Performance Analysis of Optical CDMA System with Coded Modulation Scheme

Abstract

Abstract For optimizing the performance of asynchronous optical code-division multiple-access (CDMA) system, the use of coded modulation scheme is explored in this paper. As the leading causes of the negative impacts on optical CDMA systems are beat noise (BN) and multiple access interference (MAI), relieving such deleterious impacts can successfully raise the system performance accordingly. For the sake of such adverse impacts, optical CDMA systems will encounter error floor effect; boosting optical power cannot overcome this problem. Alternatively, making use of error correction technique is an appreciative approach to restrain this problem. In the system that we have suggested, the double equal weight orthogonal (EWO)-based coded modulation of error correction mechanism is applied. The signature sequence is represented by carrier-hopping prime code for which it is possible to establish double EWO signaling scheme due to the orthogonality of carrier-hopping prime code. As our numerical results present, the performance of our system can be enhanced dramatically, which is a feasible manner to be a broadband optical access network.