R&S®FPS-K76/K77
TD-SCDMA Measurements Options
User Manual
(;ÚèM2)
1176.9029.02 ─ 04
User Manual
Test & Measurement
This manual applies to the following R&S®FPS models with firmware version 1.50 and higher:
●
R&S®FPS4 (1319.2008K04)
●
R&S®FPS7 (1319.2008K07)
●
R&S®FPS13 (1319.2008K13)
●
R&S®FPS30 (1319.2008K30)
●
R&S®FPS40 (1319.2008K40)
The following firmware options are described:
●
R&S FPS-K76 (1321.4379.02)
●
R&S FPS-K77 (1321.4385.02)
The software contained in this product uses several valuable open source software packages. For information, see the "Open
Source Acknowledgment" on the user documentation CD-ROM (included in delivery).
Rohde & Schwarz would like to thank the open source community for their valuable contribution to embedded computing.
© 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.
The following abbreviations are used throughout this manual: R&S®FPS is abbreviated as R&S FPS. "R&S FPS-K76 and R&S FPSK77" are abbreviated as "R&S FPS-K76/-K77".
R&S®FPS-K76/K77
Contents
1 Preface.................................................................................................... 5
1.1 Typographical Conventions.........................................................................................5
2 Welcome to the TD-SCDMA Applications............................................6
2.1 Starting the TD-SCDMA Application............................................................................6
2.2 Understanding the Display Information......................................................................7
3 Measurements and Result Display.......................................................9
3.1 Code Domain Analysis................................................................................................. 9
3.2 Frequency and Time Domain Measurements...........................................................24
4 Measurement Basics........................................................................... 34
4.1 Short Introduction to TD-SCDMA.............................................................................. 34
Contents
4.2 Frames, Subframes and Slots....................................................................................34
4.3 Channels and Codes...................................................................................................36
4.4 Data Fields and Midambles........................................................................................ 39
4.5 CDA Measurements in MSRA Operating Mode........................................................ 40
5 I/Q Data Import and Export..................................................................42
5.1 Import/Export Functions............................................................................................ 42
6 Configuration........................................................................................45
6.1 Result Display Configuration.....................................................................................45
6.2 Code Domain Analysis............................................................................................... 46
6.3 Frequency and Time Domain Measurements...........................................................75
7 Analysis................................................................................................ 85
7.1 Evaluation Range........................................................................................................ 85
7.2 Code Domain Analysis Settings................................................................................ 86
7.3 Traces...........................................................................................................................88
7.4 Markers........................................................................................................................ 89
8 Optimizing and Troubleshooting the Measurement......................... 95
8.1 Error Messages........................................................................................................... 95
9 How to Perform Measurements in TD-SCDMA Applications........... 96
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10 Remote Commands for TD-SCDMA Measurements....................... 101
10.1 Introduction............................................................................................................... 101
10.2 Common Suffixes......................................................................................................106
10.3 Activating the TD-SCDMA Applications..................................................................106
10.4 Selecting a Measurement......................................................................................... 110
10.5 Configuring Code Domain Analysis........................................................................111
10.6 Configuring Frequency and Time Domain Measurements................................... 141
10.7 Configuring the Result Display................................................................................143
10.8 Starting a Measurement........................................................................................... 152
10.9 Retrieving Results.....................................................................................................156
10.10 Analysis..................................................................................................................... 173
10.11 Importing and Exporting I/Q Data and Results...................................................... 183
10.12 Configuring the Slave Application Data Range (MSRA mode only).....................185
Contents
10.13 Status Registers........................................................................................................187
10.14 Deprecated Commands............................................................................................ 190
10.15 Programming Examples (TD-SCDMA BTS)............................................................ 192
11 I/Q Data File Format (iq-tar)...............................................................202
11.1 I/Q Parameter XML File Specification......................................................................203
11.2 I/Q Data Binary File................................................................................................... 206
List of Remote Commands (TD-SCDMA)......................................... 208
Index....................................................................................................212
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1 Preface
Preface
Typographical Conventions
1.1 Typographical Conventions
The following text markers are used throughout this documentation:
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-
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.
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2 Welcome to the TD-SCDMA Applications
The TD-SCDMA applications add functionality to the R&S FPS to perform code domain
analysis or power measurements according to the TD-SCDMA standard.
R&S FPS-K76 performs Base Transceiver Station (BTS) measurements (for downlink
signals).
In particular, the TD-SCDMA applications feature:
●
●
●
●
This user manual contains a description of the functionality that the application provides, including remote control operation.
