Optimal downlink power assignment for smart antenna systems

Abstract

Smart antenna systems have the potential to substantially increase the range of base stations and boost the SINR of signals. In this paper, we study several criteria in downlink weighting vector design which is key to exploit the full potential of smart antenna systems, and give the optimal power assignment when the orientations of the weighting vectors are known. Simulation results have shown significant improvement offered by the proposed optimal power assignment method. In particular, we can equalize each user's downlink performance by significantly reducing the output power. Since the power amplifiers at the base station are the most expensive subsystems, this approach can lead to significant cost reduction for a base station.