Combined fuzzy-based rate and selective power control in multimedia CDMA cellular systems

To support multimedia services in the next generation of CDMA wireless communication system, different quality of service (QoS) requirements such as minimum transmission rate, E_b/N₀, and so on, should be set for different services. In this paper, a new rate management and power control method will be proposed for multimedia CDMA cellular systems. First, a fuzzy logic controller (FLC) is designed to dynamically infer a suitable transmission rate for each service. Second, a selective power control (SPC) method is used to adjust the transmission power for each service in order to maintain its QoS. Numerical results illustrate that the new proposed method outperforms the original SPC and Lagrangian relaxation technique and power control (LRPC) methods in terms of the outage probability, the average transmission rate, the probability of unsuccessful transmission, and the change probability of transmission rate.