Linear turbo equalization with precoding for underwater acoustic communications

Long range underwater acoustic communications are challenging since this channel is severely band limited, time varying, and has a long delay spread. A linear turbo equalizer is a good candidate for communicating over this channel, because it achieves a high level of spectral efficiency with a realizable complexity. As the channel is FIR, the convergence of the turbo equalizer is improved by recursive precoding of the signal before transmission. In this paper, we present a scheme for receiving a precoded transmission using a linear equalizer. Also, experimental results demonstrating high data rates achieved via precoding for long range underwater acoustic communications are presented.