Programming an I/Q Tuning Measurement
Last updated: December 3, 2008
This section provides an example of how to make an I/Q Tuning measurement via the GPIB.
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Ensure that the mobile is in test mode and is transmitting all 1s or all 0s.
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Ensure that the expected frequency, expected power level and trigger are appropriately set.
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Configure the I/Q Tuning measurement parameters using the SETup subsystem.
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Start the I/Q Tuning measurement using the INITiate subsystem.
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Use the FETCh? command to obtain I/Q Tuning measurement results.
Programming Example
The following program shows how to make an I/Q Tuning measurement on a normal GSM TCH burst. If you want to test a CW signal all you need to change in this program is the trigger type, which should be set to Immediate, rather than RF Rise.
10 PRINT "Ensure your mobile is transmitting:" !On-screen prompts.
20 PRINT "-all 1s or all 0s."
30 PRINT "-on ARFCN 30."
40 PRINT "-a power level of 10 dBm."
50 PRINT " "
60 PRINT "Press any key to continue."
70 LOOP
80 ON KBD GOTO Key_exit
90 END LOOP
100 Key_exit: !
110 OUTPUT 714;"RFANALYZER:MANUAL:CHANNEL:SELECTED 30" !Configures the
120 !test set to expect a transmission on ARFCN 30.
130 OUTPUT 714;"RFANALYZER:EXPECTED:POWER:SELECTED 10 DBM" !Configures
140 !the test set to expect a power level of 10 dBm.
150 OUTPUT 714;"SETUP:IQTUNING:CONTINUOUS OFF" !Configures trigger
160 !mode to single for an I/Q Tuning measurement.
170 OUTPUT 714;"SETUP:IQTUNING:COUNT:SNUMBER 50" !Configures the
180 OUTPUT 714;"SETUP:IQTUNING:SPUR:STATE ON" !Configures spur on.
190 OUTPUT 714;"SETUP:IQTUNING:SPUR:FREQUENCY 10MHZ" !Configures a
200 !power measurement at 10MHz from the carrier.
210 !multi_measurement state to ON with a measurement count value
220 !of 50.
230 OUTPUT 714;"SETUP:IQTUNING:TRIGGER:SOURCE RISE" !Configures the
240 !trigger source to RF RISE.
250 OUTPUT 714;"SETUP:IQTUNING:REFERENCE:FREQUENCY AUTO" !Sets the
260 !set to choose which offset frequency is to be used as the ref.
270 OUTPUT 714;"INITIATE:IQTUNING" !Start I/Q Tuning measurement.
280 OUTPUT 714;"FETCH:IQTUNING:ALL?"!Fetches the measurement integrity
290 !value and the relative power levels at the offset frequencies.
300 ENTER 714;Integrity,N270,N203,N135,N67,Carrier,P67,P135,P203,P270,Sr
310 PRINT "I/Q Tuning Measurement Results"
320 PRINT "Integrity = ";Integrity
330 PRINT "Spur Power = ";Sr
340 PRINT "Offset (kHz) Level (dB)"
350 PRINT "------------ ----------"
360 PRINT "-270.334 ";N270
370 PRINT "-203.125 ";N203
380 PRINT "-135.417 ";N135
390 PRINT "-67.708 ";N67
400 PRINT "0.000 ";Carrier
410 PRINT "+67.708 ";P67
420 PRINT "+135.417 ";P135
430 PRINT "+203.125 ";P203
440 PRINT "+270.334 ";P270
450 END
Returned Values
The measurements returned by this program are:
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Integrity returns the measurement
Integrity Indicator
(0 means a successful measurement with no errors).
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The signal level of the following offsets are measured relative to the signal level at the reference offset (either Fc + 67.7083 kHz for all 0s or Fc -67.7083 kHz for all 1s). Note, if the TX I/Q Tuning measurement multi-measurement command is set to ON the average of all the individual results at each offset are returned.
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-270.833 kHz
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-203.125 kHz
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-135.417 kHz
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-67.7083 kHz
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Carrier Frequency
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+67.7083 kHz
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+135.417 kHz
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+203.125 kHz
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+270.833 kHz
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