Self-powered absorptive reconfigurable intelligent surfaces for securing satellite-terrestrial integrated networks

Satellite communications have attracted significant interests due to its advantages of large footprint and massive access. However, the commonly used onboard beamforming is hard to achieve reliable security because of the highly correlated legitimate and wiretap downlink channels. We exploit the benefits of satellite-terrestrial integrated network (STIN) and a novel absorptive reconfigurable intelligent surface (RIS) for improving the security of satellite downlink communications (SDC) in the presence of eavesdroppers (Eves). This paper aims to maximize the achievable secrecy rate of the earth station (ES) while satisfying the signal reception constraints, harvested power threshold at the RIS, and total…