基于光码柱面的二维地址码相关性分析和码字容量研究

Optical code-cylinder based analysis of correlation and carnality of 2-D signature codes for OCDMA

在谱域和时域同时编码的二维OCDMA系统是增加系统容量的主要方案。在一维光码盘和光码环的基础上,设计出直观描述二维λ-t地址码的几何装置-二维光码柱面,直观便捷地描述二维码字结构,给出基于光码柱面的二维码码字相关性分析方法。并根据光码柱面,建立了在光码集本身导出二维码码字容量的分析理论。所得结果与直接引用电通信中的Johnson界得出的结果一致。因此,二维光码柱面给二维的相关性分析和码字容量研究提供了便捷有效的工具。

The main method to enhance the system capacity of OCDMA networks is coding user＇s data in both time and spectral domains. Based on the I-D optical code-pattern and code-hoop, a new geometrical device is designed, called optical code-cylinder, to denote the wavelength-time 2-D optical signature codes, from which the scheme of correlation checking of 2-D signature code family is given. Then based on the optical code-cylinder, the analytical theory of maximum system capacity of 2-D OCDMA system is established in detail. The results from code-cylinder are concordant with thoses of Johnson bound of correcting code. So, the code-cylinder method is ugeful and convenient tool for the performance analysis of 2-D signature code.