A Multicarrier Digital Communication System for an Underwater Acoustic Environment

Underwater acoustic applications are popular and vast, given the low attenuation of sound waves in water. However, these mediums are a challenge to efficient digital communication systems, due to their time and frequency dispersive nature. Considering the low bandwidth typically available in acoustic systems, high spectral efficiency is also required by the communication systems. In this article an Orthogonal Frequency Division Multiplexing (OFDM) modulation based solution is presented. Significant improvements to the bandwidth limitations and the time dispersion effects of the underwater channel are achieved through this technique. For the estimation and compensation of the Doppler spread a Least Mean Squares (LMS) adaptive algorithm is also considered, obtaining a spectral efficiency of 2.95 bit/second/Hertz.