Joint power and rate allocation for the downlink in wireless CDMA data networks

In this paper, we propose a joint power and rate allocation scheme for the downlink wireless data services in CDMA networks. Our goal is to maximize total utility of the system while maximizing the utility of each mobile user. The utility of a mobile user is an increasing function of its effective throughput. We propose a distributed allocation algorithm based on dynamic pricing. The algorithm is composed of three processes, user selection, power allocation and rate allocation. Moreover, the optimization model and algorithm considering minimum rate constraints of users are established to provide quality of service for mobile users. Numerical simulations are conducted to demonstrate the performance of the algorithm. We compare our algorithm with centered social optimal allocation algorithm and fixed rate allocation schemes, and investigate the effects of the minimum rate constraints and maximum power of the base station on the utility of the system. Results show that the performance of our algorithm is close to the social optimal allocation scheme, and better than the power control scheme with fixed rate allocation.