一种基于星座恢复的相干光OFDM系统非线性抑制方法  

Method for fiber nonlinearity mitigation in coherent optical OFDM systems based on constellation restoration

作　　者：冷丹 郝耀鸿 

机构地区：[1]解放军特种作战学院,广东广州510502

出　　处：《应用光学》2015年第1期150-154,共5页Journal of Applied Optics

基　　金：国家自然科学基金(60871075);江苏省自然科学基金(Bk2012508)

摘　　要：鉴于相干光正交频分复用系统(CO-OFDM)易受非线性效应影响,严重制约系统传输性能,提出一种基于星座恢复的降低系统峰均值功率比(PAPR)的方法。对系统模型及作用机理进行分析,仿真结果显示,以10Gbit/s的速率通过单模光纤传输720km,基于星座恢复的CO-OFDM系统Q值较无非线性抑制的CO-OFDM系统有3dB提高;另外,系统最佳限幅比例系数受色度色散影响,随着色散因子的增大,星座恢复效果也逐渐减弱,在传输240km条件下,色散因子为12ps/nm·km较6ps/nm·km,限幅比例系数从0.9降低至0.8。Coherent optical orthogonal frequency division multiplexing (CO‐OFDM ) system is sensitive to nonlinearity because of high peak‐to‐average power ratio (PAPR) and closely‐packed subcarriers ,w hich seriously suppresses the transmission performance .A method for re‐ducing the PAPR was put forward based on constellation restoration ,the system model and ac‐tion mechanism were analyzed .Analyses and simulation results show that ,the system Q value of constellation restoration based CO‐OFDM system is improved by about 3 dB for 720 km dis‐tance at a speed of 10 Gbit/s transmission through standard‐single‐mode fiber (SSM F ) ,com‐pared with the CO‐OFDM system without nonlinearity suppression .Meanwhile ,the clipping factor is strongly influenced by the chromatic dispersion w hich can decrease the effect of con‐stellation restoration .At the length of 240 km ,the clipping factor is 0 .9 and 0 .8 ,while the dispersion factor is 12 ps/nm · km and 6 ps/nm · km ,respectively .

关 键 词：相干光通信 正交频分复用 峰均值功率比 星座恢复 

分 类 号：TN929.11[电子电信—通信与信息系统]