Keysight Technologies, Inc.
Measurement of periodically modulated signals under non-coherent operating conditions

Abstract:

A receiver-implemented method is for measuring a periodically modulated signal. The method includes applying a received periodically modulated signal to a mixer of a receiver, the periodically modulated signal not synchronized with the receiver, and tuning a local oscillator (LO) of the mixer using an estimate of actual carrier frequency and an estimate of an arbitrary waveform generator (AWG) sampling rate to obtain a digitized intermediate frequency (IF) signal. The method further includes applying a short time Fourier transform (STFT) to the digitized IF signal, extracting a carrier frequency offset and a AWG sampling rate offset based on the applied STFT, compensating for the carrier frequency offset, and applying a digital correction to the STFT to compensate for the AWG sampling rate offset. Compensating for the carrier frequency offset may include retuning the LO to obtain a new digitized IF signal to which the digital correction is applied.