Research On Physical Layer Security Technology Based On Wireless Relay Cooperative Network

In recent years,the number of wireless terminals has dramatically increased,the total amount of communication data has exponentially increased,and the demand for high-speed data transmission has been increasing.Secure communications are also important.In addition to the traditional security technologies,the physical layer security that takes advantage of the physical properties of communication channels is also receiving widespread attention.The related technologies are rapidly evolving to ensure the security of the data transmission physical layer.Compared with the traditional information security technology that focused on the network layer and above,physical layer security,as a security supplement technology,ensures the security of communication by utilizing the physical layer features such as the uniqueness and reciprocity of the wireless channel.First,this paper mainly studies the cooperative communication technologies of wireless network under physical layer security,including cooperative relay,cooperative jamming and buffer-aided cooperative relay.Research status are described in detail.Secondly,in view of the communication security system model,the joint utilization of cooperative relay and cooperative jamming is used to improve the secrecy rate of the system.For a given set of trustworthy intermediate nodes,it seperates the nodes according to the positions and then the optimization problem of maximizing the secrecy rate of the system is given.By giving the specific role to the node,the optimization problem of maximizing sececy rate of the system is solved.It also compares with the traditional cooperative relay system,the traditional cooperative jamming system and the proposed system in terms of the secrecy rate through the simulation.Simulation results show:Finally,based on the buffer-aided cooperative relay system model,the full-duplex relay is utilized for improving the spectrum efficiency.Based on the assurance of system communication security,it is essential to ensure lower time cost for data transmission,as well as improving system performance.Compared with the traditional cooperative relay system,the simulation results show that the system performance can be effectively improved when the system utilizes the buffer-aided cooperative relay.And the buffer-aided full-duplex relay can obtain more capacity than half-duplex relay system with effective self-interference cancellation.It is found that when the system is at low signal-to-noise ratio area,buffer-aide half-duplex relaying can achieve better performance than traditional full-duplex relay system if the effective self-interference cancellation cannot be guaranteed.