R&S FSV-K70 User manual

R&S® FSV-K70
Vector Signal Analysis
Operating Manual
Operating Manual
1176.7578.02 ─ 09
(;ÚÙÜ2)
Test & Measurement

This manual describes the following R&S®FSV/FSVA options:
●R&S FSV-K70 (1310.8455.02)
This manual describes the following R&S FSVA/FSV models with firmware version 3.30 and higher:
●R&S®FSVA4 (1321.3008K05)
●R&S®FSVA7 (1321.3008K08)
●R&S®FSVA13 (1321.3008K14)
●R&S®FSVA30 (1321.3008K31)
●R&S®FSVA40 (1321.3008K41)
●R&S®FSV4 (1321.3008K04)
●R&S®FSV7 (1321.3008K07)
●R&S®FSV13 (1321.3008K13)
●R&S®FSV30 (1321.3008K30)
●R&S®FSV40 (1321.3008K39/1321.3008K40)
It also applies to the following R&S®FSV models. However, note the differences described in Chapter 1.4,
"Notes for Users of R&S FSV 1307.9002Kxx Models", on page 9.
●R&S®FSV3 (1307.9002K03)
●R&S®FSV7 (1307.9002K07)
●R&S®FSV13 (1307.9002K13)
●R&S®FSV30 (1307.9002K30)
●R&S®FSV40 (1307.9002K39/1307.9002K40)
© 2017 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Fax: [phone]
Email: [email protected]
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 their owners.
The following abbreviations are used throughout this manual: R&S®FSV/FSVA is abbreviated as R&S FSV/FSVA.

Contents
R&S® FSV-K70
3Operating Manual 1176.7578.02 ─ 09
Contents
1 Preface.................................................................................................... 5
1.1 Documentation Overview............................................................................................. 5
1.2 Conventions Used in the Documentation...................................................................7
1.3 How to Use the Help System........................................................................................8
1.4 Notes for Users of R&S FSV 1307.9002Kxx Models.................................................. 9
2 Brief Description of Vector Signal Analysis...................................... 10
2.1 Block Diagram of Digital Signal Processing Hardware for I/Q Data.......................10
2.2 Filters and Bandwidths During Signal Processing..................................................11
2.3 Symbol Mapping......................................................................................................... 21
2.4 Demodulation Overview............................................................................................. 42
2.5 Signal Model, Estimation and Modulation Errors.................................................... 50
3 Instrument Functions for Vector Signal Analysis.............................67
3.1 Measurement Result Display..................................................................................... 69
3.2 Softkeys and Menu Overview for Vector Signal Analysis (R&S FSV-K70).......... 107
3.3 Configuring VSA Measurements............................................................................. 141
3.4 Further Information...................................................................................................201
4 Remote Control Commands - R&S FSV-K70................................... 204
4.1 Notation......................................................................................................................204
4.2 ABORt Subsystem.................................................................................................... 207
4.3 CALCulate subsystem.............................................................................................. 207
4.4 DISPlay subsystem................................................................................................... 257
4.5 FORMat subsystem...................................................................................................267
4.6 INITiate Subsystem................................................................................................... 268
4.7 INPut Subsystem.......................................................................................................270
4.8 INSTrument Subsystem............................................................................................277
4.9 MMEMory Subsystem............................................................................................... 277
4.10 OUTPut Subsystem...................................................................................................280
4.11 SENSe subsystem.....................................................................................................281
4.12 STATus:QUEStionable Subsystem......................................................................... 318
4.13 SYSTem Subsystem................................................................................................. 325

Contents
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4Operating Manual 1176.7578.02 ─ 09
4.14 TRACe subsystem.................................................................................................... 325
4.15 TRIGger subsystem.................................................................................................. 328
5 Status Reporting System (Option R&S FSV-K70)........................... 332
5.1 STATus:QUEStionable Register.............................................................................. 334
5.2 STATus:QUEStionable:SYNC<n> Register............................................................ 335
