R&S®FSV-K106
LTE NB-IoT Measurement Application
(Downlink)
User Manual
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1178.6685.02 ─ 01
User Manual
This manual describes the following firmware applications:
●
R&S®FSV-K106 LTE NB-IoT Measurement Application (1309.9797.02)
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: +49 89 41 29 - 0
Fax: +49 89 41 29 12 164
Email: info@rohde-schwarz.com
Internet: www.rohde-schwarz.com
Subject to change – Data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
Trade names are trademarks of their owners.
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol , e.g. R&S®FSV is indicated as
R&S FSV.
R&S®FSV-K106
1 Preface.................................................................................................... 5
1.1 Documentation Overview............................................................................................. 5
1.2 Conventions Used in the Documentation...................................................................6
1.3 How to Use the Help System........................................................................................7
1.4 Notes for Users of R&S FSV 1307.9002Kxx Models.................................................. 9
2 Welcome............................................................................................... 10
2.1 Installing the Software................................................................................................10
2.2 Application Overview..................................................................................................10
2.3 Support........................................................................................................................ 12
3 Measurements and Result Displays...................................................13
Contents
Contents
3.1 Numerical Results.......................................................................................................13
3.2 Power vs Time (PVT)...................................................................................................15
3.3 Error Vector Magnitude (EVM)................................................................................... 16
3.4 Spectrum Measurement............................................................................................. 19
3.5 Constellation............................................................................................................... 21
3.6 Statistics...................................................................................................................... 22
4 Configuration........................................................................................25
4.1 Performing Measurements.........................................................................................25
4.2 General Settings..........................................................................................................26
4.3 Configuring MIMO Setups.......................................................................................... 31
4.4 Advanced Settings......................................................................................................32
4.5 Trigger Configuration................................................................................................. 34
4.6 Signal Demodulation.................................................................................................. 36
4.7 Advanced Signal Characteristics.............................................................................. 38
5 Analysis................................................................................................ 39
5.1 Signal Part Selection.................................................................................................. 39
5.2 Measurement Units..................................................................................................... 40
5.3 Constellation Diagram Filter...................................................................................... 40
5.4 Y-Axis Scale.................................................................................................................41
5.5 Markers........................................................................................................................ 42
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6 File Management..................................................................................44
6.1 File Manager................................................................................................................ 44
6.2 SAVE/RECALL Key..................................................................................................... 45
7 Remote Control.................................................................................... 46
7.1 Common Suffixes........................................................................................................46
7.2 Introduction................................................................................................................. 47
7.3 Remote Commands to Select the NB-IoT Application.............................................52
7.4 Measurement Selection.............................................................................................. 52
7.5 Measurement Execution.............................................................................................53
7.6 Measurement Result Query........................................................................................55
7.7 Remote Commands to Read Numeric Results.........................................................62
7.8 Remote Commands to Configure the Application................................................... 69
Contents
7.9 Measurement Result Analysis................................................................................... 87
List of Commands................................................................................96
Index......................................................................................................99
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1 Preface
Preface
Documentation Overview
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 information, 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 firmware applications:
●
Base unit manual
Contains the description of all instrument modes and functions. It also provides an
introduction to remote control, a complete description of the remote control commands with programming examples, and information on maintenance, instrument
interfaces and error messages. Includes the contents of the getting started manual.
●
Firmware application manual
Contains the description of the specific functions of a firmware application. 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 firmware applications.
All operating manuals are also available for download or for immediate display on the
Internet.
1.1.3 Service Manual
Describes the performance test for checking the rated specifications, module replacement and repair, firmware update, troubleshooting and fault elimination, and contains
mechanical drawings and spare part lists.
The service manual is available for registered users on the global Rohde & Schwarz
information system (GLORIS, https://gloris.rohde-schwarz.com).
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Preface
Conventions Used in the Documentation
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 firmware applications and their order numbers, and optional accessories.
The brochure provides an overview of the instrument and deals with the specific characteristics.
See www.rohde-schwarz.com/brochure-datasheet/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 particular topics.
