Secure energy efficiency maximization for mobile jammer-aided UAV communication: Joint power and trajectory optimization

Abstract

This paper considers a mobile jammer-aided unmanned aerial vehicle (UAV) relay communication system, where a relay UAV assists information transmission between the source node and the destination node, while a friendly jammer UAV emits an interference signal to the eavesdropper to suppress its eavesdropping behavior. The secure energy efficiency (SEE) maximization problem is studied. The objective is to maximize the SEE via jointly optimizing power and UAVs' trajectories. The formulated problem is non-convex and subject to information-causality constraints, power constraints, and mobility constraints, which cannot be solved directly by convex optimization tools. To solve the problem, the block coordinate descent method is applied to decouple the original problem into four sub-problems. Then, an efficient iterative algorithm is proposed to address the non-convex problem through the successive convex approximation technique. Additionally, Dinkelbach's algorithm is employed to handle the fractional programming problem, thereby obtaining an approximate solution with guaranteed convergence. Different schemes are evaluated to validate the effectiveness of the proposed design. The simulation results show that the proposed design can improve SEE effectively compared with other schemes.