Construction and performance analysis of variableweight optical orthogonal codes for asynchronous OCDMA systems  

作　　者：李传起 杨梦婕 张秀容 陈美娟 贺冬冬 范庆斌 

机构地区：[1]Electronic Engineering College,Guangxi Normal University

出　　处：《Optoelectronics Letters》2014年第4期290-294,共5页光电子快报（英文版）

基　　金：supported by the University Nature Science Fund of Guangxi Province(No.2010 MS018);the Guilin Scientific Research and Technological Development Program Topics(No.20120104-18)

摘　　要：A construction scheme of variable-weight optical orthogonal codes(VW-OOCs) for asynchronous optical code division multiple access(OCDMA) system is proposed. According to the actual situation, the code family can be obtained by programming in Matlab with the given code weight and corresponding capacity. The formula of bit error rate(BER) is derived by taking account of the effects of shot noise, avalanche photodiode(APD) bulk, thermal noise and surface leakage currents. The OCDMA system with the VW-OOCs is designed and improved. The study shows that the VW-OOCs have excellent performance of BER. Despite of coming from the same code family or not, the codes with larger weight have lower BER compared with the other codes in the same conditions. By taking simulation, the conclusion is consistent with the analysis of BER in theory. And the ideal eye diagrams are obtained by the optical hard limiter.A construction scheme of variable-weight optical orthogonal codes （VW-OOCs） for asynchronous optical code division multiple access （OCDMA） system is proposed. According to the actual situation, the code family can be obtained by programming in Matlab with the given code weight and corresponding capacity. The formula of bit error rate （BER） is derived by taking account of the effects of shot noise, avalanche photodiode （APD） bulk, thermal noise and surface leakage currents. The OCDMA system with the VW-OOCs is designed and improved. The study shows that the VW-OOCs have excellent performance of BER. Despite of coming from the same code family or not, the codes with larger weight have lower BER compared with the other codes in the same conditions. By taking simulation, the conclusion is consistent with the analysis of BER in theory. And the ideal eye diagrams are obtained by the optical hard limiter.

关 键 词：OCDMA系统 光正交码 性能分析 异步 误码率性能 雪崩光电二极管 光码分多址 结构 

分 类 号：TN929.1[电子电信—通信与信息系统]