An Iterative Approach to the Power Control Problem in Multi-Service CDMA Systems: Distributed Algorithms and their Convergence

In this paper we present two decentralized Iterative Power Control Algorithms (IPCAs) for the uplink and downlink communication in multi-service CDMA wireless environments in order to expand the system capacity while at the same time satisfy the various QoS requirements. The proposed dynamic IPCAs are decentralised in the sense that they can be implemented in a distributed mode at the individual cell sites and mobile stations based on local measurements and information, and without the need of co-ordination between the different cells. The main feature of these two power control algorithms is that they combine the allocation as well as the correction of power in a multi-service wireless system. For the algorithms presented here whenever power settings exist for which all users meet the QoS requirements we prove and demonstrate exponentially fast convergence to the optimal power values. Finally we present some numerical results to assess the performance of our algorithms by applying them in some test cases.