大气湍流影响下基于自适应判决门限的逆向调制自由空间光通信系统误码率性能分析  

Bit Error Rate Performance for Modulating Retro-Reflector Free Space Optical Communication System Based on Adaptive Threshold under Atmospheric Turbulence

作　　者：李晓燕[1] 张鹏[1,2] 佟首峰[1] Li Xiaoyan;Zhang Peng;Tong Shoufeng(National and Local Joint Engineering Research Center of Space Optoelectronics Technology, Changchun University of Science and Technology, Changchun, Jilin 130022, China;School of Optoelectronic Engineering, Changchun University of Science and Technology, Changchun, Jilin 130022, China)

机构地区：[1]长春理工大学空间光电技术国家地方联合工程研究中心,吉林长春130022 [2]长春理工大学光电工程学院,吉林长春130022

出　　处：《中国激光》2018年第6期155-164,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(61705019;91438204);吉林省青年人才托举工程(2017-2018);吉林省优秀青年人才基金(20170520161JH)

摘　　要：推导了最优误码率(BER)性能对应的判决门限计算公式,并在此判决门限基础上,推导出大气湍流影响下基于自适应判决门限的逆向调制(MRR)自由空间光通信(FSOC)系统BER解析表达式,推导过程考虑了判决门限本身的干扰和探测器噪声的影响。根据所推导的表达式,仿真研究自适应判决门限参数和调制消光比对BER的影响,仿真结果表明:自适应判决门限系统BER性能优于固定判决门限17.5dB(误码率为10-5,弱湍流),并且当训练数据比特位数大于3时,自适应判决门限系统的BER性能与根据瞬时信道状态信息计算判决门限系统的BER性能相近。Evaluation for decision threshold corresponding to the minimum bit error rate（BER）of modulating retroreflector（MRR）free space optical communication（FSOC）system is presented.And based on this threshold,the closed form expression of the BER for MRR FSOC system is obtained,considering the effects of adaptive threshold noise and photodetector noise.According to the derived expressions,the effects of adaptive decision threshold parameters and modulation extinction ratio on BER are analyzed.Results show that the BER of MRR FSOC system with adaptive threshold precedes to that with fixed threshold 17.5 dB（BER is 10-5,weak turbulence）,and when the number of training data bits is greater than 3,the BER performance of the adaptive decision threshold system is similar to the BER performance of the decision threshold system based on instantaneous channel state information.

关 键 词：光通信 自由空间光通信 逆向调制器 自适应判决门限 大气湍流 误码率 

分 类 号：TN929.1[电子电信—通信与信息系统]