger to produce a
static image. a) Press the [TRIG] key.
b) Select "Video". c) Set the "Trg/Gate Level" to 50%.
The trigger level is displayed as a horizontal line across the entire measurement diagram. The R&S ESW displays the 1 kHz AF signal as a static image in zero span.
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Figure 3-12: Measurement of the AF signal of a carrier that is AM-modulated with 1 kHz
10. Activate the internal AM demodulator to output the audio signal.
a) Press the [MKR FUNC] key. b) Select "Marker Demodulation".
The R&S ESW automatically switches on the AM audio demodulator. A 1 kHz tone can be heard over headset (via the headphone connector). If necessary, use the volume control to turn up the volume.

3.1.6 Measurement examples in zero span

For radio transmission systems that use the TDMA method (for example, GSM), trans­mission quality is determined not only by spectral characteristics but also by character­istics in zero span. A timeslot is assigned to each user since several users share the same frequency. Smooth operation is ensured only if all users adhere exactly to their assigned timeslots.
Both the power during the send phase as well as the timing and duration of the TDMA burst, and rise and fall times of the burst, are important.
● Measuring the power characteristic of burst signals............................................... 34
● Measuring the signal-to-noise ratio of burst signals................................................38
3.1.6.1 Measuring the power characteristic of burst signals
To measure power in zero span, the R&S ESW offers easy-to-use functions that mea­sure the power over a predefined time.
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Measuring the power of a GSM burst during the activation phase
Signal
Generator
Figure 3-13: Test setup
Table 3-5: Signal generator settings (e.g. R&S SMW)
Frequency 890 MHz
Level 0 dBm
Modulation GSM, one timeslot activated
R&S ESW
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 890
MHz ([FREQ]).
4. Set the frequency span to 0 Hz ([SPAN] > "Zero Span").
5. Set the reference level to 10
dBm (= level of the signal generator +10 dB) (AMPT).
6. Set the attenuation to 20 dB ([AMPT] > "RF Atten Manual").
7. Set the resolution bandwidth to 1 MHz ([BW] > "Res BW").
8. Set the sweep time to 1 ms ([SWEEP] > Sweep Time Manual).
The R&S ESW shows the GSM burst continuously across the display.
9. Using the video trigger, set triggering on the rising edge of the burst.
a) Press the [TRIG] key. b) Set the "Trg Source" to "Video". c) Set the "Trg/Gate Level" to 70%.
The R&S ESW shows a static image with the GSM burst at the start of the trace. The trigger level is displayed as a horizontal line labeled with the absolute level for the trigger threshold in the measurement diagram.
10. Activate power measurement within the activation phase of the burst in zero span.
a) Press the [MEAS] key. b) Select "Time Domain Power". c) Select "Time Dom Power Config". d) Set the "Limits" state to "On". e) Select the "Left Limit" input field. f) By turning the rotary knob clockwise, move the vertical line "S1" to the start of
the burst.
g) Select the "Right Limit" input field.
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h) By turning the rotary knob clockwise, move the vertical line "S2" to the end of
the burst.
The R&S ESW displays the average (mean) power during the activation phase of the burst.
Figure 3-14: Measurement of the average power during the burst of a GSM signal
Measuring the edges of a GSM burst with high time resolution
Due to the high time resolution of the R&S ESW at the 0 Hz display range, the edges of TDMA bursts can be measured precisely. The edges can be shifted to the display area using the trigger offset.
Signal
Generator
Figure 3-15: Test setup
Table 3-6: Signal generator settings (e.g. R&S SMW)
Frequency 890 MHz
Level 0 dBm
Modulation GSM, one timeslot activated
R&S ESW
The measurement is based on the example "Measuring the power of a GSM burst dur-
ing the activation phase" on page 35.
1. Switch off the power measurement.
a) Press the [MEAS] key. b) Select "Zero Span".
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2. Increase the time resolution by setting the sweep time to 100 µs ([SWEEP] >
Sweep Time Manual).
3. Shift the rising edge of the GSM burst to the center of the display by defining a trig-
ger offset. a) Press the [TRIG] key.
b) Select "Trigger Offset". c) By turning the rotary knob counterclockwise, reduce the trigger offset until the
burst edge is displayed in the center of the display, or enter -50
µs.
The R&S ESW displays the rising edge of the GSM burst.
Figure 3-16: Rising edge of the GSM burst displayed with high time resolution
4. Move the falling edge of the burst to the center of the display. To do so, switch the
trigger "Slope" to "Falling" ([TRIG] > "Trigger/ Gate Config"). The R&S ESW displays the falling edge of the GSM burst.
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Figure 3-17: Falling edge of the GSM burst displayed with high time resolution
3.1.6.2 Measuring the signal-to-noise ratio of burst signals
When TDMA transmission methods are used, the signal-to-noise ratio or the dynamic range for deactivation can be measured by comparing the power values during the activation phase and the deactivation phase of the transmission burst. Therefore, the R&S ESW provides a measurement for absolute and relative power in zero span. In the following example, the measurement is performed using a GSM burst.
Signal-to-Noise Ratio of a GSM Signal
Signal
Generator
Figure 3-18: Test setup
Table 3-7: Signal generator settings (e.g. R&S SMW)
Frequency 890 MHz
Level 0 dBm
Modulation GSM, one time slot is switched on
R&S ESW
1. Select [PRESET] to reset the instrument.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 890
MHz.
4. Set the frequency span to 0 Hz.
5. Set the resolution bandwidth to 1 MHz.
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6. Set the reference level to 0 dBm (= level of the signal generator).
7. Set the sweep time to 2 ms ([SWEEP] > Sweep Time Manual).
The R&S ESW shows the GSM burst continuously across the display.
8. Use the trigger source "Video" and the trigger slope "Rising" to trigger on the rising
edge of the burst and shift the start of the burst to the center of the display (see
step 3 in "Measuring the edges of a GSM burst with high time resolution"
on page 36).
9. Activate power measurement within the activation phase of the burst in zero span.
a) Press the [MEAS] key. b) Select "Time Domain Power". c) Select "Time Dom Power Config". d) Set the "Limits" state to "On". e) Select the "Left Limit" input field. f) By turning the rotary knob clockwise, move the vertical line "S1" to the start of
the burst. g) Select the "Right Limit" input field. h) By turning the rotary knob clockwise, move the vertical line "S2" to the end of
the burst. i) Note down the power result for the burst, indicated by the "TD Pow RMS" result
in the marker table.
10. Measure the power during the deactivation phase of the burst by switching the trig­ger slope to "Falling" ([TRIG] > "Trigger/ Gate Config").
The R&S ESW initiates triggering in response to the falling edge of the burst. This shifts the burst to the left-hand side of the measurement diagram. The power is measured in the deactivation phase.
Figure 3-19: Measurement of the signal-to-noise ratio of a GSM burst signal in zero span
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Channel power and adjacent-channel power (ACLR) measurement
11. Note down the power result for the measured noise, indicated by the "TD Pow RMS" result in the marker table.
Subtract the measured noise power from the burst power to obtain the signal-to­noise ratio of the burst signal.

3.2 Channel power and adjacent-channel power (ACLR) measurement

Measuring the power in channels adjacent to the carrier or transmission channel is useful to detect interference. The results are displayed as a bar chart for the individual channels.
● About channel power measurements......................................................................40
● Channel power results............................................................................................ 41
● Channel power basics.............................................................................................43
● Channel power configuration.................................................................................. 56
● MSR ACLR configuration........................................................................................64
● How to perform channel power measurements...................................................... 79
● Measurement examples..........................................................................................84
● Optimizing and troubleshooting the measurement..................................................87
● Reference: predefined CP/ACLR standards........................................................... 88
● Reference: predefined ACLR user standard XML files........................................... 89

3.2.1 About channel power measurements

Measuring channel power and adjacent channel power is one of the most important tasks during signal analysis with the necessary test routines in the field of digital trans­mission. Theoretically, a power meter could be used to measure channel power at highest accuracy. However, its low selectivity means that it is not suitable for measur­ing adjacent channel power as an absolute value or relative to the transmit channel power. Only a selective power meter can measure the power in the adjacent channels.
A signal analyzer cannot be classified as a true power meter, because it displays the IF envelope voltage. However, it is calibrated such as to display the power of a pure sine wave signal correctly, irrespective of the selected detector. This calibration cannot be applied for non-sinusoidal signals. Assuming that the digitally modulated signal has a Gaussian amplitude distribution, the signal power within the selected resolution band­width can be obtained using correction factors. The internal power measurement rou­tines in a signal analyzer normally use these correction factors to determine the signal power from IF envelope measurements. These factors apply if and only if the assump­tion of a Gaussian amplitude distribution is correct.
Apart from this common method, the R&S ESW also has a true power detector, i.e. an RMS detector. It displays the power of the test signal within the selected resolution bandwidth correctly, irrespective of the amplitude distribution, without additional correc­tion factors being required.
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3.2.2 Channel power results

Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
The R&S ESW software allows you to perform ACLR measurements on input contain­ing multiple signals for different communication standards. A measurement standard is provided that allows you to define multiple discontiguous transmit channels at specified frequencies, independent from the selected center frequency. The ACLR measurement determines the power levels of the individual transmit, adjacent, and gap channels, as well as the total power for each sub block of transmit channels.
A detailed measurement example is provided in Chapter 3.2.7, "Measurement exam-
ples", on page 84.
For channel or adjacent-channel power measurements, the individual channels are indicated by different colored bars in the diagram. The height of each bar corresponds to the measured power of that channel. In addition, the name of the channel ("Adj", "Alt %1", "Tx %1", etc., or a user-defined name) is indicated above the bar (separated by a line which has no further meaning).
For "Fast ACLR" measurements, which are performed in the time domain, the power versus time is shown for each channel.
Multi-standard radio (MSR) channel power results
The channel power results for MSR signals are described in Chapter 3.2.3.4, "Mea-
surement on multi-standard radio (MSR) signals", on page 50.
Results are provided for the TX channel and the number of defined adjacent channels above and below the TX channel. If more than one TX channel is defined, you must specify the channel to which the relative adjacent-channel power values refer. By default, it is the TX channel with the maximum power.
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Table 3-8: Measurements performed depending on the number of adjacent channels
Number of adj. chan.
0 Channel powers
1
2
3
… …
12
Measurement results
●
Channel powers
●
Power of the upper and lower adjacent channel
●
Channel powers
●
Power of the upper and lower adjacent channel
●
Power of the next higher and lower channel (alternate channel 1)
●
Channel powers
●
Power of the upper and lower adjacent channel
●
Power of the next higher and lower channel (alternate channel 1)
●
Power of the second next higher and lower adjacent channel (alternate channel 2)
●
Channel powers
●
Power of the upper and lower adjacent channel
●
Power of all the higher and lower channels (alternate channels 1 to 11)
In the R&S ESW display, only the first neighboring channel of the carrier (TX) channel is labeled "Adj" (adjacent) channel; all others are labeled "Alt" (alternate) channels. In this manual, "Adjacent" refers to both adjacent and alternate channels.
The measured power values for the TX and adjacent channels are also output as a table in the Result Summary window. Which powers are measured depends on the number of configured channels.
For each channel, the following values are displayed:
Label Description
Channel Channel name as specified in the "Channel Settings" (see "Channel Names"
on page 64).
Bandwidth Configured channel bandwidth (see "Channel Bandwidth" on page 62)
Offset Offset of the channel to the TX channel (configured channel spacing, see "Channel
Bandwidth" on page 62)
Power (Lower/Upper)
The measured power values for the TX and lower and upper adjacent channels. The powers of the transmission channels are output in dBm or dBm/Hz, or in dBc, relative to the specified reference TX channel.
Retrieving Results via Remote Control
All or specific channel power measurement results can be retrieved using the
CALC:MARK:FUNC:POW:RES? command from a remote computer (see
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 474). Alter-
natively, the results can be output as channel power density, i.e. in reference to the measurement bandwidth.
Furthermore, the measured power values of the displayed trace can be retrieved as usual using the TRAC:DATA? commands (see TRACe<n>[:DATA] on page 692). In
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3.2.3 Channel power basics

