Coordinated beamforming design in multicell multicast networks

In this paper, we study the physical layer multicasting in multicell networks, where each base station equipped with multiple antennas transmits a common message using a single beamformer to multiple users equipped with a single antenna in the same cell. We consider the quality-of-service (QoS) beamforming for minimizing the total power consumption while guaranteeing that the signal-to-interference-plus-noise ratio (SINR) at each user is above a predetermined threshold. Based on the decomposition theory, we propose a novel decentralized algorithm to implement the coordinated beamforming with limited information sharing among different base stations. The algorithm is guaranteed to converge and in most cases it converges to the optimal solution. Simulation results demonstrate significant advantages of the proposed coordinated beamforming over conventional beamforming.