Design and Implementation of Channel Coding for Underwater Acoustic System

Underwater acoustic channel is a typical high bit error rate (BER) wireless channel. It is characterized by poor communication quality and high propagation delay. Based on comparing and analyzing the performances of RS code, convolutional code, Turbo code, and RA code, a RA coding based underwater acoustic channel coding scheme is proposed in this paper. The results of Matlab-based simulations show that the coding scheme can get a 100 times, or even more, performance improvement. In order to accelerate RA coding, aiming at the random mapping process of RA coding, based on the minimum sum algorithm, a look-up table based circuit design for fast iteration is introduced. Then, the experiments to test the RA coding are carried out in different channel environments, including underwater acoustic test platform and harbor. The results show that the coding scheme reduces the BER 38 times in the underwater acoustic test platform, increases the correct packet rate from 18.92% to 72.45% in the harbor(1).