3.2.3.1 Measurement methods
Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
this case, the measured power value for each sweep point (by default 1001) is returned.
For a full list of remote commands for ACLR measurements, see Chapter 6.7.3.9,
"Measurement results", on page 509.
Some background knowledge on basic terms and principles used in channel power measurements is provided here for a better understanding of the required configuration settings.
● Measurement methods........................................................................................... 43
● Measurement repeatability......................................................................................45
● Recommended common measurement parameters...............................................46
● Measurement on multi-standard radio (MSR) signals.............................................50
The channel power is defined as the integration of the power across the channel band­width.
The Adjacent Channel Leakage Power Ratio (ACLR) is also known as the Adjacent Channel Power Ratio (ACPR). It is defined as the ratio between the total power of the adjacent channel to the power of the carrier channel. An ACLR measurement with sev­eral carrier channels (also known as transmission or TX channels) is also possible and is referred to as a multicarrier ACLR measurement.
There are two possible methods for measuring channel and adjacent channel power with a signal analyzer:
●
IBW method (Integration BandWidth method)
●
Fast ACLR (Zero-span method ), i.e. using a channel filter
IBW method
When measuring the channel power, the R&S ESW integrates the linear power which corresponds to the levels of the measurement points within the selected channel. The signal analyzer uses a resolution bandwidth which is far smaller than the channel bandwidth. When sweeping over the channel, the channel filter is formed by the pass­band characteristics of the resolution bandwidth.
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Figure 3-20: Approximating the channel filter by sweeping with a small resolution bandwidth
The following steps are performed:
1. The linear power of all the trace points within the channel is calculated.
Pi = 10
(Li/10)
Where Pi = power of the trace pixel i Li = displayed level of trace point i
2. The powers of all trace points within the channel are summed up and the sum is
divided by the number of trace points in the channel.
3. The result is multiplied by the quotient of the selected channel bandwidth and the
noise bandwidth of the resolution filter (RBW).
Since the power calculation is performed by integrating the trace within the channel bandwidth, this method is called the IBW method (Integration Bandwidth method).
Fast ACLR
The integrated bandwidth method (IBW) calculates channel power and ACLR from the trace data obtained during a continuous sweep over the selected span. Most parts of this sweep are not part of the channel itself or the defined adjacent channels. There­fore, most of the samples taken during the sweep time cannot be used for channel power or ACLR calculation.
To decrease the measurement times, the R&S ESW offers a "Fast ACLR" mode. In Fast ACLR mode, the power of the frequency range between the channels of interest is not measured, because it is not required for channel power or ACLR calculation. The measurement time per channel is set with the sweep time. It is equal to the selected measurement time divided by the selected number of channels.
In the "Fast ACLR" mode, the R&S ESW measures the power of each channel in the time domain, with the defined channel bandwidth, at the center frequency of the chan­nel in question. The digital implementation of the resolution bandwidths makes it possi­ble to select filter characteristics that are precisely tailored to the signal. For CDMA2000, for example, the power in the useful channel is measured with a band­width of 1.23 MHz. The power of the adjacent channels is measured with a bandwidth of 30 kHz. Therefore the R&S ESW changes from one channel to the other and meas­ures the power at a bandwidth of 1.23 MHz or 30 kHz using the RMS detector.
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Figure 3-21: Measuring the channel power and adjacent channel power ratio for CDMA2000 signals
with zero span (Fast ACLR)
3.2.3.2 Measurement repeatability
The repeatability of the results, especially in the narrow adjacent channels, strongly depends on the measurement time for a given resolution bandwidth. A longer sweep time can increase the probability that the measured value converges to the true value of the adjacent channel power, but obviously increases measurement time.
Assume a measurement with five channels (1 channel plus 2 lower and 2 upper adja­cent channels) and a sweep time of 100 ms. This measurement requires a measure­ment time per channel of 20 ms. To calculate the power in one channel, the analyzer considers the following number of effective samples:
<sweep time in channel> * <selected resolution bandwidth>
For example, for a sweep time of 100 ms the analyzer considers (30 kHz / 4.19 MHz) * 100 ms * 10 kHz ≈ 7 samples. Whereas in Fast ACLR mode, it considers (100 ms / 5) * 30 kHz ≈ 600 samples. If you compare these numbers, you understand the increase of repeatability with a 95 % confidence level (2δ). It rises from ± 2.8 dB in normal mode to ± 0.34 dB in Fast ACLR mode for a sweep time of 100 ms.
For the same repeatability, the integration method requires a sweep time of 8.5 s. The
Figure 3-22 shows the standard deviation of the results as a function of the sweep
time.
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Figure 3-22: Repeatability of adjacent channel power measurement on CDMA2000 standard signals if
the integration bandwidth method is used
The Figure 3-23 shows the repeatability of power measurements in the transmit chan­nel and of relative power measurements in the adjacent channels as a function of sweep time. The standard deviation of measurement results is calculated from 100 consecutive measurements. Consider the scaling when you compare power values.
Figure 3-23: Repeatability of adjacent channel power measurements on CDMA2000 signals in the fast
ACLR mode
3.2.3.3 Recommended common measurement parameters
The following sections provide recommendations on the most important measurement parameters for channel power measurements.
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All instrument settings for the selected channel setup (channel bandwidth, channel spacing) can be optimized automatically using the "Adjust Settings" function (see "Opti-
mized Settings (Adjust Settings)" on page 60).
The easiest way to configure a measurement is using the configuration "Overview", see Chapter 4.2, "Configuration overview", on page 224.
● Sweep Time............................................................................................................ 47
● Frequency span...................................................................................................... 48
● Resolution bandwidth (RBW)..................................................................................48
● Video bandwidth (VBW)..........................................................................................49
● Detector...................................................................................................................49
● trace averaging....................................................................................................... 50
● Reference level....................................................................................................... 50
Sweep Time
The Sweep Time is selected depending on the desired reproducibility of results. Repro­ducibility increases with Sweep Time since power measurement is then performed over a longer time period. As a general approach, approximately 500 non-correlated mea­sured values are required for a reproducibility of 0.5 dB. (That means: 95 % of the measurements are within 0.5 dB of the true measured value). Approximately 5000 measured values are required for a reproducibility of 0.1 dB (99 %). These values are valid for white noise. The measured values are considered as non-correlated if their time interval corresponds to the reciprocal of the measured bandwidth.
The number of A/D converter values, N, used to calculate the power, is defined by the Sweep Time. The time per trace pixel for power measurements is directly proportional to the selected Sweep Time.
If the sample detector is used, it is best to select the smallest Sweep Time possible for a given span and resolution bandwidth. The minimum time is obtained if the setting is coupled, that is: the time per measurement is minimal. Extending the measurement time does not have any advantages. The number of samples for calculating the power is defined by the number of trace points in the channel.
If the RMS detector is used, the selection of Sweep Times can affect the repeatability of the measurement results. Repeatability is increased at longer Sweep Times.
If the RMS detector is used, the number of samples can be estimated as follows:
Since only uncorrelated samples contribute to the RMS value, the number of samples can be calculated from the Sweep Time and the resolution bandwidth.
Samples can be assumed to be uncorrelated if sampling is performed at intervals of 1/ RBW. The number of uncorrelated samples is calculated as follows:
N
= SWT * RBW
decorr
(N
means uncorrelated samples)
decorr
The number of uncorrelated samples per trace pixel is obtained by dividing N
decorr
by
1001 (= pixels per trace).
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The Sweep Time can be defined using the softkey in the "Ch Power" menu or in the "Sweep" configuration dialog box (see "Sweep Time" on page 61).
Frequency span
The frequency span must cover at least the channels to be measured plus a measure­ment margin of approximately 10 %.
If the frequency span is large in comparison to the channel bandwidth (or the adjacent­channel bandwidths) being analyzed, only a few points on the trace are available per channel. The calculated waveform for the used channel filter is less accurate, which has a negative effect on the measurement accuracy. It is therefore strongly recommen­ded that you consider the described formulas when you select the frequency span.
The frequency span for the defined channel settings can be optimized. Use the "Adjust Settings" function in the "Ch Power" menu or the "General Settings" tab of the "ACLR Setup" dialog box (see "Optimized Settings (Adjust Settings)" on page 60). You can set the frequency span manually in the "Frequency" configuration dialog box.
(See Chapter 4.4.4, "How to define the frequency range", on page 293.)
For channel power measurements the "Adjust Settings" function sets the frequency span as follows:
"(No. of transmission channels – 1) x transmission channel spacing + 2 x transmission channel bandwidth + measurement margin"
For adjacent-channel power measurements, the "Adjust Settings" function sets the fre­quency span as a function of the following parameters:
●
Number of transmission channels
●
Transmission channel spacing
●
Adjacent-channel spacing
●
Bandwidth of one of adjacent-channels ADJ, ALT1 or ALT2, whichever is furthest away from the transmission channels
"(No. of transmission channels – 1) * (transmission channel spacing + 2) * (adjacent­channel spacing + adjacent-channel bandwidth) + measurement margin"
The measurement margin is approximately 10 % of the value obtained by adding the channel spacing and the channel bandwidth.
Resolution bandwidth (RBW)
It is important to suppress spectral components outside the channel to be measured, especially of the adjacent channels. At the same time, you expect an acceptable mea­surement speed. To fulfill both these requirements, the appropriate resolution band­width is essential. As a general approach, set the resolution bandwidth to values between 1 % and 4 % of the channel bandwidth.
If the spectrum within the channel to be measured and the spectrum around the chan­nel has a flat characteristic, you can select a larger resolution bandwidth. In the stan­dard setting, e.g. for standard IS95A REV at an adjacent channel bandwidth of 30 kHz, a resolution bandwidth of 30 kHz is used. This yields correct results since the spectrum near the adjacent channels normally has a constant level.
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You can optimize the resolution bandwidth for the defined channel settings. Use the "Adjust Settings" function in the "Ch Power" menu or the "General Settings" tab of the "ACLR Setup" dialog box (see "Optimized Settings (Adjust Settings)" on page 60). You can set the RBW manually in the "Bandwidth" configuration dialog box, see "RBW" on page 214.
Except for the IS95 CDMA standards, the "Adjust Settings" function sets the resolution bandwidth (RBW) as a function of the channel bandwidth:
"RBW" ≤ 1/40 of "Channel Bandwidth"
The maximum resolution bandwidth (concerning the requirement RBW ≤ 1/40) result­ing from the available RBW steps (1, 3) is selected.
Video bandwidth (VBW)
For a correct power measurement, the video signal must not be limited in bandwidth. A restricted bandwidth of the logarithmic video signal causes signal averaging and thus results in a too low indication of the power (-2.51 dB at very low video bandwidths). Thus, select the video bandwidth at least three times the resolution bandwidth:
VBW ≥3 * RBW
For FFT sweeps, instead of increasing the VBW, you can also select the trace average mode "Power" to ensure correct power measurements (see "Average Mode" on page 370). Note that in power measurements this setting affects the VBW regard­less of whether or not a trace is actually averaged.
The video bandwidth for the defined channel settings can be optimized. Use the "Adjust Settings" function in the "Ch Power" menu or the "General Settings" tab of the "ACLR Setup" dialog box (see "Optimized Settings (Adjust Settings)" on page 60). You can set the VBW manually in the "Bandwidth" configuration dialog box, see "VBW" on page 311.
The video bandwidth (VBW) is set as a function of the channel bandwidth (see formula above) and the smallest possible VBW with regard to the available step size is selected.
Detector
The RMS detector correctly indicates the power irrespective of the characteristics of the signal to be measured. The whole IF envelope is used to calculate the power for each measurement point. The IF envelope is digitized using a sampling frequency which is at least five times the resolution bandwidth which has been selected. Based on the sample values, the power is calculated for each measurement point using the following formula:
Where:
si = linear digitized video voltage at the output of the A/D converter
N = number of A/D converter values per measurement point
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Z = electrical impedance
P
= power represented by a measurement point
RMS
When the power has been calculated, the power units are converted into decibels and the value is displayed as a measurement point.
In principle, the sample detector would be possible as well. Due to the limited number of measurement points used to calculate the power in the channel, the sample detector would yield less stable results.
The RMS detector can be set for the defined channel settings automatically. Use the "Adjust Settings" function in the "Ch Power" menu or the "General Settings" tab of the "ACLR Setup" dialog box (see "Optimized Settings (Adjust Settings)" on page 60). You can set the detector manually in the "Traces" configuration dialog box, see "Detec-
tor" on page 369.
trace averaging
Avoid averaging, which is often performed to stabilize the measurement results but leads to a level indication that is too low. The reduction in the displayed power depends on the number of averages and the signal characteristics in the channel to be mea­sured.
The "Adjust Settings" function switches off trace averaging. You can deactivate the trace averaging manually in the "Traces" configuration dialog box, see "Average Mode" on page 370.
Reference level
To achieve an optimum dynamic range, set the reference level so that the signal is as close to the reference level as possible without forcing an overload message. However, if the signal-to-noise ratio becomes too small, the dynamic range is also limited. The measurement bandwidth for channel power measurements is significantly smaller than the signal bandwidth. Thus, the signal path can be overloaded although the trace is still significantly below the reference level.
Selecting a predefined standard or automatically adjusting settings does not affect the reference level. The reference level can be set automatically using the "Auto Level" function in the [Auto Set] menu, or manually in the "Amplitude" menu.
3.2.3.4 Measurement on multi-standard radio (MSR) signals
Modern base stations can contain multiple signals for different communication stand­ards. A new measurement standard is provided for the R&S ESW ACLR measurement that allows you to measure such MSR signals, including non-contiguous setups. Multi­ple (also non-) contiguous transmit channels can be specified at absolute frequencies, independent from the common center frequency selected for display.
Signal structure
Up to 18 transmit channels can be grouped in a maximum of 5sub blocks. Between two sub blocks, two gaps are defined: a lower gap and an upper gap. Each gap in turn
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contains two channels (gap channels). The channels in the upper gap are identical to those in the lower gap, but inverted. To either side of the outermost transmit channels, lower and upper adjacent channels can be defined as in common ACLR measurement setups.
Figure 3-24: MSR signal structure
Asymmetrical gap channels
Gap channels between sub blocks can now also be asymmetrical, that is: channels in the lower and upper gaps are not identical. For example, in Figure 3-25, the gap between sub blocks A and B contains one lower channel (AB:Gap1L), but two upper channels (AB:Gap1U, AB:Gap2U). Furthermore, the gaps between different sub blocks need not be identical. For example, the gap between sub blocks A and B contains 3 gap channels, while the gap between sub blocks B and C contains only two gap chan­nels (BC:Gap1L, BC:Gap2L, which are not identical to the lower gap channels in gap AB.
Figure 3-25: Asymmetrical MSR signal structure
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Sub block and channel definition
The sub blocks are defined by a specified center frequency, RF bandwidth, and num­ber of transmit channels.
Figure 3-26: Sub block definition
As opposed to common ACLR channel definitions, the Tx channels are defined at absolute frequencies, rather than by a spacing relative to the (common) center fre­quency. Each transmit channel can be assigned a different technology, used to prede­fine the required bandwidth.
Gap channels and CACLR
If two or more sub blocks are defined, the power in the gaps between the sub blocks must also be measured. Gap channels are defined using bandwidths and spacings, relative to the outer edges of the surrounding sub blocks.
If the upper and lower gap channels are symmetrical, only two gap channels must be configured. The required spacing can be determined according to the following formula (indicated for lower channels):
Spacing = [CF of gap channel] - [left sub block CF] + ([RF bandwidth of left sub block] /2)
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Figure 3-27: Gap channel definition for lower gap
If the gap channels are not symmetrical, you must configure up to four channels indi­vidually. The formula indicated above applies for the lower channels. For the upper channels, the spacing is defined as:
Spacing = [right sub block CF]- [CF of gap channel] - ([RF bandwidth of right sub block] /2)
According to the MSR standard, the Cumulative Adjacent Channel Leakage Ratio (CACLR) power must be determined for the gap channels. The CACLR power is mea-
sured in the two gap channels for the upper and lower gap. The power in the gap chan­nels is then set in relation to the power of the two closest transmission channels to either side of the gap. The CACLR power for the gap channels is indicated in the Result Summary.
In addition, the ACLR power for the individual gap channels is indicated in the Result Summary. The ACLR power of the lower gap channels refers to the TX channel to the left of the gap. The ACLR power of the upper gap channels refers to the TX channel to the right of the gap. A separate relative limit value can be defined for the ACLR power.
Adjacent channels
Adjacent channels are defined as in common ACLR measurements using bandwidths and spacings, relative to the uppermost or lowermost transmit channels in the sub blocks (see also Figure 3-24):
●
The spacing of the lower adjacent channels refers to the CF of the first Tx channel in the first sub block.
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●
The spacing of the upper adjacent channels refers to the CF of the last Tx channel in the last sub block.
The upper and lower adjacent channels can also be defined asymmetrically (see "Sym-
metrical Adjacent Setup" on page 69). This is particularly useful if the lowest Tx chan-
nel and highest Tx channel use different standards and thus require different band­widths for adjacent channel power measurement.
Channel display for MSR signals
As in common ACLR measurements, the individual channels are indicated by different colored bars in the diagram. The height of each bar corresponds to the measured power of that channel. In addition, the name of the channel is indicated above the bar. Sub blocks are named A,B,C,D,E and are also indicated by a slim blue bar along the frequency axis.
Tx channel names correspond to the specified technology (for LTE including the band­width), followed by a consecutive number. (If the channel is too narrow to display the channel name, "..."is displayed instead.) The assigned sub block is indicated with the channel name, e.g. "B: LTE_5M1" for the first Tx channel in sub block B that uses the LTE 5 MHz bandwidth technology.
Adjacent and alternate channels are displayed as in common ACLR measurements.
Gap channels are indicated using the following syntax:
●
The names of the surrounding sub blocks (e.g. "AB" for the gap between sub blocks A and B),
●
The channel name ("Gap1" or "Gap2")
●
"L" (for lower) or "U" (for upper)
For example: "ABGap1L" indicates the first lower gap channel between sub blocks A and B.
Both the lower and upper gap channels are displayed.
For symmetrical configuration, gap channels can be hidden if they do not reach a mini­mum size.
For asymmetrical configuration, you can define the number of upper or lower gap channels to be displayed.
In both cases, you can deactivate all gap channels. This enhances the result display, as fewer lines and bars are displayed. If gap channels are deactivated, the power results are not calculated and thus are not shown in the Result Summary table.
Furthermore, channel names for all TX, adjacent, and alternate channels are user­definable (not gap channels).
Channel power results
The Result Summary for MSR signal measurements is similar to the table for common signals (see Chapter 3.2.2, "Channel power results", on page 41). However, the Tx channel results are grouped by sub blocks, and sub block totals are provided instead
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of a total Tx channel power. Instead of the individual channel frequency offsets, the absolute center frequencies are indicated for the transmit channels.
The CACLR and ACLR power results for each gap channel are appended at the end of the table. The CACLR results are calculated as the power in the gap channel divided by the power sum of the two closest transmission channels to either side of it.
Figure 3-28: Result summary for symmetrical channel definition
Figure 3-29: Result summary for asymmetrical channel definition
Remote command:
CALCulate:MARKer:FUNCtion:POWer<sb>:RESult? GACLr or CALCulate:MARKer:FUNCtion:POWer<sb>:RESult? MACM , see
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 474
Restrictions and dependencies
As the signal structure in multi-standard radio signals can vary considerably, you can define the channels very flexibly for the ACLR measurement with the R&S ESW. No checks or limitations are implemented concerning the channel definitions, apart from the maximum number of channels to be defined. Thus, you are not notified if transmit channels for a specific sub block lie outside the defined frequency range for the sub block, or if transmit and gap channels overlap.
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3.2.4 Channel power configuration

Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR Config"
Both Channel Power (CP) and Adjacent-Channel Power (ACLR) measurements are available.
If the "Multi-Standard Radio" standard is selected (see "Standard" on page 57), the "ACLR Setup" dialog box is replaced by the "MSR ACLR Setup" dialog box. See Chap-
ter 3.2.5, "MSR ACLR configuration", on page 64 for a description of these settings.
The remote commands required to perform these tasks are described in Chapter 6.7.3,
"Channel power and ACLR", on page 478.
● General CP/ACLR measurement settings.............................................................. 56
● Channel setup.........................................................................................................61
3.2.4.1 General CP/ACLR measurement settings
General measurement settings are defined in the "ACLR Setup" dialog, in the "General Settings" tab.
Standard........................................................................................................................57
└ Predefined Standards..................................................................................... 57
└ User Standards...............................................................................................57
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Number of channels: Tx, Adj.........................................................................................58
Reference Channel....................................................................................................... 59
Fast ACLR.....................................................................................................................59
Selected Trace..............................................................................................................59
Absolute and Relative Values (ACLR Mode)................................................................ 59
Channel power level and density (Power Unit)............................................................. 60
Power Mode..................................................................................................................60
Setting a fixed reference for Channel Power measurements (Set CP Reference)....... 60
Optimized Settings (Adjust Settings).............................................................................60
Sweep Time.................................................................................................................. 61
Standard
The main measurement settings can be stored as a standard file. When such a stan­dard is loaded, the required channel and general measurement settings are automati­cally set on the R&S ESW. However, the settings can be changed. Predefined stand­ards are available for standard measurements, but standard files with user-defined configurations can also be created.
Note: If the "Multi-Standard Radio" standard is selected, the "ACLR Setup" dialog box is replaced by the "MSR ACLR Setup" dialog box (see Chapter 3.2.5, "MSR ACLR
configuration", on page 64).
If any other predefined standard (or "NONE") is selected, the "ACLR Setup" dialog box is restored (see Chapter 3.2.4, "Channel power configuration", on page 56).
Note that changes in the configuration are not stored when the dialog boxes are exchanged.
Predefined Standards ← Standard
Predefined standards contain the main measurement settings for standard measure­ments. When such a standard is loaded, the required channel settings are automati­cally set on the R&S ESW. However, you can change the settings.
The predefined standards contain the following settings:
●
Channel bandwidths
●
Channel spacings
●
Detector
●
Trace Average setting
●
Resolution Bandwidth (RBW)
●
Weighting Filter
For details on the available standards, see Chapter 3.2.9, "Reference: predefined CP/
ACLR standards", on page 88.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:PRESet on page 478
User Standards ← Standard Access: "CP / ACLR Config" > "General Settings" tab > "Manage User Standards"
In addition to the predefined standards, you can save your own standards with your specific measurement settings in an XML file so you can use them again later. User­defined standards are stored on the instrument in the C:\Program Files (x86)\Rohde-Schwarz\ESW\<version>\acp_std direc­tory.
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A sample file is provided for an MSR ACLR measurement (MSR_ACLRExample.xml). It sets up the measurement for the MSR signal generator waveform described in the file C:\R_S\Instr\User\waveform\MSRA_GSM_WCDMA_LTE_GSM.wv.
Note that ACLR user standards are not supported for Fast ACLR measurements. Note: User standards created on an analyzer of the R&S FSP family are compatible to
the R&S ESW. User standards created on an R&S ESW, however, are not necessarily compatible to the analyzers of the R&S FSP family and may not work there.
The following parameter definitions are saved in a user-defined standard:
●
Number of adjacent channels
●
Channel bandwidth of transmission (Tx), adjacent (Adj) and alternate (Alt) chan­nels
●
Channel spacings
●
Weighting filters
●
Resolution bandwidth
●
Video bandwidth
●
Detector
●
ACLR limits and their state
●
Sweep Time and Sweep Time coupling
●
Trace and power mode
●
(MSR only: sub block and gap channel definition)
Save the current measurement settings as a user-defined standard, load a stored mea­surement configuration, or delete an existing configuration file.
For details see Chapter 3.2.6.4, "How to manage user-defined configurations", on page 83.
"File Explorer": Instead of using the file manager of the R&S ESW firmware, you can also use the Microsoft Windows File Explorer to manage files.
Remote command: To query all available standards:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:CATalog?
on page 478 To load a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:PRESet on page 478
To save a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:SAVE
on page 479 To delete a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:DELete
on page 479
Number of channels: Tx, Adj
Up to 18 carrier channels and up to 12 adjacent channels can be defined. Results are provided for the Tx channel and the number of defined adjacent channels
above and below the Tx channel. If more than one Tx channel is defined, the carrier channel to which the relative adjacent-channel power values should be referenced must be defined (see "Reference Channel" on page 59).
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Note: If several carriers (Tx channels) are activated for the measurement, the number of sweep points is increased to ensure that adjacent-channel powers are measured with adequate accuracy.
For more information on how the number of channels affects the measured powers, see Chapter 3.2.2, "Channel power results", on page 41.
Remote command: Number of Tx channels:
[SENSe:]POWer:ACHannel:TXCHannel:COUNt on page 483
Number of Adjacent channels:
[SENSe:]POWer:ACHannel:ACPairs on page 480
Reference Channel
The measured power values in the adjacent channels can be displayed relative to the transmission channel. If more than one Tx channel is defined, define which one is used as a reference channel.
Tx Channel 1 Transmission channel 1 is used.
(Not available for MSR ACLR)
Min Power Tx Channel The transmission channel with the lowest power is used as a reference channel.
Max Power Tx Chan­nel
Lowest & Highest Channel
The transmission channel with the highest power is used as a reference channel (Default).
The outer left-hand transmission channel is the reference channel for the lower adjacent channels, the outer right-hand transmission channel that for the upper adjacent channels.
Remote command:
[SENSe:]POWer:ACHannel:REFerence:TXCHannel:MANual on page 487 [SENSe:]POWer:ACHannel:REFerence:TXCHannel:AUTO on page 486
Fast ACLR
If activated, instead of using the IBW method, the R&S ESW sets the center frequency to the different channel center frequencies consecutively and measures the power with the selected measurement time (= sweep time/number of channels).
Remote command:
[SENSe:]POWer:HSPeed on page 494
Selected Trace
The CP/ACLR measurement can be performed on any active trace. Remote command:
[SENSe:]POWer:TRACe on page 477
Absolute and Relative Values (ACLR Mode)
The powers of the adjacent channels are output in dBm or dBm/Hz (absolute values), or in dBc, relative to the specified reference Tx channel.
"Abs"
The absolute power in the adjacent channels is displayed in the unit of the y-axis, e.g. in dBm, dBµV.
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"Rel"
Remote command:
[SENSe:]POWer:ACHannel:MODE on page 511
Channel power level and density (Power Unit)
By default, the channel power is displayed in absolute values. If "/Hz" is activated, the channel power density is displayed instead. Thus, the absolute unit of the channel power is switched from dBm to dBm/Hz.
Note: The channel power density in dBm/Hz corresponds to the power inside a band­width of 1 Hz and is calculated as follows: "channel power density = channel power – log10(channel bandwidth)"
Thus you can measure the signal/noise power density, for example, or use the addi­tional functions Absolute and Relative Values (ACLR Mode) and Reference Channel to obtain the signal to noise ratio.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult:PHZ on page 510
Power Mode
The measured power values can be displayed directly for each trace ("Clear/ Write"), or only the maximum values over a series of measurements can be displayed ("Max Hold"). In the latter case, the power values are calculated from the current trace and compared with the previous power value using a maximum algorithm. The higher value is retained. If "Max Hold" mode is activated, "Pwr Max" is indicated in the table header. Note that the trace mode remains unaffected by this setting.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:MODE on page 473
The level of the adjacent channels is displayed relative to the level of the transmission channel in dBc.
Setting a fixed reference for Channel Power measurements (Set CP Reference)
If only one Tx channel and no adjacent channels are defined, the currently measured channel power can be used as a fixed reference value for subsequent channel power measurements.
When you select this button, the channel power currently measured on the Tx channel is stored as a fixed reference power. In the following channel power measurements, the power is indicated relative to the fixed reference power. The reference value is dis­played in the "Reference" field (in relative ACLR mode); the default value is 0 dBm.
Note: In adjacent-channel power measurement, the power is always referenced to a transmission channel (see "Reference Channel" on page 59), thus, this function is not available.
Remote command:
[SENSe:]POWer:ACHannel:REFerence:AUTO ONCE on page 486
Optimized Settings (Adjust Settings)
All instrument settings for the selected channel setup (channel bandwidth, channel spacing) can be optimized automatically.
The adjustment is carried out only once. If necessary, the instrument settings can be changed later.
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The following settings are optimized by "Adjust Settings":
●
"Frequency span" on page 48
●
"Resolution bandwidth (RBW)" on page 48
●
"Video bandwidth (VBW)" on page 49
●
"Detector" on page 49
●
"trace averaging" on page 50
Note: The reference level is not affected by this function. To adjust the reference level automatically, use the Setting the Reference Level Automatically (Auto Level) function in the [Auto Set] menu.
Remote command:
[SENSe:]POWer:ACHannel:PRESet on page 476
Sweep Time
With the RMS detector, a longer Sweep Time increases the stability of the measure­ment results. For recommendations on setting this parameter, see "Sweep Time" on page 47.
The Sweep Time can be set via the softkey in the "Ch Power" menu and is identical to the general setting in the "Sweep" configuration dialog box.
Remote command:
[SENSe:]SWEep:TIME on page 675
3.2.4.2 Channel setup
The "Channel Settings" tab in the "ACLR Setup" dialog box provides all the channel settings to configure the channel power or ACLR measurement. You can define the channel settings for all channels, independent of the defined number of used Tx or adjacent channels (see "Number of channels: Tx, Adj" on page 58).
For details on setting up channels, see Chapter 3.2.6.2, "How to set up the channels", on page 80.
In addition to the specific channel settings, the general settings "Standard" on page 57 and "Number of channels: Tx, Adj" on page 58 are also available in this tab.
The following settings are available in individual subtabs of the "Channel Settings" tab.
Channel Bandwidth.......................................................................................................62
Channel Spacings.........................................................................................................62
Limit Check................................................................................................................... 63
Weighting Filters............................................................................................................64
Channel Names............................................................................................................ 64
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Channel Bandwidth
The Tx channel bandwidth is normally defined by the transmission standard. The correct bandwidth is set automatically for the selected standard. The bandwidth for
each channel is indicated by a colored bar in the display. For measurements that require channel bandwidths which deviate from those defined
in the selected standard, use the IBW method ("Fast ACLR" "Off"). With the IBW method, the channel bandwidth borders are right and left of the channel center fre­quency. Thus, you can visually check whether the entire power of the signal under test is within the selected channel bandwidth.
The value entered for any Tx channel is automatically also defined for all subsequent Tx channels. Thus, only enter one value if all Tx channels have the same bandwidth.
The value entered for any ADJ or ALT channel is automatically also defined for all alternate (ALT) channels. Thus, only enter one value if all adjacent channels have the same bandwidth.
Remote command:
[SENSe:]POWer:ACHannel:BANDwidth[:CHANnel<ch>] on page 481 [SENSe:]POWer:ACHannel:BANDwidth:ACHannel on page 480 [SENSe:]POWer:ACHannel:BANDwidth:ALTernate<ch> on page 480
Channel Spacings
Channel spacings are normally defined by the transmission standard but can be changed.
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If the spacings are not equal, the channel distribution in relation to the center frequency is as follows:
Odd number of Tx channels The middle Tx channel is centered to center frequency.
Even number of Tx channels The two Tx channels in the middle are used to calculate the fre-
quency between those two channels. This frequency is aligned to the center frequency.
The spacings between all Tx channels can be defined individually. When you change the spacing for one channel, the value is automatically also defined for all subsequent Tx channels. This allows you to set up a system with equal Tx channel spacing quickly. For different spacings, set up the channels from top to bottom.
Tx1-2 Spacing between the first and the second carrier
Tx2-3 Spacing between the second and the third carrier
… …
If you change the adjacent-channel spacing (ADJ), all higher adjacent channel spac­ings (ALT1, ALT2, …) are multiplied by the same factor (new spacing value/old spacing value). Again, only enter one value for equal channel spacing. For different spacing, configure the spacings from top to bottom.
For details, see Chapter 3.2.6.2, "How to set up the channels", on page 80 Remote command:
[SENSe:]POWer:ACHannel:SPACing:CHANnel<ch> on page 483 [SENSe:]POWer:ACHannel:SPACing[:ACHannel] on page 483 [SENSe:]POWer:ACHannel:SPACing:ALTernate<ch> on page 482
Limit Check
During an ACLR measurement, the power values can be checked whether they exceed user-defined or standard-defined limits. A relative or absolute limit can be defined, or both. Both limit types are considered, regardless whether the measured lev­els are absolute or relative values. The check of both limit values can be activated independently. If any active limit value is exceeded, the measured value is displayed in red and marked by a preceding asterisk in the result table.
The results of the power limit checks are also indicated in the STATus:QUEStionable:ACPLimit status registry.
Remote command:
CALCulate<n>:LIMit<li>:ACPower[:STATe] on page 493 CALCulate<n>:LIMit<li>:ACPower:ACHannel:ABSolute:STATe on page 488 CALCulate<n>:LIMit<li>:ACPower:ACHannel:ABSolute on page 488
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CALCulate<n>:LIMit<li>:ACPower:ACHannel[:RELative]:STATe
on page 489
CALCulate<n>:LIMit<li>:ACPower:ACHannel[:RELative] on page 489 CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>:ABSolute:STATe
on page 491
CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>:ABSolute on page 490 CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>[:RELative]:STATe
on page 492
CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>[:RELative]
on page 491
CALCulate<n>:LIMit<li>:ACPower:ACHannel:RESult? on page 490
Weighting Filters
Weighting filters allow you to determine the influence of individual channels on the total measurement result. For each channel you can activate or deactivate the use of the weighting filter and define an individual weighting factor ("Alpha:" value).
Weighting filters are not available for all supported standards and cannot always be defined manually where they are available.
Remote command: Activating/Deactivating:
[SENSe:]POWer:ACHannel:FILTer[:STATe]:CHANnel<ch> on page 486 [SENSe:]POWer:ACHannel:FILTer[:STATe]:ACHannel on page 485 [SENSe:]POWer:ACHannel:FILTer[:STATe]:ALTernate<ch> on page 485
Alpha value:
[SENSe:]POWer:ACHannel:FILTer:ALPHa:CHANnel<ch> on page 485 [SENSe:]POWer:ACHannel:FILTer:ALPHa:ACHannel on page 484 [SENSe:]POWer:ACHannel:FILTer:ALPHa:ALTernate<ch> on page 484
Channel Names
In the R&S ESW's display, carrier channels are labeled "Tx" by default; the first neigh­boring channel is labeled "Adj" (adjacent) channel; all others are labeled "Alt" (alter­nate) channels. You can define user-specific channel names for each channel which are displayed in the result diagram and result table.
Remote command:
[SENSe:]POWer:ACHannel:NAME:ACHannel on page 481 [SENSe:]POWer:ACHannel:NAME:ALTernate<ch> on page 482 [SENSe:]POWer:ACHannel:NAME:CHANnel<ch> on page 482

