Convex-optimization based geometric beamforming for FD-MIMO arrays

With the persistent densification of cellular networks, especially in urban environments, three-dimensional beam-forming utilizing full dimension MIMO antenna arrays becomes of interest for mobile communications, since it allows to mitigate the inter-cell interference and enables high order spatial multiplexing of a multitude of users. In this paper, we consider beamformer optimization with the goal of maximizing the signal power within a certain angular area of interest, while controlling the interference leakage caused outside this area. We relax this non-convex optimization problem to a closely related convex problem and numerically evaluate the performance of this feasible solution.