Joint transmit and receive pattern selection for reconfigurable intelligent surface-aided aerial security

In this paper we investigate the physical layer security in aerial communication with reconfigurable intelligent surface (RIS)-aided joint transmit-receive pattern selection (JTRPS), where the base station and the unmanned aerial vehicle (UAV) are equipped with reconfigurable antennas (RAs), in the presence of an aerial eavesdropper. In this setup, RIS is used to adjust its reflecting elements to enhance the end-to-end signal-to-noise ratio (SNR) of legitimate communication. To quantify the overall secrecy performance of the proposed communication model, we derived closed-form transmission secrecy outage probability (TSOP) and capacity-based secrecy outage probability (SOP) expressions to comprehensively evaluate aerial security. Our analyses show that the presence of RIS improves the outage probability, and JTRPS boosts the impact of RIS by adding spatial diversity with mirror activation patterns (MAPs) of RA. The efficiency of the proposed scenario and the correctness of the resulting secrecy performance expressions are confirmed with simulations.