光码分多址技术教学中光正交码的优化设计方案

The Optimization Design Program of Optical Orthogonal Code in the Teaching of OCDMA

本文根据正交码拚(L,w,λa,1)互相关值的分布,结合信噪比(SIR)与误码率(BER)公式推出码集拚(L,w,λa,1)的码重w的取值范围,在复合函数的增减性基础上给出码重(w)、并发用户(k)与BER之间的关系,最后在误码率小于10-9时给出正交码系统拚(L,w,1)在固定码长L下的优化设计方案,以及系统在K值固定且有码字容量约束的情况下选取的正交地址码方案,并给出了其优化设计对应的数学表达式。

This paper starts from giving the cross-correlation val-ues distribution of orthogonal codeφ （L,w,λa,1）., and then the weightrange of the codewordφ （L,w,λa,1） is given from signal noise ratio （SNR） and the bit error rate （BER） formula, further-more, the relationship of ,w k and BER is gotten on the basis of the add/drop performance of composite function. In the end, the optimization design of optical orthogonal code of the length-fixed orthogonal code system is given under the bit error rate of less than , and moreover, the selected optimal design program of the optical orthogonal code system is given under the value of a fixed codeword capacity constraint, and then the corresponded mathe-matical expression of the optimum design program is finally giv-en.