Secrecy Profits Analysis of Wireless-Powered Networks Against Randomly Distributed Eavesdroppers

摘要

The network profit is an effective performance metric to improve the flexibility of network deployment by the operators to adjust the network setting and data prices according to the network conditions. It is particularly useful for physical layer security (PLS), where the network will consume more energy on jamming. This paper studies the secrecy performance of a wireless-powered communication network (WPCN) in terms of profits (i.e. security profits), where power beacons (PBs) will first transmit energy to the energy-harvesting transmitters wirelessly, and then act as jammers to send artificial noise (AN) aided jamming signals to randomly distributed eavesdroppers (EDs) to prevent information leakage. With the use of stochastic geometry, we derive a closed-form expression of the secrecy profit gained by WPCNs which is defined as the difference between the revenue from secrecy transmission and the cost from the PBs' energy consumption. Numerical results verify the maximum secrecy profit of the proposed networks can be achieved with proper transmit power and density of the PBs, and show the flexibility of the secrecy profits compared with the secrecy energy efficiency.