Receiver Control

Last updated: December 2, 2008

The test set normally sets all receiver parameters automatically using data connection control settings. You may want to control the test set's receiver parameters manually rather than allowing the test set to control them. This ability is referred to as manual receiver control.

How Do I Access the Receiver Control Parameters?

This section details how to access the Receiver Control parameter.

Press the Call Setup key.
Press Receiver Control ( F12 ).

Selecting Manual or Automatic Receiver Control

Automatic receiver control modes are the default for all operating modes. This means parameters such as the receiver's expected power, measurement frequency, and modulation format settings are set automatically according to the control parameters you specify (for example, Traffic Channel, Packet Data Traffic Channel, Packet Data Traffic Band, MS TX Level, and Modulation and Coding Scheme).
Manual mode allows you to override some or all of the automatic settings by first selecting the manual mode for the setting and then specifying the desired value. You can view the affected settings by selecting F12 (Receiver Control ) from the Call Setup screen. A full or partial preset of the test set, including cycling power, returns the test set back to auto mode.

GPIB Examples

The following program examples use simple commands to perform a single function. Complex commands that enable manual receiver control and set a specified parameter at the same time are also available. See RFANalyzer for a listing of all receiver control syntax.

 
OUTPUT 714;"RFANalyzer:CONTrol:MEASurement:FREQuency:AUTO OFF" !Enables manual control of the measurement receiver's frequency.

 
OUTPUT 714;"RFANalyzer:MANual:MEASurement:FREQuency 825.030 MHZ" !Tunes the measurement receiver to 825.030 MHz through manual receiver control.

 
OUTPUT 714;"RFANalyzer:CONTrol:MEASurement:FREQuency:AUTO ON" !Returns measurement receiver frequency tuning control to auto.

Manual control parameter values are stored internally (as long as the test set is powered on). Enabling manual control of a parameter without providing a new value causes a previously stored value to immediately take effect. This allows you to pre-define manual control parameter values in your program before enabling manual control.

Expected Power Control

To make accurate measurements, the test set needs to know how much power to expect at the test set's RF IN/OUT port; referred to as the Expected Power. It gets this value from the call control MS TX Level setting during automatic receiver control, or by the user specifying the expected power with the expected power control set to manual.

You can set the expected power level beyond the capability of the test set's hardware because expected power is intended to reflect the potential range of RF power at the DUT . This range of RF power is meant to accommodate the use of a gain or loss network between the DUT and the test set. See Amplitude Offset for details about amplitude offset.

The upper and lower limits of expected power provide boundaries for the combination of amplitude offset and expected power. If you set expected power to +52 dBm and the amplitude offset to -3 dB, the calculated receiver power will be 49 dBm, but the test set shall be set to +43 dBm, the upper limit of the hardware. If the calculated value of receiver power goes below -25 dB, the lower limit of the hardware, the test set shall be set to -25 dB.

The expected power from the mobile is set manually using the following settings:

To set the test set receiver's expected power setting to manual use RFANalyzer:CONTrol:POWer:AUTO .
```
 
OUTPUT 714;"RFANalyzer:CONTrol:POWer:AUTO OFF"
```
To set the power level that the test set's receiver is expecting the mobile station uplink burst to transmit at for the GPRS system type, use RFANalyzer:MANual:POWer:BURSt<[1]|2|3|4|5|6|7> . Each burst is set individually.

For example, the commands below set the receiver's expected power setting for burst 1 and burst 2.
```
 
OUTPUT 714;"RFANalyzer:MANual:POWer:BURSt1 15 DBM" 
```
```
 
OUTPUT 714;"RFANalyzer:MANual:POWer:BURSt2 19 DBM" 
```
NOTE: Setting the manual expected burst power will not set expected power control to manual.

NOTE

During manual receiver control, make sure you are using the correct operating mode for the type of measurement you are making. Trying to measure a CW signal while in active cell mode will likely result in an error. This error occurs because the test set uses the expected power setting for the operating mode you are using, and uses different methods to measure analog and digital signals.

It is recommended that you specify the expected power each time you perform a handoff to a new band or traffic channel type during manual receiver control. This ensures that the correct expected power is set for the new channel settings.

