On the Intercept Probability and Secure Outage Analysis of Mixed ($\alpha$-$\kappa$-$\mu$)-shadowed and M\'alaga Turbulent Model

TL;DR

This paper analyzes the secrecy performance of a dual-hop RF-FSO relaying network under complex fading and turbulence conditions, deriving analytical expressions for outage probability, secrecy capacity, and intercept probability, validated by simulations.

Contribution

It provides the first closed-form expressions for secrecy metrics in a mixed RF-FSO system with ($\alpha$-$\kappa$-$\mu$)-shadowed fading and M\'alaga turbulence, including asymptotic analysis.

Findings

Fading, shadowing, turbulence, and pointing errors significantly impact secrecy performance.

Heterodyne detection outperforms IM/DD in enhancing secrecy.

Analytical results match Monte-Carlo simulations, confirming accuracy.

Abstract

This work deals with the secrecy performance analysis of a dual-hop RF-FSO DF relaying network composed of a source, a relay, a destination, and an eavesdropper. We assume the eavesdropper is located close to the destination and overhears the relay's transmitted optical signal. The RF and FSO links undergo ($\alpha$-$\kappa$-$\mu$)-shadowed fading and unified M\'alaga turbulence with pointing error. The secrecy performance of the mixed system is studied by deriving closed-form analytical expressions of secure outage probability (SOP), strictly positive secrecy capacity (SPSC), and intercept probability (IP). Besides, we also derive the asymptotic SOP, SPSC, and IP upon utilizing the unfolding of Meijer's G function where the electrical SNR of the FSO link tends to infinity. Finally, the Monte-Carlo simulation is performed to corroborate the analytical expressions. Our results illustrate that fading, shadowing, detection techniques (i.e., heterodyne detection (HD) and intensity modulation and direct detection (IM/DD)), atmospheric turbulence, and pointing error significantly affect the secrecy performance. In addition, better performance is obtained exploiting the HD technique at the destination relative to IM/DD technique.