See www.rohde-schwarz.com/application/FSV
1.2 Conventions Used in the Documentation
1.2.1 Typographical Conventions
The following text markers are used throughout this documentation:
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Preface
How to Use the Help System
Convention Description
"Graphical user interface elements"
KEYS Key names are written in capital letters.
File names, commands,
program code
Input Input to be entered by the user is displayed in italics.
Links Links that you can click are displayed in blue font.
"References" References to other parts of the documentation are enclosed by quota-
1.2.2 Conventions for Procedure Descriptions
All names of graphical user interface elements on the screen, such as
dialog boxes, menus, options, buttons, and softkeys are enclosed by
quotation marks.
File names, commands, coding samples and screen output are distinguished by their font.
tion marks.
When operating the instrument, several alternative methods may be available to perform the same task. In this case, the procedure using the touchscreen is described.
Any elements that can be activated by touching can also be clicked using an additionally connected mouse. The alternative procedure using the keys on the instrument or
the on-screen keyboard is only described if it deviates from the standard operating procedures.
The term "select" may refer to any of the described methods, i.e. using a finger on the
touchscreen, a mouse pointer in the display, or a key on the instrument or on a keyboard.
1.2.3 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 installed. Thus, some functions shown in the screenshots may not be available in your particular product configuration.
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.
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Preface
How to Use the Help System
For standard Windows dialog boxes (e.g. File Properties, Print dialog etc.), no contextsensitive 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 corresponding 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.
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.
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Preface
Notes for Users of R&S FSV 1307.9002Kxx Models
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 setting up networks) may have a slightly different appearance or require different settings on the Windows XP based models. For such functions, refer to the Windows
documentation or the documentation originally provided with the R&S FSV instrument.
●
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 frequency 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.
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2 Welcome
Welcome
Application Overview
The NB-IoT measurement application uses the I/Q capture functionality of the following
spectrum and signal analyzers to enable NB-IoT TX measurements conforming to the
3GPP specification.
●
R&S FSV
This manual contains all information necessary to configure, perform and analyze such
measurements.
● Installing the Software.............................................................................................10
● Application Overview...............................................................................................10
● Support....................................................................................................................12
2.1 Installing the Software
For information on the installation procedure see the release notes of the R&S FSVA/
FSV.
2.2 Application Overview
Starting the application
Access the application via the "Mode" menu.
► Press the MODE key and select "NB-IoT".
Note that you may have to browse through the "Mode" menu with the "More" softkey to find the NB-IoT entry.
Presetting the software
When you first start the software, all settings are in their default state. After you have
changed any parameter, you can restore the default state with the PRESET key.
CONFigure:PRESet on page 69
Elements and layout of the user interface
The user interface of the LTE measurement application is made up of several elements.
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Welcome
Application Overview
1 = Channel Bar: contains all currently active measurement applications
2 = Table Header: shows basic measurement information, e.g. the frequency
3 = Result Display Header: shows information about the trace
4 = Result Display Screen A: shows the measurement results
5 = Result Display Screen B: shows the measurement results
6 = Status Bar: shows the measurement progress, software messages and errors
7 = Softkeys: open settings dialogs and select result displays
The status bar
The status bar is located at the bottom of the display. It shows the current measurement status and its progress in a running measurement. The status bar also shows
warning and error messages. Error messages are generally highlighted.
Display of measurement settings
The header table above the result displays shows information on hardware and measurement settings.
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Welcome
Support
Table 2-1: Information displayed in the channel bar in the NB-IoT measurement application
Ref Level Reference level
Att Mechanical and electronic RF attenuation
Offset Reference level offset
Freq
E-UTRA Freq
Mode NB-IoT standard
MIMO Number of Tx and Rx antennas in the measurement setup
Capture Time Length of the signal that has been captured
Frame Count Number of frames that have been captured
2.3 Support
If you encounter any problems when using the application, you can contact the
Rohde & Schwarz support to get help for the problem.
To make the solution easier, use the "R&S Support" softkey to export useful information for troubleshooting. The R&S FSVA/FSV stores the information in a number of files
that are located in the R&S FSVA/FSV directory
C:\R_S\Instr\user\LTE\Support. If you contact Rohde & Schwarz to get help on
a certain problem, send these files to the support in order to identify and solve the
problem faster.
