Beamformer designs for energy-efficient multi-cell physical layer multicasting

In this paper, we address the problem of energy-efficiency for group communications over 5G networks. We consider multicast broadcast multimedia services (MBMS) where Base Stations (BS) cooperate to convey a common information to multiple users. The problem is formulated as the global energy-efficiency (GEE) maximization under power constraints. We invoke the principle of sequential convex approximation to tackle the original non-convex problem by providing a conservative approximation. Closed-form solutions are derived and a centralized scheme is designed to find stationary solutions to the original non-convex problem. A distributed implementation with limited communication overhead among the BSS is then proposed. These theoretical findings are further validated through numerical results.