Rohde & Schwarz R&S CMW-KN5 Series User manual

R&S®CMW-KN5xx
LTE eNodeB Measurements
User Manual
User Manual
1176.7690.02 ─ 05
(;ÚÚè2)
Test & Measurement
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This user manual describes the following R&S®CMW options:
●R&S®CMW-KN500 (LTE FDD R8/9, SISO, eNodeB TX measurement, downlink)
●R&S®CMW-KN550 (LTE TDD R8/9, SISO, eNodeB TX measurement, downlink)
© 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 What's New in this Revision..................................................................9
3 General Description.............................................................................10
3.1 Test Setup....................................................................................................................10
3.2 How to Measure a Downlink LTE Signal................................................................... 11
3.3 Defining the Scope of the Measurement...................................................................11
3.4 Trigger Modes............................................................................................................. 12
3.5 Calculation of Modulation Results............................................................................ 13
3.6 LTE DL Signal Properties........................................................................................... 14
3.6.1 Resources in Time and Frequency Domain..................................................................14
3.6.2 Operating Bands........................................................................................................... 16
3.7 Limit Settings and Conformance Requirements......................................................18
3.7.1 Transmit Modulation Limits........................................................................................... 18
3.7.2 Occupied Bandwidth Limits...........................................................................................19
3.7.3 Spectrum Emission Mask..............................................................................................20
3.7.4 ACLR Limits.................................................................................................................. 21
3.8 Measurement Results................................................................................................. 22
3.8.1 Overview....................................................................................................................... 23
3.8.2 Detailed Views: EVM, Magnitude Error, Phase Error....................................................24
3.8.3 Detailed Views: OFDM Symbol Power..........................................................................25
3.8.4 Detailed Views: Spectrum Flatness.............................................................................. 26
3.8.5 Detailed Views: Spectrum Emission Mask....................................................................27
3.8.6 Detailed Views: Spectrum ACLR.................................................................................. 29
3.8.7 Detailed Views: I/Q Constellation Diagram................................................................... 30
3.8.8 Detailed Views: TX Measurement.................................................................................31
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3.8.9 Selecting and Modifying Views..................................................................................... 32
3.8.10 Using Markers............................................................................................................... 32
3.8.11 Common View Elements...............................................................................................32
4 GUI Reference...................................................................................... 34
4.1 Measurement Control................................................................................................. 34
4.2 Parameters and Settings............................................................................................ 34
4.2.1 Signal Routing and Analyzer Settings...........................................................................34
4.2.2 Measurement Control Settings......................................................................................37
4.2.3 Modulation Settings.......................................................................................................40
4.2.4 Spectrum Settings.........................................................................................................42
4.2.5 Trigger Settings.............................................................................................................43
4.2.6 Limit Settings.................................................................................................................45
4.2.7 Shortcut Configuration.................................................................................................. 46
4.2.8 Additional Softkeys and Hotkeys...................................................................................46
4.3 Measurement Results................................................................................................. 47
5 Programming........................................................................................51
5.1 Key Features................................................................................................................51
5.2 Specifying General and Common Measurement Settings...................................... 51
5.3 Specifying Required Settings.................................................................................... 52
5.4 Specifying Additional Measurement-Specific Settings........................................... 52
5.5 Configuring the Trigger System................................................................................ 53
5.6 Specifying Limits........................................................................................................ 53
5.7 Performing Single-Shot Measurements....................................................................54
5.8 Single-Shot and Continuous Measurements............................................................55
6 Command Reference........................................................................... 56
6.1 Conventions and General Information......................................................................56
6.1.1 MEAS<i>....................................................................................................................... 56
6.1.2 FETCh, READ and CALCulate Commands.................................................................. 56
6.1.3 Current and Statistical Results......................................................................................57
