Research On Inter-Cell Interference Suppression Scheme Based On3D Beamforming

Inter-cell Interference (ICI) is an important factor of degrading the achievable spectrum efficiency and restricting the performance of modern wireless communication systems. Beamforming (BF) is an effective method to suppress interference in cellular communication systems. Steering beam direction in Three Dimension (3D) space, i.e.3D-BF, can further improve useful signal power that user equipments (UEs) received and eliminate interference effectively. In addition to spectrum efficiency, energy efficiency is another important aspect of wireless communication system. Energy efficiency in cellular network becomes a hot issue recently in the context of energy shortage and growing CO2emission. In this paper, we focus on ICI suppression based on3D-BF as well as power control to improve spectrum efficiency and energy efficiency.We proposed two ICI schemes based on3D-BF. In first scheme, ICI in Heterogeneous Network (HetNet) is considered to optimize spectrum efficiency. The scheme is divided into two steps, i.e. centralized interference coordination within Group Nodes (GNs) and interference suppression between GNs based on limited coordination. ICI is suppressed and the performance is improved effectively. Based on the improvement of spectrum efficiency applying3D-BF, as a second scheme, an energy-efficient ICI is addressed utilizing power control to optimize energy efficiency. The scheme is divided into two steps. In the first step, the transmit power is assumed to be the same, and3D-BF angles are determined via limited coordination between base stations (BSs) to maximize spectrum efficiency. In the second step, energy-efficient power control is employed to choose transmit power for each BS based on the limited coordination3D-BF to gain energy efficiency.We evaluate the proposed schemes via Monte Carlo simulation. Simulation result demonstrates the superiority of the proposed schemes.