Covert Communications in MEC-Based Networked ISAC Systems Toward Low-Altitude Economy

Low-altitude economy (LAE) is an emerging business model, which heavily relies on integrated sensing and communications (ISAC), mobile edge computing (MEC), and covert communications. This paper investigates the covert transmission design in MEC-based networked ISAC systems towards LAE, where an MEC server coordinates multiple access points to simultaneously receive computation tasks from multiple unmanned aerial vehicles (UAVs), locate a target in a sensing area, and maintain the UAVs’ covert transmission against multiple wardens. We first derive closed-form expressions for the detection error probability (DEP) at the wardens. Then, we formulate a total energy consumption minimization problem by optimizing communication, sensing, and computation resources as well as UAV trajectories, subject to the requirements on the quality of MEC services, DEP, and the radar signal-to-interference-and-noise ratio, and the causality constraints of UAV trajectories. An alternating optimization-based algorithm is proposed to handle the considered problem, which decomposes it into two subproblems: joint optimization of communication, sensing, and computation resources, and UAV trajectory optimization. The former is addressed by a successive convex approximation-based algorithm, while the latter is solved via a trust-region-based algorithm. Simulations validate the effectiveness of the proposed algorithm compared with various benchmarks, and reveal the trade-offs among communication, sensing, and computation in LAE systems.