Reducing the Effect of Noise for SAC-OCDMA System by using OFDM Modulation

摘要

Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system encounters several challenges because the MultipleAccess Interference (MAI) of the overlapping chips as number of simultaneous users’ increases. Objectives: Our objective is to develop SAC-OCDMA system with OFDM modulation, based on Flexible Cross Correlation (FCC) code to limit the effect of noises. Methods/Analysis: The average received signal to noise ratio (SNR) with the effects of total noise such as Phase Induced Intensity Noise (PIIN), shot noise and nonlinearity of subcarriers is derived. In addition to generated the Numerical analyses of proposed system. Findings: The results have been evaluated based on SNR, PIIN, shot noise and number of users as well as the amount of power received. The results show that the proposed system improve the capacity of system performance in term of users and suppress the system impairments, Furthermore, by using FCC code can effectively reduce the effects of total noise and mitigate the Multiple Access Interference (MAI). Therefore the applying of OFDM modulation with SAC-OCDMA system has been proven to be robust against the MAI and surely enhanced the system performance, in term of SNR and high number of user allocated, compare to SubCarrier Multiplexing (SCM)/ SAC-OCDMA system.