Review of Various Codes and Transmitter–Receiver Architecture Used in Optical Code Multiple Access System

The widespread use of optical communication in consumer and commercial field is rapidly increasing mainly due its enormous bandwidth. One of the most appealing techniques in optical communication that attracts attention for high capacity multi-access local area network is the Optical Code Division Multiple Access (OCDMA) technology. Presently different mediums of communication are being used to exchange information in any form. Hence to provide faster communication systems of higher capacity and bandwidth with the provision to build the cheapest way to provide better quality of services is the prime aim of the present day research. Among all communication categories optical fiber communication has the highest possible information transmission capacity with a relatively small cable diameter of typically less than 20 micron. Optical communication can be either wireless or wired and also having vast bandwidth of the order of Tera-Hertz range to offer faster communication. Due to the property of low interference effect OCDMA is being vastly used as multichannel access for many years in wireless network. In multi cellular case where one frequency is used to all the base stations, OCDMA performs better. One of the striking advantages of OCDMA is to provide more secure communication in a highly noisy environment using pseudo noise codes. But this is restricted to limited user’s number. With the advent of new optical component technologies and optical multiplexing mechanisms, now it is recognized that OCDMA can complement the shortcomings of WDM and TDM technologies thus making it more promising and acceptable in the future. For a bigger number of users in local area systems TDMA and WDMA schemes have remarkable downsides. Time and frequency management do not require for Optical CDMA since all the users transmit using the whole bandwidth at the same time. It can also perform asynchronously depriving packet collisions. With the advent of new optical component technologies and optical multiplexing mechanisms, now it is recognized that OCDMA can complement the shortcomings of WDM and TDM technologies thus making it more promising and acceptable in the future. This review intend to provide investigation on the basic code properties in terms code weight, length, and correlation of unipolar OCDMA codes as well as comparative analysis of various existing codes. Different OCDMA system transmitter receiver architectures are also been presented in the chapter.