基于级联变系数训练序列和预增强技术的直接检测光OFDM系统实验研究  

Experimental research on a direct-detection optical OFDM system based on cascaded variable coefficient training sequences and pre-emphasis technique

作　　者：吴巍[1,2] 肖江南[1,2] 陈明[1,2] 余建军[1,2] 陈林[1,2] 

机构地区：[1]湖南大学信息科学与工程学院,湖南长沙410082 [2]湖南大学微纳光电器件及应用教育部重点实验室,湖南长沙410082

出　　处：《通信学报》2013年第12期149-157,共9页Journal on Communications

基　　金：国家自然科学基金资助项目(60977049);国家高技术研究发展计划("863"计划)基金资助项目(2011AA010203);湖南省自然科学基金资助项目(12JJ3070)~~

摘　　要：分析了直接检测光OFDM(DDO-OFDM)传输系统中由数模转换器和光纤链路中的光纤色散所致的OFDM信号高频衰减现象,以及经光纤传输后在光电检测时存在的子载波间互拍干扰现象。提出使用级联变系数训练序列和预增强结构的光OFDM(O-OFDM)信号来降低传输系统所受到的影响。理论分析和实验验证表明,级联变系数训练序列和预增强结构的基带OFDM信号在DDO-OFDM传输系统中,接收灵敏度比常规的交叉型训练序列结构的OFDM信号要高。说明基于级联变系数训练序列和预增强结构的O-OFDM信号的传输性能在抵抗子载波间互拍干扰(SSMI)和频率选择性衰减(FF)方面要优于常规的交叉型训练序列结构的O-OFDM信号。Frequency selective fading （FF） caused by digital to analog converter and optical fiber dispersion in optical fiber link was analysed, and signal-signal mixing interference （SSMI） when the orthogonal frequency division multiplex- ing （OFDM） signal was detected by PIN after transmitting over the fiber in direct-detection optical OFDM system. The cascaded variable coefficient training sequences and pre-emphasized configuration of O-OFDM signal were proposed to decrease the influence of the SSMI and FF. The theoretical analysis and experimental results show that the receiving sen- sitivity of the cascaded variable coefficient training sequences and pre-emphasized configuration of OFDM signal is higher than the interleaved configuration of training sequence of OFDM signal in DDO-OFDM system. It is demon- strated that the fiber transmission performance of the cascaded variable coefficient training sequences and pre-emphasized configuration of O-OFDM signal is better than the interleaved configuration of training sequence of OFDM signal in robust tolerance against SSMI and FF.

关 键 词：光正交频分复用 变系数训练序列 预增强 子载波间互拍干扰 频率选择性衰减 光传输 

分 类 号：TN929.9[电子电信—通信与信息系统]