Transient Signal Extraction in a Multipath Environment

Consider the problem of estimating the arrival times of overlapping ocean-acoustic signals from a received signal which consists of an unknown deterministic signal along with scale and delayed versions due to multipath propagation plus additive noise. Our objective is to simultaneously determine the transmitted waveform and the arrival times. The proposed algorithm obtains approximately maximum liklihood estimates of the arrival times and the parameters which characterize the unknown signal. Our assumptions are that the number of different paths is known and that the signal must belong to a parametric class of signals. The algorithm is demonstrated on a class of signals consisting of gated sinusoids.