Rohde & Schwarz R&S CMW-KM70 Series User manual

R&S®CMW-KM70x/-KS70x
WiMAX Firmware Applications
User Manual
User Manual
1173.9757.02 ─ 04
(;×ïÇ2)
Test & Measurement
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This user manual describes the following R&S®CMW options:
●R&S®CMW-KM700 (WiMAX™ IEEE 802.16e, TX measurement)
●R&S®CMW-KM701 (WiMAX™ IEEE 802.16e, advanced TX measurement)
●R&S®CMW-KS700 (WiMAX™ IEEE 802.16e, basic signaling)
●R&S®CMW-KS701 (WiMAX™ IEEE 802.16e, advanced signaling)
●R&S®CMW-KS702 (WiMAX™ IEEE 802.16e MIMO 2x2, generic signaling)
●R&S®CMW-KM012 (TX measurement, multi evaluation list mode)
●R&S®CMW-KA700 (Application Enabler, convergence sublayer IPv4, IEEE 802.16e)
●R&S®CMW-KT700 (WiMAX™ IEEE 802.16e, message analyzer, online)
© 2015 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: [phone] - 0
Fax: [phone]
E-mail: [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 the owners.
The following abbreviations are used throughout this manual: R&S®CMW is abbreviated as R&S CMW.
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Contents
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Contents
1 Preface.................................................................................................... 7
1.1 How to Read Firmware Application Chapters............................................................ 7
1.1.1 General Description........................................................................................................ 7
1.1.2 Application Sheets.......................................................................................................... 8
1.1.3 GUI Reference................................................................................................................ 8
1.1.4 Programming Examples..................................................................................................8
1.1.5 Command Reference...................................................................................................... 8
2 WiMAX Measurements...........................................................................9
2.1 What's New in this Revision.........................................................................................9
2.2 General Description.................................................................................................... 10
2.2.1 Test Setup.....................................................................................................................10
2.2.2 How to Measure an OFDMA Signal.............................................................................. 10
2.2.3 Consistency Checks and Troubleshooting....................................................................11
2.2.4 Frame Settings and Burst Selection..............................................................................12
2.2.5 Dependencies between Measurement Parameters...................................................... 14
2.2.6 Multi Evaluation List Mode............................................................................................ 15
2.2.7 Limit Settings and Conformance Requirements............................................................18
2.2.8 Signal Processing......................................................................................................... 21
2.2.9 Measurement Results................................................................................................... 23
2.2.10 Measurement Diagrams................................................................................................34
2.3 Application Sheets......................................................................................................40
2.3.1 WiMAX Measurements (Remote Control).....................................................................41
2.3.2 Using WiMAX List Mode............................................................................................... 42
2.4 GUI Reference............................................................................................................. 45
2.4.1 Measurement Control....................................................................................................46
2.4.2 Signal Routing and Analyzer Settings...........................................................................46
2.4.3 Measurement Control Settings......................................................................................49
2.4.4 Measurement Parameters.............................................................................................51
2.4.5 Zone Definition.............................................................................................................. 54
2.4.6 Map of Bursts................................................................................................................ 55
2.4.7 Advanced Settings........................................................................................................ 58
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2.4.8 Trigger Settings.............................................................................................................61
2.4.9 Limit Settings.................................................................................................................63
2.4.10 List Configuration.......................................................................................................... 65
2.4.11 Additional Hotkeys........................................................................................................ 66
2.4.12 Measurement Results................................................................................................... 67
2.5 Programming...............................................................................................................68
2.5.1 Key Features.................................................................................................................69
2.6 Command Reference.................................................................................................. 69
2.6.1 Conventions and General Information.......................................................................... 70
2.6.2 General Measurement Settings.................................................................................... 74
2.6.3 Multi Evaluation Measurement Commands.................................................................. 78
2.7 List of Commands.....................................................................................................121
3 WiMAX Signaling................................................................................127
3.1 What's New in this Revision.....................................................................................128
3.2 General Description.................................................................................................. 128
