SAW COMPLEX CEPSTRUM AND ITS APPLICATION TO REAL-TIME FILTERING OF WIDEBAND MULTIPATH SIGNALS.

The possibility of implementing a SAW complex cepstrum processor, together with the inverse processor, is discussed. Such a system, having all the advantages of the SAW power cepstrum processor, has the ability to recover waveforms distorted by multipath echoes. The design considerations of the SAW direct and inverse complex cepstrum processors are given. The phase unwrapping problem encountered in the digital approach is overcome by using an RF phase detector. The performance of a simulated SAW complex cepstrum processor pair is demonstrated, and examples of filtering echoes from multipath signals are given. It is shown that for a SAW system with a moderate time bandwith product of 100, the efficiency of the filtering, defined by the rms error between the filtered and theoretical pulse, is about 5-15%, depending on the pulse shape and the echo parameters.