Welcome to the TD-SCDMA Applications
Starting the TD-SCDMA Application
Code domain analysis, providing results like code domain power, EVM, peak code
domain error etc.
Various power measurements
Spectrum Emission Mask measurements
Statistical (CCDF) evaluation
Installation
You can find detailed installation instructions in the R&S FPS Getting Started manual
or in the Release Notes.
2.1 Starting the TD-SCDMA Application
The TD-SCDMA measurements require a special application on the R&S FPS.
To activate the TD-SCDMA applications
► Select the MODE key.
A dialog box opens that contains all operating modes and applications currently
available on your R&S FPS.
A Code Domain Analysis measurement is started immediately with the default settings.
It can be configured in the TD-SCDMA "Overview" dialog box, which is displayed when
you select the "Overview" softkey from any menu (see Chapter 6.2.1, "Configuration
Overview", on page 47).
Multiple Measurement Channels and Sequencer Function
When you activate an application, a new measurement channel is created which determines the measurement settings for that application. The same application can be activated with different measurement settings by creating several channels for the same
application.
Only one measurement can be performed at any time, namely the one in the currently
active channel. However, in order to perform the configured measurements consecutively, a Sequencer function is provided.
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If activated, the measurements configured in the currently active channels are performed one after the other in the order of the tabs. The currently active measurement is
indicated by a symbol in the tab label. The result displays of the individual channels
are updated in the tabs (including the "MultiView") as the measurements are performed. Sequential operation itself is independent of the currently displayed tab.
For details on the Sequencer function see the R&S FPS User Manual.
Welcome to the TD-SCDMA Applications
Understanding the Display Information
2.2 Understanding the Display Information
The following figure shows a measurement diagram during a TD-SCDMA BTS measurement. All different information areas are labeled. They are explained in more detail
in the following sections.
1
= Channel bar for firmware and measurement settings
2+3 = Window title bar with diagram-specific (trace) information
4 = Diagram area
5 = Diagram footer with diagram-specific information
6 = Instrument status bar with error messages, progress bar and date/time display
MSRA operating mode
In MSRA operating mode, additional tabs and elements are available. A colored background of the screen behind the measurement channel tabs indicates that you are in
MSRA operating mode.
For details on the MSRA operating mode see the R&S FPS MSRA User Manual.
Channel bar information
In TD-SCDMA applications, when performing Code Domain Analysis, the R&S FPS
screen display deviates from the Spectrum application. For Frequency and time
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domain measurements, the familiar settings are displayed (see the R&S FPS Getting
Started manual).
Welcome to the TD-SCDMA Applications
Understanding the Display Information
Table 2-1: Hardware settings displayed in the channel bar in TD-SCDMA applications for Code
Ref Level Reference level
Att Mechanical and electronic RF attenuation
Freq Center frequency for the RF signal
Channel Channel number (code number and spreading factor)
Slot Slot of the (CPICH) channel
Code Power Power result mode:
Symbol Rate Symbol rate of the current channel
Domain Analysis
●
Absolute
●
Relative to total power of the data parts of the signal
Window title bar information
For each diagram, the header provides the following information:
Figure 2-1: Window title bar information in TD-SCDMA applications
1 = Window number
2 = Window type
3 = Trace color
4 = Trace number
5 = Detector
Diagram footer information
For most graphical evaluations the diagram footer (beneath the diagram) contains scaling information for the x-axis, where applicable:
●
Start slot/symbol/code
●
slot/symbol/code per division
●
Stop slot/symbol/code
Status bar information
Global instrument settings, the instrument status and any irregularities are indicated in
the status bar beneath the diagram. Furthermore, the progress of the current operation
is displayed in the status bar.
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3 Measurements and Result Display
The TD-SCDMA applications provide several different measurements for signals
according to the TD-SCDMA standard. The main and default measurement is Code
Domain Analysis. In addition to the code domain power measurements specified by the
TD-SCDMA standard, the TD-SCDMA applications offer measurements with predefined settings in the frequency and time domain, e.g. channel power or power vs time
measurements.
Evaluation methods
The captured and processed data for each measurement can be evaluated with various different methods. All evaluation methods available for the selected TD-SCDMA
measurement are displayed in the evaluation bar in SmartGrid mode.
Evaluation range
You can restrict evaluation to a specific channel, frame or slot, depending on the evaluation method. See Chapter 7.1, "Evaluation Range", on page 85.
Measurements and Result Display
Code Domain Analysis
● Code Domain Analysis..............................................................................................9
● Frequency and Time Domain Measurements.........................................................24
3.1 Code Domain Analysis
Access: "Overview" > "Select Measurement" > "Code Domain Analyzer"
The Code Domain Analysis measurement provides various evaluation methods and
result diagrams.