Frequency
Center frequency of the LTE channel (in-band deployment only)
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3 Measurements and Result Displays
Measurements and Result Displays
Numerical Results
The NB-IoT measurement application features several measurements to examine and
analyze different aspects of an NB-IoT signal.
The source of the data that is processed is either a live signal or a previously recorded
signal whose characteristics have been saved to a file.
For more information, see:
●
"Selecting the Input Source" on page 33
●
Chapter 6, "File Management", on page 44
For more information on the functionality to actually perform the measurement, see
Chapter 4.1, "Performing Measurements", on page 25.
● Numerical Results...................................................................................................13
● Power vs Time (PVT)..............................................................................................15
● Error Vector Magnitude (EVM)................................................................................16
● Spectrum Measurement..........................................................................................19
● Constellation........................................................................................................... 21
● Statistics..................................................................................................................22
3.1 Numerical Results
Access: MEAS CONFIG > "Display (Graph List)"
Result Summary............................................................................................................13
Result Summary
The Result Summary shows all relevant measurement results in numerical form, combined in one table.
Remote command:
DISPlay[:WINDow<n>]:TABLe on page 53
Contents of the result summary
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Measurements and Result Displays
Numerical Results
The table shows results that refer to the complete frame. For each result, the minimum,
mean and maximum values are displayed. It also indicates limit values as defined in
the NB-IoT standard and limit check results where available. The font of 'Pass' results
is green and that of 'Fail' results is red.
In addition to the red font, the application also puts a red star (
) in front of
failed results.
By default, all EVM results are in %. To view the EVM results in dB, change the EVM
Unit.
The second part of the table shows results that refer to a specific selection of the
frame.
The statistic is always evaluated over the subframes.
The header row of the table contains information about the selection you have made
(like the subframe).
EVM All Shows the EVM for all resource elements in the analyzed frame.
FETCh[:CC<cc>]:SUMMary:EVM[:ALL][:AVERage]? on page 63
EVM Phys Channel Shows the EVM for all physical channel resource elements in the analyzed
frame.
A physical channel corresponds to a set of resource elements carrying information from higher layers. NPDSCH, NPBCH or NPDCCH, for example, are
physical channels. For more information, see 3GPP 36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PCHannel[:AVERage]? on page 64
EVM Phys Signal Shows the EVM for all physical signal resource elements in the analyzed
frame.
The reference signal, for example, is a physical signal. For more information,
see 3GPP 36.211.
FETCh[:CC<cc>]:SUMMary:EVM:PSIGnal[:AVERage]? on page 64
Frequency Error Shows the difference in the measured center frequency and the reference
center frequency.
FETCh[:CC<cc>]:SUMMary:FERRor[:AVERage]? on page 64
Sampling Error Shows the difference in measured symbol clock and reference symbol clock
relative to the system sampling rate.
FETCh[:CC<cc>]:SUMMary:SERRor[:AVERage]? on page 66
RSTP Shows the reference signal transmit power as defined in 3GPP TS 36.141. It
is required for the "DL RS Power" test.
It is an average power and accumulates the powers of the reference symbols
within a subframe divided by the number of reference symbols within a subframe.
FETCh[:CC<cc>]:SUMMary:RSTP[:AVERage]? on page 66
OSTP Shows the OFDM symbol transmit power as defined in 3GPP TS 36.141.
It accumulates all subcarrier powers of the 4th OFDM symbol. The 4th (out of
14 OFDM symbols within a subframe (for frame type 1, normal CP length))
contains exclusively NPDSCH.
FETCh[:CC<cc>]:SUMMary:OSTP[:AVERage]? on page 65
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Measurements and Result Displays
Power vs Time (PVT)
Power Shows the average time domain power of the analyzed signal.
FETCh[:CC<cc>]:SUMMary:POWer[:AVERage]? on page 65
Crest Factor Shows the peak-to-average power ratio of captured signal.