3.2.5 MSR ACLR configuration

Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR
Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config"
ACLR measurements can also be performed on input containing multiple signals for different communication standards. A new measurement standard is provided that allows you to define multiple discontiguous transmit channels at specified frequencies, independent from the selected center frequency. If the "Multi-Standard Radio" standard
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is selected (see "Standard" on page 57), the "ACLR Setup" dialog box is replaced by the "MSR ACLR Setup" dialog box.
For more information, see Chapter 3.2.3.4, "Measurement on multi-standard radio
(MSR) signals", on page 50.
The remote commands required to perform these tasks are described in Chapter 6.7.3,
"Channel power and ACLR", on page 478.
● General MSR ACLR measurement settings........................................................... 65
● MSR sub block and tx channel definition................................................................ 69
● MSR adjacent channel setup.................................................................................. 72
● MSR gap channel setup..........................................................................................75
● MSR channel names...............................................................................................78
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config" > "MSR General Settings" tab
Standard........................................................................................................................66
└ Predefined Standards..................................................................................... 66
└ User Standards...............................................................................................66
Number of Sub Blocks.................................................................................................. 67
Reference Channel....................................................................................................... 67
Selected Trace..............................................................................................................68
Absolute and Relative Values (ACLR Mode)................................................................ 68
Channel power level and density (Power Unit)............................................................. 68
Power Mode..................................................................................................................68
Optimized Settings (Adjust Settings).............................................................................69
Symmetrical Adjacent Setup.........................................................................................69
Limit Checking...............................................................................................................69
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Standard
The main measurement settings can be stored as a standard file. When such a stan­dard is loaded, the required channel and general measurement settings are automati­cally set on the R&S ESW. However, the settings can be changed. Predefined stand­ards are available for standard measurements, but standard files with user-defined configurations can also be created.
Note: If the "Multi-Standard Radio" standard is selected, the "ACLR Setup" dialog box is replaced by the "MSR ACLR Setup" dialog box (see Chapter 3.2.5, "MSR ACLR
configuration", on page 64).
If any other predefined standard (or "NONE") is selected, the "ACLR Setup" dialog box is restored (see Chapter 3.2.4, "Channel power configuration", on page 56).
Note that changes in the configuration are not stored when the dialog boxes are exchanged.
Predefined Standards ← Standard
Predefined standards contain the main measurement settings for standard measure­ments. When such a standard is loaded, the required channel settings are automati­cally set on the R&S ESW. However, you can change the settings.
The predefined standards contain the following settings:
●
Channel bandwidths
●
Channel spacings
●
Detector
●
Trace Average setting
●
Resolution Bandwidth (RBW)
●
Weighting Filter
For details on the available standards, see Chapter 3.2.9, "Reference: predefined CP/
ACLR standards", on page 88.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:PRESet on page 478
User Standards ← Standard Access: "CP / ACLR Config" > "General Settings" tab > "Manage User Standards"
In addition to the predefined standards, you can save your own standards with your specific measurement settings in an XML file so you can use them again later. User­defined standards are stored on the instrument in the C:\Program Files (x86)\Rohde-Schwarz\ESW\<version>\acp_std direc­tory.
A sample file is provided for an MSR ACLR measurement (MSR_ACLRExample.xml). It sets up the measurement for the MSR signal generator waveform described in the file C:\R_S\Instr\User\waveform\MSRA_GSM_WCDMA_LTE_GSM.wv.
Note that ACLR user standards are not supported for Fast ACLR measurements. Note: User standards created on an analyzer of the R&S FSP family are compatible to
the R&S ESW. User standards created on an R&S ESW, however, are not necessarily compatible to the analyzers of the R&S FSP family and may not work there.
The following parameter definitions are saved in a user-defined standard:
●
Number of adjacent channels
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●
Channel bandwidth of transmission (Tx), adjacent (Adj) and alternate (Alt) chan­nels
●
Channel spacings
●
Weighting filters
●
Resolution bandwidth
●
Video bandwidth
●
Detector
●
ACLR limits and their state
●
Sweep Time and Sweep Time coupling
●
Trace and power mode
●
(MSR only: sub block and gap channel definition)
Save the current measurement settings as a user-defined standard, load a stored mea­surement configuration, or delete an existing configuration file.
For details see Chapter 3.2.6.4, "How to manage user-defined configurations", on page 83.
"File Explorer": Instead of using the file manager of the R&S ESW firmware, you can also use the Microsoft Windows File Explorer to manage files.
Remote command: To query all available standards:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:CATalog?
on page 478 To load a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:PRESet on page 478
To save a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:SAVE
on page 479 To delete a standard:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:STANdard:DELete
on page 479
Number of Sub Blocks
Defines the number of sub blocks, i.e. groups of transmission channels in an MSR sig­nal.
For more information, see Chapter 3.2.3.4, "Measurement on multi-standard radio
(MSR) signals", on page 50.
Remote command:
[SENSe:]POWer:ACHannel:SBCount on page 504
Reference Channel
The measured power values in the adjacent channels can be displayed relative to the transmission channel. If more than one Tx channel is defined, define which one is used as a reference channel.
Tx Channel 1 Transmission channel 1 is used.
(Not available for MSR ACLR)
Min Power Tx Channel The transmission channel with the lowest power is used as a reference channel.
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Max Power Tx Chan­nel
Lowest & Highest Channel
The transmission channel with the highest power is used as a reference channel (Default).
The outer left-hand transmission channel is the reference channel for the lower adjacent channels, the outer right-hand transmission channel that for the upper adjacent channels.
Remote command:
[SENSe:]POWer:ACHannel:REFerence:TXCHannel:MANual on page 487 [SENSe:]POWer:ACHannel:REFerence:TXCHannel:AUTO on page 486
Selected Trace
The CP/ACLR measurement can be performed on any active trace. Remote command:
[SENSe:]POWer:TRACe on page 477
Absolute and Relative Values (ACLR Mode)
The powers of the adjacent channels are output in dBm or dBm/Hz (absolute values), or in dBc, relative to the specified reference Tx channel.
"Abs"
The absolute power in the adjacent channels is displayed in the unit of the y-axis, e.g. in dBm, dBµV.
"Rel"
The level of the adjacent channels is displayed relative to the level of the transmission channel in dBc.
Remote command:
[SENSe:]POWer:ACHannel:MODE on page 511
Channel power level and density (Power Unit)
By default, the channel power is displayed in absolute values. If "/Hz" is activated, the channel power density is displayed instead. Thus, the absolute unit of the channel power is switched from dBm to dBm/Hz.
Note: The channel power density in dBm/Hz corresponds to the power inside a band­width of 1 Hz and is calculated as follows: "channel power density = channel power – log10(channel bandwidth)"
Thus you can measure the signal/noise power density, for example, or use the addi­tional functions Absolute and Relative Values (ACLR Mode) and Reference Channel to obtain the signal to noise ratio.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult:PHZ on page 510
Power Mode
The measured power values can be displayed directly for each trace ("Clear/ Write"), or only the maximum values over a series of measurements can be displayed ("Max Hold"). In the latter case, the power values are calculated from the current trace and compared with the previous power value using a maximum algorithm. The higher value is retained. If "Max Hold" mode is activated, "Pwr Max" is indicated in the table header. Note that the trace mode remains unaffected by this setting.
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:MODE on page 473
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Optimized Settings (Adjust Settings)
All instrument settings for the selected channel setup (channel bandwidth, channel spacing) can be optimized automatically.
The adjustment is carried out only once. If necessary, the instrument settings can be changed later.
The following settings are optimized by "Adjust Settings":
●
"Frequency span" on page 48
●
"Resolution bandwidth (RBW)" on page 48
●
"Video bandwidth (VBW)" on page 49
●
"Detector" on page 49
●
"trace averaging" on page 50
Note: The reference level is not affected by this function. To adjust the reference level automatically, use the Setting the Reference Level Automatically (Auto Level) function in the [Auto Set] menu.
Remote command:
[SENSe:]POWer:ACHannel:PRESet on page 476
Symmetrical Adjacent Setup
If enabled, the upper and lower adjacent and alternate channels are defined symmetri­cally. This is the default behavior.
If disabled, the upper and lower channels can be configured differently. This is particu­larly useful if the lowest Tx channel and highest Tx channel use different standards and thus require different bandwidths for adjacent channel power measurement.
Remote command:
[SENSe:]POWer:ACHannel:SSETup on page 509
Limit Checking
Activates or deactivates limit checks globally for all adjacent and gap channels. In addi­tion to this setting, limits must be defined and activated individually for each channel.
The results of the power limit checks are also indicated in the STATus:QUEStionable:ACPLimit status registry.
Remote command:
CALCulate<n>:LIMit<li>:ACPower[:STATe] on page 493
3.2.5.2 MSR sub block and tx channel definition
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR
Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config" > "Tx Channels" tab
The "Tx Channels" tab provides all the channel settings to configure sub blocks and Tx channels in MSR ACLR measurements.
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For details on MSR signals, see Chapter 3.2.3.4, "Measurement on multi-standard
radio (MSR) signals", on page 50.
For details on setting up channels, see Chapter 3.2.6.3, "How to configure an MSR
ACLR measurement", on page 81.
The Tx channel settings for the individual sub blocks are configured in individual sub­tabs of the "Tx Channel Settings" tab.
Sub Block Definition......................................................................................................70
└ Sub Block / Center Freq..................................................................................71
└ RF Bandwidth................................................................................................. 71
└ Number of Tx Channels (Tx Count)................................................................71
Tx Channel Definition....................................................................................................71
└ Tx Center Frequency...................................................................................... 71
└ Technology Used for Transmission.................................................................71
└ Tx Channel Bandwidth....................................................................................72
└ Weighting Filters............................................................................................. 72
Sub Block Definition
Sub blocks are groups of transmit channels in an MSR signal. Up to 5 sub blocks can be defined. They are defined as an RF bandwidth around a center frequency with a specific number of transmit channels (max. 18).
Sub blocks are named A,B,C,D,E and are indicated by a slim blue bar along the fre­quency axis.
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Sub Block / Center Freq ← Sub Block Definition
Defines the center of an MSR sub block. Note that the position of the sub block also affects the position of the adjacent gap channels.
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:FREQuency:CENTer on page 505
RF Bandwidth ← Sub Block Definition
Defines the bandwidth of the individual MSR sub block. Note that sub block ranges also affect the position of the adjacent gap channels.
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:RFBWidth on page 506
Number of Tx Channels (Tx Count) ← Sub Block Definition
Defines the number of transmit channels the specific sub block contains. The maxi­mum is 18 Tx channels.
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:TXCHannel:COUNt on page 507
Tx Channel Definition
As opposed to common ACLR channel definitions, the Tx channels are defined at absolute frequencies, rather than by a spacing relative to the (common) center fre­quency. Each transmit channel can be assigned a different technology, used to prede­fine the required bandwidth.
