Physical Layer Security for UAV Swarm Communications via Protected Zone

Along with the appealing uses cases of the unmanned aerial vehicles (UAVs) for the next-generation wireless communications, the privacy of the information and the robustness against malicious attacks are of significant concern in this paradigm shift. In this study, we investigate the physical layer security for a multiuser communications scenario where a terrestrial base station (BS) serves multiple authorized (i.e., legitimate) UAVs simultaneously. In order to improve the secrecy rates, which are compromised by the unauthorized UAVs present in the vicinity of the legitimate ones, we adopt the protected zone approach which ensures any unauthorized UAV is away by at least a certain distance (i.e., protected radius) from any legitimate UAV. The numerical results verify that the proper choice of the protected radius significantly enhances the secrecy rates.