Research On Multi-relay Secure Transmission Technology Based On Cache Assistance

With the rapid development of wireless communication and the popularization of wireless equipment,wireless communication network is more and more closely related to people's life.With the increasing number of users and access devices,the security of network communication has been widely concerned.Because of the broadcast characteristics of wireless channel,the data transmission of wireless network is easy to be eavesdropped by potential illegal users,resulting in information leakage.With the continuous improvement of the computing power of the equipment,the traditional methods base on cryptographic techniques can not meet the requirements of secure transmission gradually.Physical Layer Security(PLS),as a supplementary technology of cryptography,uses the Physical characteristics of wireless channels to achieve secure communication,and has become a research hotspot in the field of wireless communication network Security.Collaborative relay plays an important role in expanding wireless communication coverage and improving network throughput by improving end-to-end channel quality.Similarly,as a key technology of wireless communication in recent years,data buffer assisted transmission technology has shown great potential in exploring additional scheduling freedom to obtain better scheduling decisions.The main research objective of this paper is to design efficient and secure multi-relay transmission mechanism and scheduling scheme by combining cooperative relay and buffer assist technology.The main research contents of this paper include:Firstly,the paper introduces background origin of the concept of physical layer security,and introduces the performance index of physical layer security research security capacity through the simplest three-node secure communication network.At the same time,it also introduces the working mode of relay cooperation and buffer assisted relay cooperation secure communication network,and the expression of the secret capacity.The traditional multi-relay cooperative secure communication network and the selection scheme of multi-cache assisted cooperative secure communication are discussed.Secondly,the paper studies the multi-buffer-assisted relay security transmission technology network,and proposes an adaptive secure transmission(AST)scheme based on channel state information(CSI),energy state information(ESI)and data buffer queue state information(BSI).This scheme allows all relay that meet the security transmission requirements to forward the cached data to the destination at the same time.Through the power distribution of the joint source node and relay nodes and relay selection strategy,the security transmission performance of the system is optimized by Lyapunov optimization algorithm under the premise of ensuring the stability of the communication system.The analysis results show that the proposed AST scheme can significantly improve the security rate compared with the existing schemes.At the same time,in order to maximize the average security rate,the paper focuses on two relay layout problems in the two-buffer assisted relay secure communication network,and analyzes and explores the relay layout problems.In addition,this paper introduces the concept of secure communication range.The analysis results show that the secure communication range of the system can be increased by increasing the number of relays.In addition,the paper also describes the secure transmission capability of the multi-buffer auxiliary relay transmission network from a new perspective of eavesdropper placement.Finally,an active jamming technology scheme based on artificial noise is studied in this paper,which is a secure two-buffer-assisted relay cooperative network.For a two-hop and twobuffer-assisted communication network,it is assumed that all idle nodes will send artificial noise to disturb the eavesdropper during the transmission stage of each hop.A central node with known CSI,BSI,and ESI,the power allocation and relay selection problem of the joint sender and relay node is considered to maximize the system's reachable safe rate.The paper analyzes and compares the security transmission performance under different transmission modes.At the same time,the tradeoff between power,delay and average secure throughput in this communication scenario is revealed.In conclusion,the research work in this paper focuses on buffer assisted multiple relays secure transmission technology,which has important reference value for the exploration of data buffer assisted multiple relays secure transmission technology.The influence of buffer assist on user scheduling,power allocation and transmission mode selection is revealed in this paper,and the tradeoff relationship among secure transmission rate,power consumption and delay is of reference and guiding value for the design of secure communication system with cache assist multiple relay.