6.1.4 Values for RF Path Selection........................................................................................ 57
6.1.5 Keywords...................................................................................................................... 58
6.1.6 Reliability Indicator........................................................................................................ 58
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6.2 General Measurement Settings................................................................................. 61
6.2.1 Duplex Mode................................................................................................................. 61
6.2.2 Signal Routing...............................................................................................................61
6.2.3 Analyzer Settings.......................................................................................................... 62
6.3 Multi Evaluation Measurement Commands..............................................................64
6.3.1 Measurement Control and States................................................................................. 65
6.3.2 Enabling Results and Views..........................................................................................67
6.3.3 Measurement Parameters - General Part..................................................................... 69
6.3.4 Modulation Measurement Settings................................................................................72
6.3.5 Spectrum Measurement Settings..................................................................................75
6.3.6 Trigger Settings.............................................................................................................76
6.3.7 Limits (Modulation, QPSK)............................................................................................79
6.3.8 Limits (Modulation, 16-QAM / 64-QAM)........................................................................ 82
6.3.9 Limits (Spectrum).......................................................................................................... 84
6.3.10 Signal Configuration Information...................................................................................87
6.3.11 EVM Results (Traces)................................................................................................... 87
6.3.12 Magnitude Error Results (Traces)................................................................................. 88
6.3.13 Phase Error Results (Traces)........................................................................................89
6.3.14 Spectrum Flatness Results (Traces).............................................................................90
6.3.15 Spectrum Emission Results (Traces)............................................................................90
6.3.16 I/Q Constellation Results (Traces)................................................................................ 91
6.3.17 OFDM Symbol Power Results...................................................................................... 92
6.3.18 ACLR Spectrum Results............................................................................................... 92
6.3.19 Modulation Results (Single Values).............................................................................. 95
6.3.20 Spectrum Emission Results (Single Values).................................................................99
List of Commands..............................................................................104
Index....................................................................................................107
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Contents
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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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Preface
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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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What's New in this Revision
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2 What's New in this Revision
This revision describes version 3.5.10 and later of the "LTE eNodeB Multi Evaluation
Measurement" firmware application. Compared to version 3.2.71, there are only edito-
rial 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.
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General Description
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3 General Description
The "LTE eNodeB Multi Evaluation" measurement provides quick and flexible TX tests
on LTE downlink SISO and MIMO 2x2 signals. For MIMO 2x2 signals, you can mea-
sure both antenna signals, but not simultaneously.
With option R&S CMW-KN500, you can measure FDD signals. With option R&S CMW-
KN550, you can measure TDD signals.
The tests cover the following eNodeB transmitter properties:
●eNodeB output power, output power dynamics (OFDM Symbol Power)
●Modulation accuracy for each OFDM symbol (EVM, Magnitude Error, Phase Error)
●I/Q Constellation diagram
●Out-of-band emissions (Spectrum Emission Mask and ACLR)
●eNodeB power variation across subcarriers (Spectrum Flatness)
Many of the tests and conformance requirements are specified in 3GPP TS 36.104 or
3GPP TS 36.141.
The following sections describe how to perform and configure the measurement.
●Test Setup...............................................................................................................10
●How to Measure a Downlink LTE Signal.................................................................11
●Defining the Scope of the Measurement.................................................................11
●Trigger Modes.........................................................................................................12
●Calculation of Modulation Results...........................................................................13
●LTE DL Signal Properties........................................................................................14
●Limit Settings and Conformance Requirements......................................................18
●Measurement Results............................................................................................. 22
3.1 Test Setup
The external RF signal source (base station, signal generator etc.) is connected to one
of the RF input connectors (RF COM) at the front panel of the R&S CMW. No addi-
tional cabling and no external trigger is needed.
The input level ranges of all RF COM connectors are identical.
See also: "RF Connectors" in the R&S CMW user manual, chapter "Getting Started"
Test Setup
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Fig. 3-1: Connecting an RF transmitter to the instrument
To test a MIMO 2x2 signal, connect only one transmit antenna at a time.