5.3 STATus:QUEStionable:MODulation<n> Register.................................................. 335
5.4 STATus:QUESTionable:MODulation<n>:EVM Register........................................ 336
5.5 STATus:QUESTionable:MODulation<n>:PHASe Register.................................... 336
5.6 STATus:QUESTionable:MODulation<n>:MAGnitude Register.............................337
5.7 STATus:QUESTionable:MODulation<n>:CFRequency Register.......................... 337
5.8 STATus:QUESTionable:MODulation<n>:IQRHO Register.................................... 337
5.9 STATus:QUESTionable:MODulation<n>:FSK Register.........................................338
6 Support............................................................................................... 339
6.1 Explanation of Error Messages............................................................................... 339
6.2 Flow Chart for Troubleshooting...............................................................................348
6.3 Frequently Asked Questions................................................................................... 350
Annex.................................................................................................. 359
A Formulae and Abbreviations.............................................................359
A.1 Formulae.................................................................................................................... 359
A.2 Abbreviations............................................................................................................ 373
B Predefined Standards and Settings................................................. 375
List of Commands..............................................................................381
Index....................................................................................................388

Preface
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5Operating Manual 1176.7578.02 ─ 09
1 Preface
When equipped with application firmware R&S FSV-K70, the analyzer performs vector
measurements on digitally modulated signals in the time domain. Based on the vector
measurements, further evaluations, e.g. statistical evaluations, can be performed.
This document contains all information required for operation of an R&S FSVA/FSV
equipped with Application Firmware R&S FSV-K70. It describes the menus and
remote-control commands for vector signal analysis, as well as some common mea-
surements.
1.1 Documentation Overview
This section provides an overview of the R&S FSVA/FSV user documentation. Unless
specified otherwise, you find the documents on the R&S FSVA/FSV product page at:
www.rohde-schwarz.com/manual/FSVA
1.1.1 Quick Start Guide
Introduces the R&S FSVA/FSV and describes how to set up and start working with the
product. Includes basic operations, typical measurement examples, and general infor-
mation, e.g. safety instructions, etc. A printed version is delivered with the instrument.
A PDF version is available for download on the Internet.
1.1.2 Operating Manuals and Help
Separate operating manuals are provided for the base unit and the software options:
●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 com-
mands with programming examples, and information on maintenance, instrument
interfaces and error messages. Includes the contents of the getting started manual.
●Software option manual
Contains the description of the specific functions of an option. Basic information on
operating the R&S FSVA/FSV is not included.
The contents of the operating manuals are available as help in the R&S FSVA/FSV.
The help offers quick, context-sensitive access to the complete information for the
base unit and the software options.
All operating manuals are also available for download or for immediate display on the
Internet.
Documentation Overview

Preface
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6Operating Manual 1176.7578.02 ─ 09
1.1.3 Service Manual
Describes the performance test for checking the rated specifications, module replace-
ment and repair, firmware update, troubleshooting and fault elimination, and contains
mechanical drawings and spare part lists.
The service manual is available for registered users on the global Rohde & Schwarz
information system (GLORIS, https://gloris.rohde-schwarz.com).
1.1.4 Instrument Security Procedures
Deals with security issues when working with the R&S FSVA/FSV in secure areas. It is
available for download on the Internet.
1.1.5 Basic Safety Instructions
Contains safety instructions, operating conditions and further important information.
The printed document is delivered with the instrument.
1.1.6 Data Sheets and Brochures
The data sheet contains the technical specifications of the R&S FSVA/FSV. It also lists
the options and their order numbers as well as optional accessories.
The brochure provides an overview of the instrument and deals with the specific char-
acteristics.
See www.rohde-schwarz.com/brochure-datasheet/FSV
1.1.7 Release Notes and Open Source Acknowledgment (OSA)
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/FSV
1.1.8 Application Notes, Application Cards, White Papers, etc.
These documents deal with special applications or background information on particu-
lar topics.
