中国激光, 2020, 47 (11): 1106001, 网络出版: 2020-10-28
相干光FBMC-OQAM系统的时间偏移和信道联合估计算法 下载: 809次
Joint Estimation Algorithm of Time Offset and Channel Response for Coherent Optical FBMC-OQAM Systems
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 optical communications filter bank-based multicarrier system offset quadrature amplitude modulation dual-dependent pilots time synchronization channel estimation pseudo-random sequence
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。
Abstract
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.
刘俊杰, 王道斌, 拓明珊, 王伟, 元丽华, 曹明华, 王惠琴. 相干光FBMC-OQAM系统的时间偏移和信道联合估计算法[J]. 中国激光, 2020, 47(11): 1106001. Liu Junjie, Wang Daobin, Tuo Mingshan, Wang Wei, Yuan Lihua, Cao Minghua, Wang Huiqin. Joint Estimation Algorithm of Time Offset and Channel Response for Coherent Optical FBMC-OQAM Systems[J]. Chinese Journal of Lasers, 2020, 47(11): 1106001.