Performance of code division multiple access in non-directed diffuse optical wireless channel

The optical wireless channel has abundant available bandwidth and is suitable for high data rate, indoor communications. In this paper, the performance of CDMA as a multiple access technique for optical wireless communication is examined. As the signature sequence, a (43,3,1,1) and a (63,3,1,1) optical orthogonal code (OOC) are used. Information data is modulated through a simple on-off keying (OOK) modulation scheme. A data rate of 2 Mbps is used and the bit error rate (BER) performance is simulated with respect to signal-to-noise ratio (SNR), number of users, and threshold values. It is possible to find the optimum number of users and the optimum threshold value from the results. It is seen that interference from other users actually helps to improve the BER performance, up to a certain number of users.