Research On Inter-Cell Interference Based On Lte-A Heterogeneous Network

Long Term Evolution Advanced (LTE-A) is the newest mobile communication standardization developed by the3rd Generation Partnership Project (3GPP). LTE-A system has a large improvement on peak data rate, control plane delay and capacity, user plane delay, spectrum efficiency. However, since mobile users keep increasing and intelligent terminals rising at an exciting speed, mobile networks need to provide higher data speed to gurantee desirable user experience. To solve this problem,3GPP proposed Heterogeneous Network (HetNet), where radio low power nodes-Small Cells are deployed within the coverage area of Macro Cell. Small Cells can make full use of time-frequency resources and improve the system’s overall performance.Although HetNet are deployed with Small Cells, few users wculd get access to Small Cells if tranditional cell access rule were adopted, which fails to alleviate the load of Macro Cell, for the transmitting power of Small Cells is much lower than Macro Cells. To help more users get connected to Small Cells, HetNet adopts Cell Range Extension (CRE) technology and expand the coverage areas of Small Cells. After adopting CRE to expanding the coverage area of Small Cells, their cell edge users, especially CRE users will suffer from severe interference from Macro Cells. Current interference coordination shcemes for HetNet include time-domain interference coordination, power control, etc. However, there aren’t many interference coordination schemes regarding frequency-domain.This paper first analyse CRE bias value’s influences on system performance under different network deployments. Since the cell load of both Macro Cells and Small Cells wouldn’t stay all the same, different CRE bias value should be set according to varied cell load circumustances. Therefore, this paper proposed a dynamic CRE bias value setting strategy. Compared with static CRE setting, this dynamic setting scheme can bring benefit to the network performance while it can also adapt to different network deployments.For the inter-layer issue in HetNet, general schemes would consider time-domain interference coordination. However, this paper proposed an interference coordination scheme based on frequency domain trying to solve interference coordination issue in a different angle.This method dosen’t need to consider the time slot configuration, instead it can decrease the interference between Macro Cell and Small Cell by regulating frequency resources used by different cells.