Effect of AWGN on BER Performance of Multiuser Detection in DS-OCDMA System using Novel Multilevel Periodic Codes

In this paper, we study the performance of the multiuser detection in a direct sequence optical code division multiple access (DS-OCDMA) system using novel periodic optical encoder applied to fiber-to-the-X (FTTX) passive optical network (PONs). The performance of our system is analyzed in a synchronous network using multilevel periodic codes (ML-PC) with a conventional receiver model and the results are compared with those for different receivers. Two solutions to improve the performance are proposed: the parallel interference cancellation receiver (PIC) and the successive interference cancellation receiver (SIC). We investigate the performances in terms of signal to noise ratio (SNR) and bit error rate (BER) in the presence of multiple access interference (MAI) and an additive white Gaussian noise (AWGN). Keywords—direct-sequence optical code-division multiple-access (DS-OCDMA), fiber-to-the-X (FTTX), passive optical network (PONs), multilevel periodic codes (ML-PC), parallel interference cancellation (PIC), successive interference cancellation (SIC), signal to noise ratio (SNR), additive white Gaussian noise (AWGN), multiple access interference (MAI).