Non-cooperative demodulation of linearly modulated digital message transmissions involves transforming signal with non-linearity, feeding transformed signal to symbol frequency estimator

摘要

The method involves transforming the input signal with a non-linearity to produce spectral lines combined with the symbol frequency and feeding the transformed signal to a three-stage symbol frequency estimator with a Welch power density spectrum computation stage, a quadratic interpolation stage and a high resolution fast Fourier transformation stage. The control signal for the interpolator is produced by symbol frequency generator.