A Projected SIC Multi-user Detector for Asynchronous Upstream OCDMA-PON

Optical code division multiple access (OCDMA) is a promising multiple access scheme for next generation passive optical networks (NG-PON). It can afford subscribers with a flexible Gb/s bandwidth for the upstream. However, OCDMA suffers from multiple access interference (MAI) that significantly reduces the performance of the system. To alleviate the undesirable impact of the MAI, we propose a projected successive interference cancellation (PSIC) detector that makes use of the non-negativity of the solution to enhance its performance. Using filter factor analysis, we shed light on the PSIC detector’s superior performance compared to that of the linear minimum mean square error (LMMSE) detector. Similar to the PPIC detector proposed in [1], the proposed PSIC detector outperforms the conventional correlation receiver, the decorrelator detector, the linear parallel/successive interference cancellation detectors and the LMMSE detector. However, compared to the recently proposed projected PIC (PPIC) detector [1], the proposed PSIC detector is faster, always convergent and doesn’t suffer from any oscillatory convergence behavior. Keywords-Optical, OCDMA, PIC, SIC, regularization, PON, Multiuser Detection (MUD).