The Tx channel settings for the individual sub blocks are configured in individual sub­tabs of the "Tx Channel Settings" tab.
For details on configuring MSR Tx channels, see Chapter 3.2.6.3, "How to configure an
MSR ACLR measurement", on page 81.
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:NAME[:CHANnel<ch>] on page 506
Tx Center Frequency ← Tx Channel Definition
Defines the (absolute) center frequency of an MSR Tx channel. Each Tx channel is defined independently of the others; automatic spacing as in common ACLR measure­ments is not performed.
Note that the position of the adjacent channels is also affected by:
●
The position of the first Tx channel in the first sub block
●
The position of last Tx channel in the last sub block
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:CENTer[:CHANnel<ch>] on page 505
Technology Used for Transmission ← Tx Channel Definition
The technology used for transmission by the individual channel can be defined for each channel. The required channel bandwidth and use of a weighting filter are pre­configured automatically according to the selected technology standard.
"GSM" "W-CDMA"
Transmission according to GSM standard Transmission according to W-CDMA standard
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"LTE_xxx"
Transmission according to LTE standard for different channel band-
widths "USER" Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:TECHnology[:CHANnel<ch>]
on page 506
Tx Channel Bandwidth ← Tx Channel Definition
The Tx channel bandwidth is normally defined by the transmission technology stan­dard. The correct bandwidth is predefined automatically for the selected technology. Each Tx channel is defined independently of the others; automatic bandwidth configu­ration for subsequent channels as in common ACLR measurements is not performed.
The bandwidth for each channel is indicated by a colored bar in the display. Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:BANDwidth[:CHANnel<ch>]
on page 504
User-defined transmission; no automatic preconfiguration possible
Weighting Filters ← Tx Channel Definition
Weighting filters allow you to determine the influence of individual channels on the total measurement result. For each channel, you can activate or deactivate the use of the weighting filter and define an individual weighting factor ("Alpha:" value).
Remote command: Activating/Deactivating:
[SENSe:]POWer:ACHannel:FILTer[:STATe]:SBLock<sb>:CHANnel<ch>
on page 502 Alpha value:
[SENSe:]POWer:ACHannel:FILTer:ALPHa:SBLock<sb>:CHANnel<ch>
on page 501
3.2.5.3 MSR adjacent channel setup
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR
Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config" > "Adjacent Channels" tab
The "Adjacent Channels" tab provides all the channel settings to configure adjacent and gap channels in MSR ACLR measurements.
For symmetrical channel definition (see "Symmetrical Adjacent Setup" on page 69), the dialog box is reduced as the upper and lower channels are identical.
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Figure 3-30: Asymmetrical adjacent channel definition
For details on setting up channels, see Chapter 3.2.6.3, "How to configure an MSR
ACLR measurement", on page 81.
Number of Adjacent Channels (Adj Count)...................................................................73
Adjacent Channel Definition..........................................................................................73
└ Adjacent Channel Spacings............................................................................74
└ Adjacent Channel Bandwidths........................................................................74
└ Weighting Filters............................................................................................. 74
└ Limit Checking................................................................................................ 75
Number of Adjacent Channels (Adj Count)
Defines the number of adjacent channels above and below the Tx channel block in an MSR signal. You must define the carrier channel to which the relative adjacent-channel power values refer (see "Reference Channel" on page 59).
Remote command:
[SENSe:]POWer:ACHannel:ACPairs on page 480
Adjacent Channel Definition
Defines the channels adjacent to the transmission channel block in MSR signals. A maximum of 12 adjacent channels can be defined.
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For MSR signals, adjacent channels are defined in relation to the center frequency of the first and last transmission channel in the entire block, i.e.:
●
The lower adjacent channels are defined in relation to the CF of the first Tx chan­nel in the first sub block.
●
The upper adjacent channels are defined in relation to the CF of the last Tx chan­nel in the last sub block.
Adjacent channels are named "Adj" and "Alt1" to "Alt11" by default; the names can be changed manually (see Chapter 3.2.5.5, "MSR channel names", on page 78).
In all other respects, channel definition is identical to common ACLR measurements.
Adjacent Channel Spacings ← Adjacent Channel Definition
Channel spacings are normally predefined by the selected technology but can be changed.
For MSR signals, adjacent channels are defined in relation to the center frequency of the first and last transmission channel in the entire block, i.e.:
●
The spacing of the lower adjacent channels refers to the CF of the first Tx channel in the first sub block.
●
The spacing of the upper adjacent channels refers to the CF of the last Tx channel in the last sub block.
For details, see Chapter 3.2.6.3, "How to configure an MSR ACLR measurement", on page 81
Remote command:
[SENSe:]POWer:ACHannel:SPACing[:ACHannel] on page 483 [SENSe:]POWer:ACHannel:SPACing:ALTernate<ch> on page 482 [SENSe:]POWer:ACHannel:SPACing:UACHannel on page 508 [SENSe:]POWer:ACHannel:SPACing:UALTernate<ch> on page 508
Adjacent Channel Bandwidths ← Adjacent Channel Definition
The adjacent channel bandwidth is normally predefined by the transmission technology standard. The correct bandwidth is set automatically for the selected technology. The bandwidth for each channel is indicated by a colored bar in the display.
Remote command:
[SENSe:]POWer:ACHannel:BANDwidth:ACHannel on page 480 [SENSe:]POWer:ACHannel:BANDwidth:ALTernate<ch> on page 480 [SENSe:]POWer:ACHannel:BANDwidth:UACHannel on page 500 [SENSe:]POWer:ACHannel:BANDwidth:UALTernate<ch> on page 500
Weighting Filters ← Adjacent Channel Definition
Weighting filters allow you to determine the influence of individual channels on the total measurement result. For each channel, you can activate or deactivate the use of the weighting filter and define an individual weighting factor ("Alpha:" value).
Remote command: Activating/Deactivating:
[SENSe:]POWer:ACHannel:FILTer[:STATe]:ACHannel on page 485 [SENSe:]POWer:ACHannel:FILTer[:STATe]:ALTernate<ch> on page 485 [SENSe:]POWer:ACHannel:FILTer[:STATe]:UACHannel on page 503 [SENSe:]POWer:ACHannel:FILTer[:STATe]:UALTernate<ch> on page 503
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Alpha value:
[SENSe:]POWer:ACHannel:FILTer:ALPHa:ACHannel on page 484 [SENSe:]POWer:ACHannel:FILTer:ALPHa:ALTernate<ch> on page 484 [SENSe:]POWer:ACHannel:FILTer:ALPHa:UACHannel on page 501 [SENSe:]POWer:ACHannel:FILTer:ALPHa:UALTernate<ch> on page 502
Limit Checking ← Adjacent Channel Definition
During an ACLR measurement, the power values can be checked whether they exceed user-defined or standard-defined limits. A relative or absolute limit can be defined, or both, for each individual adjacent channel. Both limit types are considered, regardless whether the measured levels are absolute or relative values. The check of both limit values can be activated independently. If any active limit value is exceeded, the measured value is displayed in red and marked by a preceding asterisk in the result table.
Note that in addition to activating limit checking for individual channels, limit checking must also be activated globally for the MSR ACLR measurement (see "Limit Checking" on page 69).
Remote command:
CALCulate<n>:LIMit<li>:ACPower[:STATe] on page 493 CALCulate<n>:LIMit<li>:ACPower:ACHannel:ABSolute:STATe on page 488 CALCulate<n>:LIMit<li>:ACPower:ACHannel:ABSolute on page 488 CALCulate<n>:LIMit<li>:ACPower:ACHannel[:RELative]:STATe
on page 489
CALCulate<n>:LIMit<li>:ACPower:ACHannel[:RELative] on page 489 CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>:ABSolute:STATe
on page 491
CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>:ABSolute on page 490 CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>[:RELative]:STATe
on page 492
CALCulate<n>:LIMit<li>:ACPower:ALTernate<ch>[:RELative]
on page 491
CALCulate<n>:LIMit<li>:ACPower:ACHannel:RESult? on page 490
3.2.5.4 MSR gap channel setup
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR
Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config" > "Gap Chan­nels" tab
The "Gap Channels" tab provides all the channel settings to configure gap channels in MSR ACLR measurements.
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For details on MSR signals, see Chapter 3.2.3.4, "Measurement on multi-standard
radio (MSR) signals", on page 50.
For details on setting up channels, see Chapter 3.2.6.3, "How to configure an MSR
ACLR measurement", on page 81.
Activate Gaps................................................................................................................76
Gap Channel Definition.................................................................................................76
└ Minimum gap size to show Gap 1/ Minimum gap size to show Gap 2............77
└ Gap Channel Spacing.....................................................................................77
└ Gap Channel Bandwidths............................................................................... 78
└ Weighting Filters............................................................................................. 78
└ Limit Checking................................................................................................ 78
Activate Gaps
If enabled, the gap channels are displayed and channel power results are calculated and displayed in the Result Summary.
Remote command:
[SENSe:]POWer:ACHannel:AGCHannels on page 499
Gap Channel Definition
Between two sub blocks in an MSR signal, two gaps are defined: a lower gap and an upper gap. Each gap in turn can contain two channels, the gap channels.
Gap channels are indicated using the following syntax:
●
The names of the surrounding sub blocks (e.g. "AB" for the gap between sub blocks A and B)
●
The channel name ("Gap1" or "Gap2")
●
"L" (for lower) or "U" (for upper)
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Minimum gap size to show Gap 1/ Minimum gap size to show Gap 2 ← Gap Channel Definition
If the gap between the sub blocks does not exceed the specified bandwidth, the gap channels are not displayed in the diagram. The gap channel results are not calculated in the result summary.
Remote command:
[SENSe:]POWer:ACHannel:GAP<gap>[:AUTO]:MSIZe on page 503
Gap Channel Spacing ← Gap Channel Definition
Gap channel spacings are normally predefined by the MSR standard but can be changed.
Gap channels are defined using bandwidths and spacings, relative to the outer edges of the surrounding sub blocks.
The required spacing can be determined according to the following formula (indicated for lower channels):
Spacing = [CF of gap channel] - [left sub block CF] + ([RF band­width of left sub block] /2)
Figure 3-31: Gap channel definition for lower gap
For details, see Chapter 3.2.6.3, "How to configure an MSR ACLR measurement", on page 81.
Remote command:
[SENSe:]POWer:ACHannel:SPACing:GAP<gap>[:AUTO] on page 507
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Gap Channel Bandwidths ← Gap Channel Definition
The gap channel bandwidth is normally predefined by the transmission technology standard. The correct bandwidth is set automatically for the selected technology. The bandwidth for each channel is indicated by a colored bar in the display (if the gap is not too narrow, see "Channel display for MSR signals" on page 54).
Remote command:
[SENSe:]POWer:ACHannel:BANDwidth:GAP<gap>[:AUTO] on page 499
Weighting Filters ← Gap Channel Definition
Weighting filters allow you to determine the influence of individual channels on the total measurement result. For each channel, you can activate or deactivate the use of the weighting filter and define an individual weighting factor ("Alpha:" value).
Remote command:
[SENSe:]POWer:ACHannel:FILTer[:STATe]:GAP<gap>[:AUTO] on page 502 [SENSe:]POWer:ACHannel:FILTer:ALPHa:GAP<gap>[:AUTO] on page 501
Limit Checking ← Gap Channel Definition
During an ACLR measurement, the power values can be checked whether they exceed user-defined or standard-defined limits. A relative or absolute limit can be defined, or both, for each individual gap channel. Both limit types are considered, regardless whether the measured levels are absolute or relative values. The check of both limit values can be activated independently. Furthermore, relative limits can be defined and activated individually for ACLR or CACLR power levels.
If any active limit value is exceeded, the measured value is displayed in red and marked by a preceding asterisk in the result table.
Note that in addition to activating limit checking for individual channels, limit checking must also be activated globally for the MSR ACLR measurement (see "Limit Checking" on page 69).
Remote command:
Chapter 6.7.3.5, "Limit check", on page 487
3.2.5.5 MSR channel names
Access: "Overview" > "Select Measurement" > "Channel Power ACLR" > "CP / ACLR
Standard" > "Standard": "Multi-Standard Radio" > "CP / ACLR Config" > "Names" tab
Channel names for all TX, adjacent, and alternate channels are user-definable.
In the "Names" tab, you can define a customized name for each channel in each sub block. Note that the names are not checked for uniqueness.
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Figure 3-32: Channel name definition for asymmetric adjacent channels
Remote command:
[SENSe:]POWer:ACHannel:SBLock<sb>:NAME[:CHANnel<ch>] on page 506
[SENSe:]POWer:ACHannel:NAME:ACHannel on page 481
[SENSe:]POWer:ACHannel:NAME:ALTernate<ch> on page 482
[SENSe:]POWer:ACHannel:NAME:UACHannel on page 504
[SENSe:]POWer:ACHannel:NAME:UALTernate<ch> on page 504

