Secrecy Analysis of Overlay Mechanism in Radio Frequency Energy Harvesting Networks with Jamming under Nakagami-m fading

Overlay mechanism offers secondary users (SUs) chances to access licensed spectrum of primary users (PUs) to improve spectrum utilization efficiency. However, these chances impose serious security challenges when wire-tappers emulate legal users (SUs/PUs) to eavesdrop secret information. Moreover, energy sources available for SUs to transmit its private information as well as assist PUs in the overlay mechanism are problematic in green communication age. This paper proposes SUs who are able to scavenge radio frequency energy in signals of PUs to meet green communication requirement and jam wire-tappers to secure both secondary and primary information. Important secrecy performance indicators of overlay mechanism in radio frequency energy harvesting networks with jamming under Nakagami-m fading are evaluated by proposed precise expressions. Various results validate these expressions and show that secrecy performances of SUs and PUs are flexibly controlled, compromised and optimized with proper selections of system parameters as well as are dramatically affected by fading severity.