IMPROVED DETECTION WITH THE CROSS-AMBIGUITY FUNCTION

The cross-ambiguity function (CAF) and the Wigner distribution (WD) are mathematically related bilinear representations of signals. The former is used in sonar and radar to locate a signal with unknown time-delay and Doppler shift. The latter characterizes the time-frequency distribution of signal and noise. This paper shows that the WD is a convenient device for data-adaptive filtering leading to improved signal-to-noise ratio in CAF detections. The proposed approach is useful when the signal competes with strong, time-varying interference