Network Coordinated Inter-Cell Interference Control Using Horizontal-Plane Beamforming on Small Cells in 3D Cell Structure

3D cell structure, where small cells are three- dimensionally deployed on macro cells, is considered as one of the effective cell structures to accommodate data traffic growing rapidly in recent years. In this cell structure, inter-cell interference among small cells is one of the major issues. As a technique for mitigating inter-cell interference among small cells, we propose a network coordinated base station beamforming where small-cell base stations, applying horizontal-plane beam control, coordinate their beams by network coordination. We also clarify the throughput performance of the proposed method under a multi-cell environment considering a realistic cell structure using computer simulation.