Security Performance Analysis for Hybrid Satellite-Terrestrial Relay Networks

A hybrid satellite-terrestrial relay network (HSTRN) comprised of a satellite, multiple terrestrial relays, and a destination is researched in this paper, where a potential malicious eavesdropper exists in this network. The satellite transmits data to a destination through multiple decode-and-forward (DF) relays, where an eavesdropper attempts to wiretap the encrypted information from the satellite and relays. The optimal relay selection (ORS) is proposed to investigate the physical layer security of this hybrid satellite-terrestrial relay network. Specifically, in ORS scheme, a relay which can decode information successfully with the maximum instantaneous relay-destination channel capacity is chosen as the ‘‘best’’ relay. Additionally, this paper derives the closed-form expressions of outage probability (OP) and intercept probability (IP) as well as security-and-reliability tradeoff (SRT) of ORS scheme. Finally, numerical results provide security and reliability performance of our proposed scheme.