Secrecy Outage Analysis of Underlay Cognitive Radio Unit Over Nakagami- <inline-formula> <tex-math notation="TeX">$m$</tex-math></inline-formula> Fading Channels

Abstract

An underlay cognitive radio unit over Nakagami- m fading channel, which consists of a source S, a secondary user (SU), and an eavesdropper who wants to eavesdrop the information between S and SU, is considered. The transmit power of S is simultaneously adjusted according to the channel state information of S-PU link and a given threshold interference power that the primary user can tolerate. Closed-form analytical expressions of secrecy outage probability and the probability of nonzero secrecy capacity have been derived. The validity of our analysis models is verified by simulation results.