用于FTN系统的二阶导频辅助载波相位恢复算法  

Two-Stage Pilot-Aided Carrier Phase Recovery Algorithm for FTN System

作　　者：谭伊璇 耿敏明[1,2,3,4] 赖明彬 赖凤英 苏文俊 刘嫱 张振荣 Tan Yixuan;Geng Minming;Lai Mingbin;Lai Fengying;Su Wenjun;Liu Qiang;Zhang Zhenrong(School of Computer,Electronics and Information,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Key Laboratory of Multimedia Communications and Network Technology,Nanning 530004,Guangxi,China;Key Laboratory of Multimedia Communications and Information Processing of Guangxi Higher Education Institutes,Nanning 530004,Guangxi,China;Guangxi Experiment Center of Information Science,Guilin 541004,Guangxi,China)

机构地区：[1]广西大学计算机与电子信息学院,广西南宁530004 [2]广西多媒体通信与网络技术重点实验室,广西南宁530004 [3]广西高校多媒体通信与信息处理重点实验室,广西南宁530004 [4]广西信息科学实验中心,广西桂林541004

出　　处：《光学学报》2023年第3期31-39,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61741504,61965003,61661004);广西自然科学基金(2018GXNSFAA294133)。

摘　　要：针对超奈奎斯特系统引入的码间干扰使载波相位估计难度增大的问题,提出了一种二阶电域导频辅助载波相位估计方案,将导频辅助相位噪声补偿模块与基于Viterbi的最大似然相位估计模块级联,牺牲约1.7%的带宽开销,可以有效克服超奈奎斯特系统引入的码间干扰,对激光器线宽导致的相位噪声进行准确估计。在调制格式为16进制正交幅度调制的超奈奎斯特系统中,经仿真验证可知:该算法在加速因子不超过Mazo极限时可以有效跟踪相位噪声;在加速因子低至0.833、误码率为2×10^(-2)、光信噪比代价为1 dB的条件下,该算法能容忍的最大线宽乘积为5×10^(-4);相较于一阶导频辅助载波相位恢复算法,该算法具有更大的线宽容忍度,所需的光信噪比也更小。Objective The largescale commercialization of 5G networks promotes the development of fiber optical communication,cloud computing,and Internet of Things technologies.To realize the optical communication systems with high capacity and high spectrum efficiency,higherorder modulation formats are required.However,the higherorder modulation formats require high signaltonoise ratios(SNR)to ensure communication quality,which will limit the transmission distance.Within the same amount of time,the fasterthanNyquist(FTN)technology can transmit more signals than the Nyquist system with the same modulation format.Thus,this technology becomes a key technology for the nextgeneration optical communication networks with the advantages of high spectral efficiency and large capacity.The intersymbol interference is artificially introduced into the FTN system to make the symbol interval between two adjacent pulses much smaller than the corresponding Nyquist symbol period.Thus,highspeed digital signal processing(DSP)unit,which can equalize and compensate the signal impairments efficiently in electrical domain,is a key module in FTN systems.It can improve the signal quality and support the optical fiber communication systems with ultrahigh capacity.Pilotaided carrier phase recovery(PACPR)is an important DSP algorithm for optical receiver,which is used to compensate the frequency deviation between the lasers on both sides of the transceiver and the phase noise generated by the laser linewidth.In present study,we report a twostage electricdomain pilotaided carrier phase estimation algorithm,named PAViterbiML,in which the PACPR algorithm is combined with the Viterbibased maximum likelihood(ML)estimation algorithm.The simulation results verify that the proposed twostage PAViterbiML algorithm can effectively track the phase noise when the Mazo limit is not exceeded in the FTN16QAM system.Methods The proposed PAViterbiML,which combines the PACPR algorithm with the Viterbibased maximum likelihood estimation algorithm,can effectively overcome

关 键 词：光通信 相干通信 超奈奎斯特技术 载波相位恢复 导频辅助相位估计算法 VITERBI 

分 类 号：TN914[电子电信—通信与信息系统]