Freq Err (802.11a/g/j/p OFDM)

Freq Err shows the carrier frequency error relative to the measurement hardware's center frequency. This parameter is displayed in Hertz and is the amount of frequency shift, from the measurement hardware's center frequency, that the VSA must perform to achieve carrier lock.

For the actual FFT Fast Fourier Transform: A mathematical operation performed on a time-domain signal to yield the individual spectral components that constitute the signal. See Spectrum. demod, the carrier frequency is determined from the preamble. If the VSA has been set to sync on the channel estimation sequence only, then the short sync is ignored (see Synchronization Reference). The frequency error reported in the summary table is the value from the final frequency estimation based on the channel estimation sequence with a fine adjustment made for any frequency error detected in the pilot tracking. The pilot tracking does not correct the signal for frequency errors, it only corrects the post-FFT symbols for phase (and amplitude, if enabled).

Errors in RF Radio Frequency: A generic term for radio-based technologies, operating between the Low Frequency range (30k Hz) and the Extra High Frequency range (300 GHz). frequency, LO frequency, or digitizer clock rate could all appear as carrier frequency error.