On Secrecy Analysis for D2D Networks over ff α-μ Fading Channels with Randomly Distributed Eavesdroppers

In this paper, we study the behavior of legitimate device-to-device (D2D) transmission links when intercepted by randomly distributed eavesdroppers. To account for both large-scale and small-scale alpha-mu signal fading at the same time, the k-th best eavesdropper is introduced, which is modelled via a path-loss process with small-scale fading. In order to assess the mathematical representation of the interception behavior, as well as the outage event, the probability of interception P-int and the secrecy outage probability P-out are consequently targeted in the context of this paper. The probability density function (PDF) and the cumulative distribution function (CDF) of the received signal-to-noise ratio (SNR) for the k-th best eavesdropper are first computed. Benefiting from the obtained PDF and CDF, P-int and P-out are thereafter derived and fit into a closed-form expression in terms of the univariate and bivariate Fox's H-functions, respectively. Finally, Monte-Carlo simulation outcomes are provided for the purpose of verifying the precision of our analytical results. Moreover, the effects of the density of eavesdroppers, the fading parameters and the path-loss exponent on the probability of interception are also explored. Interestingly, the conceptual proposal of the k-th best eavesdropper is proved to be comprehensive, and the legitimate D2D link is largely threatened by the 1-st best eavesdropper.