Reduction of MAI Using Optical Normaliser in an Optical CDMA System

Optical Code Division Multiple Access (OCDMA) is a technology which supports multiple simultaneous transmissions in the same time slot and the same frequency to realize multiplexing transmission and multiple accesses by coding in the optical domain. But one of the major disadvantages of the multi user system is the Multiple Access Interference (MAI) that can occur due to the false detection of incoming signals by the users at receiver side. This MAI can be reduced by using an Optical Hard Limiter (OHL) at the receiver front end. But use of OHL has the drawback that it is incapable of handling random signals effectively. So a new technique using Optical Normaliser (ON) for dynamic thresholding is introduced, that can effectively handle random signals. The Bit Error Rate (BER), Q factor and the received power of the system using ON is analysed and improvement in above factors are observed than that of using OHL. The simulations are carried out using commercially available simulator from Rsoft, OptSim 5.3.