FETCh[:CC<cc>]:SUMMary:CRESt[:AVERage]? on page 63
3.2 Power vs Time (PVT)
Access: MEAS CONFIG > "PVT"
Capture Buffer...............................................................................................................15
Capture Buffer
The Capture Buffer result display shows the complete range of captured data for the
last data capture. The x-axis represents time. The maximum value of the x-axis is
equal to the Capture Time. The y-axis represents the amplitude of the captured I/Q
data in dBm (for RF input).
Figure 3-1: Capture buffer without zoom
The header of the diagram shows the reference level, the mechanical and electrical
attenuation and the trace mode. A green bar at the bottom of the diagram represents
the frame that is currently analyzed.
A blue vertical line at the beginning of the green bar in the capture buffer represents
the subframe start. The diagram also contains the "Start Offset" value. This value is the
time difference between the subframe start and capture buffer start.
When you zoom into the diagram, you will see that the bar is interrupted at certain
positions. Each small bar indicates the useful parts of the OFDM symbol.
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Measurements and Result Displays
Error Vector Magnitude (EVM)
Figure 3-2: Capture buffer after a zoom has been applied
Remote command:
Selecting the result display: CALCulate<n>:FEED 'PVT:CBUF'
Querying results:
TRACe:DATA?
Querying the subframe start offset: FETCh[:CC<cc>]:SUMMary:TFRame?
on page 66
3.3 Error Vector Magnitude (EVM)
Access: MEAS CONFIG > "EVM"
EVM vs Carrier..............................................................................................................16
EVM vs Symbol.............................................................................................................17
Frequency Error vs Symbol...........................................................................................18
EVM vs Subframe......................................................................................................... 19
EVM vs Carrier
Starts the EVM vs Carrier result display.
This result display shows the error vector magnitude (EVM) of the subcarriers. With the
help of a marker, you can use it as a debugging technique to identify any subcarriers
whose EVM is too high.
The results are based on an average EVM that is calculated over the resource elements for each subcarrier. This average subcarrier EVM is determined for each analyzed subframe in the capture buffer.
If you analyze all subframes, the result display contains three traces.
●
Average EVM
This trace shows the subcarrier EVM, averaged over all subframes.
●
Minimum EVM
This trace shows the lowest (average) subcarrier EVM that has been found over
the analyzed subframes.
●
Maximum EVM
This trace shows the highest (average) subcarrier EVM that has been found over
the analyzed subframes.
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Error Vector Magnitude (EVM)
If you select and analyze one subframe only, the result display contains one trace that
shows the subcarrier EVM for that subframe only. Average, minimum and maximum
values in that case are the same. For more information, see "Subframe Selection"
on page 39.
The x-axis represents the center frequencies of the subcarriers. On the y-axis, the
EVM is plotted either in % or in dB, depending on the EVM Unit.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'EVM:EVCA'
Querying results:
TRACe:DATA?
EVM vs Symbol
Starts the EVM vs Symbol result display.
This result display shows the error vector magnitude (EVM) of the OFDM symbols. You
can use it as a debugging technique to identify any symbols whose EVM is too high.
The results are based on an average EVM that is calculated over all subcarriers that
are part of a certain OFDM symbol. This average OFDM symbol EVM is determined for
all OFDM symbols in each analyzed subframe.
If you analyze all subframes, the result display contains three traces.
●
Average EVM
This trace shows the OFDM symbol EVM, averaged over all subframes.
●
Minimum EVM
This trace shows the lowest (average) OFDM symbol EVM that has been found
over the analyzed subframes.
●
Maximum EVM
This trace shows the highest (average) OFDM symbol EVM that has been found
over the analyzed subframes.
If you select and analyze one subframe only, the result display contains one trace that
shows the OFDM symbol EVM for that subframe only. Average, minimum and maximum values in that case are the same. For more information, see "Subframe Selec-
tion" on page 39.
The x-axis represents the OFDM symbols, with each symbol represented by a dot on
the line. Any missing connections from one dot to another mean that the
R&S FSVA/FSV could not determine the EVM for that symbol.
The number of displayed symbols depends on the subframe selection.
On the y-axis, the EVM is plotted either in % or in dB, depending on the EVM Unit.
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Measurements and Result Displays
Error Vector Magnitude (EVM)
Remote command:
Selecting the result display: CALCulate<n>:FEED 'EVM:EVSY'
Querying results:
TRACe:DATA?
