Joint Optimal Power Control and Beamforming in Wireless Networks Using Antenna Arrays.

摘要

The interference reduction capability of antenna arrays and power control algorithms have been considered separately as means to increase the capacity in wireless communications networks. The MVDR (Minimum Variance Distortionless Response) beamformer maximizes the Carrier to Interference Ratio (CIR) when it is employed in the receiver of a wireless link. In a system with omnidirectional antennas, power control algorithms are used to maximize CIR as well. In this paper, the authors consider a system with beamforming capabilities in the receiver and power control. An iterative algorithm is proposed to jointly update the transmission powers and the beamformer weights so that they converge to the jointly optimal beamforming and transmission power vector. The algorithm is distributed and uses only local interference measurements. In an uplink transmission scenario, it is shown how base assignment can be incorporated in addition to beamforming and power control such that a globally optimum solution is obtained. The network capacity increase and the savings in mobile power achieved by beamforming are evaluated through numerical study.