Research On Physical Layer Security Techniques In Relay Communication Based On Cooperative Jamming

With the rapid development of wireless communication technology, wireless communication has made a great impact on our daily life.In recent years, the research of the security issue in wireless communication is relatively backward. It has become an important factor to restrict the development of wireless communication technology.In relay communication, the physical security technology based on cooperative jamming is mainly use the uniqueness and reciprocity of wireless channel.By sending the artificial noise, it can interference and wiretap the reception of user and ensure the signal reception of legitimate user at the same time, thus it can improve the system security performance.In this paper,we use security sum rate as evaluation criterion. Combined with relay selection strategy,the technique of artificial noise and beam forming technology, we study the safety performance of two-way relay communication system.The main work of this paper is as follows:⑴ We discuss the relay nodes forwarding mechanism,selection criteria in rely communications,research relay selection method based on outage probability, and the relay selection method based on the concatenated channel in two-way relay communication systems.We analyze the two methods in security sum rate.The simulation results show that the two relay selection methods can significantly improve the security performance of the system.⑵ With the combination of zero space noise and relay selection strategy, we designed a twoway relay physical layer security scheme based on zero space artificial noise.In this scheme,we use relay selection method based on concatenated channel to divide relay node into cooperative jamming node and cooperative relay node. Then the cooperative jamming nodes use the noise forwarding mechanism to transmit the artificial noise, and the cooperative relay nodes use the amplify and forward mechanism to forward the message.The simulation results show that this scheme can improve the security performance of the system.⑶ A physical layer security scheme based on beam forming and relay selection is designed. In this scheme, We can make the artificial noise in the receiver node of the legitimate receiver zero, the eavesdropping node is affected by the artificial noise,so as to achieve the goal of improving the system security sum rate. The simulation results also show the effectiveness of this scheme.