Throughput Performance of Relay Backhaul Enhancement Using 3D Beamforming

Three-dimensional (3D) beamforming is expected for fifth-generation (5G) mobile systems to improve user throughput, which operates in both azimuth and elevation antenna domains. Relay transmission is also important technique for 5G particularly to improve cell-edge performance. This paper proposes relay backhaul enhancement using 3D beamforming and provides its throughput performance using system-level computer simulations. Average and 5-percentile user throughput of the proposed relay system are investigated for almost blank subframe (ABS) ratio defined in time-division relay scheme, distance between evolved node B (eNB) and relay node (RN), and the transmission power of the RN, as parameters of the number of RNs. It is confirmed that the proposed relay system can improve both average and 5-percentile user throughput compared to conventional relay system. Further, we clarify the appropriate ABS ratio, the distance between eNB and RN, and the transmission power of the RN to provide the best performance.