MIMO-OFDM Underwater Acoustic Communication Receiver Based on Intercarrier Interference Depth Estimation

Due to the unknown influence of Inter-Carrier Interference (ICI) on the signal in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) underwater acoustic communication systems, the receivers have problems with incomplete interference cancellation or high computational complexity. To solve this problem, an iterative MIMO-OFDM receiver based on ICI depth estimation is proposed. The pilot frequency domain correlation is used to estimate the ICI depth for each transmitted signal. In channel estimation, the frequency domain matrix of each channel is reconstructed by using the estimated interference depth, which avoids selecting the same interference depth for different channels. Therefore, the proposed receiver can self adapt to channel variations and reduce computational complexity. Furthermore, decision feedback equalization is introduced into the MIMO-OFDM underwater acoustic communication system, and the equalized symbols are used to eliminate ICI. Simulation results show that the correct decoding time of the proposed receiver is less than that of the ICI-progressive receiver.