3.2.6 How to perform channel power measurements

The following step-by-step instructions demonstrate the most common tasks when per­forming channel power measurements.
For remote operation, see Chapter 6.7.3.10, "Programming examples for channel
power measurements", on page 511.
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3.2.6.1 How to perform a standard channel power measurement
Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
● How to perform a standard channel power measurement...................................... 80
● How to set up the channels.....................................................................................80
● How to configure an MSR ACLR measurement......................................................81
● How to manage user-defined configurations...........................................................83
● How to compare the tx channel power in successive measurements.....................84
Performing a channel power or ACLR measurement according to common standards is a very easy and straightforward task with the R&S ESW.
1. Press the [MEAS] key or select "Select Measurement" in the "Overview".
2. Select "Channel Power ACLR".
The measurement is started immediately with the default settings.
3. Select the "CP / ACLR Standard" softkey.
4. Select a standard from the list.
The measurement is restarted with the predefined settings for the selected stan­dard.
5. If necessary, edit the settings for your specific measurement as described in Chap-
ter 3.2.6.2, "How to set up the channels", on page 80, or load a user-defined con-
figuration (see "To load a user-defined configuration" on page 83).
3.2.6.2 How to set up the channels
Channel definition is the basis for measuring power levels in certain frequency ranges. Usually, the power levels in one or more carrier (Tx) channels and possibly the adja­cent channels are of interest. Up to 18 carrier channels and up to 12 adjacent channels can be defined.
When a measurement standard is selected, all settings including the channel band­widths and channel spacings are set according to the selected standard. Select a stan­dard in the "Ch Power" menu or the "ACLR Setup" dialog box. You can adjust the set­tings afterwards.
Channel setup consists of the following settings:
●
The number of transmission (Tx) and adjacent channels
●
The bandwidth of each channel
●
For multicarrier ACLR measurements: which Tx channel is used as a reference
●
The spacing between the individual channels
●
Optionally: the names of the channels displayed in the diagram and result table
●
Optionally: the influence of individual channels on the total measurement result ("Weighting Filter")
●
Optionally: limits for a limit check on the measured power levels
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Changes to an existing standard can be stored as a user-defined standard, see Chap-
ter 3.2.6.4, "How to manage user-defined configurations", on page 83.
► To configure the channels in the "Ch Power" dialog box, select "Ch Power" > "CP /
ACLR Config" > "Channel Settings" tab.
In the "Channel Setup" dialog box, you can define the channel settings for all channels, independent of the defined number of used Tx or adjacent channels.
To define channel spacings
Channel spacings are normally defined by the selected standard but can be changed.
► In the "Channel Settings" tab of the "ACLR Setup" dialog box, select the "Spacing"
subtab. The value entered for any Tx channel is automatically also defined for all subse­quent Tx channels. Thus, only enter one value if all Tx channels have the same spacing. If the channel spacing for the adjacent or an alternate channel is changed, all higher alternate channel spacings are multiplied by the same factor (new spacing value/old spacing value). The lower adjacent-channel spacings remain unchanged. Only enter one value for equal channel spacing.
Example: Defining channel spacing
In the default setting, the adjacent channels have the following spacing: 20 kHz ("ADJ"), 40 kHz ("ALT1"), 60 kHz ("ALT2"), 80 kHz ("ALT3"), 100 kHz ("ALT4"), …
Set the spacing of the first adjacent channel ("ADJ") to 40 channels, the spacing is multiplied by factor 2: 80 kHz ("ALT1"), 120 kHz ("ALT2"), 160 kHz ("ALT3"), …
Starting from the default setting, set the spacing of the fifth adjacent channel ("ALT4") to 150 kHz. For all higher adjacent channels, the spacing is multiplied by factor 1.5: 180 kHz ("ALT5"), 210 kHz ("ALT6"), 240 kHz ("ALT7"), …
3.2.6.3 How to configure an MSR ACLR measurement
You configure ACLR measurements on MSR signals in a special configuration dialog box on the R&S ESW.
1. Press the [MEAS] key or select "Select Measurement" in the "Overview".
2. Select "Channel Power ACLR".
The measurement is started immediately with the default settings.
3. Select the "CP / ACLR Standard" softkey.
4. Select the "Multi-Standard Radio" standard from the list.
kHz. For all other adjacent
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5. Select the "CP / ACLR Config" softkey to configure general MSR settings, including
the number of sub blocks (up to 5). To configure asymmetric adjacent channels, deactivate the "Symmetrical" option in the general MSR settings.
6. Select the "Tx Channels" tab to configure the sub blocks and transmission chan-
nels. For each sub block:
a) Define the (center frequency) position and bandwidth of the sub block, as well
as the number of transmission channels it contains.
b) For each transmission channel in the sub block:
● Define the center frequency.
● Select the technology used for transmission.
● Check the bandwidth.
● If necessary, define the use of a weighting filter for the channel.
7. Select the "Adjacent Channels" tab to configure the adjacent channels.
8. Define the number of adjacent channels and the settings for each channel:
● The spacing, defined as the distance of the center frequency from the center frequency of the first transmission channel in the first sub block. For asymmetrical channels, define the upper adjacent channel spacing as the distance from the center frequency of the last transmission channel in the last sub block.
● The bandwidth
● If necessary, a weighting filter
● Optionally, define and activate relative or absolute limits, or both, against which the power levels of the channel are to be checked.
9. Select the "Gap Channels" tab to configure the gap channels.
10. Define the following settings for the two (upper or lower) gap channels. Since the upper and lower channels are identical, it is only necessary to configure two chan­nels.
● The spacing, defined as the distance of the center frequency from the outer
edge of the sub block to the left or right of the gap. You can determine the required spacing as follows: Spacing = [CF of the gap channel] - [left sub block center] + ([RF bandwidth of left sub block] /2)
● The bandwidth
● If necessary, a weighting filter
● Optionally, define and activate relative or absolute limits, or both, against which
the power levels of the channel are to be checked.
11. If power limits are defined and activated, activate global limit checking for the mea­surement on the "MSR General Settings" tab.
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3.2.6.4 How to manage user-defined configurations
Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
12. Optionally, store the settings for the MSR ACLR measurement as a user-defined standard as described in "To store a user-defined configuration" on page 83. Oth- erwise the configuration is lost when you select a different measurement standard.
You can define measurement configurations independently of a predefined standard and save the current ACLR configuration as a "user standard" in an XML file. You can then load the file and thus the settings again later.
User-defined standards are not supported for "Fast ACLR" and multicarrier ACLR mea­surements.
Compatibility to R&S FSP
User standards created on an analyzer of the R&S FSP family are compatible to the R&S ESW. User standards created on an R&S ESW, however, are not necessarily compatible to the analyzers of the R&S FSP family and may not work there.
To store a user-defined configuration
1. In the "Ch Power" menu, select the "CP / ACLR Config" softkey to display the "ACLR Setup" dialog box.
2. Configure the measurement as required (see also Chapter 3.2.6.2, "How to set up
the channels", on page 80).
3. In the "General Settings" tab, select the "Manage User Standards" button to display the "Manage" dialog box.
4. Define a filename and storage location for the user standard. By default, the XML file is stored in C:\Program Files (x86)\Rohde-Schwarz\ESW\<version>\acp_std\. However, you can define any other storage location.
5. Select "Save".
To load a user-defined configuration
1. In the "General Settings" tab of the "ACLR Setup" dialog box, select the "Manage User Standards" button to display the "Manage" dialog box.
2. Select the user standard file.
3. Select "Load".
The stored settings are automatically set on the R&S ESW and the measurement is restarted with the new parameters.
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3.2.6.5 How to compare the tx channel power in successive measurements
Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
For power measurements with only one Tx channel and no adjacent channels, you can define a fixed reference power and compare subsequent measurement results to the stored reference power.
1. Configure a measurement with only one Tx channel and no adjacent channels (see also Chapter 3.2.6.2, "How to set up the channels", on page 80).
2. In the "ACLR Setup" dialog box, select the "Set CP Reference" button. The channel power currently measured on the Tx channel is stored as a fixed ref-
erence power. The reference value is displayed in the "Reference" field of the result table (in relative ACLR mode).
3. Start a new measurement. The resulting power is indicated relative to the fixed reference power.
4. Repeat this for any number of measurements.
5. To start a new measurement without the fixed reference, temporarily define a sec­ond channel or preset the instrument.

