Load balancing with antenna tilt control in enhanced local area architecture

Small cell is an attractive and promising technology for improving capacity in traffic hotspots using cell densification. We consider the traffic load balancing problem for small cells under the enhanced Local Area (eLA) architecture utilizing the flexible 3-dimensional (3D) beamforming facilitated by the adoption of the active antenna system (AAS) at base stations (BSs). Different load balancing methods based on combinations of cell association algorithms and antenna tilt adjustment schemes are proposed and evaluated via system level simulations. Results show the potential gain of traffic load balancing with 3D beamforming in terms of cell edge user throughput. In particular, for the enhanced load balancing cell association combined with UE (user equipment)-specific tilting scheme, significant cell edge user throughput improvements can be achieved while good average cell throughput performance can still be maintained.