Resource Management And Application Of Device-To-Device Communications In Cellular Networks

With the rapid development of cellular mobile communication technologies,and the wide deployment of Internet of thing,the number of mobile subscribers and connected devices is increasing explosively.The massive number of devices generate a huge amount of mobile data,which poses a significant challenge to existing mobile communication network system.Device-to-Device(D2D)communication technology,which enables two devices which are within each other's vicinity to communicate directly without traversing the core network,is expected to improve the system capacity and spectrum efficiency of current mobile communication system.After extensive research on the future application of D2D communication,we found out that the smart home scenario is one of the most popular application scenarios.This thesis aims to study resource allocation problem for D2D communication in cellular networks under the smart home scenario with an objective to maximize the system capacity.The main contributions are as follows:First,we study a resource allocation problem of D2D communication underlaying LTE networks under static environment.Different from the"one-to-one" and "one-to-many" spectrum sharing mode,this thesis studies the "many-to-many”mode where each D2D pair can use resource blocks assigned to multiple mobile users and each mobile user's resource block can be shared by multiple D2D pairs.In this thesis,we propose a system capacity maximization problem by jointly considers user satisfaction and interference.Through the design of D2D user type and priority function,the priority of the D2D user is determined.The intra-network interference relationship among D2D pairs,and the inter-network interference between D2D pair with mobile users,are described by the double-layer interference graph.Then we propose a resource allocation scheme based on the graph coloring theory.Simulation results show that the performance of the proposed algorithm is competitive when compared with other existing algorithms.Moreover,we extend the previous network setting to a more realistic scenario by considering user mobility of cellular network users.We propose a dynamic resource allocation algorithm based on user motion trail.In order to avoid that part of D2D users can not meet the demand of communication quality due to the change of location of cellular users during the resource re-allocation interval,we allocate resources according to the prediction of the location of the cellular users.To minimize the signaling overhead and interruption of ongoing communication sessions,we propose an online algorithm which only adjusts the resource allocation for D2D pairs whose interference from mobile users exceeds the threshold due to the movement of users,while keeping the resource allocation for other D2D pairs unchanged.Simulation results show that the performance of the proposed algorithm is competitive in terms of system throughput,overhead and allocation time.