Adaptive Power Control using Channel State Information Gradient for Mobile Radio Systems

In this paper, a new adaptive, closed-loop power control algorithm is proposed for wideband code-division-multiple-access (W-CDMA) communication systems. The adjustment of power is carried out through knowledge of the past values of signal strength and signal-to-interference ratio (SIR). The gradient nature of Rayleigh fading channel is estimated in order to alleviate the effect of fast fading and to enable the channel to be tracked more effectively, hence providing stable received signal power and SIR for each user. Simulation results show that the proposed algorithm has superior convergence performance compared to existing approaches