Distributed power control algorithm in cellular radio systems using projection onto convex sets

Power control is a well-established technique in the design and operation of cellular radio systems. It can be use to reduce the co-channel interference, near-far effect. This leads to improved capacity and longer battery life. Two main approaches have been adopted for power control, centralised and distributed. Centralised power control requires knowledge of the information of all link gains between base stations and mobiles in real time, which is difficult to implement in the large system. In this paper, we consider distributed power control algorithms which are only based on local information with a cell. We adopt the method of projection onto convex sets (POCS) as an iterative approach to obtain the minimum protection ratio. Numerical results show that the POCS-method achieves much faster convergence and improved outage probability than other conventional methods.