频谱相位编码OCDMA系统的误码特性研究

Bit Error Rate of Spectral Phase Encoding OCDMA Systems

本文利用中心极限定理和雅可比变换的方法 ,对频谱相位编码 (spectralphaseencoding)OCDMA系统中多址干扰和解码器输出信号的统计特性进行了研究 ,并据此推导出多址干扰和背景噪声共同作用下系统新的误码率公式 .本文还分析了系统性能与判决门限选择的关系 ,数值结果表明 :系统最佳的判决门限Rth=P0 / 2 ,在此判决门限的条件下 。

Using the central limit theorem and the Jacobian transform method, this paper studies the statistical characteristics of multiple-access interference (MAI) in spectral phase encoding optical code-division multiple access (OCDMA) systems. The statistical characteristics of the outputs of the decoders are also studied, which are then utilized to derive the bit error rate (BER) expression with the influence of both MAI and background noise. This paper also analyzes the relationship of the system performance with the decision threshold selection. The results show that the optimal decision threshold is Rth=PO/2, with which the BER is almost minimized, no matter what the user number and the signal-to-noise ratio are. With the optimal decision threshold, the BERs are calculated and analyzed for different user numbers and different signal-to-noise ratios. The numerical results reveal that the system performance can meet the need of high-speed all-optical communications.