Research On Artificial Noise Jamming Based On Physical Layer Security Transmission Strategy

With the rapid development of wireless communication technology, wireless communication system encounters a more complicated and diverse security situation. Traditional encryption algorithms cannot effectively eliminate the security threats existing in the wireless communication system. The physical layer security provides a new perspective on the realization of the security of data communication. The basic idea is utilizing the properties of physical layer such as reciprocity, time-varying and randomness to realize the security of data communication. The paper proposes a physical layer security transmission strategy. Artificial noise is added to the private information based on power allocation technology to reduce the transmission quality of the eavesdropping channel. We study the spatial distribution of eavesdropping nodes, and the influence of channel fading on the system security performance. The main research achievements are as follows:We investigate an AF-based multi-user untrusted relay network, and employ the three-phase time switching-based cooperative multiuser transmission(TSCMT) protocol. The multi-user eavesdropping channel model is constructed, and then the expression of the system secrecy capacity is derived. The two standards are employed, one is to maximize the minimum value of user secrecy capacity and the other is to maximize the system secrecy capacity. The optimal power allocation factor is solved by the SQP algorithm. The MATLAB simulation results show that the proposed strategy jointing artificial noise jamming and cooperative diversity can effectively improve the system security performance.Secondly, we popularize the research on a DF-based two-way relay network, and propose a transmission strategy jointing artificial noise jamming and simultaneous wireless information and power transfer(SWIPT). Two-way relay network adopts a two-phase time transmission scheme, in which the energy harvesting nodes make use of the energy harvested in the first phase to launch artificial noise jamming in the second phase. The expression of the system secrecy capacity is derived by establishing channel models. The influence of SWIPT on the system power allocation factor and secrecy capacity is studied. The simulation results show that the proposed approach can further improve the secrecy performance of the two-way relay network.