Joint trajectory and power design for UAV-enabled cooperative jamming in two-way secure communication

This paper investigates a unmanned aerial vehicle (UAV)-aided two-way secure communication system, in which, two ground terminals receive and transmit confidential signals simultaneously, and UAV moves around to transmit jamming signals to confuse malicious eavesdropper. UAV and terminals have energy constraints, the location information of the legitimate terminals is known exactly while that of eavesdropper is known in part. We focus on maximizing a worst-case secrecy rate summation at the two ground terminals over all time slots. This optimization problem is solved by jointly designing the trajectory of UAV and the transmit power (ground terminals or UAV) under maximum UAV speed and transmit power constraints. Due to the non-convexity of the problem constructed by the complicated constraints, we divide the original optimization problem into four subproblems and develop an iterative algorithm to find its suboptimal solution by using the block coordinate descend and successive convex approximation techniques. Simulation results are provided to evaluate the performance of the proposed algorithm by comparing with conventional one-way design and other benchmark schemes.