3.2.1 Introduction to WiMAX Signaling Tests.......................................................................128
3.2.2 Special Test Capabilities.............................................................................................138
3.2.3 Measurement Results (Description)............................................................................152
3.2.4 Introduction to Message Logging................................................................................ 159
3.2.5 Application Enabler..................................................................................................... 168
3.3 Application Sheets....................................................................................................169
3.3.1 WiMAX Combined Signal Path Measurement............................................................ 169
3.3.2 WiMAX Signaling Tests (Remote Control).................................................................. 171
3.3.3 WiMAX Data Application Tests................................................................................... 175
3.4 GUI Reference........................................................................................................... 178
3.4.1 Signaling and Connection Control...............................................................................179
3.4.2 Initiating Measurements.............................................................................................. 179
3.4.3 Settings in the Main Dialog......................................................................................... 180
3.4.4 Settings in the Configuration Dialog............................................................................182
3.4.5 Additional Softkeys and Hotkeys.................................................................................228
3.4.6 Connection Status.......................................................................................................229
3.4.7 Measurement Results (GUI)....................................................................................... 229
3.4.8 PER Measurement Control......................................................................................... 231
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3.4.9 PER Configuration...................................................................................................... 231
3.4.10 PER Results (GUI)...................................................................................................... 238
3.4.11 Uplink Burst Measurement Control............................................................................. 239
3.4.12 Uplink Burst Configuration.......................................................................................... 239
3.4.13 Uplink Burst Results (GUI).......................................................................................... 240
3.5 Programming.............................................................................................................241
3.5.1 Key Features...............................................................................................................241
3.6 Command Reference................................................................................................ 241
3.6.1 Conventions and General Information........................................................................ 242
3.6.2 General Measurement Settings.................................................................................. 246
3.6.3 Signaling Commands.................................................................................................. 251
3.6.4 PER.............................................................................................................................307
3.7 List of Commands.....................................................................................................318
Index....................................................................................................324
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Preface
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1 Preface
The operation of the R&S CMW is described in several user manuals:
●The R&S CMW user manual describes the base software, common features of the
firmware applications and basic principles for manual operation and remote control.
There is a separate manual version for each R&S CMW model.
●Additional user manuals, like this document, describe the firmware applications.
There is only one version of these manuals for all R&S CMW models.
Rohde & Schwarz provides registered users a "CMW Customer Web" section on
GLORIS, the Global Rohde & Schwarz Information System: https://extranet.rohde-
schwarz.com. From this resource, you can download software updates, waveform
library updates and documentation updates, for example updates of this document.
1.1 How to Read Firmware Application Chapters
Each firmware application is described in a separate chapter. These chapters can be
read independently of each other. However, they are all organized as follows:
1. General Description
2. Application Sheets (optional)
3. GUI Reference
4. Programming Examples
5. Command Reference
The chapters "System Overview" and "Remote Control" in the R&S CMW user manual
provide additional important information independent of the individual firmware applica-
tions. The most important parts are referenced by the firmware application descrip-
tions.
1.1.1 General Description
This section provides a general description of the firmware application, independent of
a specific operation mode (manual or remote control). It gives a high-level introduction
to the capabilities of the firmware application. Background information related to the
network standard is given as far as it is directly related to administrable parameters.
For measurement applications a detailed description of measurement results and a
description of configurable limits is given, including the relation to conformance require-
ments defined in network standard specifications.
How to Read Firmware Application Chapters
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1.1.2 Application Sheets
This optional section provides short application examples for select issues and related
background information.
1.1.3 GUI Reference
The GUI reference describes the manual operation of the firmware application via the
Graphical User Interface (GUI).
The description of a configuration dialog usually starts with a screenshot presenting the
preset values of the parameters (sometimes preset values are modified to enable hid-
den parts of a dialog). Below the screenshot all shown parameters are described. For
each single parameter a link to the corresponding command description in the "Com-
mand Reference" is provided. Ranges for numeric parameters and reset values are
given there.
