A PI-power control algorithm for cellular radio systems

Along with "distributiveness", convergence speed of power control is one of the most important criteria by which we can determine the practical applicability of a given power control algorithm. A good power control algorithm should quickly and distributively converge to the state where the system supports as many users as possible. This paper proposes a fast and distributed power control algorithm based on the well-known PI-controller. As in the paper by Foschini and Miljanic (see IEEE Trans. Vehicular Technol., vol.42, no.4, p.641-6, Nov. 1993) we start with a differential equation form of the controller and analyze its convergence properties in the case of feasible systems. The actual power control algorithm is then derived by discretization of the continuous time version. Using the distributed constrained power control (DCPC) as a reference algorithm, we carried out computational experiments on a CDMA system. The results indicate that our algorithm significantly enhances the convergence speed of power control.