3.2 How to Measure a Downlink LTE Signal
After connecting your eNodeB to the R&S CMW, you have to adjust at least the follow-
ing analyzer settings to the properties of the analyzed DL LTE signal:
●Duplex mode
●Analyzer "Frequency"
●"Expected Nominal Power", (optional) "User Margin" and "External Attenuation
(Input)".
Recommended values: "Expected Nominal Power" = peak power of the signal dur-
ing the measurement; "User Margin" = 0 dB. The smallest possible value of the
"Expected Nominal Power" plus the "User Margin" ensures maximum dynamic
range.
For synchronization to the received signal and proper decoding, a number of "Mea-
surement Control" settings in the configuration dialog must be in accordance with the
measured signal. In particular, ensure that the following parameters match up:
●"E-UTRA test model"
●"Channel Bandwidth"
●"Physical Cell ID"
With matching "Measurement Control" settings, the R&S CMW is able to decode the
signal and to determine its frame, subframe and slot timing. No additional measure-
ment trigger is required (see chapter 3.4, "Trigger Modes", on page 12).
Non-matching "Measurement Control" settings generally result in large EVM results or
cause a synchronization error.
3.3 Defining the Scope of the Measurement
Standard 3GPP TS 36.141 requests a measurement duration of 10 consecutive down-
link subframes for all tests.
How to Measure a Downlink LTE Signal
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General Description
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For that reason all 10 subframes of a radio frame are evaluated for FDD downlink sig-
nals. For TDD signals the first 10 downlink subframes of two consecutive radio frames
are evaluated (with uplink and special subframes in-between).
The statistic count (i.e. the length of a single shot) is configurable. By default it equals
10 subframes. If you configure a different statistic count, then 10 consecutive downlink
subframes are captured repeatedly, until the statistic count is reached. Between these
repetitions there may be not captured radio frames. Up to 1000 subframes can be cap-
tured per single shot.
Example:
Statistic count = 5 subframes: 10 consecutive downlink subframes are captured.
Results are provided for the first 5 subframes.
Statistic count = 17 subframes: 10 consecutive downlink subframes are captured and
results are provided. The subsequent radio frame(s) may be ignored. Then 10 consec-
utive downlink subframes are captured. Results are provided for the first 7 subframes.
3.4 Trigger Modes
The "LTE eNodeB Multi Evaluation" measurement can be performed in the following
trigger modes:
●Free Run (Fast Sync): The measurement starts immediately after it is initiated. The
R&S CMW decodes the signal to derive its slot, subframe and frame timing so that
the measurement can start at a radio frame boundary.
●Free Run (No Sync): The measurement starts immediately after it is initiated, with-
out any synchronization.
This trigger mode is faster than the "Free Run (Fast Sync)" mode. It can be used
for ACLR and emission mask measurements. All other results must be ignored
(e.g. modulation results).
●IF Power: With an internal IF power trigger, the measurement is triggered by the
power ramp of the received bursts. This mode can for example be used for TDD
downlink signals, which are always bursted because of the uplink subframes.
●External Trigger A/B: External trigger signal fed in via TRIG A or TRIG B on the
rear panel of the instrument. The trigger signal must be aligned to the radio frame
boundary.
●Additional trigger modes: Other firmware applications, e.g. the GPRF generator,
may provide additional trigger modes. Refer to the documentation of the corre-
sponding firmware application for a description of these trigger modes. The trigger
signal/marker must be aligned to the radio frame boundary.
For configuration see chapter 4.2.5, "Trigger Settings", on page 43.
Trigger Modes
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3.5 Calculation of Modulation Results
Modulation results are based on a comparison between the measured signal, correc-
ted by the average frequency and timing offset for each measured subframe, and an
ideal reference waveform.
