关键词: 水声通信, 正交频分复用, 极化码, 蒙特卡罗构造

Abstract:

To realize high speed and high-reliability communication in shallow water environments,the performance of polar code encoding and decoding technology in shallow water acoustic communication is studied.The Monte Carlo algorithm construction is used to complete the construction of polar codes on the time-invariant,quasi-stationary,and time-variant channel models established based on the ray acoustic theory,and the complexity and performance are compared with those of the channel polarization and channel degradation construction algorithms and the base-symmetric extended polarization weight construction algorithm.The constructed polar code is adopted as the channel coding scheme for the underwater acoustic communication system based on Orthogonal Frequency Division Multiplexing and the decoding scheme uses a Cyclic Redundancy Check-Aided Successive Cancellation List decoding algorithm.The performance of polar codes on these three channels is determined by simulation in comparison with the performance of Low-Density Parity Check codes with the same code length and code rate.Experimental results show that in these three channels and the range of the signal-to-noise ratio of interest,polar codes have a gain of about 0.5 dB ~ 1.2 dB relative to Low-Density Parity Check codes.Simulation comparison results of the three channels show that polar codes based on channel construction coding have better gain effects in harsh channel environments compared to Low-Density Parity Check codes,and that polar codes have a lower encoding and decoding complexity,which proves the competitiveness and broad application prospect of the polar code in energy and resource-limited shallow sea acoustic communication.

Key words: underwater acoustic communication, OFDM, polar codes, Monte Carlo construction