脉宽对光码分多址编解码器性能的影响

光码分多址系统中,光编解码是影响系统性能的关键因素之一。给出了低折射率相移超结构光纤光栅(SSFBG)光码分多址编解码器的数学模型,采用自相关峰旁瓣比(P/W)、自互相关峰比(P/C)两个参量作为衡量编解码器性能的主要指标,仿真研究了不同脉宽及不同光栅(码片)长度条件下超结构光纤光栅编解码器的性能,得到了编解码器的P/W、P/C随输入脉冲宽度及编解码器长度的变化曲线。从对编解码器性能仿真分析的结果可以看出,当光源脉宽与编解码器的长度满足一定的匹配条件时,可获得较理想编解码效果,即可以根据输入脉冲的宽度来选择长度合适的编解码器,从而获得较好的系统的性能。

Study of Pulse Width Effect on Performance of Optical Code-Division Multiple-Access En/Decoder

Optical en/decoder is one of the key factors affecting the performance of optical code-division multiple-access(OCDMA) system.The mathematical model of OCDMA en/decoder based on phase-shifted superstructured fiber Bragg grating(SSFBG) with low reflectivity is presented,and the performance of SSFBG en/decoder is investigated with different input pulse width as well as grating chip length.Here,the auto-correlation ratios of PA to the maximum wing level(P/W) and cross-correlation level(P/C) are used to quantitatively evaluate the en/decoder performance,and the curves of the relationship between P/W,P/C and pulse width as well as the grating chip length are obtained.From the analysis of simulation result,we can see when the pulse width and grating chip length meet some condition,optimum en/decode performance can be obtained,namely,an appropriate grating chip length en/decoder can be selected accroding to input pulse width,which can result in a better system performance.