Generalizations of Cyclostationarity: A New Paradigm for Signal Processing for Mobile Communications, Radar, and Sonar

The relative motion between transmitter and receiver introduces nonstationarity to stationary signals and modifies the nonstationarity of nonstationary signals. Several Doppler channel models of interest transform almost-cyclostationary (ACS) processes, which are an appropriate nonstationary model for modulated signals adopted in communications, radar, sonar, and telemetry, into generalized ACS (GACS) processes or spectrally correlated (SC) processes. Both classes of processes include the ACS processes as special cases. A review of these new classes of nonstationary processes is presented. The problems of probabilistic characterization, statistical function estimation, and determining the effects of time-sampling on these models are addressed. The impact of these models on signal detection and source location problems is discussed.