Performance analysis of an OCDMA system by means of the Quasi Analytical and the Gaussian approaches

A synchronous, coherent Optical Code Division Multiple Access (OCDMA) system is analysed. A Quasi Analytical (QA) approach to the Bit Error Rate (BER) estimation is developed which is simple to implement and capable of yielding an accurate estimation with a feasible computational burden. Exploiting the approach, the system threshold is discussed and optimised, showing that, in order to maximize the performance, it should be dynamically adjusted to the number of users. Furthermore BER estimation by means of the Gaussian Approximation (GA) is presented and its accuracy evaluated by comparison with the QA approach. It is shown that, while the GA tends to over estimate the BER, the accuracy can be increased by properly selecting the threshold.