High-frequency acoustic communications achieving high bandwidth efficiency

A recent communications experiment was conducted in a shallow water environment at high-frequency permitting the use of a large bandwidth (11-19 kHz). This paper investigates the communication performance versus various symbol rates (or bandwidths) in terms of output signal-to-noise ratio with, an assortment of constellations, illustrating a trade-off between performance and data rate. A high bandwidth efficiency of 4 bits/s Hz is demonstrated using 32 quadrature amplitude modulation with a data rate of 31.25 kbits/s over a 2.2-km range. (C) 2009 Acoustical Society of America. [DOI: 10.1121/1.3160284]