Different quality of service (QoS) requirements must be guaranteed in multimedia code division multiple access (CDMA) mobile communication system to support various applications such as voice, video, file transfer, e-mail, and Internet access. In this paper, we analyze the system in a mixed-traffic environment consisting of voice, stream data, and packet data where preemptive priority is granted to delay-intolerant voice service and a buffer is offered to delay-tolerant stream data services. In the case of best-effort packet data service, the probability of access control by transmission permission is applied to obtain throughput improvement. To analyze the multimedia CDMA mobile communication system, we built a two-dimensional Markov chain model on high-priority voice and stream data services, and then performed numerical analyses in conjunction with packet data services based on a residual capacity equation. We investigate the performance of an integrated voice/stream-data/packet-data CDMA mobile system with the finite buffer size of stream data in terms of voice service blocking probability, average stream data service delay, average packet data service delay, and throughput.

An effective transmitter power control method is indispensable in combating the near-far problem and minimizing the effect of interference on the system capacity. This paper investigates the power control problem for the uplink direct sequence-code division multiple access (DS-CDMA) system. In recent works on power control problem, power levels are assumed to take on any positive real value. However, in practical systems, power levels are discrete. This paper therefore proposes a power control algorithm over a discrete set of power levels in which each base station locally optimizes the power set of all users in its own cell. Also, we investigate its convergence and power consumption properties. Simulation results indicate that the proposed power control algorithm converges faster and provides an improved performance.