一种基于限幅的降低相干光OFDM系统非线性效应的方法  

A method for fiber nonlinearity mitigation by signal clipping in coherent optical OFDM system

作　　者：郝耀鸿[1] 李玉权[2] 王荣[2] 黄卫卫[1] 李波[1] 

机构地区：[1]军事体育进修学院,广东广州510502 [2]解放军理工大学通信工程学院,江苏南京210007

出　　处：《电路与系统学报》2012年第5期115-119,共5页Journal of Circuits and Systems

基　　金：国家自然科学基金(60871075)

摘　　要：相干光正交频分复用系统(Coherent Optical-orthogonal frequency division multiplexing,简称CO-OFDM)可有效降低光纤色散效应,是近年来光传输领域研究热点之一。由于OFDM信号具有较高的峰均值功率比(Peak-to-average Power Ration,PAPR)和较窄的载波间隔,系统对非线性效应十分敏感,严重影响传输性能。文章介绍了一种基于信号限幅的CO-OFDM系统,通过载波选择和信号限幅,有效提高系统非线性容限,同时消除限幅噪声带来的影响。理论分析和仿真结果表明,在不需任何在线色散补偿条件下,基于限幅的CO-OFDM系统在单模光纤中传输960km,系统Q值较传统CO-OFDM系统有2dB提高,可完全消除限幅噪声影响。Abstract： Coherent optical orthogonal frequency division multiplexing （CO-OFDM） has drawn significant attention in optical transmissions due to its resilience to fiber chromatic dispersion （CD） with computation efficiency. CO-OFDM system is sensitive to nonlinearity, because of the high peak-to-average power ratio （PAPR） and the closely-spaced subcarriers. A new technique for using clipped OFDM signal in long-haul Coherent Optical 0FDM system （Clipped CO-OFDM） to mitigate fiber nonlinear effects is presented. Clipped OFDM is generated by clipping conventional CO-OFDM signal at zero and selects the odd subcarriers to carry data. With such a scheme, simulation demonstrates that Clipped CO-OFDM is to be able to increase the nonlinear threshold and system Q value is substantially improved more than 2dB at a reach of 960km.

关 键 词：相干光通信 光纤非线性 信号限幅 正交频分复用 

分 类 号：TN929[电子电信—通信与信息系统]