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A Survey on Physical Layer Security Schemes in Satellite Networks

The terrestrial and the non-terrestrial networks have been envisaged to be amalgamated to form the next generation networks. Further development in wireless communications may enable Internet of Things (IoT) to be extended to the large-scale wireless networks including satellites, which are vulnerable to both eavesdropping and malicious attacks by illegal users. In this context, physical layer security (PLS) has been attracting increasing attention on the ground of its potential to overcome those vulnerabilities with the randomness of the wireless channels. In this paper, we review the existing works on PLS in satellite communications and present the background of the satellite systems and the current challenges that need to be solved in the future.