Securing FC-RIS and UAV Empowered Multiuser Communications Against a Randomly Flying Eavesdropper

TL;DR

This paper enhances physical-layer security in UAV and FC-RIS aided multiuser wireless networks against a randomly located eavesdropper by proposing new scheduling schemes and analyzing secrecy performance.

Contribution

It introduces two novel scheduling schemes for FC-RIS aided systems and derives closed-form expressions for secrecy metrics, improving security analysis.

Findings

Proposed GCSI-PFS scheme achieves performance similar to full-CSI schemes.

Optimizing UAV hovering altitude significantly improves security.

Closed-form ZSRP expressions validate the analytical approach.

Abstract

This paper investigates a wireless network consisting of an unmanned aerial vehicle (UAV) base station (BS), a fully-connected reconfigurable intelligent surface (FC-RIS), and multiple users, where the downlink signal can simultaneously be captured by an aerial eavesdropper at a random location. To improve the physical-layer security (PLS) of the considered downlink multiuser communications, we propose the fully-connected reconfigurable intelligent surface aided round-robin scheduling (FCR-RS) and the FC-RIS and ground channel state information (CSI) aided proportional fair scheduling (FCR-GCSI-PFS) schemes. Thereafter, we derive closed-form expressions of the zero secrecy rate probability (ZSRP). Numerical results not only validate the closed-form ZSRP analysis, but also verify that the proposed GCSI-PFS scheme obtains the same performance gain as the full-CSI-aided PFS in FC-RIS-aided communications. Furthermore, optimizing the hovering altitude remarkably enhances the PLS of the FC-RIS and UAV empowered multiuser communications.