A signal section containing at least two TD-SCDMA subframes is recorded for analysis
and then searched through to find the start of the first subframe. If a subframe start is
found in the signal, the code domain power analysis is performed for the selected slot.
The different evaluations are calculated from the captured I/Q data set. Therefore it is
not necessary to start a new measurement to change the evaluation.
The TD-SCDMA applications provide the peak code domain error measurement and
composite EVM specified by the TD-SCDMA standard, as well as the code domain
power measurement of assigned and unassigned codes. The power can be displayed
either for all channels in one slot, or for one channel in all slots. The composite constellation diagram of the entire signal can also be displayed. In addition, the symbols
demodulated in a slot, their power, and the determined bits or the symbol EVM can be
displayed for an active channel.
The power of a channel is always measured in relation to its symbol rate within the
code domain. It can be displayed either as absolute values or relative to the total signal
(data parts only). By default, the power relative to the total signal is displayed.
The composite EVM, peak code domain error and composite constellation measurements are also always referenced to the total signal.
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Remote command:
CONF:CDP[:BTS]:MEAS CDP, see CONFigure:CDPower:MEASurement
on page 110
● Code Domain Parameters.......................................................................................10
● Evaluation Methods for Code Domain Analysis......................................................11
● CDA Measurements in MSRA Operating Mode......................................................24
Measurements and Result Display
Code Domain Analysis
3.1.1 Code Domain Parameters
Two different types of measurement results are determined and displayed in the Result
Summary: global results and channel results (for the selected channel).
The number of the slot and channel (code) at which the measurement is performed is
indicated globally for the measurement in the channel bar.
The spreading code of the selected channel is indicated with the channel number in
the channel bar and above the channel-specific results in the Result Summary.
In the Channel Table, the analysis results for all (active) channels are displayed individually.
Table 3-1: General and slot-specific code domain power results in the Result Summary
Parameter Description
Chip Rate Error The chip rate error in ppm. A large chip rate error results in symbol errors and, there-
fore, in possible synchronization errors for code domain measurements. This measurement result is also valid if the application could not synchronize to the TDSCDMA signal.
Trigger to Frame The time difference between the beginning of the recorded signal section to the start
of the first slot.
For triggered measurements, this difference is identical with the time difference of
frame trigger (+ trigger offset) and the start of the first slot. If synchronization of the
analyzer and input signal fails, the value of "Trigger to Frame" is not significant.
For non-triggered measurements, no result is available.
P Data Average power of the slot's data parts (total and for each data part)
P Midamble Power of the slot's midamble
Carrier Freq Error The frequency error relative to the center frequency of the analyzer. The absolute fre-
quency error is the sum of the analyzer and DUT frequency error. The specified value
is averaged for one slot (see also "Synchronization fails" on page 95)
IQ Offset DC offset of the signal in the selected slot in %
IQ Imbalance I/Q imbalance of signals in the selected slot in %
Active Channels The number of active channels detected in the signal in the selected slot. Both the
detected data channels and the control channels are considered active channels.
RHO Quality parameter RHO for each slot.
According to the TD-SCDMA standard, Rho is the normalized, correlated power
between the measured and the ideally generated reference signal.
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The channel-specific results are displayed in the Result Summary, the Channel Table,
or both.
Table 3-2: Channel-specific code domain power results
Measurements and Result Display
Code Domain Analysis
Parameter Description
Average RCDE Average Relative Code Domain Error over all channels. The Average RCDE is calcu-
lated according to release 8 of the standard.
Composite EVM The error vector magnitude (EVM) over the total signal in the selected slot. The EVM
is the root of the ratio of the mean error power to the power of an ideally generated
reference signal.
See also "Composite EVM" on page 16
Pk CDE (15 ksps) The Peak Code Domain Error projects the difference between the measured signal
and the ideal reference signal onto the spreading factor in the selected slot (see
"Peak Code Domain Error" on page 18). The symbol rate, from which the spreading
factor can be determined, is indicated in brackets.
Parameter Description
Channel Type Detected type of channel (see Table 4-4)
Ch.SF Channel number including the spreading factor (in the form <Channel>.<SF>).
SymRate[ksps] Symbol rate at which the data in the channel is transmitted (in ksps)
Symbol EVM RMS and peak EVM values per symbol (see "Symbol EVM" on page 22)
Mod Modulation type (QPSK, 8PSK, 16QAM or 64QAM)
Power [dBm] Channel power, absolute
Power [dB] Channel power, relative to total power of the data parts of the signal
MA.shift Midamble shift
For channels, this is the shift of the associated midamble if a common or default midamble assignment is detected (see Chapter 4.4, "Data Fields and Midambles",
on page 39)
ΔMid1/2 The power offset between the midamble and the sum power of its channels in data
part 1 or 2, respectively.
