Securing the UAV-Aided Non-Orthogonal Downlink in the Face of Colluding Eavesdroppers

Non-orthogonal unmanned aerial vehicle (UAV)-aided secure downlink transmissions are investigated. A single-antenna UAV serves multiple ground users in the face of colluding eavesdroppers (EVs) and only imperfect location information EVs is available. Specially, a power splitting based non-orthogonal transmission scheme considered, where transmit divided into two parts for transmitting confidential artificial noise. Explicitly, we maximize minimum average secrecy rate among all by optimizing trajectory, ratio. In order to tackle this non-convex optimization problem, propose an iterative algorithm on block coordinate descent successive convex approximation techniques. Numerical results demonstrate superiority our proposed algorithm.