See www.rohde-schwarz.com/appnlication/FSV
Documentation Overview

Preface
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7Operating Manual 1176.7578.02 ─ 09
1.2 Conventions Used in the Documentation
1.2.1 Typographical Conventions
The following text markers are used throughout this documentation:
Convention Description
"Graphical user interface ele-
ments"
All names of graphical user interface elements on the screen, such as
dialog boxes, menus, options, buttons, and softkeys are enclosed by
quotation marks.
KEYS Key names are written in capital letters.
File names, commands,
program code
File names, commands, coding samples and screen output are distin-
guished by their font.
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-
tion marks.
1.2.2 Conventions for Procedure Descriptions
When operating the instrument, several alternative methods may be available to per-
form 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 addition-
ally 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 pro-
cedures.
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 key-
board.
1.2.3 Notes on Screenshots
When describing the functions of the product, we use sample screenshots. These
screenshots are meant to illustrate as much 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 instal-
led. Thus, some functions shown in the screenshots may not be available in your par-
ticular product configuration.
Conventions Used in the Documentation

Preface
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8Operating Manual 1176.7578.02 ─ 09
1.3 How to Use the Help System
Calling context-sensitive and general help
► To display the general help dialog box, press the HELP key on the front panel.
The help dialog box "View" tab is displayed. A topic containing information about
the current menu or the currently opened dialog box and its function is displayed.
For standard Windows dialog boxes (e.g. File Properties, Print dialog etc.), no context-
sensitive help is available.
► If the help is already displayed, press the softkey for which you want to display
help.
A topic containing information about the softkey and its function is displayed.
If a softkey opens a submenu and you press the softkey a second time, the submenu
of the softkey is displayed.
Contents of the help dialog box
The help dialog box contains four tabs:
●"Contents" - contains a table of help contents
●"View" - contains a specific help topic
●"Index" - contains index entries to search for help topics
●"Zoom" - contains zoom functions for the help display
To change between these tabs, press the tab on the touchscreen.
Navigating in the table of contents
●To move through the displayed contents entries, use the UP ARROW and DOWN
ARROW keys. Entries that contain further entries are marked with a plus sign.
●To display a help topic, press the ENTER key. The "View" tab with the correspond-
ing help topic is displayed.
●To change to the next tab, press the tab on the touchscreen.
Navigating in the help topics
●To scroll through a page, use the rotary knob or the UP ARROW and DOWN
ARROW keys.
●To jump to the linked topic, press the link text on the touchscreen.
Searching for a topic
1. Change to the "Index" tab.
How to Use the Help System

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R&S® FSV-K70
9Operating Manual 1176.7578.02 ─ 09
2. Enter the first characters of the topic you are interested in. The entries starting with
these characters are displayed.
3. Change the focus by pressing the ENTER key.
4. Select the suitable keyword by using the UP ARROW or DOWN ARROW keys or
the rotary knob.
5. Press the ENTER key to display the help topic.
The "View" tab with the corresponding help topic is displayed.
Changing the zoom
1. Change to the "Zoom" tab.
2. Set the zoom using the rotary knob. Four settings are available: 1-4. The smallest
size is selected by number 1, the largest size is selected by number 4.
Closing the help window
► Press the ESC key or a function key on the front panel.
1.4 Notes for Users of R&S FSV 1307.9002Kxx Models
Users of R&S FSV 1307.9002Kxx models should consider the following differences to
the description of the newer R&S FSVA/FSV 1321.3008Kxx models:
●Functions that are based on the Windows 10 operating system (e.g. printing or set-
ting up networks) may have a slightly different appearance or require different set-
tings on the Windows XP based models. For such functions, refer to the Windows
documentation or the documentation originally provided with the R&S FSV instru-
ment.
●The R&S FSV 1307.9002K03 model is restricted to a maximum frequency of
3 GHz, whereas the R&S FSVA/FSV1321.3008K04 model has a maximum fre-
quency of 4 GHz.
●The bandwidth extension option R&S FSV-B160 (1311.2015.xx) is not available for
the R&S FSV 1307.9002Kxx models. The maximum usable I/Q analysis bandwidth
for these models is 28 MHz, or with option R&S FSV-B70, 40 MHz.
