DETECTION OF BROAD-BAND SIGNALS IN FREQUENCY AND TIME DISPERSIVE CHANNELS

A major problem for active sonar systems operating in shallow water is reverberation, High time-bandwidth waveforms and coherent matched fil tering are often used to improve detection performance in reverberatio n, However, an active sonar echo undergoes distortion during two-way p ropagation and reflection from the target, As a result, the full perfo rmance gain is not achievable, and this approach is severely limited, In this case, more robust detectors are needed. In this paper, we eval uate the detection performance of several commonly used detectors in a n ideal nondistorting channel, a fast-fading distortion (FFD) channel, and a channel with time-spreading distortion (TSD), We examine the ro bustness of the various detectors by evaluating the performance in the case of mismatch between the detector and the channel parameters, Stu dying the relation between the FFD model and the TSD, we show that, un der certain conditions, the TSD and FFD channels have an equivalent ef fect on the waveform.