Improved frequency reuse schemes with horizontal sector offset for LTE

Abstract

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 Equipment (UE) throughputs. Recently, it has been shown that for two-carrier HSDPA networks a horizontal sector offset configuration for the second carrier can significantly enhance network performance at the cost of an increased number of handovers. In this paper, this sector offset configuration is extended to LTE through a novel approach, which allows deploying offset antennas in eNodeBs without significantly increasing the number of handovers. The proposed sector offset configuration is compatible with current channel dependent schedulers, and provides significant gains. Simulation results show that for LTE the proposed sector offset configuration can increase the average UE throughput and 5%-tile UE throughput by up to 22% and 32%, respectively, while slightly increasing the number of handovers compared to the traditional eNodeB configuration. Moreover, results show that the new configuration can significantly reduce the handover failure rate by up to 69%.