单载波数字相干接收系统中基于导频的自适应色散补偿技术(英文)  

Fast and Accurate Adaptive Chromatic Dispersion Compensation Method Utilizing Pilot Tones for Digital Coherent Single Carrier Systems

作　　者：徐梦然 方晓之[1,2,3] 崔晟[1,2,3] 

机构地区：[1]下一代互联网接入系统国家工程实验室 [2]华中科技大学光学与电子信息学院 [3]武汉国家光电实验室,武汉430074

出　　处：《光子学报》2014年第7期84-88,共5页Acta Photonica Sinica

基　　金：2013 Major National Development of Special Equipment(No.2013YQ160487);2013 Beijing University of Post and Communication 863 Program(Nos.2013AA013403,2012AA010407);the Natural Science Foundation fo China(No.61007043)

摘　　要：提出一种用于单载波数字相干光通信系统的自适应色散补偿方法.在发射机端,利用强度光调制器在光信号两侧加入脉冲幅度调制导频光信号.搜索信号谱的峰值确定光信号两侧的PAM-PTs线状谱.在色散估计之前,通过其中一个PAM-PTs的频率漂移来估计激光器发射频偏,并将信号谱线沿着频率轴反向平移,补偿发射频偏,实现信号谱频域均衡.在接收机端,利用幅度脉冲调制导频信号脉冲时延估计色散大小,在色散补偿之前通过幅度脉冲调制导频信号频移补偿,并消除接收机本振频偏对频域色散补偿的影响.最终,幅度脉冲调制导频的光场信息被充分用来精确进行色散估计和色散补偿.数值仿真表明:每次色散估计的误差小于±65ps/nm,而且距离从200km到1 000km之间的平均色散估计误差小于±10ps/nm.该方法色散补偿精度高,计算量小.A novel adaptive chromatic dispersion（CD）compensation method was proposed for digital coherent single carrier systems.Two pulse amplitude modulated pilot tones（PAM-PTs）were inserted at both sidebands of the signal in the transmitter.The two line spectra of the PAM-PTs can be found by searching the spectrum peaks in the upper and lower sideband.Before CD estimation（CDE）,the laser frequency offset（LFO）can be directly estimated from the frequency drift of one of the PAM-PTs.Then the signal spectrum was shifted on the reverse of the frequency axis to adjust the received spectrum of OFDE and compensate LFO.After that,the relative time delay between the two line spectra of the PAM-PTs was recovered at the receiver and used for CD estimation,while the frequency of the PAM-PT recovered was used for spectrum pre-adjustment of frequency domain CD equalization,Therefor by using this method,the field information of the PAM-PTs was fully utilized for accurate CDE and CDC.Numerical simulations show that the CDE error is less than ±65ps/nm for single time CDE and the averaged error is below±10ps/nm for all the distances from 200to 1 000km.The method enables much faster and more accurate CD adaptive compensation and reduces computational complexity.

关 键 词：相干通信 色散估计 自适应补偿 色散频域均衡 反馈控制 

分 类 号：O438[机械工程—光学工程] TN914[理学—光学]