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int32 __stdcall niWLANA_GetOFDMDemodSampleClockOffset (niWLANAnalysisSession session, char channelString, float64 *clockOffset);
Returns the estimated Sample clock offset. The Sample clock offset is the difference between the Sample clocks at the digital-to-analog converter (DAC) of the transmitting device under test (DUT) and the digitizer. This value is expressed in parts per million (ppm).
If the clock offset value is more than 25 ppm, the estimated value might be inaccurate. The clock offset measurement follows section 184.108.40.206 of IEEE Standard 802.11a-1999 and section 220.127.116.11 of IEEE Standard 802.11n-2009, section 18.104.22.168 of IEEE Standard 802.11ac-2013, section 22.214.171.124 of IEEE P802.11ah/D1.3, and section 126.96.36.199 of IEEE P802.11ax/D3.0.
To understand which active channel strings are required to configure this function, refer to the NIWLANA_RESULT_OFDM_DEMOD_SAMPLE_CLOCK_OFFSET_AVERAGE attribute.
|Note If the magnitude of the carrier or the sample clock frequency offset is greater than 25 ppm the estimated value may be inaccurate.|
|session||niWLANAnalysisSession||Specifies the niWLAN analysis session refnum.|
|channelString||char||Set this parameter to "" (empty string) or NULL.|
|clockOffset||float64*||Returns the estimated Sample clock offset The estimated offset is the difference between the Sample clocks at the DAC of the transmitting DUT and the digitizer. If the clock offset value is greater than 25 ppm, the estimated value may be inaccurate. This value is expressed in ppm.|
|status||int32||Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an niWLAN function to determine if an error has occurred.
To obtain a text description of the status code and additional information about the error condition, call the niWLANA_GetErrorString function.
The general meaning of the status code is as follows: