Exact Outage Analysis of Cognitive Energy Harvesting Relaying Networks under Physical Layer Security

Abstract

In this paper, we study the secure communication of cognitive energy harvesting relay networks when there exist multiple eaves droppers who can overhear the message of the second hop, and multiple primary users are present. The data transmission from the secondary source to the secondary destination is assisted by the best decode-and-forward relay, which is selected by means of three relay selection schemes. We study the system security performance by deriving the exact analytical secrecy outage probability. These analytical expressions are then verified by comparison to the results of Monte Carlo simulations. Herein we evaluate and discuss the outage performance of the three schemes under variations in important system parameters: the number and locations of relay nodes, primary user nodes, and eavesdroppers; the transmit power threshold; the energy harvesting efficiency coefficient; the power splitting ratio; and the target secure rate.