For measurement results links to the corresponding command descriptions are provi-
ded (commands to retrieve the results). The measurement results are described in
detail in the "General Description".
1.1.4 Programming Examples
The programming examples show how to control and configure the firmware applica-
tion via a remote-control program and how to retrieve measurement results. The exam-
ples consist of comprehensive command sequences. You can check just a single com-
mand of a sequence to get an example for the syntax of this single command. But you
can also consider an entire sequence showing the commands in the context of a com-
mand script, under consideration of dependencies and required orders of the com-
mands.
The command sequences are written with the intention to list most commands of the
firmware application. They do not show the fastest way for a given configuration task.
The fastest way would use many reset values and omit the corresponding commands.
The examples are referenced by the command descriptions of the "Command Refer-
ence".
1.1.5 Command Reference
The command reference provides information on the remote commands of the firm-
ware application. The commands are grouped according to their function.
Each command description indicates the syntax of the command header and of the
parameters. For input parameters the allowed ranges, reset values and default units
are listed, for returned values the expected ranges and default units. Most commands
have a command form and a query form. Exceptions are marked by "Setting only",
"Query only" or "Event". Furthermore a link to the "Programming Examples" is provided
and the first software version supporting the command is indicated.
How to Read Firmware Application Chapters
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2 WiMAX Measurements
The "WiMAX measurement" firmware application provides fast and flexible tests on
uplink or downlink OFDMA signals (TDD). The tests cover the following properties of a
WiMAX transmitter:
●Power measurements (average burst and subframe power, crest factor, occupied
bandwidth)
●Center frequency error
●Modulation accuracy (EVM, I/Q offset, I/Q imbalance)
●Spectral flatness
●Off-carrier measurements (adjacent channel power, spectral emission mask)
The measured quantities have been defined in accordance with the IEEE 802.16™
standard wherever possible. For basic information about WiMAX signals refer to stand-
ard IEEE Std 802.16™-2005, "IEEE standard for local and metropolitan area networks"
and later revisions, e.g. P802.16Rev2/D2.
The R&S CMW provides the following WiMAX measurement options:
●WiMAX Multi Evaluation Measurement (option R&S CMW-KM700)
●Measurement diagrams for WiMAX Multi Evaluation Measurement (option R&S
CMW-KM701)
Related applications
In addition to the WiMAX measurements described in this chapter, the following
WiMAX firmware applications are available:
●WiMAX Signaling (including additional measurements which rely upon the
exchange of signaling messages)
2.1 What's New in this Revision
This revision describes version 3.5.10 and later of the "WiMAX Measurements" firm-
ware application. Compared to version 2.1.10, there are only editorial changes.
Software Version
To check your R&S CMW software version, open the "Setup" dialog and click "HW/SW
Equipment". The initial software version for each remote control command is quoted in
the reference description.
What's New in this Revision
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2.2 General Description
The WiMAX "Multi Evaluation" measurement (option R&S CMW-KM700) captures an
OFDMA signal and evaluates the signal properties in a selectable PUSC zone and
burst.
The following sections describe how to perform and configure the measurement and
interpret the results. For a description of the method of measurement refer to Signal
Processing.
●Test Setup...............................................................................................................10
●How to Measure an OFDMA Signal........................................................................10
●Consistency Checks and Troubleshooting..............................................................11
●Frame Settings and Burst Selection........................................................................12
●Dependencies between Measurement Parameters................................................14
●Multi Evaluation List Mode...................................................................................... 15
●Limit Settings and Conformance Requirements......................................................18
●Signal Processing................................................................................................... 21
●Measurement Results............................................................................................. 23
●Measurement Diagrams..........................................................................................34
2.2.1 Test Setup
Connect the external RF signal source (mobile station, signal generator etc.) to one of
the bidirectional RF connectors on the front panel of the R&S CMW.
