Programming an Adjacent Channel Leakage Ratio Measurement

Last updated: January 16, 2009

This section provides an example of how to make an adjacent channel leakage ratio measurement via GPIB. The following program example assumes that the mobile station's (UE's) antenna output is connected to the RF IN/OUT connector, and that the mobile station is transmitting an uplink signal.

The program example demonstrates how individual offsets, such as the ± 10 MHz measurements, can be turned off to increase measurement speed, but would normally be left on when making the 3GPP TS 34.121, 5.10 measurement.

The basic procedure to test adjacent channel leakage ratio is as follows:

Set the adjacent channel leakage ratio setup parameters as desired using the SETup:WACLeakage commands.
Use the INITiate:WACLeakage command to start the measurement.
Use the FETCh:WACLeakage? query to obtain the measurement results.

Programming Example

10    OUTPUT 714;"SETup:WACLeakage:CONTinuous OFF"   !Set the adjacent
20                 !channel leakage ratio measurement to single trigger mode.
30    OUTPUT 714;"SETup:WACLeakage:TIMeout 1S"!Set a timeout value of 1 second
40                                  !in case the measurement cannot be made.
50    OUTPUT 714;"SETup:WACLeakage:COUNt 5"!Set multi-measurements to 5 and      
60                                     !enable multi-measurements.
70    OUTPUT 714;"SETup:WACLeakage:TRIGger:SOURce AUTO" !Set the trigger source
80                                                   !to use automatic triggering.
90    OUTPUT 714;"SETup:WACLeakage:LOWer2:STATe OFF"  !Turn off the lower
100                              !second alternate (-10 MHz) measurement.
110   OUTPUT 714;"SETup:WACLeakage:UPPer2:STATe OFF"  !Turn off the upper
120                              !second alternate (+10 MHz) measurement.
130   OUTPUT 714;"INITiate:WACLeakage"!Start the adjacent channel leakage                    
140                                   !ratio measurement.
150   OUTPUT 714;"FETCh:WACLeakage?"!Query the returned integrity indicator, and the
160                                             !measurement values for each offset.
170   ENTER 714;Integrity,Low_1st_alt,Hi_1st_alt,Low_2nd_alt,Hi_2nd_alt  !Enter the
180                                             !returned values into variables.
190   IF Integrity<>0 THEN !Integrity <> 0 indicates  an invalid measurement.
200     PRINT "Measurement problem; check for signal level over/under range condition."
210   ELSE
220   END IF
230   END

Returned Values

Integrity stores the returned integrity indicator value (see Integrity Indicator ); 0 means a successful measurement with no errors.
Because multi-measurements are being used, Low_1st_alt and Hi_1st_alt (± 5 MHz) measurements return the average adjacent channel leakage ratio measurement values for those offsets, in dB. If multi-measurements were not being used, the returned values would be a single measurement value for each frequency offset.
Because the Low_2nd_alt and Hi_2nd_alt (± 10 MHz) measurements are turned off in this example, the returned values are always 9.91E+37 (NAN).

Programming an Adjacent Channel Leakage Ratio Measurement

Programming Example

Returned Values

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