See also: "Modulation Accuracy" in the R&S CMW user manual, chapter "System
Overview"
As specified in 3GPP TS 36.104, Annex E, the EVM calculation is based on two differ-
ent FFT processing windows in time domain, separated by the "EVM window length"
W. The minimum test requirement applies to the larger of the two obtained EVM val-
ues.
The definition of the EVM window and the two FFT processing windows is shown
below.
Fig. 3-2: EVM window definition
The EVM window is centered on the Cyclic Prefix (CP) at the beginning of the OFDM
symbol. Its length is specified in the standard, depending on the channel bandwidth
and the cyclic prefix type (see 3GPP TS 36.104, tables E.5.1-1 and F.5.1-2).
The CP is a cyclic extension of the OFDM symbol. As a consequence the EVM for a
signal with good modulation accuracy is expected to be largely independent of the
EVM window size.
Fig. 3-3: Cyclic prefix
Calculation of Modulation Results
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EVM window length settings
Use the settings in the "Config... > Measurement Control > Modulation > EVM Window
Length" section to adjust the length of the EVM window (see "EVM Window Length"
on page 41). The minimum value of 1 FFT symbol actually corresponds to a window
of zero length so that EVMh = EVMl.
3.6 LTE DL Signal Properties
This section describes the following selected topics related to LTE DL signal proper-
ties.
●Resources in Time and Frequency Domain............................................................14
●Operating Bands..................................................................................................... 16
3.6.1 Resources in Time and Frequency Domain
The DL radio resources in an LTE system are divided into time-frequency units called
resource elements. In the time domain a resource element corresponds to one OFDM
symbol. In the frequency domain it corresponds to one subcarrier.
For the mapping of physical channels to resources, the resource elements are grouped
into Resource Blocks (RB). Each RB consists of 12 consecutive subcarriers (180 kHz)
and 6 or 7 consecutive OFDM symbols (0.5 ms). The positions of resource elements
carrying reference signals (pilots) are standardized and depend on the number of
transmit antennas.
Fig. 3-4: Resource element grid (7 OFDM symbols per RB, 1 TX antenna)
The total number of resource blocks available per channel depends on the channel
bandwidth as shown in the following table.
LTE DL Signal Properties
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Channel Bandwidth [MHz] 1.4 3 5 10 15 20
Resource Blocks (RB) 6 15 25 50 75 100
In the time domain the additional units radio frame, subframe and slot (containing the
OFDM symbols) are defined. A guard time called Cyclic Prefix (CP) is added to each
OFDM symbol. Depending on the duration of the guard time, it is either called normal
CP or extended CP and the slot contains either 7 or 6 OFDM symbols. For the "LTE
eNodeB Multi Evaluation" measurement only signals with normal CP are relevant. So
each slot contains 7 OFDM symbols.
The basic time unit in LTE is the sample interval Ts. Ts can be calculated from the sam-
pling frequency 30.72 MHz: 1 Ts = 1/30.72 MHz ≈ 32.55 ns.
Fig. 3-5: LTE DL slot structure, normal CP
The radio frame structure depends on the duplex mode. An FDD DL radio frame con-
tains 20 DL slots, grouped into 10 subframes.
Fig. 3-6: LTE DL frame structure for FDD
A TDD radio frame is also divided into 10 subframes. But for TDD three subframe
types are defined: DL subframe (2 DL slots), UL subframe (2 UL slots) and special
subframe. A special subframe contains the fields DwPTS, GP and UpPTS. 3GPP
defines several possible special subframe configurations, resulting in different lengths
of these fields, see 3GPP TS 36.211, table 4.2-1. The total length of a special sub-
frame equals 1 ms (same length for all subframe types).
LTE DL Signal Properties
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Fig. 3-7: LTE frame structure for TDD
The type of subframe number 0, 1, 2 and 5 is fixed. The type of the other subframes
depends on the used UL-DL configuration.
