Relaying Communications in Cognitive Radio Networks with Energy Scavenging and Artificial Noise: Reliability-Security Trade-off Analysis

Relaying communications (RC) in cognitive radio networks (CRNs) can ameliorate transmission coverage and spectrum utilization efficiency. Notwithstanding, the open nature of CRNs hardly assures security against eavesdropping. To overcome the security problem in CRNs, this paper proposes cognitive radios to transmit concurrently desired signal and artificial noise with appropriate power allocation. Apparently, such a proposal causes a trade-off between security and reliability. Moreover, to enhance energy efficiency, relaying operation should use available energy scavenged from radio frequency sources in CRNs. This paper evaluates a security-reliability trade-off of RC in CRNs with energy scavenging and artificial noise (RCiCRNwESaAN), which may benefit from improvement of transmission coverage, spectrum utilization efficiency, energy efficiency, and security capability. To do this, we recommend explicit intercept and outage probability formulas and then corroborate them by computer simulations. Eventually, multiple results are provided to have insights on RCiCRNwESaAN under these realistic operation conditions.