The TD-SCDMA specifications require that the midamble and its channels must have
the same power. These parameters show if a common or default midamble assignment is detected (see Chapter 4.4, "Data Fields and Midambles", on page 39).
3.1.2 Evaluation Methods for Code Domain Analysis
Access: "Overview" > "Display Config"
The captured I/Q data can be evaluated using various different methods without having
to start a new measurement. All evaluation methods available for the selected TDSCDMA measurement are displayed in the evaluation bar in SmartGrid mode.
The selected evaluation also affects the results of the trace data query (see Chap-
ter 10.9.3, "Measurement Results for TRACe<n>[:DATA]? TRACE<n>", on page 165).
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Bitstream.......................................................................................................................12
Channel Table...............................................................................................................12
Code Domain Power.....................................................................................................14
Code Domain Error Power............................................................................................14
Composite Constellation............................................................................................... 15
Composite EVM............................................................................................................ 16
Mag Error vs Chip......................................................................................................... 17
Marker Table ................................................................................................................18
Peak Code Domain Error..............................................................................................18
Phase Error vs Chip......................................................................................................19
Power vs Slot................................................................................................................ 20
Power vs Symbol.......................................................................................................... 21
Result Summary............................................................................................................21
Symbol Constellation.................................................................................................... 22
Symbol EVM................................................................................................................. 22
Symbol Magnitude Error............................................................................................... 23
Symbol Phase Error......................................................................................................23
Measurements and Result Display
Code Domain Analysis
└ Channel Table Configuration.......................................................................... 13
Bitstream
The Bitstream evaluation displays the demodulated bits of a selected channel for a
given slot.
Figure 3-1: Bitstream display for TD-SCDMA BTS measurements
Depending on the spreading factor (symbol rate) of the channel, a slot can contain a
minimum of 44 and a maximum of 704 symbols. Depending on the modulation type, a
symbol consists of 2 to 6 bits (see Table 4-8).
TIP: Select a specific symbol using the MKR key while the display is focused. If you
enter a number, the marker jumps to the selected symbol, which is highlighted by a
blue circle.
Remote command:
LAY:ADD? '1',RIGH, BITS, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Channel Table
The Channel Table evaluation displays the detected channels and the results of the
code domain power measurement. The measurement evaluates the total signal over
the selected slot. The Channel Table can contain a maximum of 16 entries, which corresponds to the 16 codes that can be assigned for a spreading factor of 16.
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The sort order of the table is configurable (see "Channel Table Sort Order"
on page 87). It can be sorted:
●
Figure 3-2: Channel Table display for TD-SCDMA BTS measurements
By default, only active channels are included in the display; to include inactive channels, see "Channel Table Configuration" on page 13. Inactive channels are marked
with dashes in the "Channel Type", "SymRate" and "Modulation" columns.
For details on the displayed results, see Table 3-2.
Remote command:
LAY:ADD? '1',RIGH, CTABle, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Measurements and Result Display
Code Domain Analysis
By code number, starting with midambles, then control channels, then data chan-
nels
By midamble, where all channels are listed below the midamble they belong to
Channel Table Configuration ← Channel Table
You can configure which parameters are displayed in the Channel Table by selecting
the table header. A "Table Configuration" dialog box is displayed in which you can
select the columns to be displayed.
By default, only active channels are displayed. To display all channels, including the
inactive ones, enable the "Show Inactive Channels" option.
For details on the displayed results , see Table 3-2.
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Code Domain Power
The Code Domain Power evaluation shows the power of all possible codes in the
selected slot in the total signal. Channel detection is based on a power threshold (see
Chapter 4.3, "Channels and Codes", on page 36). Thus, it is important that all codes
have a similar power level (no more than 1.5 dB difference to the average power in the
slot). Thus, the scaling of the code domain power is relative to the average power of
the data parts in the specified slot in the total signal by default. The x-axis shows the
possible codes from 0 to the highest spreading factor. Due to the circumstance that the
power is regulated from slot to slot, the result power can differ between different slots.
