Low-Complexity Joint Power Allocation and Trajectory Design for UAV-Enabled Secure Communications With Power Splitting

Abstract

An unmanned aerial vehicle (UAV)-aided secure communication system is conceived and investigated, where the UAV transmits legitimate information to a ground user in the presence of an eavesdropper (Eve). To guarantee the security, the UAV employs a power splitting approach, where its transmit power can be divided into two parts for transmitting confidential messages and artificial noise (AN), respectively. We aim to maximize the average secrecy rate by jointly optimizing the UAVs trajectory, the transmit power levels and the corresponding power splitting ratios allocated to different time slots during the whole flight time, subject to both the maximum UAV speed constraint, the total mobility energy constraint, the total transmit power constraint, and other related constraints. To efficiently tackle this non-convex optimization problem, we propose an iterative algorithm by blending the benefits of the block coordinate descent (BCD) method, the concave-convex procedure (CCCP) and the alternating direction method of multipliers (ADMM). Specially, we show that the proposed algorithm exhibits very low computational complexity and each of its updating steps can be formulated in a nearly closed form. Besides, it can be easily extended to the case of three-dimensional (3D) trajectory design. Our simulation results validate the efficiency of the proposed algorithm.

UAV Placement and Trajectory Design Optimization: A Survey

“…Geometry-based methods including dynamic clustering algorithm [63] and circle packing method [64] are frequently applied to optimize the UAV placement and power consumption. However, these methods may fail in a complicated situation [65]. The graph theory-based design framework for trajectory optimization may result in low complexity and good performance [33].…”

“…Another common approach is to apply different algorithms concurrently. For example, combining the block coordinate descent method, the concave-convex procedure, and the alternating direction method of multipliers show low computational complexity [65]. Recently, artificial intelligence and machine learning techniques have demonstrated promising performance gains and complexity reduction in wireless networks.…”

Resource Allocation for Joint Interference Management and Security Enhancement in Cellular-Connected Internet-of-Drones Networks

“…In [13], dual-drone based cooperative jamming, where one drone transmits confidential messages and another drone simultaneously transmits AN signals to reduce the eavesdropping capability of the ground adversaries, was developed. In [14], a powersplitting method was developed to split the transmit power of the legitimate drone between the confidential messages and AN signals. The studies in [10], [11], [13], [14] assumed accurate estimation of the eavesdroppers' locations.…”

Robust 3D-Trajectory and Time Switching Optimization for Dual-UAV-Enabled Secure Communications

“…In [20], a utility optimization problem was considered to maximize the average secrecy rate in UAV-assisted mobile jamming system by jointly designing the UAV's trajectory and jamming power. An average secrecy rate maximization problem for an UAV-enabled secure communication system was studied in [21], where a joint design of UAV trajectory, transmit power levels and power splitting ratios was proposed. Moreover, a UAV-assisted secure system in the presence of multiple eavesdroppers was investigated in [22], where the secrecy rate was maximized by jointly optimizing the trajectory and transmit power of the UAV.…”