Multiple-Length Variable-Weight Optical Orthogonal Codes for Multi-Rate Multi-Quality Optical CDMA Systems

A new class of optical signature codes; multiple-length variable-weight optical orthogonal codes (MLVW-OOC) is proposed for multi-rate multi-quality optical CDMA systems. The proposed codes are more flexible in codelength and codeweight with low correlation properties to accommodate many different types of services and many different levels of data rates in the systems. The code analysis for obtaining the exact value of maximum cross-correlation function or multiple-access interference (MAI) computation for several levels of codes is also suggested. Finally, the bit error probability performance of the proposed codes for two-level (i.e., two different lengths and weights) is evaluated analytically in this paper. The result shows that the proposed MLVW-OOC can provide differentiated performance for several combinations of rates and qualities.