Physical layer security of hybrid satellite‐terrestrial relay networks with multiple colluding eavesdroppers over non‐identically distributed Nakagami‐ m fading channels

Abstract

This study investigates the physical layer security of a downlink hybrid satellite-terrestrial relay network (HSTRN) where the satellite channel follows shadowed-Rician fading and terrestrial channels are assumed to undergo independent and non-identically distributed Nakagami- m fading. Herein, the authors consider a multi-antenna satellite, which communicates with a terrestrial user via an amplify-and-forward relay in the presence of multiple colluding eavesdroppers at the earth. They derive novel expressions of secrecy outage probability (SOP), ergodic secrecy capacity, and probability of positive secrecy capacity for the proposed network. They further obtain the achievable secrecy diversity order of the considered HSTRN by employing asymptotic analysis of SOP expression. Finally, numerical and simulation results are provided to validate the accuracy of the proposed analysis and to highlight the impact of a multi-antenna satellite on future wireless systems.