Interference coordination for FD-MIMO cellular network with D2D communications underlaying

In this paper, we investigate the interference coordination for downlink full-dimension multiple-input multiple-output (FD-MIMO) systems with device-to-device (D2D) communications underlaying. With three-dimensional (3D) beamforming transmission applied for cellular users (CUEs), an approximation of the interference to signal ratio for CUEs is derived, and a coordination strategy is proposed to mitigate the interference from D2D pairs to CUEs. Based on the lower bound of the interference to signal ratio for D2D pairs, we propose coordination strategies for D2D pairs to mitigate the interference caused by base station (BS) and the interference between D2D pairs. The proposed strategies require only some statistical channel state information (CSI) of each user and the reduced-dimensional effective CSI of a few CUEs and D2D pairs. Simulation results show that the proposed coordination strategy performs well in terms of achieving good tradeoff between the achievable rate of CUEs and D2D pairs.