Physical Layer Security Age of Information Optimization for UAV-Jammer Assisted Relay Cooperation System

Due to the broadcast nature, wireless communications can be easily overheard by malicious eavesdroppers. In this paper, artificial noise sent by the friendly unmanned aerial vehicle (UAV)-jammer is used to weaken the eavesdropping channel from the secondary relay (SR) to the eavesdropper, in order to achieve the objective of optimizing the secrecy AoI (SAoI) of the system. With this consideration, this paper interests the SAoI of a relay cooperation system with the assistance of a UAV jammer and proposes two optimal policies. The Optimization problem is described as a joint optimization of the secondary system transmission power, the UAV transmission power and the UAV trajectory. This work designs the optimal framework that is solved with a tractable CVX tool and slack variables. Simulation results show that the UAV trajectory perform well in minimizing the AoI, and indicate that the information secrecy and freshness are simultaneously guaranteed.