Secrecy Energy Efficiency Maximization for UAV Relay Communication System under Artificial Noise

In this paper, we investigate the secrecy energy efficiency (SEE) maximization problem for UAV relay communication system with artificial noise. In the presence of eavesdroppers, artificial noise is added to degrade the eavesdropping channel. Through system modeling and problem description, we formulate a secrecy energy efficiency maximization problem with constraints concerning UAV communication scheduling, transmission power allocation and UAV trajectory. The proposed problem is a complex mixed integer non-convex fractional problem. In order to solve this problem, we propose a joint optimization algorithm leveraging well-established Successive Convex Approximation(SCA) and Dinkelbach methods. Subsequently the problem is decomposed into three sub-problems, and each sub-problem is optimized and solved iteratively until convergence. To verify the effectiveness of the scheme, we compare the scheme with the dual-cycle scheme with optimal resource allocation and the scheme of maximal energy efficiency. Numerical results show that compared with benchmark schemes, our proposed algorithm significantly improves the secrecy energy efficiency of the UAV relay system.