Underwater acoustic channel simulations for communication

Discusses communication from a transmitter to a receiver, one or both of which may be mobile. From recordings obtained regularly during the year in the Mediterranean Sea, the authors show in the first part the propagation modifications and their influence on the transmission conditions. From many experimental results already obtained in the authors´ laboratory, they present briefly a general characterization of the underwater medium as a horizontal acoustic communication channel. They emphasize that this channel within communication frequencies range (inferior to 10 kHz) does not behave like a Rayleigh channel. They present a channel simulator, which takes into account the horizontal and vertical receiver movement and the bandpass modulation to reconstruct the interferences generated by the multipath propagation. Those interferences represent the most difficult problem in underwater communication