Variance minimization stochastic power control in CDMA systems

In this paper, the uplink power control problem is considered for CDMA cellular systems, where stochastic SIR measurements are performed at base stations. A distributed stochastic power control algorithm is proposed assuming SIR measurements contain white noise. The proposed scheme minimize the sum of variances of mobile´s transmission power and signal-to-interference error. The algorithm derived is fully distributed in the sense that each user only needs to know its own signal-to-interference measurement and channel variation. Uncertainties of wireless channels are accommodated by using a robust estimator. Simulation results indicate that the proposed power control scheme has very fast convergence. In addition, it also works fine with 4-bit quantization.