Coordinated Inter-Cell Interference Management for Expanded Region Picocells in Heterogeneous Network

To deal with the shrink of Picocell Downlink (DL) coverage areas, the concept of Cell Range Expansion (CRE) has been proposed, in which a positive value is added to the DL Reference Signal Received Power (RSRP) of picocell pilot signals.Although CRE will expand DL picocell footprint, it may also lead to severe DL inter-cell interference from macrocells since some picocell User Equipments (UEs) are not connected to the cells that provide the strongest RSRP. In this paper, we propose a new coordinated interference management scheme for macrocell-picocell Heterogeneous Network (HetNet) to improve the signal quality of picocell UEs. The proposed method is to coordinate frequency and power resources within a set of resource allocation restrictions. Based on the Third Generation Partnership Project (3GPP) LTE-Advanced (LTE-A) standardization, system level simulation results show that compared with alternative approaches, the proposed method can mitigate outages, improve cell-edge UEs´ performance and bring a significant increase in overall system throughput.