Measurements and Result Display
Code Domain Analysis
The codes are displayed using the following colors:
●
Yellow: detected channels
●
Red: selected channel (if a channel is made up of more than one code, all codes
that belong to the channel are red)
●
Green: no channel detected
Remote command:
LAY:ADD? '1',RIGH, CDPower, see LAYout:ADD[:WINDow]? on page 145
CALC:MARK:FUNC:CDP:RES? CDP, see CALCulate<n>:MARKer:FUNCtion:
CDPower:RESult? on page 157
TRACe<n>[:DATA]? on page 161
Code Domain Error Power
The Code Domain Error Power is the difference in power between the measured and
an ideally generated reference signal. The number of codes corresponds to the
spreading factor. The y-axis shows the error power for each code. Since it is an error
power (as opposed to the measured power), both active and inactive channels can be
analyzed at a glance.
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Measurements and Result Display
Code Domain Analysis
Figure 3-3: Code Domain Error Power Display for TD-SCDMA BTS measurements
The codes are displayed using the following colors:
●
Yellow: detected channels
●
Red: selected channel (if a channel is made up of more than one code, all codes
that belong to the channel are red)
●
Green: no channel detected
Remote command:
LAY:ADD? '1',RIGH, CDEPower, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Composite Constellation
In the Composite Constellation result display, the constellation points of the 864 chips
are displayed for the specified slot. This data is determined inside the DSP even before
the channel search. Thus, it is not possible to assign constellation points to channels.
The constellation points are displayed normalized with respect to the total power.
Note: The red circle indicates the value "1"
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Figure 3-4: Composite Constellation display for TD-SCDMA BTS measurements
Remote command:
LAY:ADD? '1',RIGH, CCONst, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Measurements and Result Display
Code Domain Analysis
Composite EVM
The Composite EVM evaluation determines the error vector magnitude (EVM) over the
total signal. The EVM is the root of the ratio of the mean error power to the power of an
ideally generated reference signal. To calculate the mean error power, the root mean
square average of the real and imaginary parts of the signal is used. The EVM is
shown in %. This evaluation is useful to determine the modulation accuracy.
Figure 3-5: Composite EVM display for TD-SCDMA BTS measurements
The result display shows the composite EVM values per slot.
The slots are displayed according to the detected channels using the following colors:
●
Yellow: active channel
●
Red: selected channel (if a channel is made up of more than one code, all codes
that belong to the channel are red)
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●
Only the channels detected as being active are used to generate the ideal reference
signal. Due to low power, for example, a channel may not be detected as being active.
In this case, the difference between the test signal and the reference signal - and
therefore the composite EVM - is very large.
Distortions also occur if unassigned codes are wrongly given the status of "active channel". To obtain reliable measurement results, select an adequate channel threshold.
Remote command:
LAY:ADD? '1',RIGH, CEVM, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Mag Error vs Chip
The Magnitude Error versus chip display shows the magnitude error for all chips of the
selected slot.
The magnitude error is calculated as the difference of the magnitude of the received
signal to the magnitude of the reference signal. The reference signal is estimated from
the channel configuration of all active channels. The magnitude error is related to the
square root of the mean power of reference signal and given in percent.
Measurements and Result Display
Code Domain Analysis
None: no active channels
Where:
MAG
k
s
k
x
k
k Index number of the evaluated chip
N Number of chips at each CPICH slot
n Index number for mean power calculation of reference signal
Figure 3-6: Magnitude Error vs Chip display for TD-SCDMA BTS measurements
Magnitude error of chip number k
Complex chip value of received signal
Complex chip value of reference signal
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Remote command:
LAY:ADD? '1',RIGH, MECHip, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? TRACE<1...4>
Marker Table
Displays a table with the current marker values for the active markers.
This table is displayed automatically if configured accordingly (see " Marker Table Dis-
play " on page 92).
Remote command:
LAY:ADD? '1',RIGH, MTAB, see LAYout:ADD[:WINDow]? on page 145
Results:
CALCulate<n>:MARKer<m>:X on page 175
CALCulate<n>:MARKer<m>:Y? on page 172
Measurements and Result Display
Code Domain Analysis
Peak Code Domain Error
The Peak Code Domain Error is defined as the maximum value for the Code Domain
Error for all codes.
In line with the TD-SCDMA specifications, the error is calculated:
●
Between the measurement signal and the ideal reference signal
●
For a given slot
●
For each active code
●
For any of the supported spreading codes
For inactive slots (containing no active channels), no results are available as no refer-
ence power is available.
Figure 3-7: Peak Code Domain Error display for TD-SCDMA BTS measurements
The result display shows the peak error values per slot.
The slots are displayed according to the detected channels using the following colors:
●
Yellow: active channel
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●
●
Only the channels detected as being active are used to generate the ideal reference
signal. If a channel is not detected as being active, e.g. due to low power, the difference between the test signal and the reference signal is too large. The result display
therefore shows a peak code domain error that is too high for all slots.
