双硬限幅器异步光码分多址系统误码性能分析

Bit Error Performance Analysis of Asynchronous OCDMA Systems with Double Optical Hard-limiter

针对基于单硬限幅器(OHL)异步光码分多址(OCDMA)系统的解码器不能完全消除信道串扰产生的误码,提出了具有双OHL的解码器结构来优化系统传输性能。通过数值分析给出了地址码(光正交码,OOC)的码长、码重、用户数与系统误码率的关系,结果表明:双OHL异步OCDMA系统误码率相对于单OHL系统误码率下降明显,系统传输性能得到改善。

The decoder with double optical hard-limiters（OHL） is proposed to optimize the transfer performance based on asynchronous OCDMA systems. The bit error probability of the optical asynchronous systems with the single OHL was reduced lightly by relating to the systems without OHL. This is because the bit error which is produced by channel interference is not eliminated completely by the decoder with the single OHL. Through numerical analysis, this paper presents the relations of signature sequence codes（optical orthogonal codes, OOC＇s）, code length, code weight and the system＇s bit error probability. The result demonstrates that the decoder with double OHL has much better performance than that with single OHL.