Cross-Layer Antenna Beamforming and Power Control in Wireless Uplinks
We consider backlog-driven power control and antenna beamforming as a means to maximize network throughput in a wireless uplink, where a base station receives with an antenna array from single-antenna wireless users. Throughput maximization gives rise to an optimization problem which is in general non-concave. We introduce a cross-layer, alternating maximization algorithm searching for the optimal solution, and a variant of the algorithm with reduced complexity. The algorithm alternates between a power control step and a beamforming step. Simulation results illustrate the convergence of the proposed scheme to a locally optimal pair of power vector and beamforming matrix, and quantify its throughput gains in a system with stochastic arrivals.