Research On Physical Layer Security Based On Cooperative Jamming

With the acceleration of information era and the gradual maturity and popularization of 5G technology,the transmission rate and spectrum efficiency of wireless communication system have been improved.At the same time,the reliable and secure transmission of information has attracted more and more attention.How to ensure faster and more secure transmission of information has become a hot topic in academia and industry.This also brings higher requirements and challenge for the design and implementation of wireless systems.Secure transmission based on traditional computing encryption technology is facing serious security risks.Unlike the "computational security",physical layer security realizes the security of information theory from the characteristics of the wireless channel,and realizes the confidential information transmission by using the difference between the legitimate user channel and the eavesdropping user channel.Artificial noise and cooperative jamming are effective ways to enhance the physical layer security and anti-wiretapping ability of the system,and the security performance of the system depends heavily on the channel state at the transmitter.In view of the fact that the channel CSI is not perfect between the cooperative node and the legitimate user,this paper studies and analyzes the security performance of the AN-assisted and cooperative jamming system and the wireless powered based cooperative jamming system based on the finite rate feedback channel model At the same time,the ergodic achievable secrecy rate of the system is studied and derived,and compared with the case without feedback,it proves that the finite rate feedback CSI plays an important role in improving the system performance.It provides a theoretical reference and basis for the design and selection of the actual system parameters.The main contributions and work of this paper are summarized as follows:Aiming at the artificial noise and cooperative interference system,a secure transmission scheme based on limited feedback is proposed.The closed-loop solution of the system's connection interruption probability and secret interruption probability is derived.Contrast simulation and analysis of the connection interruption probability and the secret interruption probability of the ideal situation,no feedback and in the case of artificial interference noise and cooperative interference are carried out..The reliability-security performance boundary in various situations is studied,so that it can be selected according to different system requirements and designing system parameters,demonstrating the superiority of the finite-rate feedback system in terms of complexity and reliability-security compromise.Finally,the system traversal reaches the confidentiality rate,and the influence of the number of feedback bits on the traversal of the system can be analyzed,which provides a theoretical basis and reference for the application and design of the actual system.A cooperative interference scheme for cooperative nodes to transmit interference signals is proposed for wireless power supply systems.The secure transmission performance of the system under five different CSI model is studied.The probability of connection interruption and confidentiality under various circumstances are derived.The closed-form solution of the outage probability is given,and the expression under the high SNR approximation is given.The compromise relationship between the system's connection interruption probability and the secret interruption probability is revealed,and the minimum feedback of CSI required by the system under the condition of the secret interruption probability is given.The number of bits.Finally,the confidentiality rate the system traversal reaches is studied and the traversal reachable confidentiality gain that can be obtained with respect to non-feedback at high SNR is analyzed.The research results show that compared with the system without cooperative nodes,the secure transmission system based on wireless power supply cooperative interference nodes can obtain good complexity and security-reliability compromise without additional energy.Based on the limited rate feedback cooperative jamming system model with wireless power supply,the cooperative jamming node uses the expected collection power to transmit the jamming signal.The system's security transmission performance is studied under five kinds of cooperative jamming schemes,and the closed form expressions of the connection outage probability and the secrecy outage probability under various circumstances are derived.The expression of the high SNR approximation is given,and the connection interruption of the system is revealed.The trade-off between connection outage probability and secrecy outage probability is given,and the minimum number of feedback bits required by the system under the condition of secrecy outage probability is given.Furthermore,the ergodic achievable secrecy rate of the system is studied and derived,and the ergodic achievable secrecy rate gains of high SNR relative to no feedback are analyzed and studied.The research results show that the number of antennas and the number of feedback bits of cooperative jamming nodes have an important impact on the system's secrecy rate performance,and prove the important role of the key parameters of the system in the security performance and the advantage of the finite rate feedback method.