Performance analysis of multiple access protocols for CDMA cellular and personal communications services

The performance of a direct-sequence/code-division multiple-access (DS CDMA) spreading ALOHA access protocol, which can be applied to wireless data network and personal communications services, is investigated. A Markov model is used to derive upper and lower bounds of the throughput of the underlying system. Time-driven simulation is also performed to investigate the tightness of the bounds. The results indicate that the upper bound is very tight. Numerical results also show that, unlike the conventional ALOHA system, the DS/CDMA spreading mainslotted ALOHA system provides better delay and throughput performance than the DS/CDMA spreading-slotted ALOHA system.>