Anti-multipath technique of underwater acoustic channel in complex cepstrum domain

Because of boundary reflections and the non-homogeneity of water in the sea, an underwater acoustic channel is regarded as a multipath channel. Therefore managing multipath interference effectively has always been a difficult and hot issue in underwater acoustics. Based on the fundamental theory of homomorphic filters, the characteristics of an underwater multipath acoustic channel in a complex cepstrum domain were analyzed. Then a new kind of feature filter, pinnacle search method, which is suitable for separation of the signal and the channel in a complex cepstrum domain, was put forward. The features of this method were analyzed and compared with the low-pass feature filter and the comb feature filter. The results show that the proposed method can manage the multipath effects effectively. Compared with the other two feature filters, the pinnacle search feature filter can easily be established with smaller error in reconstructing signals, and so is valuable in engineering application.