Keysight M9421A - Track Timing; Track Mode

3 WLAN Mode
3.7 WLAN MIMO Modulation Analysis Measurement
State Saved Saved in instrument state
Range On|Off
Track Timing
The Track Timing parameter specifies whether the analyzer tracks timing changes in
the pilot subcarriers. When Track Timing is selected the analyzer applies pilot
subcarrier timing error correction (frequency offset correction) to the pilot and data
subcarriers. This is in addition to Track Amplitude and Track Phase error correction if
selected.
Remote
Command
:CALCulate:EVMMimo:PILot:TRACk:TIMing OFF | ON | 0 | 1
:CALCulate:EVMMimo:PILot:TRACk:TIMing?
Example
:CALC:EVMM:PIL:TRAC:TIM 1
:CALC:EVMM:PIL:TRAC:TIM?
Preset OFF
State Saved Saved in instrument state
Range On|Off
Track Mode
The Tracking Mode parameter specifies where the Pilot Tracking occurs. Traditional
single channel modulation always has the phase tracked after the equalizer. With
multiple data streams, that may not be the best place to do it. If the phase noise is
being generated by the receiver, the signal after the equalizer has a mixture of phase
noise from the two oscillators. Because of this mixing, it is difficult to track the
phase noise after applying the equalizer. The Pre EQ tracking algorithm tracks and
remove the phase noise before the equalizer. The Post EQ tracks and removes the
phase noise after the equalizer and is the default Tracking Mode.
Typically, if the phase noise is primarily caused by the receiver rather than the
transmitter, it's beneficial to select Pre EQ and do pilot tracking before the equalizer.
If the phase noise primarily comes from the transmitter and the phase noise from the
receiver is minimal, select Post EQ. Try both, look at the EVM and use the one that
gives the best result.
Remote
Command
:CALCulate:EVMMimo:PILot:TRACk:MODE POSTeq | PREeq
:CALCulate:EVMMimo:PILot:TRACk:MODe?
Example
:CALC:EVMM:PILot:TRACk:MODE POST
:CALC:EVMM:PILot:TRAck:MODE?
Preset
POSTeq
1241 WLAN Mode User's &Programmer's Reference