Combined fuzzy-based power control with window-based transmission rate management in multimedia CDMA cellular systems

Power control and transmission rate management play vital roles in multimedia CDMA cellular systems. To support multimedia services in CDMA cellular systems, different quality of service (QoS) requirements, such as minimum transmission rate or bit energy to interference spectral density ratio, should be set for different services. In this paper, we propose a novel scheme which combines fuzzy-based power control with window-based transmission rate management for use in multimedia CDMA cellular systems. We use window-based measurements to adjust transmission power by using fuzzy logic control (FLC) so that each service can maintain its signal-to-interference ratio (SIR). Simulation results show that the new proposed method outperforms the original SPC (selective power control) and LRPC (Lagrangian relaxation technique and power control) methods in various measurements, such as outage probability, average transmission rate, probability of unsuccessful transmission, and probability of changes in transmission rates.