Research On Energy Efficiency Technology Of D2D Communication In LTE-A System

With the continuous development of mobile Internet services,the demand for battery power from terminals has become greater and greater,which makes the energy consumption and spectrum resources of the mobile terminal become increasingly serious,especially in device-to-device(D2D)communication.The short battery life of the mobile terminal seriously affects the service experience of the user,making how to improve the energy efficiency of the system is particularly important.Therefore,this paper mainly studies the energy efficiency of D2 D communication technology under the Long Term Evolution Advanced(LTE-A)system,which improves the energy efficiency of D2 D communication through appropriate resource allocation and power control strategies while all user meet their quality of service(QoS)conditions.In a scenario where one D2 D pair reuse uplink resources of multiple cellular users and one cellular user's(CU)uplink resources can only be multiplexed by one D2 D pair(DP),this document mainly considers how DP reuses the resources of cellular users and how to perform power control after resource allocation to obtain the maximum energy efficiency of DP.In this paper,the problem of energy efficiency optimization under this model is decomposed into two sub problems about resource allocation and power control.Through the resource allocation strategy based on Particle Swarm Optimization(PSO),the uplink resources in the system can be effectively utilized.This paper considers the DP's QoS and the total energy efficiency of the system to designs a fitness function based on channel gain and DP's QoS.At the same time,the inertial weight adjustment strategy of adaptive disturbance is designed.Then,based on the resource allocation,the appropriate power control strategy is carried out.Taking the total energy efficiency of DP as the optimization objective,the Dinkelbach algorithm is used to solve the optimal power allocation,to enhance the total energy efficiency of the DP and to implement one DP reusing multiple CU's resources.Finally,the simulation results and analysis verify the feasibility of the proposed strategy and have strong adaptability to the changing communication environment.The strategy not only improves the energy efficiency which is about 38%,but also allows more DPs to access the network,reduces the power and effectively improves the throughput of the system.In the research of energy efficiency of D2 D communication under the scenario where multiple DP can reuse one CU's uplink resource,aiming at the problem of complex interference in the system,this paper proposes an improved adaptive differential evolution(IADE)algorithm for joint resource allocation and power control strategy.The proposed strategy IADE combines resource allocation and power allocation matrix as an individual gene,and considers the QoS constraints of cellular users as an optimization goal,which transforms the energy efficiency optimization problem into multi-objective optimization with two objective functions,meanwhile the constraints of D2 D users' QoS are used to revise the individual.To improve the searching ability and convergence speed of the algorithm,the difference of the individual fitness value is used to guide the updating of the scaling factor,and the crossover probability is increased nonlinearly.Simultaneously,when individuals are infeasible solutions,the selection strategy of the individual fragments is adopted,which makes the better segment into next generation of individuals.Eventually,it is reasonable to improve the total energy efficiency of DP and achieve the multi-reuse of DP and CU resources.Simulation results show that the proposed algorithm not only improves energy efficiency significantly which increased by nearly 75%,but also increases the access rate.