Position optimization algorithm for UAV in NOMA-based covert communication system

Abstract

This paper investigates a Non-Orthogonal Multiple Access (NOMA)-enabled Unmanned Aerial Vehicle (UAV)-assisted covert communication system designed for military scenarios where a ground base station becomes inoperative, requiring a UAV to function as a temporary base station. To determine the optimal deployment position of the UAV base station, a Sine–Cosine Marine Predators Algorithm (SC-MPA) is proposed. In this system, a single UAV establishes communication links with two ground users, utilizing the high-power signal transmitted between the UAV and the public user to effectively mask the low-power signal exchanged between the UAV and the covert user, thereby achieving communication covertness. Simultaneously, a ground-based warden attempts to detect the UAV’s communication activities. Specifically, under the dual constraints of system covertness and reliability, the SC-MPA algorithm is utilized to determine the optimal position of the UAV base station, aiming to maximize the communication throughput between the UAV and the covert user, thereby enhancing the overall system performance. Simulation results demonstrate that the proposed algorithm can rapidly and accurately determine the optimal UAV position. This not only significantly improves the system’s covert throughput but also exhibits excellent convergence and global optimization capabilities.