Auto Expected Power Control

The expected power is derived from the MS TX Level setting for the specified system type when using automated control:

GSM:
- CALL:MS:TXLevel[:SELected]
GPRS and EGPRS:
- CALL:(PDTCH|PDTChannel):MS:TXLevel[:SELected]:BURSt<[1]|2|3|4|5>

Operating Considerations

The expected power control parameter is applicable to all operating modes, with the exception of CW.

Measurement Frequency

Measurement frequency is used to tune the test set's measuring receiver for all bands:

To set the receiver to manual mode and change the measurement frequency use RFANalyzer:MANual:MEASurement[:MFRequency] .

 
OUTPUT 714;"RFANalyzer:MANual:MEASurement 942.6 MHZ" !Enables manual measurement
!receiver control and sets the test set's measurement receiver frequency to 942.6 MHz.

Auto Measurement Frequency Control

If the receiver control parameter is set to auto, the test set's receiver frequency is set using the parameters in the following table. See CALL:TCHannel[:ARFCn][:SELected] traffic channel details and CALL:TCHannel:BAND for traffic band details. See CALL[:CELL]:BAND<[:SELected]|:GSM> for cell band details. See CALL:BCHannel for broadcast channel details.

Test Set Receiver Frequencies (Auto)
Operating Mode	Measurement Band	Measurement Frequency
Cell Off	Cell Band	Broadcast Channel (1)
Active Cell	TCH Traffic Band (3)	TCH Traffic Channel (2,4)
GSM BCH	Cell Band	Broadcast Channel (1)
GSM BCH+TCH	TCH Traffic Band	TCH Traffic Channel (2)
GPRS BCH	Cell Band	Broadcast Channel (1)
GPRS BCH+PDTCH	PDTCH Traffic Band	PDTCH Traffic Channel (2)
EGPRS BCH	Cell Band	Broadcast Channel (1)
EGPRS BCH+PDTCH	PDTCH Traffic Band	PDTCH Traffic Channel (2)
CW	Cell Band	Broadcast Channel (1)

Table Footnotes
1	Actual frequency depends on current broadcast band (PGSM, EGSM, GSM450, GSM480, GSM750, GSM850, PCS, DCS or RGSM) and is defined in GSM as the uplink frequency.
2	Actual frequency depends on current traffic channel band (PGSM, EGSM, GSM450, GSM480, GSM750, GSM850, PCS, DCS or RGSM) and is defined in GSM as the uplink frequency.
3	TCH Traffic Band when the system type is GSM; PDTCH Traffic Band when the system type is GPRS or EGPRS
4	TCH Traffic Channel when the system type is GSM; PDTCH Traffic Channel when the system type is GPRS or EGPRS

Measurement Channel in BCH Only Mode

Measurement Channel in BCH Only Mode sets which channel is measured by the test set in BCH Only operation mode. You can choose to measure one of the following channels: RACH, TCH or PDTCH.

NOTE

RACH here represents uplink channel type not burst type as in "Expected Burst" on page 10 setting.

To set the Measurement Channel in BCH Only Mode use RFANalyzer:CONTrol:BTESt:CHANnel .

 
OUTPUT 714;"CALL:OPERATING:MODE GBTest"
!Sets the operating mode to GSM BCH.

 
OUTPUT 714;"RFANalyzer:CONTrol:BTESt:CHANnel TCH" 
!Sets the Measurement Channel in GSM BCH Only Mode to TCH.

You are suggested to set the "Measurement Frequency" on page 7 and "Expected Power Control" on page 6 to Auto when selecting a measurement channel in BCH Only Mode. the test set's receiver frequency and Expected Power Level is set automatically using the parameters in the following table.

Measurement Channel	Measurement Band	Measurement Frequency	Expected Power Level
RACH	Cell Band	Broadcast Channel (1)	0 (5)
TCH	TCH Traffic Band (3)	TCH Traffic Channel (2,4)	TCH MS TX Level
PDTCH	PDTCH Traffic Band	PDTCH Traffic Channel (2)	PDTCH MS TX Level

Table Footnotes
1	Actual frequency depends on current broadcast band (PGSM, EGSM, GSM450, GSM480, GSM750, GSM850, PCS, DCS or RGSM) and is defined in GSM as the uplink frequency.
2	Actual frequency depends on current traffic channel band (PGSM, EGSM, GSM450, GSM480, GSM750, GSM850, PCS, DCS or RGSM) and is defined in GSM as the uplink frequency.
3	TCH Traffic Band when the system type is GSM; PDTCH Traffic Band when the system type is GPRS or EGPRS
4	TCH Traffic Channel when the system type is GSM; PDTCH Traffic Channel when the system type is GPRS or EGPRS
5	Fix to the maximum MS TX Level

