Field trial evaluation of UE specific antenna downtilt in an LTE downlink

The benefits of horizontal beamforming in cellular networks are well unterstood, and the technology is already used in commercial products. Recently, vertical beamforming (basically a user specific downtilt (DT)) receives a lot of attention as well. However, available channel models do not allow for an accurate simulation of this transmission scheme. This publication investigates the impact of antenna DT in a typical urban area using field trials. Two models are presented and compared with measurement data in order to study their value and limitations for the evaluation of vertical beamforming, which is an important basis for planning and deploying of such schemes in order to increase cellular downlink (DL) throughput.