Research On D2D Communication Resource Allocation Technology In Cellular Network

The number of smart devices is increasing with the improvement of mobile communication technology,and the demand for mobile network communication is also increasing,which will lead to the shortage of spectrum resources.As one of the key technologies of 5G,Device-to-Device(D2D)is a short-distance device direct communication technology,which can effectively improve resource utilization and system communication performance,and reduce the pressure on the base station.However,in the cellular network,when users interact with each other in D2 D communication,the sharing of communication resources between D2 D users and cellular users will also cause co-channel interference between users,which will reduce the communication quality of users and affect the performance of communication system.Therefore,it is necessary to use a reasonable communication resource allocation scheme to eliminate the co-channel interference among users and improve the performance of the communication system.In this paper,based on the closed-loop power control,a packet-based resource allocation algorithm is adopted for the scenario of single cell in multiplexing mode.The algorithm controls the closed-loop power of cellular users and D2 D users at the same time.According to the distance between the D2 D users and the base station,the D2 D users are divided into high interference group,medium interference group and low interference group,and the corresponding path loss compensation coefficients are assigned to each interference group.The algorithm’s simulation data indicates that they can effectively improve the signal-to-noise ratio and throughput of cell users and the total throughput of the system.In addition,this paper proposes a resource allocation algorithm combining mode selection and channel assignment based on greedy selection,aiming at the situation that both dedicated mode and multiplexing mode exist in a single cell.On the basis of greedy algorithm,this algorithm takes the maximum interference threshold of cellular users to D2 D users and the set interference threshold of base stations as constraints,calculates the interference matrix of D2 D users to base stations,and makes greedy selection.It selects the multiplexing mode for the D2 D users who meet the constraints and have less link interference,and shares the link resources with cellular users,while the rest of the D2 D users choose the dedicated mode and allocate the dedicated channel resources.The simulation results show that this algorithm can effectively improve the access of D2 D users and reduce the interference of the system.