Enhancing Secrecy Rates in UAV Communications via Phase Optimization and Artificial Noise Beamforming

This paper addresses physical layer security in unmanned aerial vehicle (UAV)-assisted communication. We propose a secure beamforming optimization algorithm based on an Improved Artificial Bee Colony (I-ABC) framework to solve the non-convex problem of maximizing the system's secrecy rate. The algorithm concurrently designs the information-bearing signal beam and the artificial noise (AN) beam, ensuring quality of service (QoS) for the legitimate user while degrading the eavesdropper's channel. A key innovation is the I-ABC's channelaware dynamic perturbation strategy, which effectively explores the non-convex solution space to avoid local optima and ensure rapid convergence. Simulation results demonstrate that our algorithm exhibits rapid convergence and significantly enhances the secrecy rate compared to schemes without AN, confirming its efficacy for secure transmission.