Research On Interference Modelling And Simulation For 5G Heterogeneous Network

In order to meet the demand of the flow blowout growth of the data throughput and the user experience rate,the next generation Mobile Communications(5G)heterogeneous network will use Ultra-Dense Network(UDN).The deployment of UDN is to increase the number of low-power nodes(small cell)in the original heterogeneous network,including Micro base station(Microcell),Pico base station(Picocell),Femto base sation(Fmtocell),which is also known as family base station,D2D,and so on.In the 5G system,the deployment density of the nodes will be more than 10 times as much as now.Although the UDN improves the network spectrum efficiency greatly and expands the system capacity,but with the dramatically increase of the low-power node number and the decrease of the distance between the nodes,the network topology is more complex,diversified and isomerized,which leads to more complex interference.Therefore,it is of great significance to research on the interference model of 5G heterogeneous network.The traditional hexagonal grid model is relatively fixed but not inaccurate.It is not suitable for future 5G Ulltra-Dense Network with multi-tier isomerizations.About this problem,the most commonly used model in recent years is the Poisson point process of stochastic geometry,which is basically assumed that each layer of the base station conforms to the same point process or uses a Poisson point process of completely random.It does not use different points process for different scenarios.Due to the distribution of the base stations is not the same in different scenarios,such as the cell edge scenarios(blind area),the hot spot scenarios(busy area)and the D2D scenarios,which the distribution of the base stations and the terminals in different scenarios is different,the simple Poisson point process will no longer be accurate.In view of this problem,this paper uses different point process to establish different interference models for different scenarios.Firstly,a two-tier MPP-PHP(Matern Hard-core Point Processes and Poisson Hole Process)interference model with inter-layer correlation(spatial correlation between different types of base stations)is established for the cell edge scenarios.The accuracy and applicability of the model are verified by comparing with the traditional hexagonal model and the existing simple MPP-PPP(Poisson Point Process)model.Tthe interference distribution and the influence of the exclusion radius of PHP to system performance has carried on the simulation,which suggests the best value of the rejection radius to achieve the best system performance under the given simulation parameters.Then,a two-tier MPP-MCP(Matern Cluster Process)interference model with intra-layer correlation(spatial correlation between the same type of base station)is established for the hots pot scenarios.The accuracy and applicability of the model are verified by simulation and comparison with the traditional hexagonal model and the existing simple PPP-MCP model,and the interference distribution is simulated.Finally,a three-tier MPP-PHP-PPP interference model with inter-layer correlation is established for D2D scenario.The accuracy of this model is verified by comparing with the established two-tier MPP-PHP model.The interference distribution and the D2D distance influence to system performance is simulated.It is shown that the system performance is getting worse with the increase of the distance between D2D under the given simulation parameters,but the influences is not great.