Table 3-1: Uplink-downlink configuration 0 to 6
Subframe Number
Configuration 0 1 2 3 4 5 6 7 8 9
0 DSUUUDSUUU
1 DSUUDDSUUD
2 DSUDDDSUDD
3 DSUUUDDDDD
4 DSUUDDDDDD
5 DSUDDDDDDD
6 DSUUUDSUUD
D = downlink, U = uplink, S = special subframe
3.6.2 Operating Bands
The carrier frequencies for LTE downlink signals are defined in 3GPP TS 36.104. Each
operating band contains a number of uplink carrier frequencies identified by channel
numbers (EARFCN, E-UTRA Absolute Radio Frequency Channel Number). The
assignment between channel numbers N and carrier center frequencies F is defined
as:
The tables below provide an overview of the supported downlink channels for FDD and
TDD signals. For each band, they list the offset frequencies FOffset, channel numbers N,
channel number offsets NOffset and carrier center frequencies F.
LTE DL Signal Properties
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FDD
Band
FOffset [MHz] NOffset Channel No N F [MHz]
1 2110 0 0 to 599 2110 to 2169.9
2 1930 600 600 to 1199 1930 to 1989.9
3 1805 1200 1200 to 1949 1805 to 1879.9
4 2110 1950 1950 to 2399 2110 to 2154.9
5 869 2400 2400 to 2649 869 to 893.9
6 875 2650 2650 to 2749 875 to 884.9
7 2620 2750 2750 to 3449 2620 to 2689.9
8 925 3450 3450 to 3799 925 to 959.9
9 1844.9 3800 3800 to 4149 1844.9 to 1879.8
10 2110 4150 4150 to 4749 2110 to 2169.9
11 1475.9 4750 4750 to 4949 1475.9 to 1495.8
12 729 5010 5010 to 5179 729 to 745.9
13 746 5180 5180 to 5279 746 to 755.9
14 758 5280 5280 to 5379 758 to 767.9
15 2600 5380 5380 to 5579 2600 to 2619.9
16 2585 5580 5580 to 5729 2585 to 2599.9
17 734 5730 5730 to 5849 734 to 745.9
18 860 5850 5850 to 5999 860 to 874.9
19 875 6000 6000 to 6149 875 to 889.9
20 791 6150 6150 to 6449 791 to 820.9
21 1495.9 6450 6450 to 6599 1495.9 to 1510.8
22 3510 6600 6600 to 7499 3510 to 3599.9
23 2180 7500 7500 to 7699 2180 to 2199.9
24 1525 7700 7700 to 8039 1525 to 1558.9
25 1930 8040 8040 to 8689 1930 to 1994.9
26 859 8690 8690 to 9039 859 to 893.9
27 852 9040 9040 to 9209 852 to 868.9
28 758 9210 9210 to 9659 758 to 802.9
TDD Band FOffset [MHz] NOffset Channel No N F [MHz]
33 1900 36000 36000 to 36199 1900 to 1919.9
34 2010 36200 36200 to 36349 2010 to 2024.9
35 1850 36350 36350 to 36949 1850 to 1909.9
LTE DL Signal Properties
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TDD Band FOffset [MHz] NOffset Channel No N F [MHz]
36 1930 36950 36950 to 37549 1930 to 1989.9
37 1910 37550 37550 to 37749 1910 to 1929.9
38 2570 37750 37750 to 38249 2570 to 2619.9
39 1880 38250 38250 to 38649 1880 to 1919.9
40 2300 38650 38650 to 39649 2300 to 2399.9
41 2496 39650 39650 to 41589 2496 to 2689.9
42 3400 41590 41590 to 43589 3400 to 3599.9
43 3600 43590 43590 to 45589 3600 to 3799.9
44 703 45590 45590 to 46589 703 to 802.9
3.7 Limit Settings and Conformance Requirements
Conformance test requirements for LTE eNodeB transmitter tests are specified in
3GPP TS 36.141 section 6, "Transmitter Characteristics".
