Joint optimization of Trajectory and Resource Allocation for Secure UAV Communication with Artificial Noise

Unmanned aerial vehicles (UAVs) play a vital role in future wireless communications due to their low cost, high mobility, and on-demand deployment. This paper studies the physical layer security in a secure UAV communication system with multiple users and eavesdroppers subject to no-fly zone constraints. By mixing artificial noise (AN) with an information signal, the network’s security performance is improved. We formulate an optimization problem to maximize the minimum average secrecy rate over all users, which is challenging to solve due to its non-convexity. By dividing the problem into three sub-problems of user scheduling, power allocation, and trajectory design, an approximate solution can be readily obtained via successive convex approximation technique and block coordinate descent method. Simulation shows that our proposed scheme can significantly improve network security performance, compared with circular trajectory or no AN scheme.