Frequency Error vs Symbol
Starts the Frequency Error vs Symbol result display.
This result display shows the Frequency Error on symbol level. You can use it as a
debugging technique to identify any frequency errors within symbols.
The result is an average over all subcarriers.
The x-axis represents the OFDM symbols, with each symbol represented by a dot on
the line. The number of displayed symbols depends on the Subframe Selection and the
length of the cyclic prefix. Any missing connections from one dot to another mean that
the R&S FSVA/FSV could not determine the frequency error for that symbol. On the yaxis, the frequency error is plotted in Hz.
Note that the variance of the measurement results in this result display can be much
higher compared to the frequency error display in the numerical result summary,
depending on the NPDSCH and control channel configuration. The potential difference
is caused by the number of available resource elements for the measurement on symbol level.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'EVM:FEVS'
Querying results:
TRACe:DATA?
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Measurements and Result Displays
Spectrum Measurement
EVM vs Subframe
Starts the EVM vs Subframe result display.
This result display shows the Error Vector Magnitude (EVM) for each subframe. You
can use it as a debugging technique to identify a subframe whose EVM is too high.
The result is an average over all subcarriers and symbols of a specific subframe.
The x-axis represents the subframes, with the number of displayed subframes being
10.
On the y-axis, the EVM is plotted either in % or in dB, depending on the EVM Unit.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'EVM:EVSU'
Querying results:
TRACe:DATA?
3.4 Spectrum Measurement
Access: MEAS CONFIG > "Spectrum"
Power Spectrum............................................................................................................19
Channel Flatness.......................................................................................................... 20
Group Delay.................................................................................................................. 20
Channel Flatness Difference.........................................................................................21
Power Spectrum
Starts the Power Spectrum result display.
This result display shows the power density of the complete capture buffer in dBm/Hz.
The displayed bandwidth is always 7.68 MHz.
The x-axis represents the frequency. On the y-axis, the power level is plotted.
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Measurements and Result Displays
Spectrum Measurement
Remote command:
Selecting the result display: CALCulate<screenid>:FEED 'SPEC:PSPE'
Querying results:
TRACe:DATA?
Channel Flatness
Starts the Channel Flatness result display.
This result display shows the relative power offset caused by the transmit channel.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the channel flatness is plotted in
dB.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'SPEC:FLAT'
Querying results:
TRACe:DATA?
Group Delay
Starts the Group Delay result display.
This result display shows the group delay of each subcarrier.
The measurement is evaluated over the currently selected slot in the currently selected
subframe.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the group delay is plotted in ns.
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Measurements and Result Displays
Constellation
Remote command:
Selecting the result display: CALCulate<n>:FEED 'SPEC:GDEL'
Querying results:
TRACe:DATA?
Channel Flatness Difference
Starts the Channel Flatness Difference result display.
This result display shows the level difference in the spectrum flatness result between
two adjacent physical subcarriers.
The currently selected subframe depends on your selection.
The x-axis represents the frequency. On the y-axis, the power is plotted in dB.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'SPEC:FDIF'
Querying results:
TRACe:DATA?
3.5 Constellation
Access: MEAS CONFIG > "Constell"
Constellation Diagram...................................................................................................21
Constellation Diagram
Starts the Constellation Diagram result display.
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Measurements and Result Displays
Statistics
This result display shows the in-phase and quadrature phase results and is an indicator of the quality of the modulation of the signal.
In the default state, the result display evaluates the full range of the measured input
data. You can filter the results in the Constellation Selection dialog box.
The ideal points for the selected modulation scheme are displayed for reference purposes.
The constellation diagram also contains information about the current evaluation
range. It also shows the number of points that are displayed in the diagram.
Remote command:
Selecting the result display: CALCulate<n>:FEED 'CONS:CONS'
Querying results: TRACe:DATA?
3.6 Statistics
Access: MEAS CONFIG > "Statistics"
CCDF............................................................................................................................ 22
Allocation Summary...................................................................................................... 23
CCDF
Starts the Complementary Cumulative Distribution Function (CCDF) result display.
This result display shows the probability of an amplitude exceeding the mean power.