The following sections give an overview of the "LTE eNodeB Multi Evaluation" limit set-
tings and the related test requirements.
●Transmit Modulation Limits..................................................................................... 18
●Occupied Bandwidth Limits.....................................................................................19
●Spectrum Emission Mask........................................................................................20
●ACLR Limits............................................................................................................ 21
3.7.1 Transmit Modulation Limits
A poor modulation accuracy of the eNodeB transmitter increases the transmission
errors in the downlink channel of the LTE network and decreases the system capacity.
The Error Vector Magnitude (EVM) is the critical quantity to assess the modulation
accuracy of an eNodeB.
3GPP defines requirements for the frequency error and for the EVM. They shall be
verified for the test models E-TM 2, E-TM 3.1, E-TM 3.2 and E-TM 3.3.
In the configuration dialog you can set limits for both measurement results, depending
on the modulation scheme. You can also set limits for other modulation results.
Limit Settings and Conformance Requirements
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Fig. 3-8: Modulation limit settings for QPSK
The following table provides an overview of the related limits defined by 3GPP. The
default values correspond to the requirements for a home BS.
Characteristics Refer to 3GPP TS 36.141 V10.6.0,
section...
Modulation or BS Class Test Requirement
EVM (RMS) 6.5.2 Error Vector Magnitude QPSK < 18.5 %
16-QAM < 13.5 %
64-QAM < 9 %
Frequency Error 6.5.1 Frequency Error home BS < 0.25 ppm
local area BS < 0.1 ppm
wide area BS < 0.05 ppm
3.7.2 Occupied Bandwidth Limits
The occupied bandwidth is the width of a symmetric frequency interval around the
nominal RF carrier frequency that contains 99 % of the total integrated power of the
transmitted spectrum.
According to 3GPP the occupied bandwidth shall be less than the (theoretical) channel
bandwidth. This shall be verified with the test model E-TM1.1.
In the configuration dialog you can set a limit for the occupied bandwidth, depending
on the channel bandwidth.
Fig. 3-9: Occupied bandwidth limit setting for 1.4 MHz channel bandwidth
Characteristics Refer to 3GPP TS 36.141 V10.6.0, section... Test Requirement
Occupied Bandwidth (OBW) 6.6.1 Occupied Bandwidth < channel bandwidth
Limit Settings and Conformance Requirements
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3.7.3 Spectrum Emission Mask
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 spectrum emission mask and the Adjacent
Channel Leakage power Ratio (ACLR).
3GPP specifies spectrum emission masks depending on the type of the eNodeB, the
channel bandwidth and the operating band.
In the configuration dialog you can define one spectrum emission mask per channel
bandwidth. The figure below shows the default settings for a channel bandwidth of 1.4
MHz.
Fig. 3-10: Emission mask settings for 1.4 MHz channel bandwidth
For each emission mask area you can define the start and stop frequencies, set an
upper absolute and an upper relative power limit and select the resolution bandwidth to
be used.
The start and stop frequencies are defined relative to the edge of the channel band-
width. Example: Assume 0 MHz as start frequency and 1 MHz as stop frequency for a
channel bandwidth of 1.4 MHz. The resulting area ranges from +0.7 MHz to +1.7 MHz
relative to the carrier frequency. As all ranges are symmetrical, it ranges also from -0.7
MHz to -1.7 MHz relative to the carrier frequency.
The absolute power limit is configured via a <power> parameter and a <slope> param-
eter. The absolute limit line is calculated from these parameters, the configured start
frequency <start> and the <frequency> relative to the channel edge, using the follow-
ing formula:
absolute limit = <power> + <slope> * (<frequency> - <start>)
The relative power limit is defined as power relative to the "TX Power" measurement
result. If the relative limit is enabled, the less stringent of the two limits applies (abso-
lute or relative power limit).
Limit Settings and Conformance Requirements
深圳德标仪器 135-1095-0799