Research On OCDMA/WDM Hybrid Optical Network System

In the fiber communication industry, the traditional optical access network has been confronted with several tough problems by the geometrically expanding number of users and the numerous kinds of demands from different users. Not only the system bandwidth, but also the system security, the symmetry of up/down load speed and the flexibility of the user accessing are all under serious challenging. The optical code division multiplexing over wavelength division multiplexing (OCDM/WDM) hybrid system fully integrates the huge capacity of WDM system and the high security and flexibility of the OCDMA system, making it an extremely attractive solution for the next generation optical access network.In this thesis, we investigate the performances of OCDMA/WDM hybrid systems based on different code methods and encoder/decoders. And finally we propose a novel scheme of OCDMA/DWDM hybrid system, based on super-structured fiber Bragg gratings (SSFBG) related spectrum slicing and parallelly combined SSFBG technique. Theoretical analyses as well as system simulations are carried out, and the system feasibility is verified. The contents are outlined as follows:1. Summarize the background and key technologies of optical access network, propose the scheme of OCDMA/DWDM hybrid system based on SSFBG related spectrum slicing and parallelly combined SSFBG;2. Investigate the key technologies of OCDMA/WDM hybrid system, including OCDMA code theory, operation principle of SSFBG's encoding/decoding, and design of super-band OCDMA en/decoder based on arrayed SSFBG;3. Analyze and simulate the system performance of OCDMA/DWDM optical access network system, in which the spectrum slicing technique and the super-band OCDMA en/decoder are adopted;In addition, we also propose an OCDMA over WDM steganographic transmission system based on temporal phase coding SSFBG. Theoretical analysis and experiment are carried out and the stealth transmission of OCDMA signal over WDM channel is achieved.