Notes for Users of R&S FSV 1307.9002Kxx Models

Brief Description of Vector Signal Analysis
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10Operating Manual 1176.7578.02 ─ 09
2 Brief Description of Vector Signal Analysis
The "Vector Signal Analysis" software option R&S FSV-K70 performs vector and scalar
measurements on digitally modulated single-carrier signals. To perform the measure-
ments it converts RF signals into the complex baseband. It can also use the optional
Digital Baseband interface (R&S FSV-B17 option) to analyze I/Q signals already deliv-
ered to the complex baseband.
For details on the Digital Baseband interface (R&S FSV-B17 option), see the base unit
description.
The following sections describe the digital signal processing hardware, the interplay of
analog and digital filters for bandwidth limiting, modulation and demodulation filters, as
well as the algorithms used by the measurement demodulator. The implemented mod-
ulation modes and the associated predefined symbol mappings are also listed.
The last part of this chapter deals with vector and scalar modulation errors.
2.1 Block Diagram of Digital Signal Processing Hardware
for I/Q Data
The following sections describe the digital hardware used to capture I/Q data for vector
signal analysis with the R&S FSV-K70.
2.1.1 Block Diagram for RF Input
The following block diagram provides an overview on how RF input is processed in the
R&S FSV-K70 option.
Figure 2-1: Block diagram of digital hardware for RF input in vector signal analysis
After having passed several RF, IF and filter stages, the RF input signal is converted to
an IF of 96 MHz and applied to an A/D converter with a sample frequency of exactly
128 MHz.
The digitized signal is then routed through two ICs for resampling (conversion of sam-
ple rate by a real factor) and for filtering and decimation (reduction of sample rate by
Block Diagram of Digital Signal Processing Hardware for I/Q Data

Brief Description of Vector Signal Analysis
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11Operating Manual 1176.7578.02 ─ 09
an integral factor). An equalizer filter before the resampler compensates for the fre-
quency response of the analyzer's analog filter stages which would otherwise add to
the modulation errors.
During operation, the filters and decimation factors of the instrument are set so that a
sample frequency is obtained at the output of the decimation stage, which exactly cor-
responds to the following equation:
Sample rate = Symbol rate * Capture Oversampling (see "Capture Oversampling"
on page 154)
The complex output signal of the decimation stage is stored in the I/Q memory
(record buffer) and forwarded to a signal processor (DSP) for further processing.
2.1.2 Block Diagram for Digital Baseband Input
The following block diagram provides an overview on how digital baseband input is
processed in the R&S FSV-K70 option. The digital baseband input requires option
R&S FSV-B17.
Figure 2-2: Block diagram of digital hardware for digital baseband input (B17) in vector signal analy-
sis
The digital I/Q data stream is fed into the analyzer via the connector of the digital base-
band interface (R&S FSV-B17 option). There is no need to equalize any IF filter or mix
the signal into the complex baseband. The digital hardware just has to ensure that the
final I/Q data stored in the record buffer has the correct sample rate; therefore, the sig-
nal is resampled and filtered.
2.2 Filters and Bandwidths During Signal Processing
This section describes the used filters in vector signal analysis with an R&S FSVA/
FSV, as well as the bandwidth after each filter.
The relevant filters for vector signal analysis are shown in Figure 2-3.
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
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12Operating Manual 1176.7578.02 ─ 09
Figure 2-3: Block diagram of bandwidth-relevant filters for vector signal analysis
●After the IF Filter (only for RF input operation): bandwidth = 40 MHz.
●After the digital hardware section:
The phase and amplitude distortions of the IF filter have been compensated for.
Usually, the I/Q data has a usable bandwidth of about:
0.8 * sample rate = 0.8 * symbol rate * "Capture Oversampling"
For details refer to Chapter 2.2.1, "I/Q Bandwidth", on page 13.
