自由空间光通信中极化码的应用研究  

Research on Application of Polar Codes in Free Space Optical Communication

作　　者：邢莉娟[1] 李卓[1] 王卓[1] XING Lijuan;LI Zhuo;WANG Zhuo(State Key Laboratory of Integrated Services Networks,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学空天地一体化综合业务网全国重点实验室,西安710071

出　　处：《光通信研究》2024年第3期134-139,共6页Study on Optical Communications

基　　金：国家自然科学基金资助项目(61372072);111工程基金资助项目(B08038)。

摘　　要：【目的】在自由空间光(FSO)通信中,大气湍流效应会导致通信链路性能下降。【方法】文章提出了一种极化码信道编译码方案,使用蒙特卡洛算法构造了针对FSO通信中常见的Gamma⁃Gamma分布大气湍流信道的极化码。比较了文章提出的极化码编译码方案与未编码以及相近码长的低密度奇偶校验(LDPC)码在Gamma⁃Gamma分布大气湍流信道下的误码率(BER)。【结果】仿真结果表明,所提极化码与未编码比较时,在弱湍流强度下,当信噪比>6.7 dB时,极化码方案性能相较于未编码更优;在中湍流强度下,当信噪比>10.3 dB时,极化码方案性能相较于未编码更优;在强湍流强度下,当信噪比>11.5 dB时,极化码方案性能相较于未编码更优。所提极化码与LDPC码比较时,在弱湍流情况下,当信噪比>7.1 dB时,极化码整体性能优于LDPC码;在中湍流条件下,当信噪比>10.6 dB时,极化码整体性能优于LDPC码;在强湍流条件下,当信噪比>12 dB时,极化码整体性能优于LDPC码。此外,在码长短、码率低和译码宽度小时,文章所提出的极化码编译码方案具有更优的性能。【结论】使用所提极化码编码后,有效改善了FSO通信系统中的大气湍流效应,而且在中、高湍流强度这两种恶劣的大气湍流信道环境中,文章所提方案展现出了比LDPC码更为明显的优势。表明在FSO通信中,极化码具有良好的发展前景。【Objective】In Free Space Optical(FSO)communication,atmospheric turbulence can cause a decrease in communica tion link performance.【Methods】In this paper,a polar coding channel coding scheme is proposed for this problem,and Monte Carlo algorithm is used to construct polar codes for Gamma⁃Gamma distribution atmospheric turbulence channels commonly used in FSO communication.By comparing the Block Error Rates(BER)of the proposed polar coding scheme,uncoded transmission,and Low Density Parity Check(LDPC)codes with similar code lengths under Gamma⁃Gamma distribution atmospheric turbu lence channels.【Results】The simulation results show that when the Signal⁃to⁃Noise Ratio(SNR)is greater than 6.7 dB in weak turbulence,10.3 dB in moderate turbulence,and 11.5 dB in strong turbulence,the proposed polar coding scheme performs better than uncoded transmission.Compared with LDPC codes,under weak turbulence conditions,when the SNR is greater than 7.1 dB,the overall performance of the proposed polar coding scheme is better than that of LDPC codes.Under moderate turbulence condi tions,when the SNR is greater than 10.6 dB,the overall performance of the proposed polar coding scheme is better than that of LDPC codes.Under strong turbulence conditions,when the SNR is greater than 12 dB,the overall performance of the proposed polar coding scheme is better than that of LDPC codes.In addition,it is found that when the code length is short,the code rate is low,and the decoding width is small,the proposed polar coding scheme has better performance.【Conclusion】The use of the pro posed polar coding scheme effectively improves the atmospheric turbulence effect in FSO communication systems.Moreover,in the harsh atmospheric turbulence channel environment of moderate and high turbulence intensities,the proposed polar coding scheme exhibits more obvious advantages than LDPC codes.This indicates that polar codes have good development prospects in FSO communication.

关 键 词：信道编码 自由空间光通信 极化码 Gamma⁃Gamma分布 

分 类 号：TN911.22[电子电信—通信与信息系统]