Distortions also occur if unassigned codes are wrongly given the status of "active channel". To obtain reliable measurement results, select an adequate channel threshold.
Remote command:
LAY:ADD? '1',RIGH, PCDerror, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Phase Error vs Chip
Phase Error vs Chip activates the phase error versus chip display. The phase error is
displayed for all chips of the selected slot.
The phase error is calculated by the difference of the phase of received signal and
phase of reference signal. The reference signal is estimated from the channel configuration of all active channels. The phase error is given in degrees in a range of +180° to
-180°.
Measurements and Result Display
Code Domain Analysis
Red: selected channel (if a channel is made up of more than one code, all codes
that belong to the channel are red)
None: no active channels
Figure 3-8: Calculating the magnitude, phase and vector error per chip
Where:
PHI
k
s
k
x
k
k Index number of the evaluated chip
Phase error of chip number k
Complex chip value of received signal
Complex chip value of reference signal
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Remote command:
LAY:ADD? '1',RIGH, PECHip, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? TRACE<1...4>
Measurements and Result Display
Code Domain Analysis
N Number of chips at each CPICH slot
φ(x) Phase calculation of a complex value
Power vs Slot
The Power vs Slot evaluation displays the power of the selected channel for each slot.
The power is displayed either absolute or relative to the total power of the data parts of
the signal. The measurement evaluates a single channel over all slots.
Figure 3-9: Power vs Slot Display for TD-SCDMA BTS measurements
The slots are displayed according to the detected channels using the following colors:
●
Yellow: active channel
●
Green: channel with alias power (power results from channels with a different code
class)
●
Cyan: inactive channel
●
Red: selected channel (if a channel is made up of more than one code, all codes
that belong to the channel are red)
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Remote command:
LAY:ADD? '1',RIGH, PSLot, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Power vs Symbol
The Power vs Symbol evaluation shows the power measured for each symbol in the
selected channel and the selected slot. The power is not averaged here.
Measurements and Result Display
Code Domain Analysis
Figure 3-10: Power vs Symbol display for TD-SCDMA BTS measurements
Depending on the spreading factor (symbol rate) of the channel, a slot can contain a
minimum of 44 and a maximum of 704 symbols (see Table 4-8).
Remote command:
LAY:ADD? '1',RIGH, PSYMbol, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Result Summary
The Result Summary evaluation displays a list of measurement results on the screen.
For details , see Chapter 3.1.1, "Code Domain Parameters", on page 10.
Figure 3-11: Result Summary display for TD-SCDMA BTS measurements
Remote command:
LAY:ADD? '1',RIGH, RSUMmary, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
CALCulate<n>:MARKer:FUNCtion:CDPower:RESult? on page 157
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Symbol Constellation
The Symbol Constellation evaluation shows all modulated symbols of the selected
channel and the selected slot.
Note: The red circle indicates the value "1"
Measurements and Result Display
Code Domain Analysis
Figure 3-12: Symbol Constellation display for TD-SCDMA BTS measurements
Remote command:
LAY:ADD? '1',RIGH, SCONst, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Symbol EVM
The Symbol EVM evaluation shows the error between the measured signal and the
ideal reference signal in percent for the selected channel and the selected slot. A trace
over all symbols of a slot is drawn. The number of symbols depends on the symbol
rate (or spreading factor) of the channel (see Table 4-8).
Figure 3-13: Symbol EVM display for TD-SCDMA BTS measurements
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Remote command:
LAY:ADD? '1',RIGH, SEVM, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? on page 161
Symbol Magnitude Error
The Symbol Magnitude Error is calculated analogous to symbol EVM. The result is one
symbol magnitude error value for each symbol of the slot of a special channel. Positive
values of symbol magnitude error indicate a symbol magnitude that is larger than the
expected ideal value. Negative symbol magnitude errors indicate a symbol magnitude
that is less than the expected ideal value. The symbol magnitude error is the difference
between the magnitude of the received symbol and that of the reference symbol, related to the magnitude of the reference symbol.
Measurements and Result Display
Code Domain Analysis
Figure 3-14: Symbol Magnitude Error display for TD-SCDMA BTS measurements
Remote command:
LAY:ADD? '1',RIGH, SMERror, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? TRACE<1...4>
Symbol Phase Error
The Symbol Phase Error is calculated analogous to symbol EVM. The result is one
symbol phase error value for each symbol of the slot of a special channel. Positive values of symbol phase error indicate a symbol phase that is larger than the expected
ideal value. Negative symbol phase errors indicate a symbol phase that is less than the
expected ideal value.
