Iterative polar coded OFDM-based underwater acoustic communication

Underwater communication and networking technologies are essential for exploring marine life, extracting subsea resources, and conducting national defence missions. However, underwater communications face significant challenges due to the complexity of underwater acoustic channels, leading to delays and reduced reliability. Recent studies have demonstrated that polar coding is highly effective in improving performance, when applied to underwater acoustic communications using Orthogonal Frequency Division Multiplexing (OFDM). However, the iterative turbo-detection capability of polar codes has not been utilized for underwater acoustic communication. In this paper, we propose and analyze an iterative polar-coded OFDM scheme for a time-varying underwater acoustic communication system. The performance of the proposed scheme is compared to that of a system employing the Recursive Systematic Convolutional (RSC)channel decoder. Furthermore, to characterize the proposed system, Extrinsic Information Transfer (EXIT) charts have been utilized to analyze the convergence behaviour of the iterative system considered. Our simulation results show that both the soft-decision Soft Cancellation (SCAN) and the hard-decision Successive Cancellation List (SCL) polar decoding algorithm scan outperform the RSC decoding, providing approximately 7dB and 9 dB gain at a bit error rate (BER) of 10−4, respectively, when communicated over a time-varying underwater acoustic channel.