Secrecy Performance of Cognitive Radio Sensor Networks Over $\alpha -\mu$ Fading Channels

Abstract

This letter addresses the physical layer security for an underlay cognitive radio sensor network over α - μ fading channels, where α and μ denote the nonlinearity and clustering of fading channels, respectively. In the considered network, a secondary sensor transmitter communicates with the secondary sensor receiver in the presence of a primary sensor receiver, and a passive secondary eavesdropper intercepts the information. Specifically, the exact and asymptotic expressions for the secrecy outage probability are derived. Based on the asymptotic analysis, it is revealed that the system achieves a secrecy diversity order of α <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> /2 (α <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> and μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> are fading parameters of the main link) when signal-to-noise ratio (SNR) of main link tends to infinity with fixed wiretap link SNR. However, the secrecy diversity order becomes zero when SNRs of both the main and wiretap links tend to infinity. Numerical and simulation results validate the proposed analytical studies, and demonstrate the impacts of channel conditions on the system secrecy performance.