The I/Q data's sample rate and bandwidth automatically scale themselves with the
set symbol rate. For most modulated signals even the smallest allowed value for
"Capture Oversampling" leads to a sufficient I/Q data bandwidth. The whole spec-
trum of the input signal is captured, but most adjacent channels and interferers are
effectively suppressed. Only for very wide signals (FSK, no TX-filter used) it can be
necessary to try higher values for "Capture Oversampling" (see "Capture Oversam-
pling" on page 154), increasing the I/Q bandwidth. The I/Q data delivered to the
DSP section has no considerable amplitude or phase distortion and a suitable
bandwidth.
The "I/Q Capture" dialog of the vector signal analysis shows the sample rate and the
usable I/Q bandwidth achieved for the current settings (see "I/Q Capture"
on page 152).
●After the optional measurement filter:
The measurement signal and the reference signal can be filtered by various mea-
surement filters which have different bandwidths.
The filters described above are the ones that directly affect the bandwidth of the cap-
tured I/Q data and the final measurement signal and reference signal. Note, however,
that several other filters are also involved in the DSP section but are not mentioned
above:
●Receive filter to prevent ISI (intersymbol-interference)
●filters necessary for various estimators
●others
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
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13Operating Manual 1176.7578.02 ─ 09
2.2.1 I/Q Bandwidth
The bandwidth of the I/Q data used as input for the vector signal analysis is filtered as
described in Chapter 2.2, "Filters and Bandwidths During Signal Processing",
on page 11. Its flat, usable bandwidth (no considerable amplitude or phase distortion)
depends on:
●the used sample rate, which depends on the
– defined "Symbol Rate" (see "Symbol Rate" on page 145)
– defined "Capture Oversampling" (see "Capture Oversampling" on page 154
●the type of input used (digital baseband input, RF input, etc)
The sample rate of the I/Q input data is:
Sample rate = Symbol rate * Capture Oversampling
Table 2-1: Value range for sample rate and symbol rate
Model/option Max. sample rate Min. symbol rate Max. symbol rate
(= max. sample rate / capt. oversam-
pling)
R&S FSVA/FSV
without bandwidth
extension option
45 MHz 25 Hz 11 MHz
with bandwidth
extension option
R&S FSV-B70/
R&S FSVA-B40
128 MHz 25 Hz 32 MHz
R&S FSVA/FSV
with (active) band-
width extension
option B160
1.28 GHz 25 Hz restricted to 160 MHz
1307.9002K39 12.5 MHz 25 Hz 3.125 MHz
Using this sample rate, the resulting I/Q data bandwidth can be determined from the
figure "Relation between maximum usable bandwidth and sample rate (RF input)" in
the base unit description (section "Working with I/Q data)" for RF input operation or the
figure "Bandwidths depending on sample rate for active digital input" in the description
of the Digital Baseband interface (R&S FSV option B17).
The sample rate and the usable I/Q bandwidth achieved for the current settings is dis-
played in the "I/Q Capture Settings" dialog, see "I/Q Capture" on page 152.
2.2.2 Bandwidth Extension Option R&S FSV-B160
The bandwidth extension option R&S FSV-B160 provides additional hardware, which
makes a maximum usable I/Q bandwidth of 160 MHz possible. As opposed to the
R&S FSVA/FSV base unit, the R&S FSV-K70 application uses a software resampler
which allows for a maximum sample rate up to 1.28 GHz.
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
R&S® FSV-K70
14Operating Manual 1176.7578.02 ─ 09
Usage of the optional hardware can be deactivated, if necessary, for example to
reduce possible spurious effects.
2.2.2.1 Restrictions
The optional bandwidth extension R&S FSV-B160 can not be activated if any of the fol-
lowing conditions apply:
●R&S FSV firmware versions previous to 2.0
●R&S FSV models 1307.9002Kx
●For R&S FSV models 1321.3008K13/30/39/40: For center frequencies larger than
7 GHz
●For sample rates < 32 MHz
●With any trigger except for an external trigger
2.2.3 Demodulation Bandwidth (Measurement Bandwidth)
Some modulation systems do not use a receive filter. In these cases special care
should be taken that no interference or adjacent channels occur within the demodula-
tion bandwidth. The "Capture Oversampling" parameter should be set to a low value
(see "Capture Oversampling" on page 154).
