Research On Inter-cell Interference Coordination Technology Based On Picocell Range Extension

Nowadays, with mobile communication technique rapidly developing, the heterogeneous networks(HetNets) have become a hot research field. Low-power nodes Picos in the HetNets, which is considered as one of the core technologies of the 4th Generation wireless communication systems, have been widely researched. Macro-Pico heterogeneous networks can not only improve both spectrum efficiency but also extend the coverage area of hot spots, then implementing load balance. However, deploying Pico-eNBs within the coverage areas of Macro-eNBs will cause inter-cell interference and bring about technical challenge to HetNets.This paper first introduces the performance characteristics and outdoor distribution schemes of Pico-eNBs. The introduction of Pico nodes is critical for meeting the requirements of 4G and making up the performance defects of traditional macrocells. Due to the transmission power difference between the Macro-eNBs and Pico-eNBs, Max RSRP-based cell selection will lead to Macro-eNBs overload, which is no longer suitable for Macro-Pico HetNets. So this paper put forwards a new cell selection method based on cell range extension(CRE), in order to realize load balance.Especially, this paper also introduces the enhanced Inter-Cell Interference Coordination(e ICIC) technologies from time domain, frequency domain and power control. According to Macro-Pico HetNets outdoor networking schemes, this paper firstly summarizes various mainstream technologies of inter-cell interference coordination. Then the paper proposes two eICIC schemes Almost Blank Frame(ABS) and Low Power-Almost Blank Frame(LP-ABS) combing cell range extension technology for eliminating severe downlink interference imposed on Pico CRE UEs. Finally, by establishing system-level simulation platform of LTE-A and adding CRE scheme, ABS scheme, the simulation results in the paper demonstrate that eICIC technologies can effectively improve syatem performance in different Pico deployment scenarios.