Research On D2D Communication Relay Selection And Power Allocation Algorithm

D2D communication is a kind of communication technology in which users do not need to forward data through the base station.Introducing D2 D communication into the traditional cellular network can improve the spectrum efficiency of the system and reduce the load of the base station.The introduction of relay technology in D2 D communication can avoid the communication interruption caused by the large distance between users and increase the coverage area of the network.However,when D2 D users reuse cellular user resources,they will have the same frequency interference problem.So it is very important to design effective relay selection and power allocation algorithm.This paper focuses on the power distribution problem and the selection of relay nodes in a single cell.For single-cell D2 D communication,in order to reduce the same frequency interference in the system and improve the total capacity of the system,an improved power distribution method based on simulated annealing algorithm with maximum channel capacity as the goal is studied.A new adaptive temperature updating function is designed.Increase the memory function,memory search when the optimal solution.The global search ability of the algorithm is improved by using the best solution as the initial state to supplement the search process.Simulation results show that this algorithm can get out of the local optimal solution more effectively.Compared with the traditional simulated annealing algorithm and random selection algorithm,the channel capacity is improved by 6.5% and 12.3%.Aiming at the problem of the same frequency interference caused by the introduction of the relay node into D2 D communication,a relay selection and power allocation algorithm with the maximum channel capacity as the target is studied.Firstly,the relay nodes are screened according to the distance between users,and the available relay nodes are selected as alternative nodes for each pair of D2 D users.Then,the power is allocated according to the improved simulated annealing algorithm.The node with the largest channel capacity in the alternative nodes is the optimal relay.Simulation results show that the proposed optimal relay selection and optimal power allocation algorithm can effectively improve the channel capacity of the system.Compared with the optimal relay and traditional power allocation algorithm,the total channel capacity of the random relay selection and fixed power allocation algorithm is improved by 3.9% and 5.5%.