Typical communication systems demand special receive or measurement filters (e.g.
root-raised cosine receive filter or EDGE measurement filter).
If no such filtering is performed, care should be taken that neither interfering signals
nor adjacent channels fall within the demodulation bandwidth.
2.2.4 Modulation and Demodulation Filters
Sample points are required for demodulation in the analyzer, where only information of
the current symbol and none of neighbouring symbols is present (symbol points).
These points are also called ISI-free points (ISI = intersymbol interference). If the trans-
mitter does not provide an ISI-free signal after the transmit filter (TX filter), this condi-
tion can be fulfilled by signal-specific filtering of the analyzer input signal (receive filter
or Rx filter). If an RRC (root-raised cosine) filter is used in the transmitter, an RRC fil-
ter is also required in the analyzer to obtain ISI-free points.
In many PSK systems, RRC filters are used as transmit, ISI and measurement filters.
To determine the I/Q modulation error, the measurement signal must be compared
with the corresponding ideal signal. For this purpose a reference filter is required
which is calculated by the analyzer by convolving the coefficient of the transmit filter
(Tx filter) and the meas filter (see Figure 2-4).
If unfiltered signals have to be measured as well (e.g. to determine nonlinear signal
distortions), no measurement filter is switched into the signal path and the reference
filter is identical to the Transmit filter (see Figure 2-4).
Filters and Bandwidths During Signal Processing

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In the baseband block diagrams (see Figure 2-4), the system-theoretical transmitter
and analyzer filters are shown for PSK and QAM demodulation. For the sake of clear-
ness, RF stages, IF filters and the filter stages of the digital hardware section are not
shown.
For a correct demodulation, the following filters have to be accurately specified for the
analyzer:
●Transmit filter: filter characteristic of transmitter
●Meas filter:
– PSK, QAM, UserQAM, MSK:
The I and the Q part of the measurement and the reference signal are filtered
with this filter.
– FSK:
The instantaneous frequency of the measurement reference signal are filtered.
In many applications, this filter is identical with the ISI filter.
The receive filter (ISI filter) is configured internally depending on the Transmit filter.
The goal is to produce intersymbol-interference-free points for the demodulation.
The reference filter synthesizes the ideal transmitted signal (after meas filtering). It is
calculated by the analyzer from the above filters (convolution operation Transmit filter
* Meas Filter).
Table 2-2: Typical combinations of Tx and Meas filters
Transmit filter Measurement filter
(analyzer)
Remarks
RC (raised cosine) - filter combination without intersymbol
interference (ISI)
RRC (root raised cosine) RRC filter combination without ISI
GMSK - filter combination with low ISI
Linearized GMSK EDGE NSR standard specific filter; filter combina-
tion with ISI
Gauss - filter combination with low ISI
Rectangular - filter combination without ISI
Half Sine - filter combination without ISI
CDMA2000 1X FORWARD Low ISI Meas Filter filter combination without ISI
CDMA2000 1X REVERSE Low ISI Meas Filter filter combination without ISI
APCO25 C4FM Rectangular filter combination without ISI
APCO25 H-CPM Rectangular filter combination without ISI
APCO25 H-DQPSK Low ISI Meas Filter filter combination without ISI
APCO25 H-D8PSK Narrow Low ISI Meas Filter filter combination without ISI
APCO25 H-D8PSK Wide Low ISI Meas Filter filter combination without ISI
EDGE Narrow Pulse Shape EDGE HSR (Narrow
Pulse)
standard specific filter; filter combina-
tion with ISI
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
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16Operating Manual 1176.7578.02 ─ 09
Transmit filter Measurement filter
(analyzer)
Remarks
EDGE Wide Pulse Shape EDGE HSR (Wide
Pulse)
standard specific filter; filter combina-
tion with ISI
User Low ISI Meas Filter filter combination with low ISI
Typical combinations of Tx and Meas filters are shown in the table above; they can be
set in the R&S FSVA/FSV using "Meas filter = AUTO" (see "Auto" on page 175). If RC
(raised cosine), RRC (root-raised cosine) and Gaussian filters are used, the Alpha
(RC, RRC filters) or BT (Gaussian filters) parameters must be set in addition to the fil-
ter characteristic (roll-off factor). Typically the Alpha/BT value of the measurement filter
should be the same as that of the transmission filter.
