SyncCorr (802.11n/ac/ax/be)
(Sync Correlaton) is the correlation coefficient between the measured preamble and an ideal preamble. This can be used as an indication of the quality of the preamble. For HT high throughput and VHT very high throughput (VHT) physical (PHY) layer protocol data unit (PPDU):A PPDU transmitted using the TXVECTOR FORMAT parameter equal to VHT. frames, Sync Correlation is computed from the initial Legacy Short Training Field (L-STF Non-HT Short Training field) part of the preamble, except for HT-greenfield frames where the Sync Correlation is calculated from HT-STF High-Throughput Short Training field. A value of 1 indicates perfect correlation and a value of 0 indicates no correlation.
Large Frequency Errors and Incorrect Sync Corr Values
Large frequency errors may cause the VSA to show incorrect low Sync Correlation values. These low values are a result of frequency error and do not necessarily indicate poor signal quality. Therefore, for low Sync Correlation values, always validate the cause of the low Sync Correlation data result.
If the Sync Correlation is low and the frequency error is large, check the EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format.. If the EVM is low and the measured signal data is good, then the low Sync Corr value can generally be ignored. To correct for frequency errors, adjust the center frequency so that the Frequency Error decreases to approximately 0 Hz. If the Sync Correlation increases in value then the contributing factor to the initial low Sync Correlation value was the frequency error and not the measured signal.
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