The Effect of Four Wave Mixing on Bit Error Rate Performance of a Direct Sequence Optical Code Division Multiple Access System

A theoretical analysis is presented to evaluate the effect of four wave mixing (FWM) on bit error rate (BER) performance of a direct sequence optical code division multiple access (DS-OCDMA) system with intensity modulation and direct detection (IM/DD) transmission link using dispersion shifted fibe (DSF) sequence inversion keyed (SIK) switched correlator. The BER performance results are evaluated with m-sequence as well as Gold sequence considering the effect of FWM using Matlab simulation and compared with theoretical results. The BER performance is found to be degraded due to FWM effect if the transmitted power and number of users are increased. It is found that BER performance can be improved by increasing the number of chips per bit.