See also: "RF Connectors" in the R&S CMW user manual, chapter "Getting Started"
Fig. 2-1: Connecting an RF transmitter to the instrument
2.2.2 How to Measure an OFDMA Signal
After connecting your WiMAX transmitter to the R&S CMW, you have to adjust the fol-
lowing RF analyzer settings to the properties of the analyzed signal:
●The analyzer "Frequency"
●The "Expected Nominal Power" and a "User Margin" (optional) and "External
Attenuation".
General Description
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For proper signal decoding, the settings in the "Measurement Parameters" section of
the configuration dialog and its subsections must be compatible with the measured sig-
nal. The settings are grouped in hierarchical order:
●The "Measurement Parameters" select the link mode (uplink for mobile station
tests, downlink for base station tests) and the basic properties of the measured
subframe, see Measurement Parameters.
●The "Zone Definition" parameters specify the measured PUSC zone within the
measured frame and the assignment of subcarriers to logical sub-channels, see
Zone Definition.
●The "Map of Bursts" settings select the analyzed burst within the measured PUSC
zone, see Map of Bursts.
Consistency of measurement parameters
The ranges of many burst parameters depend on the selected "Bandwidth" and "Zone
Length"; see Dependencies between Measurement Parameters. The R&S CMW auto-
adjusts the ranges. To ensure consistency, it is recommended to configure the param-
eters from top to bottom, i.e. in the order "Measurement Parameters" – "Zone Defini-
tion" – "Map of Bursts".
A power trigger synchronizes the analyzer of the R&S CMW to the measured uplink
(UL) or downlink (DL) signal.
Consistency check after signal detection
After triggering a WiMAX subframe, the R&S CMW checks whether the actual frame
length complies with the setting in the "Measurement Parameters" section. If not a
"Synchronization Error" message is displayed.
2.2.3 Consistency Checks and Troubleshooting
The R&S CMW shows a tooltip with an error message if it is unable to capture a signal,
or if one of the consistency checks after signal detection fails.
The following table shows typical errors and remedies.
Table 2-1: Errors and Remedies
Error Message / Mea-
surement Result
Cause Remedy
"Trigger Timeout" The RF input power is too low Decrease the "Expected Nominal Power"
setting
"Signal Overload" The RF input power is too high Increase the "Expected Nominal Power"
setting
General Description
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Error Message / Mea-
surement Result
Cause Remedy
"Synchronization Prob-
lem"
Bandwidth is not set correctly Set the correct "Bandwidth" in section
Measurement Parameters
"Synchronization Prob-
lem"
Zone length is not set in accord-
ance with the received burst length
(UL only)
Adjust the "Zone Length" in section Zone
Definition.
Select a compatible number of "Slots".
See also parameter Check Burst Length
Pilot EVM is reasonably
small but data EVM is
bad
Modulation type setting is wrong Select the correct "Modulation" in section
Map of Bursts
2.2.4 Frame Settings and Burst Selection
In the Time Division Duplex (TDD) scheme, an OFDMA signal is a sequence of alter-
nating UL and DL subframes; each of which can be depicted as a rectangle in the fre-
quency/time plane. The subframes contain a number of parallel subcarriers, each com-
prising a series of symbols which are transmitted at the same carrier frequency. In the
frequency/time representation, a subcarrier corresponds to a horizontal band.
The nominal "Bandwidth" of the OFDMA channel is the critical parameter, determining
the covered frequency interval and the number of used subcarriers (FFT Size) and
their spacing. The duration of a subframe (which must not be confused with the "Frame
Length" comprising a DL and an UL subframe) is given by the number of symbols in
the subframe times the symbol duration.
In the simplest case, a subframe consists of a single PUSC "permutation zone" con-
taining several bursts. Each burst has its individual coding and modulation scheme
(burst profile). The bursts are transmitted in parallel and can vary in size.
Due to the uniform burst profile, many of the OFDMA signal properties are evaluated
on a bust-by-burst basis. The selection of the measured burst is a three-stage process:
1. Selection of the link mode and bandwidth: "Measurement Parameters"
General Description
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Many of the OFDMA signal properties depend on the "Link Mode" (uplink or down-
link). The R&S CMW can measure UL and DL subframes with different bandwidths.
