Performance enhancement with directional antenna in heterogeneous network

Deploying low power nodes in traditional macro-only cell is a significant way to promote the throughput of network in long-term evolution advanced (LTE-A). In this paper, we focus on the position of the low power nodes since sometimes they cannot be deployed at the center of hotspot. In our model, there is an offset between the center of hotspot and the location of low power node. Due to this reason, the traffic load cannot be offload from macro cell to low power nodes efficiently. To tackle this problem, directional antenna is introduced and utilized with offset pico station to guarantee the load balance while mitigating the co-channel interference. The simulation results demonstrate that the load balance and the total throughput can be improved with proper beamwidth of directional antenna when there is an offset between the center of hotspots and the low power node.