Analysis of the performance of time-spread optical code-division multiple access systems with integrate-and-dump receivers

The BER performance of asynchronous time-spread optical code-division multiple access (TS-OCDMA) systems employing integrate-and-dump receivers with partially coherent optical sources was analyzed. Monte-Carlo simulations of the system were performed to verify the validity of the model. Using the developed analytic model, the TS-OCDMA systems with integrate-and-dump receivers were compared with those employing optical thresholders. It was found that: (1) as the integration time (or gating time) increases, the systems with optical thresholders outperform those using integrate-and-dump receivers, (2) while the performance of both systems is improved as the optical sources become more incoherent, those with integrate-and-dump receivers benefit more, (3) when the systems are spectral-efficiency limited, the performance does not improve by using partially coherent sources.