相干光FBMC-OQAM系统的时间偏移和信道联合估计算法  

Joint Estimation Algorithm of Time Offset and Channel Response for Coherent Optical FBMC-OQAM Systems

作　　者：刘俊杰 王道斌[1] 拓明珊 王伟[1] 元丽华[1] 曹明华[2] 王惠琴[2] Junjie Liu;Daobin Wang;Mingshan Tuo;Wei Wang;Lihua Yuan;Minghua Cao;Huiqin Wang(School of Science,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;School of Computer and Communication,Lanzhou University of Technology,Lanzhou,Gansu 730050,China)

机构地区：[1]兰州理工大学理学院,甘肃兰州730050 [2]兰州理工大学计算机与通信学院,甘肃兰州730050

出　　处：《中国激光》2020年第11期186-195,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(61367007,61875080,61861026);甘肃省自然科学基金(17JR5RA123)

摘　　要：针对交错正交幅度调制的相干光滤波器组多载波通信系统,提出了一种新型联合估计算法。该算法通过对训练序列进行特殊的设计,同时完成了时间同步与信道估计任务,有效地提高了频谱效率。首先,根据相干光滤波器组多载波系统模型,仔细推导了时域波形的共轭对称性条件。在此基础上,提出了一种时间同步方法,该方法将伪随机序列与共轭对称性结合,提高了时间同步的准确性。然后,利用双相关导频原理进行信道估计,该方法既能规避固有虚部干扰的影响,同时又能保持时域波形的共轭对称性。最后,通过搭建数值仿真平台,研究了该系统的传输性能,仿真结果表明该算法可以有效地完成对时间同步和信道响应的联合估计任务。An innovative joint estimation algorithm for coherent optical filter bank-based multicarrier systems with offset quadrature amplitude modulation was proposed.The training sequence design enables simultaneously time synchronization and channel estimation.Thus,the proposed algorithm effectively improves spectral efficiency.First,the conjugate symmetry condition of the time domain waveform was derived from the system model.Based on the derived condition,a time synchronization method was proposed.The proposed method combines the pseudo-random sequence with conjugate symmetry to improve time synchronization accuracy.Then,channel estimation was performed based on the principle of dual-dependent pilots.The method avoids the impact of intrinsic imaginary interference and maintains the conjugate symmetry of the time domain waveform.Finally,numerical simulations were performed to investigate the system''s transmission performance.The simulation results demonstrate that the proposed algorithm can effectively accomplish joint estimation of the time offset and channel response.

关 键 词：光通信 滤波器组多载波通信系统 交错正交幅度调制 双相关导频 时间同步 信道估计 伪随机序列 

分 类 号：TN913.7[电子电信—通信与信息系统]