Operating Considerations

The Measurement Channel in BCH Only Mode receiver control parameter is only applicable to the following operating modes:

GSM BCH
GPRS BCH
EGPRS BCH

If the operating mode is set to GSM BCH , PDTCH is greyed on the front panel; if the operating mode is set to GPRS BCH or EGPRS BCH , TCH is greyed on the front panel.

When Operating Mode is switched from one BCH only Mode to another:

if the value of Measurement Channel in BCH Only Mode is valid in current operating mode, the value keeps unchanged.
if the value of Measurement Channel in BCH Only Mode is not valid in current operating Mode, the value is reset to RACH.

Uplink Frequency

Uplink Frequency sets the test set's demodulation receiver frequency, used to demodulate information from the mobile's uplink transmission:

To set the receiver to manual mode and set the demodulation receiver frequency use RFANalyzer:MANual:UPLink[:MFRequency] .

 
OUTPUT 714;"RFANalyzer:MANual:UPLink 942.6 MHZ" !Enables manual demodulation
!receiver control and sets the test set's demodulation receiver frequency to 942.6 MHz.

NOTE

Manual control of the demodulation receiver frequency is rarely needed. Use the measurement receiver when manual receiver frequency control is required. Automatic control is always used when the cell operating mode is active cell.

Operating Considerations

The uplink frequency receiver control parameter is only applicable to the following operating modes:

GSM BCH
GSM BCH+TCH
GPRS BCH
GPRS BCH+PDTCH
EGPRS BCH
EGPRS BCH+PDTCH

Expected Burst

See Expected Burst for more information.

Operating Considerations

The expected burst receiver control parameter is only applicable to the following operating modes:

GSM BCH
GSM BCH+TCH
GPRS BCH
GPRS BCH+PDTCH
EGPRS BCH
EGPRS BCH+PDTCH

Modulation Format Control (EGPRS only)

The expected modulation format is used by transmitter measurements which support both GMSK and 8PSK signals. The Modulation Format Control parameter allows you to select either Auto or Manual mode.

Auto Mode

If the modulation format control is set to Auto, the test set determines which modulation format to expect based on the current Operating Mode, current System Type, and the current Uplink Modulation and Coding Scheme. Coding Schemes MCS-1, MCS-2, MCS-3, and MCS-4 use GMSK modulation while MCS-5, MCS-6, MCS-7, MCS-8, and MCS-9 use 8PSK modulation.

The following table indicates which modulation format the test set expects based on each combination of operating parameters.

NOTE

8PSK is represented as EPSK in the test set.

Automatic Determination of Measurement Modulation Format
Operating Mode	System Type	Uplink Coding Scheme (CS) or Modulation and Coding Scheme (MCS)	Expected Modulation
Active Cell (GSM)	GSM	N/A	GMSK
Active Cell (GPRS)	GSM	N/A	GMSK
Active Cell (GPRS)	GPRS	CS1 - CS4	GMSK
Active Cell (EGPRS)	GSM	N/A	GMSK
	EGPRS*	MCS1 - MCS4	GMSK
	EGPRS*	MCS5 - MCS9	EPSK
GSM BCH	GSM	N/A	GMSK
GSM BCH+TCH	GSM	N/A	GMSK
GPRS BCH	GPRS	CS1 - CS4	GMSK
GPRS BCH+PDTCH	GPRS	CS1 - CS4	GMSK
EGPRS BCH	EGPRS	MCS1 - MCS4	GMSK
EGPRS BCH	EGPRS	MCS5 - MCS9	EPSK
EGPRS BCH+PDTCH	EGPRS	MCS1 - MCS4	GMSK
EGPRS BCH+PDTCH	EGPRS	MCS5 - MCS9	EPSK
CW	N/A	N/A	GMSK
Cell Off	N/A	N/A	GMSK

NOTE

* When the operating mode is Active Cell (EGPRS) and the connection type is BLER, the expected modulation is GMSK because the uplink TBF uses the PACCH. All control channels use GMSK modulation.

