Investigation on Transmission Power Control in Heterogeneous Network Employing Cell Range Expansion for LTE-Advanced Uplink

Abstract:
In Long-Term Evolution (LTE)-Advanced, heterogeneous networks where femtocells and picocells are overlaid onto macrocells are extensively discussed in addition to traditional well-planned macrocell deployments to improve further the system throughput. In heterogeneous networks, cell range expansion (CRE), which is a technique for expanding the cell radius of picocells by biasing the handover criteria, is applied so that the UEs will more frequently select the picocells. This paper investigates the transmission power control (TPC) method in the heterogeneous networks that employ CRE and evaluates the cell-edge user throughput and cell throughput performance. Simulation results (4 picocells and 25 UEs are located within 1 macrocell and the difference in transmission power between the macrocell and picocells is 16 dB) show that almost the same celledge user throughput is obtained by setting the appropriate difference in the target received signal power between the macrocell and picocells according to the CRE offset value. Keywords-?? LTE-Advanced, heterogeneous network, transmission power control, cell range expansion