一种适用于大气弱湍流信道的极化纠错编码调制方案

针对服从对数正态分布的大气弱湍流信道模型，基于高斯近似的方法计算分析信道的极化现象，提出了一种适用于大气弱湍流信道的极化编码调制方案，并对其性能进行了仿真分析.不同湍流强度下采用串行抵消译码算法时的仿真结果表明，相比于递归构造方案，文中所提方案在达到1e-5误码率时可获得大约1.0dB到1.4dB的编码增益提升.对极化码分别采用开关键控（OOK）调制与脉冲位置调制（PPM）时的仿真结果表明，采用2-PPM的极化编码调制方案可有效提升无线光通信链路在弱湍流条件下的译码纠错性能.

A Suitable Polar Coding Modulation Scheme for Atmospheric Weak Turbulence Channel

For atmospheric weak turbulence channel model with lognormal distribution,a class of suitable polar codes was constructed based on Gaussian Approximation method.Then their error correction performance were simulated and ana-lyzed over the channel with different turbulence strengths.Simulation results show that the constructed polar codes can get 1. 0dB to 1. 4dB coding gains at 1e-5 bit error rate,rather than the heuristic recursive structural polar codes under the same successive cancellation decoding algorithm.Furthermore,the performance of polar coded On-Off Keying (OOK)modulation and Pulse Position modulation (PPM)schemes was compared.The results show that polar coded 2-PPM modulation scheme can obtain better performance under weak turbulence channel conditions.