基于三次样条插值的M-QAM载波相位估计  

Carrier phase estimation of M‑QAM based on cubic spline interpolation

作　　者：陈睿 李传起 周省邦 陈东 陆叶[4] 刘志强 曾倩[1,2] 崔冰琪 CHEN Rui;LI Chuanqi;ZHOU Shengbang;CHEN Dong;LU Ye;LIU Zhiqiang;ZENG Qian;CUI Bingqi(Guangxi Key Laboratory of Information Functional Materials and Intelligent Information Processing,Nanning Normal University,Nanning 530001,China;Smart Logistics Industry School of Nanning Normal University,Demonstrative Modern Industrial School of Guangxi University,Nanning 530001,China;The 34th Research Institute,China Electronics Technology Group Corporation,Guilin 541004,China;College of Electronic and Information Engineering,Guangxi Normal University,Guilin 541004,China)

机构地区：[1]南宁师范大学广西信息功能材料与智能信息处理重点实验室,广西南宁530001 [2]广西普通本科高校示范性现代产业学院,南宁师范大学智慧物流产业学院,广西南宁530001 [3]中国电子科技集团公司第三十四研究所,广西桂林541004 [4]广西师范大学电子与信息工程学院,广西桂林541004

出　　处：《量子电子学报》2024年第4期679-689,共11页Chinese Journal of Quantum Electronics

基　　金：广西省研究生教育创新计划项目(YCSW2022396)。

摘　　要：在基于高阶调制的相干光通信传输系统中,接收端信号受相位噪声干扰会对系统性能产生直接的影响。传统的盲相位搜索(BPS)算法具有较高的线宽容差,适用于多种调制格式,但随着调制阶数的增加,用于BPS的测试相位数量会急剧加大。针对M元正交振幅调制(M-QAM)格式,本研究提出了一种新的低复杂度载波相位估计(CPE)算法。首先利用BPS算法,得到B个测试相位和平均欧氏距离之间的关系;然后在此基础上,提出了一种基于三次样条插值(CSI)的两级BPS载波相位估计算法,得到(2B−1)个等间隔插值相位和平均欧氏距离之间的光滑曲线关系;最后取曲线的最小值处所对应的相位值为最优相位估计值。仿真结果表明,在使用少量测试相位的前提下,通过CSI算法可以有效地对载波相位进行恢复,与BPS算法相比,CSI算法乘、加法器计算复杂度分别降低了38%和42%(16-QAM),为载波相位恢复提供了新思路。In coherent optical communication transmission systems based on higher-order modulation,the signal at the receiver side is subject to phase noise interference,which has a direct impact on the system performance.The conventional blind phase search(BPS)algorithm has high line tolerance and is suitable for a variety of modulation formats.However,as the modulation order increases,the number of test phase used for BPS will sharply increase.A new low-complexity carrier phase estimation(CPE)algorithm is proposed in this work for M-ary quadrature amplitude modulation(M-QAM)format.Firstly,the relationship between the B test phase and the average Euclidean distance is obtained using the BPS algorithm.Then,a carrier phase estimation based on a two-stage BPS with cubic spline interpolation(CSI)is proposed,and the smooth curve relationship between the(2B−1)equally spaced interpolated phase and the average Euclidean distance is obtained.Finally,the phase value corresponding to the minimum of the curve is taken as the optimal phase estimation value.The simulation results show that with a small number of test phases,the carrier phase can be effectively recovered by the CSI algorithm,and compared with that of the BPS algorithm,the computational complexity of multiplier and additive of the CSI algorithm is reduced by 38%and 42%(16-QAM)respectively,which provides a new idea for carrier phase recovery.

关 键 词：光通信 载波相位估计 三次样条插值 线宽容差 计算复杂度 

分 类 号：TN929.11[电子电信—通信与信息系统]