Uplink Power Control and Interference Coordination for Heterogeneous Network

Heterogeneous deployment is a promising solution to enhance both system capacity and coverage, where the planed macro cell is overlaid with pico cells. However, higher transmit power of macro eNodeB results in small coverage for pico cell, which causes insufficient offloading from macro cell to pico cells and inefficient cell splitting gain exploration. Cell range expansion (CRE) is one of alternative cell associations to enhance offloading, but would bring severe interference on the uplink reception of macro cell. Hence, the use of enhanced inter-cell interference coordination (eICIC) techniques is required to realize the promised performance of macro UEs. In this paper, an adaptive uplink power control scheme is proposed for heterogeneous network with CRE, wherein the uplink power control parameters of pico cells could be dynamically optimized based on admissible interference level of macro cell. In addition, the proposed scheme manages to improve the performance of pico UEs on condition that the Quality of Service (QoS) of macro UEs can be well guaranteed with low signaling overhead. Numerical simulation results verify the validity of the proposed scheme.