For the measurement, the complete capture buffer is used.
The x-axis represents the power relative to the measured mean power. On the y-axis,
the probability is plotted in %.
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Measurements and Result Displays
Statistics
Remote command:
Selecting the result display: CALCulate<n>:FEED 'STAT:CCDF'
Querying results: TRACe:DATA?
Allocation Summary
Starts the Allocation Summary result display.
This result display shows the results of the measured allocations in a table.
The rows in the table represent the allocations, with allocation ALL being a special allocation that summarizes all allocations that are part of the subframe. A set of allocations
form a subframe. The subframes are separated by a dashed line. The columns of the
table contain the following information:
●
Subframe
Shows the subframe number.
●
Allocation ID
Shows the type / ID of the allocation.
●
Number of RB
Shows the number of resource blocks assigned to the corresponding NPDSCH
allocation.
●
Rel. Power [dB]
Shows the relative power of the allocation.
●
Modulation
Shows the modulation type.
●
Power per RE [dBm]
Shows the power of each resource element in dBm.
●
EVM
Shows the EVM of the allocation. The unit depends on your selection.
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Measurements and Result Displays
Statistics
Remote command:
Selecting the result display: CALCulate<n>:FEED 'STAT:ASUM'
Querying results: TRACe:DATA?
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4 Configuration
Configuration
Performing Measurements
Before you can start a measurement, you have to configure the R&S FSVA/FSV in
order to get valid measurement results. This chapter contains detailed information on
all settings available in the application.
You can access the two main settings dialog boxes via the "Settings (Gen Demod)"
softkey. Pressing the softkey once opens the "General Settings" dialog box. The "Gen"
label in the softkey turns orange to indicate an active "General Settings" dialog box.
Pressing the softkey again opens the "Demod Settings" dialog box. When the "Demod
Settings" dialog box is active, the "Demod" label in the softkey turns orange.
In the "General Settings" dialog box, you can set all parameters that are related to the
overall measurement. The dialog box is made up of several tabs. By default, the "General" tab is the active one.
In the "Demod Settings" dialog box you can set up the measurement in detail, e.g. the
demodulation configuration. The dialog box is made up of several tabs. By default, the
"DL Demod" tab is the active one.
You can switch between the tabs by touching the tab on the touchscreen or with the
cursor keys.
● Performing Measurements......................................................................................25
● General Settings..................................................................................................... 26
● Configuring MIMO Setups.......................................................................................31
● Advanced Settings.................................................................................................. 32
● Trigger Configuration.............................................................................................. 34
● Signal Demodulation...............................................................................................36
● Advanced Signal Characteristics............................................................................ 38
4.1 Performing Measurements
Access: SWEEP
The sweep menu contains functions that control the way the R&S FSVA/FSV performs
a measurement.
Single Sweep and Continuous Sweep.......................................................................... 25
Auto Level..................................................................................................................... 26
Refresh..........................................................................................................................26
Single Sweep and Continuous Sweep
In continuous sweep mode, the R&S FSVA/FSV continuously captures data, performs
measurements and updates the result display according to the trigger settings.
To activate single sweep mode, press the "Run Single" softkey. In single sweep mode,
the R&S FSVA/FSV captures data, performs the measurement and updates the result
display exactly once after the trigger event. After this process, the R&S FSVA/FSV
interrupts the measurement.
You can always switch back to continuous sweep mode with the "Run Cont" softkey.
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Configuration
General Settings
Remote command:
INITiate:CONTinuous on page 53
Auto Level
The "Auto Level" softkey initiates a process that sets an ideal reference level for the
current measurement.
For more information, see "Defining a Reference Level" on page 29.
Remote command:
[SENSe:]POWer:AUTO<instrument>[:STATe] on page 78
Refresh
Updates the current result display in single sweep mode without capturing I/Q data
again.
If you have changed any settings after a single sweep and use the Refresh function,
the R&S FSVA/FSV updates the current measurement results regarding the new settings. It does not capture I/Q data again but uses the data captured last.
Remote command:
INITiate:REFResh on page 54
4.2 General Settings
Access: MEAS CONFIG > "Settings General"
The general settings contain settings to describe the basic measurement configuration.
