Newton iteration acceleration of the Nash game algorithm for power control in 3G wireless CDMA networks

In wireless communication systems, each user's signal contributes to the interference seen by the other users. Given limited available battery power, this creates a need for effective and efficient power control strategies. These strategies may be designed to achieve quality of service (QoS) or system capacity objectives, or both. We show how the power control problem is naturally suited to formulation as a noncooperative game in which users choose to trade off between signal-to-interference ratio (SIR) error and power usage. Koskie (2003) studied the static Nash game formulation of this problem. The solution obtained led to a system of nonlinear algebraic equations. In this paper we present a novel distributed power control strategy based on the Newton iteration used to solve the corresponding algebraic equations. That method accelerates the convergence of the Nash game algorithm owing to the quadratic convergence of the Newton iterations. A numerical example demonstrates the efficiency of the new algorithm.