The Research Of OCDMA Codec

Optical fiber communication through optical fiber to used as information carrier, and used light to transmit information. Optical fiber has a massive bandwidth, that make it has incomparable communication ability compared with electrical communication. It has larger information capacity, longer transmission distance, and higher signal quality, so it has a wide range of applications in computer communication field and telecommunications, and make communication and lifestyle have breakthrough changes. Optical fiber communication and computer technology formed as two important pillar of modern high-tech, largely promote the prosperity and development of the society and human civilization.The CDMA technology has been successfully used in the mobile communication and satellite communications, and showed a lot of advantages that other technologies don't have, such as anti-multipath decline, anti-jamming, increased system capacity, etc. But because of mobile communication and satellite communications have bandwidth constraints, these advantages of CDMA technology didn't get sufficient play.The paper introduces the research background of OCDMA, and introduces the structure and function of the key parts in detail, especially in codec. This article mainly includes: (1) Studied the dispersion compensation of long period fiber grating, simulate the dispersion compensation fiber by setting up the system, and verified that the dispersion compensation is effective for transmitting signals recovery.(2) Make theory validating and analysis of the codec based on LPG. This is the key part. First, introduced the basic knowledge of long period fiber, including writing method, analysis method, etc. used coupled-mode theory method as the key analyzed methods. Through analysis these two modes exist in long period grating, it has concluded the crossing transmission spectrum of LPG, and design the parameters of the codec.(3) Through optisystem, simulation software, simulate the OCDMA codec system based on the LPFG, and conclude the simulation result.(4) Introduce more application prospect of OCDMA.