Design aspects of signal waveform for underwater acoustic communication system

The underwater acoustic channel belongs to a complicated class of stochastic communication channels, which are frequency and energy (at long range) limited and time-frequency doubly spread. Underwater acoustic data telemetry is a taxing problem because many unique channel characteristics such as fading, extended multipath, retroactive properties of sound channels preclude direct applications of classical communication techniques. For such channels Channel identification, channel tracking and optimum linear decoding will be the approach in order to solve the problems of communication over a possible doubly spread channel. This paper describes a reliable mechanism and signal design for underwater sensor node.