Figure 3-15: Symbol Phase Error display for TD-SCDMA BTS measurements
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Remote command:
LAY:ADD? '1',RIGH, SPERror, see LAYout:ADD[:WINDow]? on page 145
TRACe<n>[:DATA]? TRACE<1...4>
Measurements and Result Display
Frequency and Time Domain Measurements
3.1.3 CDA Measurements in MSRA Operating Mode
The TD-SCDMA BTS application can also be used to analyze data in MSRA operating
mode.
In MSRA operating mode, only the MSRA Master actually captures data; the MSRA
applications receive an extract of the captured data for analysis, referred to as the
application data. The application data range is indicated in the MSRA Master by vertical blue lines.
However, the individual result displays of the application need not analyze the complete data range. The data range that is actually analyzed by the individual result display is referred to as the analysis interval.
In the TD-SCDMA BTS application, the analysis interval is automatically determined. It
depends on the selected channel/ slot/ frame to analyze, which is defined for the evaluation range, and on the result display. The currently used analysis interval (in seconds,
related to capture buffer start) is indicated in the window header for each result display.
For details on the MSRA operating mode, see the R&S FPS MSRA User Manual.
3.2 Frequency and Time Domain Measurements
Access: "Overview" > "Select Measurement"
In addition to the Code Domain Analysis measurements, the TD-SCDMA applications
also provide some frequency and time domain measurements as defined in the TDSCDMA standard. Frequency and time domain measurements are identical to the corresponding measurements in the base unit, but configured according to the requirements of the TD-SCDMA standard.
For details on these measurements, see the R&S FPS User Manual.
MSRA operating mode
Frequency and time domain measurements are not available in MSRA operating
mode.
For details on the MSRA operating mode, see the R&S FPS MSRA User Manual.
3.2.1 Measurement Types and Results in the Frequency and Time Domain
Access: "Overview" > Select Measurement
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The TD-SCDMA applications provide the following frequency and time domain measurements:
Power vs Time.............................................................................................................. 25
Power............................................................................................................................27
Channel Power ACLR...................................................................................................27
Spectrum Emission Mask..............................................................................................28
Occupied Bandwidth..................................................................................................... 29
CCDF............................................................................................................................ 30
Power vs Time
Access: "Overview" > "Select Measurement" > "Power vs Time"
The Power vs Time measurement checks the signal power in the time domain against
a transmission power mask defined by the TD-SCDMA specification ("transmit
ON/OFF power time mask"). This measurement is meant to ensure that each burst
remains within a tight power range, i.e. rises and falls very quickly.
For downlink measurements, the power in the slots reserved for the uplink transmission must quickly fall to the low value. It must then quickly rise to high again in the slots
for downlink transmission. Thus, the slots of interest in downlink Power vs Time measurements are slot 1 to the slot indicated by the Switching Point, in which the OFF
power is checked.
Measurements and Result Display
Frequency and Time Domain Measurements
Figure 3-16: Power vs Time diagram for TD-SCDMA BTS application
In the TD-SCDMA UE application, it is assumed that only one uplink device is
checked during one measurement. Furthermore, it is assumed that each uplink device
uses only a single slot for transmission. Thus, for uplink measurements, only one slot
is checked against the transmit mask. Since the TD-SCDMA UE application has no
information which slot is being used, it assumes the first slot in which a burst is detected to be slot 1, the first slot for uplink transmission. In this slot, the power must quickly
rise to the high value, and quickly fall back to low at the end. Thus, the slot of interest
in uplink Power vs Time measurements is slot 1, which cannot be changed, and in
which the ON power is checked.
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Figure 3-17: Power vs Time diagram for TD-SCDMA UE application
To perform the power check, the TD-SCDMA application must synchronize the transmit mask to the current signal, as the mask is defined relative to a slot start.
The application measures the power in the defined number of subframes in the time
domain and calculates the average power in the slots of interest. It then compares the
averaged power of the signal against the mask for allowed transmission power.
The mask consists of four defined intervals:
●
●
●
●
Note: For UE measurements, the ON power is checked, thus the mask is defined for
the following intervals:
●
●
●
●
As a result, the power vs time trace is displayed. The result of the limit check (Pass/
Fail) is also indicated in the diagram.
The numeric results are provided in the List Evaluation result display (see "List Evalua-
tion" on page 32).
For details, see Chapter 6.3.1, "Power vs Time", on page 76.
