Study of optical wireless CDMA receivers

In this paper, we have studied the performance of an optical wireless CDMA system using four receiver designs - optical correlator, optical correlator with single optical hard limiter (OHL), optical correlator with double OHL and the chip level receiver. These receiver designs have been previously proposed in a fiber optic environment and use mainly optical components with minimum electronic processing. Optical Orthogonal codes (OOC) are used as signature sequences. The information data is modulated by using an On-Off Keying (OOK) modulation scheme and the ambient light noise is modelled as Additive White Gaussian Noise (AWGN). The performance of various receivers are then evaluated by using Monte Carlo Simulation. We found that at a lower SNR the optical correlator has the best performance, while at a higher SNR, the other three receivers gave a better performance.