Effects of Dispersion & MAI on Optical Code Division Multiple Access Systems

Optical Code Division Multiple Access (OCDMA) is an optical processing system which allows multiple users to share the same bandwidth simultaneously without interfering with each other using unique optical codes. As the number of user increases, the dispersion and multiple access interference begin to rise, which led to high bit error rate and low quality of service of the system. This paper presents the effect of Dispersion and Multi Access Interference (MAI) of optical fiber on the Bit Error Rate (BER) performance of a Direct Sequence Optical Code Division Multiple Access (DS-OCDMA) network. By using Matlab simulations, Signal-to-Noise Ratio (SNR) versus Received Optical Power (ROP) of an OCDMA transmission system can be evaluated for different numbers of system users. Mat lab simulations can be performed in order to illustrate the reduction of the dispersion index gamma, or to visualize different scenarios, e.g., what amount of transmitted power is required in order to obtain a BER of 10 when the length of the optical fiber is increased.