Research On Physical Layer Security In SWIPT Networks

In today's world,wireless communication technology is rapidly developing,constantly changing the way people access and send information,and it also changes the way information is transmitted around the world.However,due to the open nature of the wireless channel,the information is easily interfered or eavesdropped during the transmission process.This will make confidential information leak.The physical layer security technology utilizes the ph ysical characteristics of the wireless channel to design the protocol to achieve the purpose of secure transmission,and can effectively improve the overall security performance of the communication system.At the same time,the various types of terminal devices that make up the wireless communication network are more powerful,work harder,consume more power.Therefore,insufficient energy has become an obstacle to the improvement of network service quality.The wireless simultaneous wireless information and power transfer(SWTPT)network supplements the wireless device with energy harvesting technology,which can effectively extend the life of the wireless network.Combining the physical layer security technology with the energy harvesting technology can not only enhance the security of wireless informartion transmission,but also alleviate the problem of insufficient energy of n.etwork equipment.Therefore,this paper studies the physical layer security performance of the SWIPT network,and the main work is summarized as the follows:The effects of different strategies on the security outage performance of SWIPT networks are studied.Firstly,the jammer is added in the wireless SWIPT network,and the influence of artificial noise on the security performance of the system is analyzed.Theoretical analysis and simulation results show that the addition of jammer can effectively improve the security performance of the system.Secondly,we consider the scenario where there is a direct link between the source and the eavesdropper node.The relay node uses the randomize-and-forward protocol to forward the confidential information.Analysis shows that the system can obtain a lower security outage probability(SOP)through a reasonable protocol design.Finally,we propose a selection strategy for relay and jammer for wireless SWIPT networks with multiple intermediate nodes.We derive the closed-form expression of the system SOP and verify the theoretical results through simulation.The simulation results show that reasonable selection of relay and interference nodes can achieve better security performance.For a wireless SWIPT network consisting of multiple power stations and multiple intermediate nodes,we propose a secure transmission strategy for joint relay and jammer selection.Firstly,an optimal power station is selected according to the channel gain between the power station and the intermediate node.Secondly,the optimal relay and jammer are selected by comprehensively considering the channel gains of the power station-the intermediate node,the intermediate node-the eavesdropper and the intermediate node-the destination.Finally,the security outage performance of the system is analyzed,and the closed-form expression of the system SOP is derived.The simulation results show that the joint selection strategy of relay and jammer proposed in this paper is better than the existing node selection scheme and is close to the best strategy obtained by the exhaustive method.