Intelligent Reflecting Surface Enabled Secure Cooperative Transmission for Satellite-Terrestrial Integrated Networks

In this paper, we propose an intelligent reflecting surface (IRS) empowered secure cooperative transmission strategy for satellite-terrestrial integrated networks. In such networks, an IRS is deployed near the satellite user to reflect the common-spectrum friendly interference from the terrestrial network to help protect the satellite downlink transmission from being eavesdropped. We seek to minimize the target signal-to-interference-plus-noise-ratio (SINR) at the eavesdropper required to guarantee the reliable communication at the terrestrial network user and to limit the maximum tolerable interference at the satellite user. Then, an alternation optimization scheme is developed. Simulation results verify that the proposed IRS enabled cooperative jamming scheme can reduce the target SINR at the eavesdropper significantly, thus achieving a great secrecy gain.