User`s guide

2-6
GPIB Tutorial and Examples
Example C - Making Measurements
Example C - Making Measurements
In this section we first add a TX Power measurement, then modulation accuracy and
receiver sensitivity tests.
TX Power Measurement
TX peak power is measured using the Fast TX Carrier Power measurement. This
measurement can take place in parallel with GSM signalling operations such as ARFCN
or TX Level changes. TX peak power is normally displayed on the Cell Control screen.
The Agilent 8922M/S RF Analyser automatically adjusts its input attenuation and gain to
match the power expected from the mobile. The Expected Input power is displayed at the
bottom of the Cell Control screen. This expected power provides a convenient
comparison with the measured power. For a perfect mobile, the expected and measured
values are the same. Select GPIB commands from section “GPIB Commands Used in
Exercises” to query the measured and expected power and insert them immediately before
the PRINT statement in your program. Modify the PRINT statement to display ARFCN,
TX Level, Expected Power and Measured Power. The program flow should be as follows:
❒ Establish call as in exercise A.
❒ Set up a loop to count through three ARFCN.
❒ Command the phone to the new ARFCN.
❒ Check the reported ARFCN, loop until the reported value matches the programmed
value, or too much time has elapsed.
❒ Set up a loop to count through the TX Levels.
❒ Command the phone to the new TX Level.
❒ Check the reported TX Level, loop until the reported value matches the programmed
value, or too much time has elapsed.
❒ Query the Fast TX Carrier Power (TX Peak Power).
❒ Query the RF Analyser Expected Input.
❒ Print the ARFCN, TX Level, Expected Power, Measured TX Peak Power.
❒ Repeat for the next TX Level.
❒ Repeat for the next ARFCN.
❒ End call as in Exercise A.