Importance Sampling Applied to An Optical DS-CDMA System

In this paper, we evaluate the performances of a Direct-Sequence Optical Code Division Multiple Access (DS-OCDMA) system. We estimate the bit error rate (BER) of the system using Importance Sampling (IS) technique by taking into account multiple access interferences (MAI) and noises from the receiver. Conventional Monte-Carlo method uses a great number of samples to derive BER evaluation but only a very small fraction of them contributes to error determination. By using IS method, we increase artificially the number of errors by biasing the input distribution, and therefore it is possible to reduce the number of simulations required for BER estimation. We validate the IS method and demonstrate a BER agreement between simulation results and experiments.