Rotatable Antenna-Enabled Secure Wireless Communication

Rotatable antenna (RA) is a promising technology that exploits new spatial degrees of freedom (DoFs) to improve wireless communication and sensing performance. In this letter, we investigate an RA-enabled secure communication system where confidential information is transmitted from an RA-based access point (AP) to a single-antenna legitimate user in the presence of multiple eavesdroppers. We aim to maximize the achievable secrecy rate by jointly optimizing the transmit beamforming and the deflection angles of all RAs. Accordingly, we propose an efficient alternating optimization (AO) algorithm to obtain a high-quality suboptimal solution in an iterative manner, where the generalized Rayleigh quotient-based beamforming is applied and the RAs' deflection angles are optimized by the successive convex approximation (SCA). Simulation results show that the proposed RA-enabled secure communication system achieves significant improvement in achievable secrecy rate as compared to various benchmark schemes.