Downlink adaptive power control algorithm for 3G cellular CDMA networks

Adaptive power control algorithms has been widely studied for interference reduction, base station radiation decrease and terminal battery saving in 3G cellular systems. We study some of the existent adaptive power control algorithms and we propose an evolution of these algorithms in the forward link. In the proposed algorithm, we try to maintain the intercell interference stable and to reduce intracell interference when it is possible. Therefore, the power control steps of mobiles requesting a power increase may be reduced to limit the total power increase if some constraints are verified. The proposed algorithm uses an adaptive step, which is updated using the instantaneous mobile power control command and the command history. Moreover, a stabilization zone above the SIR target is used to limit oscillations. The proposed algorithm has been compared to the 3GPP standardized power control and to a recently proposed adaptive power control. Simulation results has shown that the proposed algorithm decreases slightly the outage probability as the already proposed adaptive power control and reduces the power consumption.