Research On Interference Management For Heterogeneous Networks

With the rapid development of mobile communication from voice service in 2G(the 2nd generation telecommunication),data service in 3G(the 3rd generation telecommunication to large-scale data service in 4G(the 4th generation telecommunication)and 5G(the 5 th generation telecommunication)in the future,data requirements of mobile communication network grow explosively.To cope with these large requests,denser radio networking technology is needed.Here comes to the definition of femtocell,femtocells can significantly improve the capacity of mobile network.Femtocells are deployed with the same frequency bandwidth as macrocells to increase spectral efficiency in conditions of limited spectrum resource.But it will cause serious co-channel interference,including interferences between macrocell and femtocell and interferences among femtocells.As a result,it's very critical of the effectives of interference management.Interference management technology refers to the scheduling and distribution of network elements comprehensively according to certain rules and methods to reduce intercell co-channel interferences.Firstly,a Redistributed Fractional Frequency Reuse(RPFR)scheme,which can effectively reduce co-tier interferences among femtocells based on reduction of cross-tier interferences,is proposed by research of femtocell-heterogeneous networks and relevant interference management technology.The system throughput is analyzed from the point of macrocell partitioning.This thesis applies a Fluid Model to approximate the Signal to Interference Ratio and convert the capacity maximum problem into a convex optimization.The optimal cell partitioning percentage is calculated.Simulation results show that the optimal reuse partitioning of proposed RFFR for the HetNet is 0.79.The solution has reference value for the other frequency reuse based networks.Secondly,emergency communication is a special and temporary radio communication which is deployed on emergency conditions.It involves the coexistence problem between emergency network and public network with the same spectrum deployment.This thesis carries out the research of interference management in the interconnected scenario between emergency network and public network,consisting of frequency reuse and power control technology.The position relations of two networks are divided into five conditions and are faced with different deployment scheme respectively in order to reduce interferences and guarantee the connectivity for each other.Simulation results show that the proposed interference management scheme can reduce interferences,improve the network performance and guarantee the connectivity between emergency network and public mobile networks.