Research On Energy Efficiency Optimization Scheme In D2D Communication System

With the rapid development of 5G cellular network,more attention is paid to Device-to-Device(D2D)communication due to its high transmission rate,high energy and spectrum efficiency.D2 D communication can greatly increase the throughput of the cell and improve the user experience in the cell edge under the premise of reasonable power control and resource allocation configuration.However,the base station scheduling should make the battery life of user equipment longer due to the limited capacity of handheld devices.Because of the short-distance and one-hop transmission without relaying of the base station,D2 D communication has achieved the advantage of the energy efficiency,which is also the key indicator of 5G network.However,it is difficult and important to take full advantage by jointly design the resource allocation and power control,etc.The topic of this thesis comes from the National Natural Science Foundation of China(61372126).The D2 D communications underlaying the single cellular networks is employed as the system model.Firstly,the current research status of the D2 D technology and the energy efficiency are summarized,and the optimization objective function is achieved by utilizing the definition of energy efficiency and its relation with path loss,transmit power and circuit energy consumption.And then the overall energy efficiency optimization is analyzed based on the fractional optimization theory.The simulation results show that reasonable scheduling scheme can improve the energy efficiency significantly.In addition,employed by the stepwise method to achieve the optimization value in different communication modes for single user from the perspective of power control,the scheme that determines the transmit power of D2 D users and their sharing partner are proposed,which is proved effective by simulation results.Finally,taking the target to maximize the energy efficiency and introducing the bipartite graph theory,a new resource allocation and user matching scheme is proposed,which further considers the access criteria and mode selection against the great number of D2 D users.The simulation results show that the scheme can bring notable gains to the system energy efficiency performance.