Based DS/FH Hybrid OCDMA/WDM Networks

Optical code-division multiple access (OCDMA) technology is a spread spectrum technique which combines optical fiber communications with CDMA technique, which allows all of communication development at present and in the future: asynchrony, high-speed, broad-band, reliability. It will play an important role in the processof all-optical networks. With the optical code division multiplexing and optical wavelength division multiplexing (WDM) network composed of mixed and it applied to the local area network are the most promising trends in OCDMA development.This paper do some research by analyzing and finishing the previous work on iris recognition, and propose some new ideas in hybrid WDM/OCDMA system topology and OCDMA code technology feature extraction.First of all, in the presence of a variety of network topology analysis and comparison of the premise, is proposed OCDMA/WDM network based on the mixed tree and ring topology. It describes the operation of the network, the network node bifurcation optical multiplexer ports up and down road conditions.Second, for the system to increase the code word with code weight and code length also increased the problem, this paper introduces DS-OCDMA, FH-OCDMA spreading code. The hybrid DS/FH code structure is based fiber delay line and fiber grating-based code. That effectively solve the word problem in the system code, because the coding of the system in time domain and frequency domain simultaneously.Finally, based on hybrid DS/FH code technology, the establishment of a hybrid OCDMA/WDM network model. Then the system through the Matlab simulation model to compare and analyze the performance of the hybrid OCDMA/WDM systems. After that, the experiment proved the feasibility of the hybrid network system has. The hybrid DS/FH code technology can effectively solve the address code constraints. The hybrid OCDMA/WDM and the pure OCDMA more than mere practicality.