● Signal Characteristics............................................................................................. 26
● Level Settings..........................................................................................................28
● Configuring the Data Capture................................................................................. 30
4.2.1 Signal Characteristics
Access: MEAS CONFIG > "Settings General" > "General"
The general signal characteristics contain settings to describe the general physical
attributes of the signal.
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Configuration
General Settings
Selecting the NB-IoT mode........................................................................................... 27
Deployment................................................................................................................... 27
Defining the Signal Frequency...................................................................................... 27
Defining physical settings for NB-IoT stand alone deployment.....................................27
Defining physical settings for NB-IoT in band deployment............................................28
Selecting the NB-IoT mode
The "Mode" selects the NB-IoT link direction you are testing.
FDD and TDD are duplexing methods.
●
FDD mode uses different frequencies for the uplink and the downlink.
●
TDD mode uses the same frequency for the uplink and the downlink.
Note that the NB-IoT standard only supports FDD mode.
Downlink (DL) and Uplink (UL) describe the transmission path.
●
Downlink is the transmission path from the base station to the user equipment.
The physical layer mode for the downlink is always OFDMA.
●
Uplink is the transmission path from the user equipment to the base station.
Remote command:
not supported
Deployment
The 3GPP standard specifies several operating modes, or deployment. The deployment specifies where the NB-IoT signal is located in the frequency spectrum.
You can select the deployment of the signal you are testing from the "Deployment"
dropdown menu.
The application supports the following deployments.
●
"Stand Alone"
The NB-IoT signal uses its own band outside of an LTE band, for example a frequency band currently used by GSM. With a carrier bandwidth of 200 kHz in GSM,
there is enough room for an NB-IoT carrier (180 kHz), including a guard interval of
10 kHz on both sides of the carrier.
●
"In Band"
The NB-IoT signal uses resource blocks within an LTE carrier.
Remote command:
CONFigure[:LTE]:DEPLoyment on page 71
Defining the Signal Frequency
For measurements with an RF input source, you have to match the center frequency
of the analyzer to the frequency of the signal.
The available frequency range depends on the hardware configuration of the analyzer
you are using.
Note that the center frequency for the in-band deployment is the center frequency of
the used LTE channel (E-UTRA frequency).
Remote command:
Center frequency: [SENSe:]FREQuency:CENTer[:CC<cc>] on page 74
Defining physical settings for NB-IoT stand alone deployment
The physical properties of the NB-IoT signal depend on the channel bandwidth.
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Configuration
General Settings
Currently, the 3GPP standard specifies a 200 kHz bandwidth for an NB-IoT carrier.
This bandwidth corresponds to one LTE resource block (RB).
The application derives various other physical properties of the measured signal from
the bandwidth.
●
"Number of Resource Blocks" (NB_1RB)
●
"FFT Size"
●
"Sample Rate"
All values are read only.
Remote command:
not supported
Defining physical settings for NB-IoT in band deployment
When you use the in band deployment, you have to specify the characteristics of the
LTE (E-UTRA) channel that the NB-IoT channel is located in.
Define the following E-UTRA properties:
●
"E-UTRA Center Frequency"
Center frequency of the LTE channel.
●
"E-UTRA Channel Bandwidth"
Channel bandwidth of the LTE channel (3 MHz, 5 MHz, 10 MHz, 15 MHz or
20 MHz).
Note that the 1.4 MHz bandwidth is not supported for in band transmission of NBIoT signals.
●
"E-UTRA CRS Sequence Info"
Cell-specific reference signal sequence. The sequence defines the assignment of
resources between LTE and NB-IoT. These sequences are defined in 3GPP
36.213, chapter 16.8.
●
"E-UTRA PRB Index"
The PRB index depends on the CRS sequence you have selected. The PRB index
is also used to assign resources between LTE and NB-IoT.
It is automatically calculated by the application.
In addition, the application shows various physical properties of the NB-IoT signal.
●
"NB-IoT Channel Bandwidth", which is currently always 200 kHz.
●
"NB-IoT Center Frequency", which is calculated from the E-UTRA channel characteristics.
