Reduced complexity adaptive array processing for multi-user communications

The problem of multi-user communications through channels such as the shallow water acoustic channel presents a challenge in managing receiver complexity. On one hand, the multi-access interference and extended time-varying multipath which are often encountered seemingly push for using arrays of hydrophones, complex algorithms, and a corresponding increase in computing power to successfully separate and demodulate received signals. On the other hand, the sometimes rapid rate of channel fluctuations which may need to be tracked and potential constraints on the available computing power can make the direct expansion of algorithms designed for less complex scenarios impractical. A new receiver structure is proposed which exploits channel structure to facilitate multi-user communications in the shallow water environment without a significant increase in receiver complexity.