Work in progress: 3D beamforming methods with user-specific elevation beamfoming

In recent years, attentions have been focused on 3D (three-dimensional) beamforming which can improve cell average and cell edge throughput and eliminate the interference to adjacent cells. In the work towards calibration of 3D channel model, it seems that elevation beamforming with fixed electrical downtilt of 102 degrees has a good SINR (signal to interference and noise ratio) performance in 3D-UMi (Urban Micro) and 3D-UMa (Urban Macro) scenarios. In order to improve the user´s SINR of elevation beamforming, in this paper, two user-specific elevation beamforming methods are proposed to improve the performance, one (method I) selecting the EoD (elevation angle of departure) as the electrical downtilt for each user, the other (method II) selecting the optimal electrical downtilt by considering user signal strength and inter-cell interference. Simulation results with the 3D channel model show that method I achieves a little improvement in 3D-UMi scenario but poor performance in 3D-UMa scenario compared with the fixed 102-degree elevation beamforming method from SINR. Method II in both scenarios outperforms the fixed downtilt method from SINR.