Novel Adaptive Step Power Control algorithm for 3G WCDMA cellular system

Abstract

Power control is an essential radio resource management method in CDMA cellular communication systems, where co-channel and adjacent-channel interferences are the primary capacity limiting factors. Power control intends to control the transmission power levels in such a way that required quality of service for the users is guaranteed with lowest possible transmission powers. In this paper, a modulation of power control algorithm is proposed for the 3G WCDMA system. The algorithm is figured on a modification of the transmitted power update step size. Instead of the fixed value presently suggested, the step size is modified dynamically in order to obtain more adapted power variations as well as the step is also represented as a function of the difference between the target and estimated SIR of the MS to obtain more stability of the system. A general form of this algorithm is presented and it is then studied in a simple simulation. Performance of the algorithm was evaluated with the outage percentage, which is the percentage of the number of MS's whose received SIR falls below the fixed threshold. The focused requirement, which had been tried to achieve by this algorithm, is the stability, which was studied and represented through simulation.