Study of single-carrier coherent high-speed underwater acoustic communication

Sparse channel estimation algorithms and frequency-time domain combined equalization technique used in single-carrier coherent high-speed underwater acoustic (UWA) communication are researched. First the UWA channels are estimated by a modified MP algorithm called DAMP. Then, frequency domain time reversal (FDTR) processing (in fact same to the frequency domain zero-forcing equalization, FDEQ) is used to combine the multiple channels at low computation complexity compared with time domain equal. At the same time, equalization in frequency domain is done. Then the multi-channel combined signal is processed by the decision-feedback equalization (DFE) algorithm. At Jan and Mar, 2013, sea tests at Xiamen Harbor, China were done. According to the results, the bit error rates of FDTR-DFE are about 10^-3 in SISO system. In SIMO system, the bit error rates are less than 0.05% (three channels, except one test).