3.2.7 Measurement examples

The R&S ESW has test routines for simple channel and adjacent channel power mea­surements. These routines give quick results without any complex or tedious setting procedures.
A programming example demonstrating an ACLR measurement in a remote environ­ment is provided in Chapter 6.7.3.10, "Programming examples for channel power mea-
surements", on page 511.
● Measurement example 1 – ACPR measurement on a CDMA2000 signal............. 84
● Measurement example 3 – measuring the intrinsic noise of the R&S ESW with the
channel power function........................................................................................... 86
3.2.7.1 Measurement example 1 – ACPR measurement on a CDMA2000 signal
Test setup:
Signal
Generator
R&S ESW
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Signal generator settings (e.g. R&S SMW):
Frequency: 850 MHz
Level: 0 dBm
Modulation: CDMA2000
Procedure:
1. Preset the R&S ESW.
2. Enter the Spectrum application via the [MODE] key.
3. Set the center frequency to 850 MHz.
4. Set the span to 4 MHz.
5. Set the reference level to +10 dBm.
6. Press the [MEAS] key or select "Select Measurement" in the "Overview".
7. Select the "Channel Power ACLR" measurement function.
8. Set the "CDMA2000" standard for adjacent channel power measurement in the "ACLR Setup" dialog box.
The R&S ESW sets the channel configuration according to the 2000 standard with two adjacent channels above and 2 below the transmit channel. The spectrum is displayed in the upper part of the screen, the numeric values of the results and the channel configuration in the lower part of the screen. The various channels are rep­resented by vertical lines on the graph. The frequency span, resolution bandwidth, video bandwidth and detector are selected automatically to give correct results. To obtain stable results – especially in the adjacent channels (30 kHz bandwidth) which are narrow in comparison with the transmission channel bandwidth (1.23 MHz) – the RMS detector is used.
9. Set the optimal reference level and RF attenuation for the applied signal level using the "Auto Level" function in the [Auto Set] menu.
The R&S ESW sets the optimal RF attenuation and the reference level based on the transmission channel power to obtain the maximum dynamic range. The Figure 3-33 shows the result of the measurement.
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Figure 3-33: Adjacent channel power measurement on a CDMA2000 signal
3.2.7.2 Measurement example 3 – measuring the intrinsic noise of the R&S ESW with
the channel power function
Noise in any bandwidth can be measured with the channel power measurement func­tions. Thus the noise power in a communication channel can be determined, for exam­ple.
If the noise spectrum within the channel bandwidth is flat, the noise marker can be used to determine the noise power in the channel by considering the channel band­width. However, in the following cases, the channel power measurement method must be used to obtain correct measurement results:
●
If phase noise and noise that normally increases towards the carrier is dominant in the channel to be measured
●
If there are discrete spurious signals in the channel
Test setup:
► Leave the RF input of the R&S ESW open-circuited or terminate it with 50 Ω.
Procedure:
1. Preset the R&S ESW.
2. Set the center frequency to 1 GHz and the span to 1 MHz.
3. To obtain maximum sensitivity, set RF attenuation to 0 dB and the reference level to -40 dBm.
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4. Select the "Channel Power ACLR" measurement function from the "Select Mea­surement" dialog box.
5. In the "ACLR Setup" dialog box, set up a single Tx channel with the channel band­width 1.23 MHz.
6. Select the "Adjust Settings" softkey. The settings for the frequency span, the bandwidth (RBW and VBW) and the detector are automatically set to the optimum values required for the measure­ment.
7. Stabilize the measurement result by increasing the Sweep Time. Set the Sweep Time to 1
s.
The trace becomes much smoother because of the RMS detector and the channel power measurement display is much more stable.
Figure 3-34: Measurement of the R&S ESW's intrinsic noise power in a 1.23 MHz channel band-
width.

3.2.8 Optimizing and troubleshooting the measurement

If the results do not meet your expectations, or if you want to minimize the measure­ment duration, try the following methods to optimize the measurement:
●
Only activate as many adjacent channels as necessary to minimize the required span and thus the required measurement time for the measurement.
●
Increase the RBW to minimize the measurement time; however, consider the requirements of the standard if you need to measure according to standard! The automatic settings are always according to standard.
●
Take advantage of the speed optimization mode in the "Sweep" settings if you do not require the larger dynamic range (see "Optimization" on page 314).
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3.2.9 Reference: predefined CP/ACLR standards

Measurements and results
Channel power and adjacent-channel power (ACLR) measurement
●
Reduce the Sweep Time and thus the amount of data to be captured and calcula­ted; however, consider the requirements regarding the standard deviation.
●
To improve the stability of the measured results, increase the Sweep Time, which also leads to more averaging steps.
●
Instead of trace averaging, use an RMS detector with a higher Sweep Time to obtain better average power results in less time.
●
To determine a channel power level quickly, use the Time domain power mea-
surement (TDP) rather than a Channel Power measurement. The TDP measure-
ment is a zero span measurement where the sweep time determines the measure­ment time. Due to the FFT measurement, duplicate averaging is performed, provid­ing very stable results very quickly. Note, however, that for TDP measurements, channel filters are not available and a fixed RBW is used. Thus, the measurement may not be according to standard for some test cases.
When using predefined standards for ACLR measurement, the test parameters for the channel and adjacent-channel measurements are configured automatically.
You can select a predefined standard via the "CP / ACLR Standard" softkey in the "Ch Power" menu or the selection list in the "General Settings" tab of the "ACLR Setup" dialog box (see "Standard" on page 57).
Table 3-9: Predefined CP / ACLR standards with remote command parameters
Standard Remote parameter
None NONE
Multi-Standard Radio MSR
EUTRA/LTE Square EUTRa
EUTRA/LTE Square/RRC REUTra
5G NR DL FR1 20MHz F1D20nr5g
5G NR DL FR1 100MHz F1D100nr5g
5G NR UL FR1 20MHz F1U20nr5g
5G NR UL FR1 100MHz F1U100nr5g
5G NR DL FR2 100MHz F2D100nr5g
5G NR DL FR2 200MHz F2D200nr5g
5G NR UL FR2 100MHz F2U100nr5g
5G NR UL FR2 200MHz F2U200nr5g
W-CDMA 3GPP FWD FW3Gppcdma
W-CDMA 3GPP REV RW3Gppcdma
CDMA IS95A FWD F8CDma
CDMA IS95A REV R8CDma
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Standard Remote parameter
CDMA IS95C Class 0 FWD*) FIS95c0
CDMA IS95C Class 0 REV*) RIS95c0
CDMA J-STD008 FWD F19Cdma
CDMA J-STD008 REV R19Cdma
CDMA IS95C Class 1 FWD*) FIS95c1
CDMA IS95C Class 1 REV*) RIS95c1
CDMA2000 S2CDma
TD-SCDMA FWD FTCDma
TD-SCDMA REV TRCDma
WLAN 802.11A AWLAN
WLAN 802.11B BWLAN
WIMAX WIMax
WIBRO WIBRo
GSM GSM
RFID 14443 RFID14443
TETRA TETRa
PDC PDC
PHS PHS
CDPD CDPD
APCO-25 P2 PAPCo25
User Standard USER
Customized Standard <string>
For the R&S ESW, the channel spacing is defined as the distance between the center frequency of the adjacent channel and the center frequency of the transmission chan­nel. The definition of the adjacent-channel spacing in standards IS95C and CDMA 2000 is different. These standards define the adjacent-channel spacing from the center of the transmission channel to the closest border of the adjacent channel. This defini­tion is also used by the R&S ESW for the standards marked with an asterisk *).

3.2.10 Reference: predefined ACLR user standard XML files

In addition to the predefined standards, some user standards with specific measure­ment settings for common ACLR measurements are provided in XML files on the instrument in the C:\Program Files (x86)\Rohde-Schwarz\ESW\<version>\acp_std direc­tory.
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Furthermore, the following XML files are provided:
5GNR\DL
●
5GNR\DL\5GNR_DL_FR1_20MHz
●
5GNR\DL\5GNR_DL_FR1_100MHz
●
5GNR\DL\5GNR_DL_FR2_100MHz
●
5GNR\DL\5GNR_DL_FR2_200MHz
5GNR\UL
●
5GNR\UL\5GNR_UL_FR1_20MHz
●
5GNR\UL\5GNR_UL_FR1_100MHz
●
5GNR\UL\5GNR_UL_FR2_100MHz
●
5GNR\UL\5GNR_UL_FR2_200MHz
LTE\DL
●
LTE\DL\LTE_DL_5MHZ.XML
●
LTE\DL\LTE_DL_10MHZ.XML
●
LTE\DL\LTE_DL_15MHZ.XML
●
LTE\DL\LTE_DL_20MHZ.XML
Measurements and results
Carrier-to-noise measurements
LTE\UL
●
LTE\UL\LTE_UL_5MHZ.XML
●
LTE\UL\LTE_UL_10MHZ.XML
●
LTE\UL\LTE_UL_15MHZ.XML
●
LTE\UL\LTE_UL_20MHZ.XML
WLAN
●
WLAN\802_11ac\802_11ac_20MHZ.XML
●
WLAN\802_11ac\802_11ac_40MHZ.XML
●
WLAN\802_11ac\802_11ac_80MHZ.XML
●
WLAN\802_11ac\802_11ac_160MHZ.XML
To load a stored measurement configuration, in the "General Settings" tab of the "ACLR Setup" dialog box, select the "Manage User Standards" button to display the "Manage" dialog box. Select the user standard file, then "Load".
The stored settings are automatically set on the R&S ESW and the measurement is restarted with the new parameters.
For details, see Chapter 3.2.6.4, "How to manage user-defined configurations", on page 83.