The "FFT Size" for each bandwidth is a fixed value. This value is displayed,
together with the "Cyclic Prefix" and "Frame Length" that the R&S CMW assumes
for the measured burst.
2. Definition of the PUSC zone parameters: "Zone Definition"
The R&S CMW offers the length of the measured PUSC zone (Zone Length) and
of the control region (for UL subframes) as configurable parameters. The zone
length is a duration (see "Map of Bursts" below); it does not depend on the
selected bandwidth.
The symbols in the zone are arranged in UL "tiles" or DL "clusters". Tiles or clus-
ters from distributed subcarriers are renumbered (permutated) and combined into
logical subchannels. The permutation rule depends on the parameter Perm Base.
Permutation of tiles or clusters ensures that each subchannel uses non-adjacent
subcarriers, which reduces the impact of interferences and multipath fading on the
transmission.
3. Burst selection: "Map of Bursts"
The sub-channels (slots) provide an alternative description of the UL frame as a
rectangle in the subchannel/time plane. A burst contains an integer number of sub-
channels and corresponds to a contiguous area within this UL frame. The shape
and size of the bursts depend on the link mode as described below.
In an UL PUSC zone, a burst is a sequence of "slots" with a length of 3 symbols and a
width of 1 subchannel. This means that the number of symbols in the burst must be an
integer multiple of 3. The same applies to the total "Zone Length". The range of the
burst parameters are auto-adjusted according to the selected "Bandwidth" and "Zone
Length"; see Dependencies between Measurement Parameters.
The definition of a burst within an UL PUSC zone is shown in the following figure. Note
that the width of a control region at the beginning of the UL subframe (if present) is
also an integer multiple of the slot length:
In a DL PUSC zone, a burst forms a rectangle. The DL slot duration is 2 symbol peri-
ods, so the number of symbols in the burst must be an integer multiple of 2. The same
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applies to the total "Zone Length" (not counting the preamble). The R&S CMW auto-
adjusts the range for the no. of "Symbols" so that the maximum is equal to the selected
"Zone Length". The ranges for the no. of "Subchannels" and the "Subchannel Offset"
are auto-adjusted to the selected "Bandwidth"; see Dependencies between Measure-
ment Parameters.
The definition of a burst within an DL PUSC zone is shown in the following figure:
2.2.5 Dependencies between Measurement Parameters
The ranges of the "Map of Burst" parameters depend to the selected "Bandwidth" and
"Zone Length". The following tables give an overview of the minimum and maximum
values for FFT Length = 512 (corresponding to bandwidths <= 5 MHz) and FFT Length
= 1024 (corresponding to bandwidths > 5 MHz).
Table 2-2: Burst parameter ranges: FFT Length = 512, Uplink
"Map of Burst"parameter Minimum Value Maximum Value
Slots 1 17 * <Zone Length>/3
Subchannel Offset 0 16
Symbol Offset Inside 0 <Zone Length> – 3
Table 2-3: Burst parameter ranges: FFT Length = 1024, Uplink
Dependent parameters Minimum Value Maximum Value
Slots 1 35 * <Zone Length>/3
Subchannel Offset 0 34
Symbol Offset Inside 0 <Zone Length> – 3
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Table 2-4: Burst parameter ranges: FFT Length = 512, Downlink
Dependent parameters Minimum Value Maximum Value
Subchannels 1 15
Subchannel Offset 0 15 – <Subchannels>
Symbols 2 <Zone Length>
Symbol Offset 0 <Zone Length> – <Symbols>
Table 2-5: Burst parameter ranges: FFT Length = 1024, Downlink
Dependent parameters Minimum Value Maximum Value
Subchannels 1 30
Subchannel Offset 0 30 – <Subchannels>
Symbols 2 <Zone Length>
Symbol Offset 0 <Zone Length> – <Symbols>
2.2.6 Multi Evaluation List Mode
The WiMAX multi evaluation list mode requires option R&S CMW-KM012. In this mode
the measurement interval is subdivided into segments, according to the expected
power and frequency steps of the measured UL or DL signal. With the exception of
traces, the R&S CMW provides all multi-evaluation result types.