For FSK, the measurement filter filters the instantaneous frequency of the signal, not
the I/Q signal.
For MSK, the measurement filter filters the I and Q parts of the measurement signal
and the reference signal (i.e. not the instantaneous frequency or magnitude of the MSK
signal).
2.2.5 Transmit filters
The transmit filters required for common standards are provided by the R&S FSV-K70.
Table 2-3: Overview of predefined Transmit filters
RC Raised cosine
RRC Root raised cosine
Gauss Gauss filter
GMSK Gauss filter convolved with a rectangular filter; typically used for
MSK
Linearized GMSK Standard-specific filter for GSM EDGE (3GPP TS 45.004), normal
symbol rate
EDGE Narrow Pulse Shape Standard-specific filter for GSM EDGE (higher symbol rate)
EDGE Wide Pulse Shape Standard-specific filter for GSM EDGE (higher symbol rate)
Half Sine Half Sine filter
APCO25 C4FM Filter for the APCO25 C4FM standard.
APCO25 H-CPM Filter for the APCO25 Phase 2 standard.
APCO25 H-DQPSK Filter for the APCO25 Phase 2 standard.
APCO25 H-D8PSK Narrow Filter for the APCO25 Phase 2 standard.
APCO25 H-D8PSK Wide Filter for the APCO25 Phase 2 standard.
CDMA2000 1X Forward Filter for CDMA ONE forward link (TIA/EIA/IS-95-A May 1995) and
CDMA2000 1X forward link (http://www.3gpp2.org/Public_html/
specs/C.S0002-C_v1.0.pdf 28/05/2002)
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
R&S® FSV-K70
17Operating Manual 1176.7578.02 ─ 09
CDMA2000 1X Reverse Filter for CDMA ONE forward link (TIA/EIA/IS-95-A May 1995) and
CDMA2000 1X reverse link (http://www.3gpp2.org/Public_html/
specs/C.S0002-C_v1.0.pdf 28/05/2002)
Rectangular Rectangular filter in the time domain with a length of 1 symbol
period
None No filter is used.
USER User-defined filter. Define the filter using the [SENSe:]DDEMod:
TFILter:USER command.
2.2.6 Measurement Filters
The measurement filter can be used to filter the following two signals in the same way:
●the measurement signal (after coarse frequency, phase and timing synchronization
have been achieved)
●the reference signal, i.e the I/Q symbols that have been determined in the demodu-
lator and have already been filtered with the Transmit filter;
For MSK, PSK, QAM and User QAM the measurement filter filters the real part and
imaginary part of these signals. For FSK, the measurement filter filters the instantane-
ous frequency of these signals.
The R&S FSV-K70 defines the error signal as the difference between the reference
signal and the measurement signal. Thus, the measurement filter also shapes the
spectrum of the error signal, which is used to calculate the EVM, for example.
In many applications the measurement filter is the same as the RX filter. However,
unlike the measurement filter, the RX filter is not relevant for the measurement, but is
only required to create the reference signal optimally.
The RX filter and the Transmit filter are usually chosen such that their combination
results in an Inter-Symbol Interference (ISI) free system (see Figure 2-4 and Fig-
ure 2-5).
Filters and Bandwidths During Signal Processing

Brief Description of Vector Signal Analysis
R&S® FSV-K70
18Operating Manual 1176.7578.02 ─ 09
Figure 2-4: Measurement filter in the block diagram (MSK, PSK, QAM and UserQAM)
Figure 2-5: Modulator with Transmit filter in detail
As the measurement filters of the R&S FSV-K70 have low-pass characteristics, they
suppress high frequency distortion components in the Meas/Ref/Error signal. The
errors are weighted spectrally. Thus, turning off the measurement filter can have an
influence on the numeric and graphical error values. However, the measurement filter
should be switched off if non-linear distortions have to be measured (they usually pro-
duce high frequency components).
