摘要
提出了一种基于改进的latin方阵光正交码(MLSOOC)、适合光谱幅度编码(SAC)光码分多址(OCDMA)系统的地址码构造方法,码字间有理想的互相关,容量达到了SAC的上限。分析了SAC编解码的原理、光纤Bragg光栅(FBGs)谱幅编解码的工作过程及在考虑相位引起的强度噪声(PIIN)、热噪声和散弹噪声情况下的系统信噪比(SNR)和误码率(BER)。结果表明:在光源和信道理想条件下,多址干扰(MAI)可以消除;在考虑噪声的情况下,可以有效抑制PIIN减小BER;在满足一定BER下,系统承载的同步上路用户多容量比用Had-amard码大大增加。
A new code structure for spectral-amplitude-coding（SAC） optical CDMA system based on modified LSOOC（MLSOOC） was proposed. It has an ideal in-phase cross correlation（CC） and reaches the upper bound. The structure based on fiber Bragg gratings spectral encoder/decoder was proposed. The principle analysis of SAC based spectral encoder/decoder and the characteristic anlalysis of the new code have been done. We also analysed the SNR and BER by taking into account the effects of phase-induced intensity noise（PIIN） ,shot noise,thermal noise and dark current noise. Our results reveal that MAI can be canceled at an ideal source and channel and the new code can effectively suppress the intensity noise. For a stated BER, the total active synchronous users are increased greatly compared with that using Hadamard.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2007年第2期204-208,共5页
Journal of Optoelectronics·Laser
基金
广州市重点攻关资助项目(33105001)