GUI for list mode
The list mode can be controlled manually using the "List Configuration" settings; see
chapter 2.4.10, "List Configuration", on page 65 and chapter 2.4.11, "Additional Hot-
keys", on page 66. The results appear in the in the "Measurement Overview" tables.
2.2.6.1 List Mode Configuration
Each segment contains an integer number of WiMAX frames and is measured at con-
stant analyzer settings (i.e. at constant expected nominal power and RF frequency).
The WiMAX frames are assumed to have a constant 5 ms duration. The R&S CMW
measures either UL or DL bursts ("Steps"), according to the basic configuration of the
multi evaluation measurement.
The figure below shows a series of four segments with different lengths. Orange bars
depict measured steps. The last step in each segment, where the R&S CMW changes
its analyzer settings, is not measured.
General Description
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Fig. 2-2: Masurement in list mode
Global and list mode parameters
The "Frequency", "Expected Nominal Power", and "Retrigger" settings are special list
mode settings. While the list mode is enabled the R&S CMW uses these list mode set-
tings and ignores the corresponding multi evaluation parameters. The statistical set-
tings ("Repetition", "Stop Condition", "Statistic Count") are also ignored; the segments
are always measured once (single shot mode). All other measurement settings, in par-
ticular the "Measurement Parameters", are taken from the multi evaluation measure-
ment.
See also Conditions and Restrictions.
2.2.6.2 List Mode Results
The measurement results that the R&S CMW provides in list mode are grouped
(power, modulation, I/Q, ACP, SEM); the result groups can be enabled individually
using the "List Mode > Assign Measurement" hotkey. If an error occurs in a particular
segment (e.g. an overflow due to a low "Expected Nominal Power" setting), the list
mode results in this segment are set invalid ("– – –").
The list mode is a single-shot application. When a measurement is initiated, all defined
segments are measured once. The "Measurement Overview" tables provide a statisti-
cal overview of the results for each segment.
For a segment with n steps, the statistical values are calculated as follows:
●The "Current" result is the result obtained in step no. (n – 1). This is the last mea-
sured step in the segment.
●The "Average", "Min", and "Max" results are calculated over the (n – 1) measured
steps. (n – 1) replaces the statistic count for unsegmented multi evaluation mea-
surements.
General Description
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Fig. 2-3: List mode results (detail)
Remote Control
The results can be retrieved using the general
FETCh:WIMax:MEAS:MEValuation...? or
READ:WIMax:MEAS:MEValuation...? commands. When the measurement is initi-
ated after the list mode is enabled, the commands return one result per segment.
For a remote control example refer to chapter 2.3.2, "Using WiMAX List Mode",
on page 42.
2.2.6.3 Conditions and Restrictions
To avoid invalid results, the list mode parameters must be compatible with the proper-
ties of the measured signal.
Note the following list mode properties:
●The R&S CMW supports up to 55 segments with up to 10 steps per segment. The
maximum capture time is 2.75 s.
●The measurement is performed at constant multi evaluation settings. The settings,
in particular the "Measurement Parameters", must comply with the properties of the
measured signal. This means that the basic signal properties (e.g. the modulation
scheme) must be equal for all measured steps.
●The measurement is performed in narrow-band mode. This restricts the Adjacent
Channel Power (ACP) results to channels ±1; see "Force IF BW <40 MHz"
on page 60.
●The measurement is most conveniently performed using an "IF Power" or an
"External" trigger source. The "Trigger Offset" setting is ignored (a 0 s offset is
used).
●The list mode is unavailable while a "Combined Signal Path" scenario is active.
