基于CNN-SPGD算法的相干光通信像差校正方法研究  

Research on aberration correction method of coherent optical communication based on CNN-SPGD algorithm

作　　者：刘维[1] 徐珺楠 金玳冉 石文孝[1] 曹景太[1,2] LIU Wei;XU Junnan;JIN Dairan;SHI Wenxiao;CAO Jingtai(College of Communication Engineering,Jilin University,Changchun 130012,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]吉林大学通信工程学院,吉林长春130012 [2]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《光学精密工程》2022年第6期743-754,共12页Optics and Precision Engineering

基　　金：国家自然科学基金青年科学基金项目(No.62001448)。

摘　　要：为了降低大气湍流对自由空间光通信系统传输性能的影响,建立了一套自适应光学校正系统来校正高阶像差。对该系统的混频效率,误码率和迭代次数等参数进行研究。首先,将图像的Zernike系数划分为8个大类,256个小类,通过CNN模型预测输入光斑的大类。对于每一小类的像差,取每一阶系数范围的中点作为标准点形成一个标准Zernike系数向量,按照其对应的标准电压作为初始校正电压进行校正。实验结果表明:随机并行梯度下降算法使混频效率达到0.80、0.85和0.9需要的迭代次数分别为110次、161次和280次;在使混频效率达到相同值的前提下,CNN-SPGD(Convolutional Neural Networks-Stochastic Parallelism Gradient Descent)算法所需的迭代次数分别为4次、37次和141次。而在相同的迭代次数下,CNN-SPGD算法在系统中的混频效率更高,误码率更低。CNN-SPGD算法与SPGD算法相比,像差校正速度更快。该CNN-SPGD算法可以大幅度减少传统自适应光学系统的迭代次数,满足激光通信的各种需求。In order to reduce the influence of atmospheric turbulence on the transmission performance of free-space optical communication systems,an adaptive optical correction system is established to correct high-order aberrations. The mixing efficiency,bit error rate,and iteration times of the system are studied.First,the Zernike coefficient of the image is divided into 8 categories and 256 sub-categories,and the categories of input spots are predicted by a CNN model. For each small class of aberrations,the midpoint of the coefficient range of each order is taken as the standard point to form a standard Zernike coefficient vector,and its corresponding standard voltage is taken as the initial correction voltage. The experimental results show that the number of iterations required by the SPGD algorithm to achieve mixing efficiencies of 0. 80,0. 85,and 0. 9 is 110,161,and 280,respectively. To reach the same mixing efficiencies,the number of iterations required by the CNN-SPGD algorithm is 4,37,and 141. For the same number of iterations,the mixing efficiency of the CNN-SPGD algorithm in the system is higher and the bit error rate is lower. Moreover,the CNN-SPGD algorithm has a faster aberration correction speed compared to the SPGD algorithm. The CNN-SPGD algorithm can considerably reduce the number of iterations required by traditional adaptive optics systems and meet the various needs of laser communication.

关 键 词：自由空间光通信 无波前传感 混频效率 误码率 

分 类 号：O436[机械工程—光学工程]