Impact of access scheme selectability on traffic performance in wireless multimedia communications system

This correspondence proposes a flexible wireless multimedia communications system where time-division multiple-access (TDMA) and direct sequence code- division multiple-access (DS-CDMA) schemes are flexibly selectable accordin g to user's quality of services (QoSs) and channel conditions. We evaluate the traffic performance of the proposed system and discuss the impact of th e access scheme selectability on the traffic performance. The key element o f the proposed system is how to determine an appropriate access scheme for a user. Therefore, we theoretically derive a simple selection algorithm to maximize the system capacity. Our computer simulation results show that the proposed system with the derived access scheme selection algorithm can sig nificantly improve the traffic performance as compared with conventional TI )NUL and CDMA systems.