Abstract
In this paper optical code-division multiple-access(CDMA)systems with repetitional cyclic-shifted sequences(RCS)is proposed for mitigation of multiple access interferece(MAI). When the number of reptition is k, a user transmit k sequeces in each frame, and the k sequences are generated by arbitrary cyclic-shifting a code assigned to each user. At the receiver side the outputs from the correlators over k sequences are summed as the desired signal. RCS/CDMA system can mitigate MAI because the peak power of the desired signal in the RCS/CDMA is k times larger than that in the system without RCS, while the interference probability of each frame is almost same as that of the system without RCS for the variety of the numbers of cyclic-shift sequences among the users. We evaluate the bit error probability of on-off keying(OOK)-RCS/CDMA system and pulse-position modulation(PPM)-RCS/CDMA system with k = 2 by the theoretical analysis and compare with the conventional system. We show that the RCS can improve the bit error probability of the conventional system.
