Study On Resource Allocation Technology Of D2D Communication In Cellular Networks

As one of the key technologies of the 5th Generation(5G)mobile communication system,device-to-device(D2D)communication has the advantages of extremely high spectrum efficiency,great quality of user experience,and communication application expansion.However,the introduction of D2D technology into traditional cellular networks will cause interference to existing users.The cellular user who providing spectrum may not be able to communicate normally due to severe interference.Therefore,a reasonable and effective resource allocation method is the most important problem to be solved when D2D technology is introduced into cellular networks.The thesis studies the channel allocation and power control for the interference between users in two resource reuse scenarios.The main work is as follows:In the case of one-to-one resource reuse of cellular users and D2D pairs,D2D pairs have the same frequency interference with cellular users,resulting in system performance degradation.In order to ensure the performance of cellular users while optimizing D2D energy efficiency,a resource allocation algorithm that combines access control,power control,and channel allocation was proposed.This method first controls the D2D pairs shared subchannel resources according to the user's signal-to-interference and noise ratio(SINR)requirement.D2D pairs who do not meet the requirement will be removed from the subchannel set.Then,based on the convex optimization method,the Dinkelbach algorithm was used to transform the objective function,and the Lagrangian dual method was used to solve the optimal transmit power of the D2D pair.Finally,based on the result of power control,the SINR of cellular users and the energy efficiency of D2D pairs are used as matching preferences,and the one-to-one stable matching between the cellular and the D2D users is achieved based on matching game.A simulation analysis validates the performance of the proposed algorithm from three aspects.The simulation results show that the proposed algorithm effectively improves the energy efficiency of a single D2D pair,and improves the system energy efficiency while ensuring the performance of cellular communications.The interference between users is severe when multiple D2D pairs reuse the same cellular resources.Aiming at optimizing the spectral efficiency of D2D pairs,a resource allocation algorithm based on overlapping coalition game was proposed.The method first establishes a cellular user preference sequence according to the interference level of D2D pairs,and quickly establishes an initial coalition on the premise of ensuring the cellular and D2D pair rate requirements.Then,with the goal of improving D2D utility,an overlapping coalition game algorithm based on the coalition game criteria and candidate sequence replacement criteria is proposed to guide the formation of the coalition,and finally form a stable coalition structure.During the coalition game,the user's minimum transmission rate is fully considered.At the same time,the proposed algorithm is demonstrated from three aspects: convergence,stability and complexity.The thesis also designs a power allocation scheme based on interference intensity to further improve the utility of the coalition.The simulation results show that the proposed algorithm can effectively improve the spectral efficiency in the many-to-many reusing scenario on the premise of ensuring the user's transmission rate.