Spatial processing of broadband underwater acoustic communication signals in the presence of co-channel interference

High throughput multiple-access communication networks are being considered for use in underwater acoustic channels. The bandwidth limitations of underwater acoustic channels require the receivers to process broadband signals in the presence of several active users. To deal with the resulting multiple-access interference in addition to the high intersymbol interference, the spatial variability of ocean multipath is exploited in a multichannel, multiuser receiver. Two configurations of such a receiver, a centralized and a decentralized one, are presented in fully adaptive modes of operation. The results of their performance in an experimental shallow water channel demonstrate superior performance of spatial signal combining. The use of multiple input channels is shown to provide a high level of tolerance for the near-far effect in both centralized and decentralized receivers