A novel interference cancellation technique for optical CDMA system

Multiple Access Interference (MAI) is a serious source of noise in Optical Code Division Multiple Access (OCDMA) system. In this perspective, a new technique has been proposed in this paper to reduce the effect of MAI in OCDMA receiver. The effect of interference arising from other user code to the intended user has been reduced by subtracting the interference (multiplied by a factor) from the received signal. It has been observed that the distance between different codes influences the value of MAI on the intended user. Hence a new technique has been proposed to optimize the hardware requirement and complexity of the receiver for reducing MAI. The structure has been implemented using Advanced Binary Optical Logic Gates (ABLOGs) leading to reduction of optical-electrical conversion time. Simulations have been carried out using MATLAB to obtain the variation of error probability with number of users for different iterations. Thus, the effectiveness of the proposed technique has been established in terms of the improvement in the Bit Error Rate (BER). It has also been established that this new method gives better result in first iteration leading to faster simulation time.