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Brief Description of Vector Signal Analysis
R&S® FSV-K70
19Operating Manual 1176.7578.02 ─ 09
Predefined measurement filters
The most frequently required measurement filters are provided by the R&S FSV-K70.
Table 2-4: Overview of predefined measurement filters
EDGE NSR Measurement filter required for the "EDGE, Normal Symbol
Rate" standard. (see 3GPP TS 45.005, chapter 4.6 Modulation
Accuracy). The resulting system is NOT inter-symbol interfer-
ence free.
EDGE HSR (Narrow Pulse) Measurement filter required for the "EDGE, High Symbol Rate,
Narrow Pulse" standard.
EDGE HSR (Wide Pulse) Measurement filter required for the "EDGE, High Symbol Rate,
Wide Pulse" standard.
Gauss Classic Gauss filter with an adjustable BT
Low ISI Meas Filter Measurement filter implemented to retain a low intersymbol
inferference. Best suited for eye diagrams or I/Q vector dia-
grams. Not necessarily suited for EVM evaluation due to amplifi-
cation in the pass band.
Low Pass (Narrow) Pass band up to Fsymbol/2
Stop band starts at Fsymbol (-40dB)
Low Pass (Wide) Pass band up to Fsymbol
Stop band starts at 1.5*Fsymbol (-40dB)
Rectangular Rectangular filter in the time domain with a length of 1 symbol
period; integrate and dump effect
RRC Root Raised Cosine Filter. The roll-off parameter "Alpha" is set
according to the Transmit filter if the "Auto (according to Trans-
mit filter)" option is enabled (see "Auto" on page 175). Other-
wise it must be set manually.
If the Transmit filter is also a Root Raised Cosine filter with the
same roll-off parameter, the resulting system is inter-symbol
interference free.
USER User-defined filter.
Define the filter using the "Load User Filter" on page 175 func-
tion or the [SENSe:]DDEMod:MFILter:USER command.
For details see Chapter 2.2.7, "Customized Filters",
on page 19.
NONE No measurement filter is used.
The frequency response of the available standard-specific measurement filters is
shown in Chapter A.1.6.2, "Measurement Filter", on page 367.
2.2.7 Customized Filters
The analytical filter types RC (raised cosine), RRC (root-raised cosine) and GAUS-
SIAN as well as the most important standard-specific filters are already integrated in
the R&S FSV-K70. In addition, it is possible to use user-defined measurement and
Transmit filters. Customized filters may be useful for the following purposes:
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Brief Description of Vector Signal Analysis
R&S® FSV-K70
20Operating Manual 1176.7578.02 ─ 09
●Development of new networks and modulation methods for which no filters are
defined yet.
●Measurements of transmitter characteristics with slightly modified (e.g. shortened)
transmitter filters.
An external program ("FILTWIZ") is offered to convert user-defined filters. This pro-
gram generates filter files (*.vaf) which can be transferred to the analyzer with a USB
device, for example. The program can be downloaded together with a detailed descrip-
tion as a precompiled MATLAB® file (MATLAB pcode) on the Internet, at http://
www.rohde-schwarz.com (search term "FILTWIZ").
Figure 2-6: FILTWIZ - filter tool for the R&S FSV-K70
It is possible to load customized transmit filters and customized measurement filters. If
a customized transmit filter is selected, the internal receive filter coefficients are calcu-
lated automatically on the fly.
Note that this is different to the R&S FSQ-K70, where it is necessary to also transfer a
user receive filter.
If you upload a customized transmit filter and leave the measurement filter set to "auto-
matic", the internally calculated receive filter will be used as measurement filter. Note
that this filter is not necessarily suitable for your specific signal. The filter is optimized
Filters and Bandwidths During Signal Processing