Remote command:
CONF:CDP[:BTS]:MEAS PVT, see CONFigure:CDPower:MEASurement
on page 110
Querying results:
TRAC:DATA? TRACE1, see TRACe<n>[:DATA]? on page 161
CALCulate<n>:LIMit<k>:FAIL? on page 170
CONFigure:CDPower[:BTS]:PVTime:LIST:RESult? on page 159
Measurements and Result Display
Frequency and Time Domain Measurements
Before the burst
During fall time
During the low time
During the rise time
Before the burst
During the rise time
During the high time
During fall time
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Power
Access: "Overview" > "Select Measurement" > "Power"
The Power measurement determines the TD-SCDMA signal channel power. The
R&S FPS measures the signal power in a single channel with a bandwidth of
1.2288 MHz. The results are based on the root mean square.
Measurements and Result Display
Frequency and Time Domain Measurements
Figure 3-18: Signal channel power measurement in TD-SCDMA BTS application
For details, see Chapter 6.3.2, "Signal Channel Power Measurements", on page 79.
Remote command:
CONF:CDP[:BTS]:MEAS POW, see CONFigure:CDPower:MEASurement
on page 110
Querying results: CALC:MARK:FUNC:POW:RES? CPOW, see CALCulate<n>:
MARKer<m>:FUNCtion:POWer<sb>:RESult? on page 170
CALC:MARK:FUNC:POW:RES? ACP, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
Channel Power ACLR
Access: "Overview" > "Select Measurement" > "Channel Power ACLR"
Channel Power ACLR performs an adjacent channel power measurement in the
default setting according to TD-SCDMA specifications (adjacent channel leakage
ratio).
The measurement range can be adapted to a slot range of the current TD-SCDMA signal.
The R&S FPS measures the channel power and the relative power of the adjacent
channels and of the alternate channels. The results are displayed below the diagram.
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Figure 3-19: ACLR measurement in TD-SCDMA BTS application
For details, see Chapter 6.3.3, "Channel Power (ACLR) Measurements", on page 80.
Remote command:
CONF:CDP[:BTS]:MEAS ACLR, see CONFigure:CDPower:MEASurement
on page 110
Querying results:
CALC:MARK:FUNC:POW:RES? ACP, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
CALC:MARK:FUNC:POW:RES? ACP, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
Measurements and Result Display
Frequency and Time Domain Measurements
Spectrum Emission Mask
Access: "Overview" > "Select Measurement" > "Spectrum Emission Mask"
The Spectrum Emission Mask measurement determines the power of the TD-SCDMA
signal in defined offsets from the carrier and compares the power values with a spectral mask specified by TD-SCDMA.
For details, see Chapter 6.3.4, "Spectrum Emission Mask", on page 81.
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Figure 3-20: SEM measurement results for TD-SCDMA BTS measurement
Remote command:
CONF:CDP[:BTS]:MEAS ESP, see CONFigure:CDPower:MEASurement
on page 110
Querying results:
CALC:MARK:FUNC:POW:RES? CPOW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
CALC:MARK:FUNC:POW:RES? ACP, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
CALCulate<n>:LIMit<k>:FAIL? on page 170
Measurements and Result Display
Frequency and Time Domain Measurements
Occupied Bandwidth
Access: "Overview" > "Select Measurement" > "OBW"
The Occupied Bandwidth measurement determines the bandwidth that the signal occupies.
The occupied bandwidth is defined as the bandwidth in which – in default settings 99 % of the total signal power is found. The percentage of the signal power to be included in the bandwidth measurement can be changed.
The occupied bandwidth (Occ BW) and the frequency markers are displayed in the
marker table.
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Figure 3-21: Occupied bandwidth measurement in TD-SCDMA BTS application
For details, see Chapter 6.3.5, "Occupied Bandwidth", on page 82.
Remote command:
CONF:CDP[:BTS]:MEAS OBAN, see CONFigure:CDPower:MEASurement
on page 110
Querying results:
CALC:MARK:FUNC:POW:RES? OBW, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
CALC:MARK:FUNC:POW:RES? ACP, see CALCulate<n>:MARKer<m>:FUNCtion:
POWer<sb>:RESult? on page 170
Measurements and Result Display
Frequency and Time Domain Measurements
CCDF
Access: "Overview" > "Select Measurement" > "CCDF"
The CCDF measurement determines the distribution of the signal amplitudes (complementary cumulative distribution function). The CCDF and the Crest factor are displayed. For the purposes of this measurement, a signal section of user-definable
length is recorded continuously in the zero span, and the distribution of the signal
amplitudes is evaluated.
For details, see Chapter 6.3.6, "CCDF", on page 83.
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