Research On Resource Allocation Algorithm In Device To Device Mode Of Future Mobile Communication Network

Device-to-Device(D2D),one of the key technologies of 5G system,has broad prospects in improving system performance,user experience and extending the application of mobile communication system.The introduction of D2 D communication technology in cellular networks enables the direct communication between neighboring users without the involvement of the base station.Because of the short communication distance,the D2 D provides a new transmission manner with low channel attenuation which helps to improve the spectral and energy efficiency of communications.However,more co-channel interference may be induced by the adoption of D2 D,which deteriorates the transmission environment of the cellular network.This paper will focus on the resource allocation issues of cellular network with D2 D,and two different D2 D application scenarios are considered in this paper.First of all,the D2 D induced interference problems under the scenario where users are within the coverage of base station are analyzed,and the corresponding mathematical model is established.In order to optimize the spectrum efficiency of the system,a centralized resource allocation algorithm based on graph theory and greedy algorithm is proposed.In addition,the proposed algorithm is verified through computer simulation.It can be seen from the simulation results that the proposed algorithm outperforms the traditional one in the aspects of user data rate and the system throughput.Then,the resource allocation issues under the scenario that D2 D users are out of the coverage of base station are addressed.We propose an adaptive power allocation method based on game theory and fuzzy logic to meet the special transmission characteristics of D2 D system under its complexity and various transmission channel conditions.To verity the proposed algorithm,we build up a system level simulation platform.Through the Monte-carlo simulatin,we can observe that the method described in this paper brings more than 30% gain compared with the traditional average power allocation algorithm and distributed waterfilling method,the fairness problem among users with different channel conditions can be easily adjusted by dynamically power allocation parameter.Finally,some conclusions and expectations on the future research are drawn at the end of this paper.