Manual Mode

If the modulation format control is set to Manual, you can set the modulation format the test set should expect for each uplink burst individually.

To set the modulation format control setting to manual, use CALL:MODulation[:FORMat]:CONTrol:AUTO .
```
 
OUTPUT 714;"CALL:MODulation:CONTrol:AUTO OFF"
```
To set the modulation format the transmitter measurements are expecting for each uplink burst, use CALL:MODulation[:FORMat]:MANual:BURSt[1]|2|3|4|5|6|7 . Each burst is set individually.
```
 
OUTPUT 714;"CALL:MODulation:MANual:BURSt EPSK"
```
```
 
OUTPUT 714;"CALL:MODulation:MANual:BURSt2 EPSK"
```

Operating Considerations

Modulation Format Control is only available in Active Cell (EGPRS), EGPRS BCH, and EGPRS BCH+PDTCH operating modes. Attempting to change the modulation format control parameter value in other operating modes generates the following error:
Operation rejected: Command is not supported in this operating mode.

You can make changes to the expected modulation format for each individual uplink burst in any operating mode programatically using GPIB commands. These parameters are only accessible via the front panel when the operating mode is valid for this parameter.

Changes to operating mode cause the modulation format control parameter value to be reset to Auto. However, the individual burst settings are not reset and retain any changes you have made.

NOTE

When the operating mode is either EGPRS BCH or EGPRS BCH+PDTCH and the modulation format control is set to Auto, the test set assumes that the uplink uses the same modulation format as is specified for the downlink to automatically determine the modulation format. If this is not the case, you should set the modulation format control to Manual and set the appropriate modulation format settings.

Expected CW Power (CW Operating Mode only)

The expected CW power from the mobile is set manually using the following setting:

To set the power level that the test set's receiver is expecting the mobile station to transmit at in CW operating mode, use RFANalyzer:CW:EXPected:POWer .
```
 
OUTPUT 714;"RFANalyzer:CW:EXPected:POWer 15 DBM"
```

See Expected Power Control for more information on expected power settings.

Measurement Burst (GPRS and EGPRS only)

Measurement Burst sets the mobile uplink burst number on which the measurement is performed (not the absolute timeslot number, but the burst number relative to the first uplink burst in the TDMA frame):

To set the measurement burst use CALL:(PDTCH|PDTChannel):MSLot:MEASurement:BURSt .
```
 
OUTPUT 714;"CALL:PDTCH:MSL:MEAS:BURS 2" !Sets the receiver to measure the second uplink !burst.
```
The Measurement Burst parameter is always controlled manually. The choice of bursts available is based on the selection table shown under the multislot selection command, CALL:(PDTCH|PDTChannel):MSLot:CONFig .

Effects on Receiver Control When Changing Operating Mode

After selecting the operating mode to use and setting one or more receiver controls to manual, the receiver control settings remain as you set them until you change operating mode. Changing operating mode causes all receiver parameters to return to automatic control.

Asymmetric Guard Period Length

For information about this parameter see the description in the GPIB command for this parameter, which is located at CALL:MS:TX:BURSt:GPLength .

This parameter is located in the Receiver Control menu on the front panel. Refer to How Do I Access the Receiver Control Parameters? for instructions on how to access this menu.

Uplink Frame Segmentation

For information about this parameter see the description in the GPIB command for this parameter, which is located at CALL:MS:TX:FRAMe:SEGMentation .

This parameter is located in the Receiver Control menu on the front panel. Refer to How Do I Access the Receiver Control Parameters? for instructions on how to access this menu.

Receiver Control

How Do I Access the Receiver Control Parameters?

Selecting Manual or Automatic Receiver Control

GPIB Examples

Expected Power Control

Auto Expected Power Control

Operating Considerations

Measurement Frequency

Auto Measurement Frequency Control

Measurement Channel in BCH Only Mode

Operating Considerations

Uplink Frequency

Operating Considerations

Expected Burst

Operating Considerations

Modulation Format Control (EGPRS only)

Auto Mode

Manual Mode

Operating Considerations

Expected CW Power (CW Operating Mode only)

Measurement Burst (GPRS and EGPRS only)

Effects on Receiver Control When Changing Operating Mode

Asymmetric Guard Period Length

Uplink Frame Segmentation

Related Topics