A Secure Hybrid Satellite-Terrestrial Communication Network With AF/DF and Relay Selection

Abstract

This paper makes research on a secure hybrid satellite-terrestrial communication network with eavesdroppers at the primary and secondary receivers. To secure the transmitted messages, we adopt the null space beamforming to the amplified-and-forward (AF) relay protocol and weighted fractional data carrying artificial noise (WFDCAN) to the decoded-and-forward (DF) relay protocol at the satellite. Considering the time delay may be brought by the WFDCAN, we introduce a parameter θ to indicate the delay severity. The secrecy capacity is combined with θ to derive the maximum secrecy delay constrain. The secrecy capacity, the ASER of the up-link channel and the delay constrain of the down-link channel are applied as factors for a three level relay protocol selection scheme. To simplify the analyses and expressions, the models of the AF protocol and the DF protocol are integrated to form a new transmission model. Furthermore, the secrecy performance at the destination receiver is considered for terrestrial relay selection to enhance the security performance. We also apply the columns of the frequency hopping based multi-term weighted fractional fourier transform (FH-MWFRFT) matrix as signal processing vector to the base station of the terrestrial network to minimize the interference it brings to the terrestrial relays. The simulation results demonstrate that the proposed system could maintain the security at the relays and the secondary receiver while reducing the delay at the satellite in some conditions.

Hybrid Satellite-Terrestrial Relay Network: Proposed Model and Application of Power Splitting Multiple Access

“…For example, in [13][14][15], amplify-and-forward (AF) relaying is employed to enhance the performance of HSTRN. In contrast, HSTRN was considered in relaying mode using the decode-and-forward (DF) as in [16,17]. The HSTRN was studied in a system model that combines the beamforming technique and AF transmission mode [18].…”

“…Outage performance is defined as the maximum rate that can be guaranteed for considered system. Outage probability is one of the critical metrics for determining the performance of emergency services [16]. In other words, the minimum outage probability is closely related to the capacity.…”

“…Using the results of [Eq.4] in [16] and after some straightforward mathematical steps, outage probability is expressed as the generalized incomplete Gamma function…”

“…where Γ(a, x, b) is the generalized incomplete Gamma function [16]. Then, substituting Equation (A3) into Equation (A2), the expression in Equation (19) can be obtained.…”

“…Proof of Proposition 1 By using Equations ( 2 ), ( 7 ) and ( 8 ), the outage probability for the case of DF relay can be expressed as where . Based on result from Equation ( 15 ) and CDF of , it can be rewritten as Using the results of [Eq.4] in [ 16 ] and after some straightforward mathematical steps, outage probability is expressed as the generalized incomplete Gamma function where is the generalized incomplete Gamma function [ 16 ]. Then, substituting Equation (A3) into Equation (A2), the expression in Equation ( 19 ) can be obtained.…”