Sector offset configuration with static vertical beam-forming for LTE

Macrocellular networks with frequency reuse across sectors of the same eNodeB and neighbouring eNodeBs suffer from high interference at the cell boundaries, resulting in an uneven distribution of user throughputs. Recently, it has been shown that for LTE macrocell networks a horizontal sector offset configuration can mitigate this problem and significantly increase network performance. In this paper, applying static beam-forming ideas, we extend the proposed horizontal-only sector offset configuration to the vertical dimension, where two physical antennas with the same azimuth but different downtilt reuse the same antenna port. In this way, adding antennas with higher downtilt does not result in an increased number of cell boundaries per eNodeB. Simulation results show that, compared with traditional schemes, the proposed horizontal-and-vertical sector offset configuration can increase the average and 5%-tile UE throughputs by up to 102% and 157%, respectively. The approach is compatible with current channel dependent schedulers and gains scale well with higher sectorizations.