doi:10.16186/j.cnki.1673-9787.2022030036

Received:2022/03/15

Revised:2022/05/16

Published:2024/05/15

Analysis of physical layer security performance of multi-satellite hybrid satellite-terrestrial relay network

WANG Xiaoqi1, HOU Zheng2, ZHANG Hanwei3, SHI Chuang4

1.School of Physics & Electronic Information Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China 2.School of Surveying and Land Information Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China 3.School of Resources and Environment，Henan Polytechnic University，Jiaozuo  454000，Henan，China 4.Electronic Information Engineering，Beihang University，Beijing  100191，China

Abstract:Satellite communication has shown broad application prospects in various scenarios such as reconnaissance，broadcasting，early warning，resources exploration，topographic mapping due to its advantages of high transmission quality，long transmission distance and wide coverage.   Objectives  To address the security problem，   Methods  multiple-input-multiple-output （MIMO） technology is applied to the satellite relay system，a hybrid satellite-terrestrial relay network（HSTRN） with multiple satellites is constructed，and the physical layer security performance is studied in this paper.The relay is adopted either amplify-and-forward（AF） or decode-and-forward（DF） protocol to assist the transmission.The satellite link follows shadowed-Rician distribution，while terrestrial link and eavesdropper link follows Rayleigh distribution.The the theoretical expressions of the system security outage probability（SOP）based on AF and DF relay are derived，as well as approximate expression and the system throughput under high signal-to-noise ratio conditions，the correctness of the theoretical analysis through computer simulation experiments is also verified.   Results  The results showed that，the security performance of the considered network gets better with the increase of the number of the satellites，and the decrease of the severity of the channel fading scenario；the security performance of the system based on the DF relaying is better than AF at low SNR region，while they will get increasingly consistent at high SNR region；the improvement of the channel fading scenario and high SNR can result in high throughput of the system.   Conclusions  The satellite number，security rate threshold，the channel fading degree and other parameters have great impact on the security performance of AF and DF HSTRN，which can provide reference for subsequent research on the security performance of satellite communication physical layer.  

Key words:hybrid satellite-terrestrial relay network;multi-satellite;physical layer security;shadowed-Rician fading;security outage probability