Research On Enhancing The Security Performance Of Device-to-Device In Cellular Networks

Device-to-device(D2D)is a technology in which users communicate directly without transmitting signals through the base station.D2 D has the characteristics of reducing base station load,increasing system capacity and improving system spectrum utilization.Therefore,D2 D communication technology has been widely studied by scholars in various fields in recent years.In the future of 5G communication,D2 D communication also faces the security problem of eavesdropping.In order to enhance the security performance of D2 D communication,this thesis uses the time-reversal(TR)technology of temporal and spatial focusing to study the security performance of D2 D in single cell and cross-cell scenarios:Firstly,aiming at the security problem that D2 D user communication is easy to be eavesdropped,this thesis proposes a transmission scheme based on time reversal technology to improve the reachable security rate in this single-cell environment.Firstly,TR technology is used in D2 D multi-input and single-output eavesdropping channel model improve the confidentiality of signal transmission process.Secondly,Because eavesdropping user's location may steal transmission information in the information focus area,the D2 D user uses the TR technology and uses the Stackelberg game auction algorithm to find a partner who satisfies the condition.The collaborator transmits an interference signal to the eavesdropping user,which reduces the ability of the user to steal the information,thereby improving the security performance of the D2 D communication.The simulation results show that the proposed secure transmission scheme effectively improves the systematic reachable security rate.Secondly,aiming at the security problem that D2 D user communication is easy to be eavesdropped,an anti-eavesdropping secure transmission scheme assisted by artificial noise and time inversion is proposed in the cross-cell environment.This strategy includes the following aspects: firstly,inter-cell interference is eliminated in this cross-cell channel model;secondly,the ability of eavesdropping users to steal information is deteriorated by TR technology assisted by artificial noise transmitted by base stations;lastly,in order to meet the needs of cellular users for quality of service and maximize the traversal secrecy rate of the system,the power control allocation scheme with convex optimization is adopted to maximize the transmitted power of D2 D users.The simulation results show that the proposed scheme effectively improves the security performance of the system.