A 3D-beamforming scheme for throughput optimization in Heterogeneous Network

Beamforming (BF) is an effective method to restrain interference in cellular communication systems. Steering beam direction in 3D space can improve useful signal power that user equipments (UEs) received and eliminate interference effectively. In this paper, we focus on how to choose 3D-BF angles of beam and propose a cooperative angle selecting scheme based on maximum signal to leakage plus noise ratio (SLNR) (CAS-MSLNR) to increase sum throughput of Heterogeneous Network (HetNet). In the proposed scheme, 3D-BF angles of every node in the same group node (GN) are chosen preliminarily by centralized coordination method to restrain intra-GN interference. Then, in each GN, the macro cell base station (MBS) adjusts the 3D-BF angles to maximize SLNR. Simulation result demonstrates that CAS-MSLNR 3D-BF outperforms 2D-BF and UE-specific 3D-BF in terms of sum throughput and cell-edge throughput.