3.3 Carrier-to-noise measurements

Measures the carrier-to-noise ratio. C/No measurements normalize the ratio to a 1 Hz bandwidth.
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3.3.1 About the measurement

Measurements and results
Carrier-to-noise measurements
● About the measurement..........................................................................................91
● Carrier-to-noise results............................................................................................92
● Carrier-to-noise configuration..................................................................................92
● How to determine the carrier-to-noise ratio.............................................................94
The largest signal in the frequency span is the carrier. It is searched when the C/N or C/N0 function is activated and is marked using a fixed reference marker ("FXD").
To determine the noise power, a channel with a defined bandwidth at the defined cen­ter frequency is analyzed. The power within this channel is integrated to obtain the noise power level. (If the carrier is within this channel, an extra step is required to determine the correct noise power level, see below.)
The noise power of the channel is subtracted from the maximum carrier signal level, and in the case of a C/N0 measurement, it is referred to a 1 Hz bandwidth.
For this measurement, the RMS detector is activated. The carrier-to-noise measurements are only available in the frequency domain (span
>0).
Measurement process
Depending on whether the carrier is inside or outside the analyzed channel, the mea­surement process for the carrier-to-noise ratio varies:
●
The carrier is outside the analyzed channel: In this case, it is sufficient to switch on the desired measurement function and to set the channel bandwidth. The carrier/ noise ratio is displayed on the screen.
●
The carrier is inside the analyzed channel: In this case, the measurement must be performed in two steps:
– First, perform the reference measurement by switching on either the C/N or the
C/N0 measurement and waiting for the end of the next measurement run. The fixed reference marker is set to the maximum of the measured carrier signal.
– Then, switch off the carrier so that only the noise of the test setup is active in
the channel. The carrier-to-noise ratio is displayed after the subsequent mea­surement has been completed.
Frequency Span
The frequency span should be set to approximately twice the channel bandwidth in order to measure the carrier-to-noise ratio correctly. This setting is defined automati­cally by the "Adjust Settings" function.
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3.3.2 Carrier-to-noise results

Measurements and results
Carrier-to-noise measurements
As a result of the carrier-to-noise measurement the evaluated bandwidth and the cal­culated C/N ratio are displayed in the result window. The fixed reference marker is indi­cated in the diagram.
Remote command:
You can also query the determined carrier-to-noise ratio via the remote command
CALC:MARK:FUNC:POW:RES? CN or CALC:MARK:FUNC:POW:RES? CN0, see
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 474.

3.3.3 Carrier-to-noise configuration

Access: "Overview" > "Select Measurement" > "C/N"/"C/N0" > "Carrier Noise Config"
Both a carrier-to-noise ratio (C/N) and a carrier-to-noise ratio in relation to the band­width (C/N0) measurement are available.
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Measurements and results
Carrier-to-noise measurements
Carrier-to-noise measurements are not available in zero span mode.
The easiest way to configure a measurement is using the configuration "Overview", see Chapter 4.2, "Configuration overview", on page 224.
The remote commands required to perform these tasks are described in Chapter 6.7.4,
"Carrier-to-noise ratio", on page 519.
C/N................................................................................................................................93
C/N0..............................................................................................................................93
Channel Bandwidth.......................................................................................................94
Adjust Settings.............................................................................................................. 94
C/N
Switches the measurement of the carrier/noise ratio on or off. If no marker is active, marker 1 is activated.
The measurement is performed on the trace that marker 1 is assigned to. To shift marker 1 and measure another trace, use the "Marker To Trace" softkey in the "Marker" menu (see "Assigning the Marker to a Trace" on page 211).
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:SELect on page 475 CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 474 CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>[:STATe] on page 476
C/N0
Switches the measurement of the carrier/noise ratio with reference to a 1 Hz bandwidth on or off. If no marker is active, marker 1 is activated.
The measurement is performed on the trace that marker 1 is assigned to. To shift marker 1 and measure another trace, use the "Marker To Trace" softkey in the "Marker" menu (see "Assigning the Marker to a Trace" on page 211).
Remote command:
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:SELect on page 475 CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 474 CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>[:STATe] on page 476
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3.3.4 How to determine the carrier-to-noise ratio

Measurements and results
Occupied bandwidth measurement (OBW)
Channel Bandwidth
Defines the channel bandwidth. The default setting is 14 kHz. Remote command:
[SENSe:]POWer:ACHannel:BANDwidth[:CHANnel<ch>] on page 481
Adjust Settings
Enables the RMS detector and adjusts the span to the selected channel bandwidth according to:
"4 x channel bandwidth + measurement margin" The adjustment is performed once; if necessary, the setting can be changed later on. Remote command:
[SENSe:]POWer:ACHannel:PRESet on page 476
The following step-by-step instructions demonstrate how to determine the carrier-to­noise ratio.
For remote operation, see Chapter 6.7.17, "Programming example: carrier-to-noise
ratio", on page 618.
1. Press the "C/N", "C/N0" softkey to configure the carrier-to-noise ratio measure­ment.
2. To change the channel bandwidth to be analyzed, press the "Channel Bandwidth" softkey.
3. To optimize the settings for the selected channel configuration, press the "Adjust Settings" softkey.
4. To activate the measurements without reference to the bandwidth, press the "C/N" softkey. To activate the measurements with reference to the bandwidth, press the "C/N0"
softkey .
5. If the carrier signal is located within the analyzed channel bandwidth, switch off the carrier signal so that only the noise is displayed in the channel and perform a sec­ond measurement.
The carrier-to-noise ratio is displayed after the measurement has been completed.

3.4 Occupied bandwidth measurement (OBW)

An important characteristic of a modulated signal is its occupied bandwidth, that is: the bandwidth which must contain a defined percentage of the power. In a radio communi-
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3.4.1 About the measurement

Measurements and results
Occupied bandwidth measurement (OBW)
cations system, for instance, the occupied bandwidth must be limited to enable distor­tion-free transmission in adjacent channels.
● About the measurement..........................................................................................95
● OBW results............................................................................................................97
● OBW configuration..................................................................................................97
● How to determine the occupied bandwidth............................................................. 99
● Measurement example..........................................................................................101
The occupied bandwidth is defined as the bandwidth containing a defined percentage of the total transmitted power. A percentage between 10 % and 99.9 % can be set.
Measurement principle
The bandwidth containing 99% of the signal power is to be determined, for example. The algorithm first calculates the total power of all displayed points of the trace. In the next step, the points from the right edge of the trace are summed up until 0.5 % of the total power is reached. Auxiliary marker 1 is positioned at the corresponding frequency. Then the points from the left edge of the trace are summed up until 0.5 % of the power is reached. Auxiliary marker 2 is positioned at this point. 99 % of the power is now between the two markers. The distance between the two frequency markers is the occupied bandwidth which is displayed in the marker field.
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Measurements and results
Occupied bandwidth measurement (OBW)
OBW within defined search limits - multicarrier OBW measurement in one sweep
The occupied bandwidth of the signal can also be determined within defined search limits instead of for the entire signal. Thus, only a single sweep is required to determine the OBW for a multicarrier signal. To do so, search limits are defined for an individual carrier and the OBW measurement is restricted to the frequency range contained within those limits. Then the search limits are adapted for the next carrier and the OBW is automatically recalculated for the new range.
For step-by-step instructions, see "How to determine the OBW for a multicarrier signal
using search limits" on page 100.
Prerequisites
To ensure correct power measurement, especially for noise signals, and to obtain the correct occupied bandwidth, the following prerequisites and settings are necessary:
●
Only the signal to be measured is displayed in the window, or search limits are defined to include only one (carrier) signal. An additional signal would falsify the measurement.
●
RBW << occupied bandwidth (approx. 1/20 of occupied bandwidth, for voice com­munication type: 300 Hz or 1 kHz)
●
VBW ≥ 3 x RBW
●
RMS detector
●
Span ≥ 2 to 3 x occupied bandwidth
Some of the measurement specifications (e.g. PDC, RCR STD-27B) require measure­ment of the occupied bandwidth using a peak detector. The detector setting of the R&S ESW has to be changed accordingly then.
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3.4.2 OBW results

Measurements and results
Occupied bandwidth measurement (OBW)
As a result of the OBW measurement the occupied bandwidth ("Occ Bw") is indicated in the marker results. Furthermore, the marker at the center frequency and the tempo­rary markers are indicated.
The measurement is performed on the trace with marker 1. In order to evaluate another trace, marker 1 must be placed on another trace (see Assigning the Marker to
a Trace).
The OBW calculation is repeated if you change the search limits, without performing a new sweep. Thus, the OBW for a multicarrier signal can be determined using only one sweep.
Centroid frequency
The centroid frequency is defined as the point in the center of the occupied bandwidth, calculated using the temporary OBW markers T1 and T2. This frequency is indicated as a function result ("Occ Bw Centroid") in the marker table.
Frequency offset
The offset of the calculated centroid frequency to the defined center frequency of the R&S ESW is indicated as a function result ("Occ Bw Freq Offset") in the marker table.
Remote command:
The determined occupied bandwidth can also be queried using the remote command CALC:MARK:FUNC:POW:RES? OBW or CALC:MARK:FUNC:POW:RES? AOBW. While the OBW parameter returns only the occupied bandwidth, the AOBW parameter also returns the position and level of the temporary markers T1 and T2 used to calculate the occupied bandwidth.
CALC:MARK:FUNC:POW:SEL OBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:SELect on page 475
CALCulate<n>:MARKer<m>:FUNCtion:POWer<sb>[:STATe] on page 476
CALC:MARK:FUNC:POW:RES? OBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 474
CALC:MARK:FUNC:POW:RES? COBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 474

3.4.3 OBW configuration

Access: "Overview" > "Select Measurement" > "OBW" > "OBW Config"
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Measurements and results
Occupied bandwidth measurement (OBW)
This measurement is not available in zero span.
Configuring search limits for OBW measurement
The OBW measurement uses the same search limits as defined for marker search (see search limits). However, only the left and right limits are considered.
The remote commands required to perform these tasks are described in Chapter 6.7.5,
"Occupied bandwidth", on page 520.
% Power Bandwidth......................................................................................................98
Channel Bandwidth.......................................................................................................98
Adjust Settings.............................................................................................................. 99
Search Limits (Left / Right)............................................................................................99
Deactivating All Search Limits.......................................................................................99
% Power Bandwidth
Defines the percentage of total power in the displayed frequency range which defines the occupied bandwidth. Values from 10 % to 99.9 % are allowed.
Remote command:
[SENSe:]POWer:BANDwidth on page 520
Channel Bandwidth
Defines the channel bandwidth for the transmission channel in single-carrier measure­ments. This bandwidth is used to optimize the test parameters (for details see "Adjust
Settings" on page 99). The default setting is 14 kHz.
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Measurements and results
Occupied bandwidth measurement (OBW)
For measurements according to a specific transmission standard, define the bandwidth specified by the standard for the transmission channel.
For multicarrier measurements, this setting is irrelevant. Remote command:
[SENSe:]POWer:ACHannel:BANDwidth[:CHANnel<ch>] on page 481
Adjust Settings
Optimizes the instrument settings for the measurement of the occupied bandwidth according to the specified channel bandwidth.
This function is only useful for single carrier measurements. All instrument settings relevant for power measurement within a specific frequency
range are optimized:
●
Frequency span: 3 × channel bandwidth
●
RBW ≤ 1/40 of channel bandwidth
●
VBW ≥ 3 × RBW
●
Detector: RMS
The reference level is not affected by "Adjust Settings". For an optimum dynamic range,select the reference level such that the signal maximum is close to the reference level.
(See "Setting the Reference Level Automatically (Auto Level)" on page 299). The adjustment is carried out only once. If necessary, the instrument settings can be
changed later. Remote command:
[SENSe:]POWer:ACHannel:PRESet on page 476
Search Limits (Left / Right)
If activated, limit lines are defined and displayed for the search. Only results within the limited search range are considered.
For details on limit lines for searches, see "Peak search limits" on page 425. Remote command:
CALCulate<n>:MARKer<m>:X:SLIMits[:STATe] on page 727 CALCulate<n>:MARKer<m>:X:SLIMits:LEFT on page 726 CALCulate<n>:MARKer<m>:X:SLIMits:RIGHt on page 726
Deactivating All Search Limits
Deactivates the search range limits. Remote command:
CALCulate<n>:MARKer<m>:X:SLIMits[:STATe] on page 727 CALCulate<n>:THReshold:STATe on page 728

3.4.4 How to determine the occupied bandwidth

The following step-by-step instructions demonstrate how to determine the occupied bandwidth.
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Measurements and results
Occupied bandwidth measurement (OBW)
For remote operation, see Chapter 6.7.5.2, "Programming example: OBW measure-
ment", on page 521.
How to determine the OBW for a single signal
1. Press the [MEAS] key or select "Select Measurement" in the "Overview".
2. Select the "OBW" measurement function. The measurement is started immediately with the default settings.
3. Select the "OBW Config" softkey. The "Occupied Bandwidth" configuration dialog box is displayed.
4. Define the percentage of power ("% Power Bandwidth") that defines the bandwidth to be determined.
5. If necessary, change the channel bandwidth for the transmission channel.
6. To optimize the settings for the selected channel configuration, select "Adjust Set­tings".
7. Start a sweep.
The result is displayed as OBW in the marker results.
How to determine the OBW for a multicarrier signal using search limits
1. Press the [MEAS] key or select "Select Measurement" in the "Overview".
2. Select the "OBW" measurement function.
3. Select the "OBW Config" softkey.
4. Define the percentage of power ("% Power Bandwidth") that defines the bandwidth to be determined.
5. Define search limits so the search area contains only the first carrier signal: a) Enter values for the left or right limits, or both.
b) Enable the use of the required limits.
6. Start a sweep. The result for the first carrier is displayed as OBW in the marker results.
7. Change the search limits so the search area contains the next carrier signal as described in step 5.
The OBW is recalculated and the result for the next carrier is displayed. A new sweep is not necessary!
8. Continue in this way until all carriers have been measured.
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