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Adjustment of analyzer settings
In general, consecutive segments are measured at different RF frequencies and
expected powers so that the R&S CMW must change its analyzer settings at the end of
each segment. The R&S CMW uses the last step of each segment for the adjustment;
no measurement results are available for this step. To avoid "empty" segments, a mini-
mum segment length of 2 steps is required.
2.2.7 Limit Settings and Conformance Requirements
Conformance requirements for WiMAX transmitter tests are specified in the IEEE
802.16™ standard, section 8.4.12, "Transmitter Requirements", and in various other
documents quoted in the following.
The following sections give an overview of the R&S CMW limit settings and the related
test requirements.
Limits are defined in the configuration dialog; see Limit Settings.
●Modulation Limits.................................................................................................... 18
●ACP Limits.............................................................................................................. 18
●Spectrum Emission Mask........................................................................................19
2.2.7.1 Modulation Limits
A poor modulation accuracy of the transmitter increases the transmission errors in the
WiMAX network. The Error Vector Magnitude (EVM) is the critical quantity to assess
the modulation accuracy of a WiMAX signal.
According to the WiMAX standard (see P802.16Rev2/D2, section 8.4.12.3), the EVM
for a QPSK-1/2 burst type shall not exceed –15 dB. Smaller values are specified for
larger encoding rates and higher-order modulation schemes.
In section 8.4.12.2, the standard specified the following limits for the spectral flatness:
●–4 dB for the "Outer Minimum" spectral flatness
●–2 dB for the "Inner Minimum" spectral flatness
●+2 dB for the "Outer Maximum" and "Inner Maximum" spectral flatness
●+0.4 dB for the absolute difference between adjacent subcarriers ("Neighbor" spec-
tral flatness)
2.2.7.2 ACP Limits
The energy that spills outside the designated radio channel increases the interference
with adjacent channels and decreases the system capacity. The amount of unwanted
off-carrier energy is assessed by the out-of-band emissions (excluding spurious emis-
sions) that are specified in terms of the Adjacent Channel Power (ACP) and the Spec-
trum Emission Mask.
General Description
深圳德标仪器 135-1095-0799

WiMAX Measurements
R&S®CMW-KM70x/-KS70x
19User Manual 1173.9757.02 ─ 04
The following ACP limits have been proposed for band class 3A mobile stations:
●30 dB for the first adjacent channels (channels +1 and –1)
●44 dB for the second adjacent channels (channels +2 and –2)
The R&S CMW supports two different ACP test scenarios proposed by the WiMAX
forum; see ACP Scenario.
2.2.7.3 Spectrum Emission Mask
The spectrum emission mask (SEM) complements the ACP Limits. Several spectrum
emission masks have been defined in the literature. IEEE 802.16 defines an emission
mask with the main objective that the signal does not interfere with devices operating
in adjacent channels:
Fig. 2-4: Spectral emission mask: IEEE 802.16
The WiMAX forum has specified a different spectral mask for band class 3A equip-
ment. The following mask is applied if "WiMAX Forum Profile 3A Mask 1" or "WiMAX
Forum Profile 3A Mask 2" is selected for parameter Spectrum Emission Mask.
General Description
深圳德标仪器 135-1095-0799

WiMAX Measurements
R&S®CMW-KM70x/-KS70x
20User Manual 1173.9757.02 ─ 04
Fig. 2-5: Spectral emission mask: WiMAX Forum Profile 3A Mask 1 / 2
The limits in the WiMAX Forum masks are absolute power values (in dBm).
A third spectral mask has been specified by the Telecommunication Technology Asso-
ciation, Korea. The following mask is applied if "TTA Wibro" is selected for parameter
Spectrum Emission Mask.
Fig. 2-6: Spectral emission mask: TTA Wibro
Different channel bandwidths
The emission masks in this section have been designed for WiMAX with a channel
bandwidth of 10 MHz. The R&S CMW automatically adjusts the mask when a different
bandwidth is selected. The SEM parameters are listed in the configuration dialog; see
Limit Settings.
General Description
深圳德标仪器 135-1095-0799