Use of the Cepstrum for Processing Multipath Signals. II

The report summarizes an investigation into the use of cepstrum analysis in connection with the processing of communication signals which have been corrupted by multipath effects. Following up on an earlier phase of work, the primary objective consisted of the development and performance evaluation of an experimental setup, incorporating a minicomputer, for on-line cepstrum analysis of baseband communication signals. The purpose of the cepstrum analysis is the extraction of multipath information which can then be used to maintain a multipath cancellation filter in correct adjustment. Another objective was the design of signal waveforms whose cepstra have desirable properties for this type of processing. The basic experimental setup was completed and is described in this report. Test data is presented which was obtained with signals from various modems and with simulated simple discrete multipath interference. Various sources of error are discussed and analyzed.