Research On D2D Physical-layer Security Scheme Underlaying A Cellular Network

D2D technology will play an important role in future 5G communication because it can be combined with traditional cellular networks to alleviate the shortage of spectrum resources faced by cellular systems and the overload of core networks.However,the explosive growth of access terminals and the rising traffic data caused by 5G's emerging mobile application scenarios will make user privacy and data security more challenging.Therefore,security issues will grow up to be a key factor limiting the application of D2 D technology.Currently,the research on D2 D communication security is mainly based on application-layer encryption or authentication technologies.However,application-layer encryption and authentication technologies cannot meet the needs of future mobile applications due to its high computational load and the existence of defects that can break through security vulnerabilities.Fortunately,the emerging physical-layer security technology will be a new breakthrough to solve D2 D security problems due to its theoretical full confidentiality and low computing load.In view of this,this thesis focuses on the security threats of D2 D communication underlaying a cellular network,combined with its system characteristics,based on the mainstream technology of physical-layer security,studies the physicallayer security protection scheme of D2 D communication underlaying a cellular network.The main research contents are as follows:(1)Firstly,this thesis summarizes the characteristics of D2 D communication underlaying a cellular network and common attack types,and thus establishes the idea of physical layer security design and its characteristic problems in D2 D communication.(2)Secondly,in order to meet the security requirements between D2 D devices,this thesis proposes a physical-layer key scheme based on the mobility characteristics of D2 D devices.Among them,the speed of the D2 D device is used as a random source to generate the physical-layer key and the details of the key generation step are redesigned.On this basis,the base station is introduced to perform privacy protection and operation sharing according to the characteristics of the D2 D scene to improve the overall performance of the solution.(3)Finally,in order to meet the security requirements of cellular users participating in D2 D spectrum multiplexing,a distance-based D2 D protection pair access control scheme is proposed.The scheme subtly turns the originally harmful D2 D co-channel interference into a beneficial interference signal and uses this signal to interrupt the eavesdropping link.Among them,this thesis first gives a description of distance-based access control scheme and distance threshold.Second,the quantified secrecy throughput is derived to measure the performance of the scheme with the aid of stochastic geometry.Based on this,based on the optimization method,the optimal threshold is deduced and the search algorithm based on the advance and retreat method is designed to reduce the computational complexity of the scheme.