Improvement of communication quality using compressed sensing in underwater acoustic communication system with orthogonal signal division multiplexing

We propose the use of compressed sensing for an underwater acoustic (UWA) communication system with orthogonal signal division multiplexing (OSDM) to achieve reliable communication in UWA channels with large delay and Doppler spreads. However, OSDM does not fully exploit the characteristics of UWA channels, which have long but sparse reverberation tails. Hence, we propose an OSDM channel estimator using compressed sensing and evaluate its performance in simulations and experiments. The simulations revealed that the optimal gain determining the performance of the channel estimator depends on standard deviation of noise sigma, and OSDM using compressed sensing outperforms normal OSDM. We also evaluate OSDM performance using compressed sensing in field testing in the coastal area of Suruga Bay, Japan. The experimental results suggest that compressed sensing can boost OSDM performance; the number of OSDM error blocks using compressed sensing is half that in normal OSDM. Thus, OSDM using compressed sensing provides reliable communication. (C) 2020 The Japan Society of Applied Physics