Key Secrecy Performance Metrics of Overlay Networks with Energy Scavenging and Artificial Noise

Main design objectives of future wireless networks are information security and efficient spectrum-and-energy utilization to serve a tremendous number of users and applications. This paper proposes overlay networks with energy scavenging and artificial noise to achieve these objectives concurrently. In these networks, unlicensed user assists and secures licensed transmission in reward for its access to licensed spectrum by relaying licensed information, producing artificial noise, and transmitting its private information. Key secrecy performance metrics of these networks such as secrecy outage probability, positive secrecy capacity probability, intercept probability, and secrecy throughput are represented in exact formulas, which are helpful in quickly assessing secrecy performances in important specifications as well as optimizing system design without computer simulations. Numerous results are provided to corroborate these formulas and have insightful understandings into secrecy capability of overlay networks with energy scavenging and artificial noise.