Cooperative UAV jammer for enhancing physical layer security

Abstract

An unmanned aerial vehicle (UAV)-aided network is becoming a promising application for the future wireless communication in both military and civilian fields, due to its advantages over traditional ground communication of the flexible deployment and dominant line-of-sight (LoS) channel. On the other hand, due to broadcast and LoS nature, there are challenges in that it is vulnerable in security, so many studies are being conducted to compensate for this. In this paper, we consider the UAV is operated as a cooperative jammer to enhance the physical layer security of the ground legitimated nodes in the presence of an eavesdropper (Eve). Furthermore, we assume that the UAV has imperfect information on the locations of the ground legitimated nodes and Eve due to GPS jamming and covert operation of Eve, respectively. We also further studied the extended situation where Eve is not single but multiple operation. With these uncertainties of the nodes' locations, we formulate a robust joint optimization problem of the UAV's jamming power and trajectory to maximize the average secrecy rate. To handle the non-convexity of the optimization problem, we propose an iterative suboptimal algorithm based on the block coordinate descent method. Simulation results present that the proposed algorithm has outstanding performance in terms of physical layer security compared to other benchmark methods.