基于LDPC编码的双工逆向调制自由空间光通信系统  

LDPC-coded duplex modulating retro-reflector free-space optical communication systems

作　　者：陈天宁 杨国伟[1] 毕美华[1] CHEN Tian-ning;YANG Guo-wei;BI Mei-hua(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310016,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310016

出　　处：《光电子．激光》2020年第7期753-760,共8页Journal of Optoelectronics·Laser

基　　金：浙江省自然基金项目(LY20F050004);教育厅一般科研项目(Y201942104)资助项目。

摘　　要：在逆向调制(modulating retro-reflector,MRR)自由空间光通信(free-space optical,FSO)系统中,激光信号在传输过程中受到双程大气湍流的严重影响,导致系统误码率性能恶化。本文提出采用低密度奇偶校验编码(low density parity check,LDPC)方法来降低MRR FSO通信系统的误码率,并且尝试使用微角锥棱镜阵列(microcorner cube retroreflector arrays,MCCRA)来改善MRR FSO信道的传输稳定性。本项研究中搭建了MRR FSO通信实验平台,进行了基于LDPC编码的频分双工MRR FSO通信实验。实验结果表明使用LDPC编码的MRR FSO系统增益约为3 dB,使用微角锥棱镜阵列作为MRR FSO反射器件能够通过补偿大气湍流引起的相位畸变来提升系统性能。结果还证明了LDPC编码相较于MCCRA,更能够提升MRR FSO系统的误码率性能。由此可见,将LDPC编码方式与微角锥棱镜阵列结合运用于MRR FSO系统能获得更加优化的系统性能。In a modulation retro-reflector free-space optical(MRR FSO) system,the laser signal is severely affected by two-way atmospheric turbulence during transmission,causing the system′s bit error rate performance to deteriorate.This paper proposes to adopt a low-density parity check(LDPC) method to reduce the bit error rate of the MRR FSO communication system.At the same time,experiments have also tried to use microcorner cube retroreflector arrays(MCCRA) to improve the transmission stability of MRR FSO channels.In this study,we built MRR FSO communication experiment platform,and we did a frequency division duplex MRR FSO communication experiment based on LDPC coding.The experimental results show that the MRR FSO system using the LDPC coding method has a gain of about 3 dB compared to the system using the common coding method and the use of a micro-corner prism array as the MRR FSO reflective device can resist the effect of atmospheric turbulence on the laser signal to a certain extent.The results also prove that LDPC coding can improve the bit error rate performance of MRR FSO system more than MCCRA.It can be seen that the combination of the LDPC coding method and the microcorner cube retroreflector arrays used in the MRR FSO system can obtain more optimized system performance.

关 键 词：自由空间光通信 逆向调制 大气湍流 低密度奇偶校验编码 微角锥棱镜阵列 

分 类 号：TN929.12[电子电信—通信与信息系统]