Physical Layer Secrecy Analysis of Multihop Hybrid Satellite‐Terrestrial Relay Networks with Jamming

Abstract

This paper explores the secrecy analysis of a multihop hybrid satellite-terrestrial relay network (HSTRN) with jamming, where one satellite source is aimed at communicating with destination users via multihop decode-and-forward (DF) terrestrial relays, in the existence of an eavesdropper. All the destination users are deployed randomly following a homogeneous Poisson point process (PPP) based on stochastic geometry. Each relay operates not only as a conventional DF relay to forward the received signal but also as a jammer to generate intentional interference to degrade the eavesdropper link, considering shadowed-Rician fading for legitimate link and wiretap link while Rayleigh fading for jamming link. To characterize the secrecy performance of the considered network, the accurate analytical expression for the secrecy outage probability (SOP) is derived. In order to reveal further insights on the achievable diversity order of the network, the asymptotic behavior of SOP expression at high signal-to-noise ratio (SNR) region is deduced. Moreover, the throughput of the system is discussed to characterize the secrecy performance. Finally, the theoretical results are validated through comparison with simulation results and show that (1) the secrecy performance of the considered network gets better with the decreasing of the hops and with the decreasing severity of the channel fading scenario, (2) the relay of the network operating as a jammer can provide better secrecy performance without extra network resources, and (3) small hops and high SNR can yield to high throughput of the system.

Secrecy Performance of Multi-Antenna Satellite-Terrestrial Relay Networks with Jamming in the Presence of Spatial Eavesdroppers

“…And the definition of secrecy capacity is the capacity difference of the legitimate link and eavesdropper link. Given no direct link of − S E , the secrecy capacity of − S R and − N R D link can be represented as (17) and (20).…”

“…Comparing to traditional encryption method at upper layers, physical layer secrecy has become a popular approach for its advantage of preventing information delivery from eavesdropping [17]. And research on physical layer secrecy in HSTRN has become an attractive concern [18][19][20]. [18] gave a performance comparison of AF and DF HSTRN based on multi-antenna relay, and indicated that the proposed DF HSTRN always had a better secrecy performance than AF HSTRN.…”

“…[19] considered a HSTRN composed of a multi-antenna satellite, multiple relays and users with multiple eavesdroppers, and presented a selection rule of best user-relay pair aiming at minimizing secrecy outage probability(SOP). In [20], authors investigated a multi-hop HSTRN, and characterized accurate and asymptotic expressions for SOP to explore the physical layer secrecy performance. And on this basis, relays or even the destinations themselves can be used to help provide additional jamming to confuse the eavesdropper.…”