Research of Channel Polarization for Orthogonal Frequency Division Multiplexing Underwater Acoustic Communications

Construction and application of polar codes are dependent on the channel polarization phenomenon; presently, the research on the application of polar codes in underwater acoustic communication (UWC) is in the primary stage, and few relevant research has yet explored the underwater acoustic channel polarization phenomenon. This study extended the original channel polarization theory to the orthogonal frequency division multiplexing (OFDM) parallel UWC scenario. By simulating time-varying underwater acoustic channels in real communication environments, this study analyzed channel polarization phenomena including the distribution of the reliability parameters of the polarized subchannel and its changing law, after the incomplete channel polarization transformation, based on the Monte Carlo approximation method. Furthermore, this study investigated the effects of the underwater acoustic channel parameters, such as Doppler shift and spread, the multipath structure, and the channel time variation on the performance of the OFDM UWC system with channel polarization.