PERFORMANCE ANALYSIS OF DIGITAL ACOUSTIC COMMUNICATION IN A SHALLOW-WATER CHANNEL

High data rate acoustic transmission is required for diverse underwate r operations such as the retrieval of targe amounts of data from botto m packages and real time transmission of signals from underwater senso rs, The major obstacle to underwater acoustic communication is the int erference of multi-path signals due to surface and bottom reflections, High speed acoustic transmission over a shallow water channel charact erized by small grazing angles presents formidable difficulties. The r eflection losses associated with such small angles are low, causing la rge amplitudes in multi-path signals. In this paper we propose a simpl e but effective model for multi-path interference, which is then used to assess the performance of a digital communication system operating in a shallow water channel, The results indicate that transmission rat es in excess of 8 k-bits/s are possible over a distance of 13 km and c hannel depth of only 20 meters. Such a system offers improved performa nce in applications such as data collection from underwater sensors.