Multiple input multiple output underwater communication based on differential amplitude phase shift keying modulation

The MIMO-OFDM combining time, spatial and frequency diversity can effectively improve channel capacity and transmission efficiency of underwater acoustic (UWA) communication system. Space-time coding needs a large number of pilot signals to estimate UWA channel at the receiving end, which increases the complexity of the systems and limits the communication rate. For this, space-time coding combined with differential amplitude phase shift keying modulation (DAPSK) is proposed in this paper. It can complete the decoding without any prior knowledge of UWA channel, reducing the complexity of the system, saving channel resources and improving the transmission efficiency. Simulation analysis on UWA MIMO-OFDM systems shows this algorithm is feasible, which provides a feasible method for high-speed transmission in UWA communication.