Mobility enhancements for heterogeneous networks through interference coordination

In this paper, mobility performance of heterogeneous networks (HetNets) is studied in terms of handover failure and ping-pong rates of user equipments (UEs) in co-channel deployment of macro- and pico- cells. Simulation assumptions and parameters of a related study item in 3GPP are used to investigate the impact of various handover-related parameters on mobility performance. Then, a mobility-based inter-cell interference coordination (MB-ICIC) technique is proposed, in which picocells configure almost blank subframes in order to protect high-mobility macrocell UEs. Through extensive simulations, MB-ICIC is shown to provide handover performance gains for both low-mobility and high-mobility UEs. In addition, we show through simulations that performance of the mobility state estimation technique in 3GPP standard specifications is good enough for supporting the proposed MB-ICIC in HetNets.