●
"FFT Size"
●
"Sample Rate"
Remote command:
E-UTRA center frequency: CONFigure[:LTE]:EUTRa:FREQuency on page 71
E-UTRA channel bandwidth: CONFigure[:LTE]:DL[:CC<cc>]:BW on page 72
E-UTRA CRS sequence: CONFigure[:LTE]:DL:SINFo on page 72
E-UTRA PRB index: CONFigure[:LTE]:DL:PINDex on page 72
4.2.2 Level Settings
Access: MEAS CONFIG > "Settings General" > "General"
The level settings contain settings that control the input level of the analyzer.
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Configuration
General Settings
Defining a Reference Level...........................................................................................29
Attenuating the Signal................................................................................................... 29
Defining a Reference Level
The reference level is the power level the analyzer expects at the RF input. Keep in
mind that the power level at the RF input is the peak envelope power for signals with a
high crest factor like NB-IoT.
To get the best dynamic range, you have to set the reference level as low as possible.
At the same time, make sure that the maximum signal level does not exceed the reference level. If it does, it will overload the A/D converter, regardless of the signal power.
Measurement results can deteriorate (e.g. EVM), especially for measurements with
more than one active channel near the one you are trying to measure (± 6 MHz).
Note that the signal level at the A/D converter can be stronger than the level the application displays, depending on the current resolution bandwidth. This is because the
resolution bandwidths are implemented digitally after the A/D converter.
You can either specify the RF Reference Level (in dBm) or Baseband Reference
Level (in V), depending on the input source.
You can also use automatic detection of the reference level with the "Auto Level"
function.
If active, the application measures and sets the reference level to its ideal value before
each sweep. This process slightly increases the measurement time. You can define
the measurement time of that measurement with the Auto Level Track Time (➙
"Advanced" tab).
Automatic level detection also optimizes RF attenuation.
Remote command:
Manual (RF): CONFigure:POWer:EXPected:RF<instrument> on page 77
Manual (BB): CONFigure:POWer:EXPected:IQ<instrument> on page 76
Automatic: [SENSe:]POWer:AUTO<instrument>[:STATe] on page 78
Auto Level Track Time: [SENSe:]POWer:AUTO<instrument>:TIME on page 79
Attenuating the Signal
Attenuation of the signal becomes necessary if you have to reduce the power of the
signal that you have applied. Power reduction is necessary, for example, to prevent an
overload of the input mixer.
The NB-IoT measurement application provides several attenuation modes.
●
External attenuation is always available. It controls an external attenuator if you
are using one.
●
Mechanical (or RF) attenuation is always available. The mechanical attenuator
controls attenuation at the RF input.
Mechanical attenuation is available in the "Advanced" tab of the "General Settings"
dialog box.
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Configuration
General Settings
Positive values correspond to an attenuation and negative values correspond to an
amplification.
RF attenuation is independent of the reference level. It is available if automatic reference level detection is inactive. The range is from 0 dB to 75 dB.
Remote command:
RF attenuation: INPut<n>:ATTenuation<instrument> on page 77
External attenuation: DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:
OFFSet on page 77
4.2.3 Configuring the Data Capture
Access: MEAS CONFIG > "Settings General" > "General"
The data capture settings contain settings that control the amount of data and the way
that the application records the LTE signal.
Capture Time................................................................................................................ 30
Overall Frame Count.....................................................................................................30
Number of Frames to Analyze...................................................................................... 31
Auto According to Standard.......................................................................................... 31
Capture Time
Defines the capture time.
The capture time corresponds to the time of one measurement. Hence, it defines the
amount of data the application captures during a single measurement (or sweep).
By default, the application captures 20.1 ms of data to make sure that at least one
complete NB-IoT frame is captured in the measurement.
Remote command:
[SENSe:]SWEep:TIME on page 81
Overall Frame Count
Turns the manual selection of the number of frames to capture (and analyze) on and
off.
If the overall frame count is active, you can define a particular number of frames to
capture and analyze. The measurement runs until all required frames have been analyzed, even if it takes more than one sweep. The results are an average of the captured frames.
If the overall frame count is inactive, the application analyzes all complete NB-IoT
frames currently in the capture buffer.
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