Improved frequency reuse through sector offset configuration in LTE Heterogeneous Networks

In order to realise the potential benefits of co-channel deployments in Heterogeneous Networks (HetNets) and achieve an efficient spectrum reuse, a joint optimisation of small cell and macrocell network operation is highly beneficial. In this paper, a novel cellular network and frequency reuse configuration for both small cells and macrocells is proposed to address inter-cell interference and handover issues in HetNets. The proposed configuration complements Release 10 enhanced inter-cell interference coordination, and further increases its interference mitigation capabilities. Simulations for LTE show that compared to a network that uses standardised Release 10 Almost Blank Subframes (ABS), the proposed configuration can improve expanded-region User Equipments (UEs) performance by 50 % for a given ABS duty cycle. Moreover, for a given targeted expanded-region UEs performance, the proposed configuration can decrease the ABS duty cycle by up to a factor of 2, thus improving macrocell UEs performance up to 31 %. The proposed configuration also mitigates handover failures by 46 %, since handovers start at a higher signal quality.