基于动量因子DD-LMS算法在高速相干接收机中的应用  

Application of Momentum Factor DD-LMS Algorithm in High Speed Coherent Receiver

作　　者：龚闯 刘志强 陆叶[1] 周鹏[1] 武康康 李传起 GONG Chuang;LIU Zhiqiang;LU Ye;ZHOU Peng;WU Kangkang;LI Chuanqi(College of Electronic Engineering,Guangxi Normal University,Guilin Guangxi 541004,China;The No.34 Research Institute of CETC,Guilin Guangxi 541004,China;College of Physics and Electronic,Nanning Normal University,Nanning Guangxi 530001,China)

机构地区：[1]广西师范大学电子工程学院,广西桂林541004 [2]中国电子科技集团公司第三十四研究所,广西桂林541004 [3]南宁师范大学物理与电子学院,广西南宁530001

出　　处：《广西师范大学学报（自然科学版）》2022年第2期71-80,共10页Journal of Guangxi Normal University:Natural Science Edition

基　　金：广西科技计划项目重点研发计划课题(桂AB17292082)。

摘　　要：光纤中的色散是引起传输信号码间串扰(ISI)的直接原因,传统的用于均衡ISI的自适应盲均衡算法收敛速度慢、误差大,不适用于高速相干接收机。为解决该问题,本文引入动量因子,改进基于判决引导的最小均方(DD-LMS)算法用于优化光纤信道色散影响,理论推导并论证动量因子对盲均衡算法的收敛性能及误差函数的影响,同时探究不同函数的动量因子对算法的优化性能。本文在OptiSystem光仿真软件上搭建单载波传输速率224 Gib/s相干光传输系统。结果表明,相较于传统时域均衡器(TDE),在其后端添加此自适应滤波器,系统平均误码率能下降约2.5 dB。在光信噪比为15 dB、传输距离为500~1000 km的情况下,色散补偿模块误码率能稳定在10^(-2)左右,在色散信道中具有较强鲁棒性。The chromatic dispersion in the optical fiber is the direct cause of the inter-symbol interference(ISI)of the transmission signal,and the signal degradation is particularly serious when the transmission environment fluctuates.Traditional adaptive blind equalization algorithms have slow convergence speed and large errors,which are not suitable for high-speed coherent receivers.In order to solve this problem,the momentum factor is introduced to improve the decision-directed least means square(DD-LMS)algorithm to optimize the effect of fiber channel dispersion.Theoretically,the momentum factor is derived and demonstrated on the convergence performance and error function of the blind equalization algorithm.At the same time,the momentum factor of different functions is explored on the optimization performance of the algorithm.A coherent optical transmission system with a single carrier transmission rate of 224 Gib/s is built on the OptiSystem optical simulation software.The results show that,compared with the traditional time domain equalizer(TDE),adding this adaptive filter at the back end of the system can reduce the average bit error rate of the system by about 2.5 dB.When the optical signal-to-noise ratio is 15 dB and the transmission distance is 500-1000 km,the error rate of the dispersion compensation module can be stabilized at about 10^(-2),and it has strong robustness in the dispersion channel.

关 键 词：相干光接收机 色散补偿 盲均衡 DD-LMS算法 动量因子 

分 类 号：TN929.1[电子电信—通信与信息系统]