Dual-UAV-Enabled Secure Communication and Sensing for A2G-ISAC Systems with Maneuverable Jamming

TL;DR

The paper addresses secure communication and ground-target sensing in air-to-ground ISAC by deploying a dual-UAV system where a source UAV and a maneuverable jamming UAV collaborate to maximize the average secrecy rate ($ASR$). It introduces a two-phase optimization framework (secure communication and secure communication-plus-sensing, SC and SCS), leveraging SDR, SCA, and a BCD algorithm to jointly optimize trajectories and beamformers, while modeling residual interference from imperfect SIC. A greedy weighted-distance approach selects dual-UAV sensing locations for the SCS phase, and a penalized SCA-based beamforming design achieves the dual objectives of secrecy and sensing within power and maneuvering constraints. Simulation results show significant ASR gains of the proposed SCS scheme over benchmarks, underline the benefits of dual-UAV cooperation, and reveal how residual interference and system parameters influence performance. The work provides practical insights for robust, dual-purpose UAV networks in dynamic A2G-ISAC environments.

Abstract

In this paper, we propose a dual-unmanned aerial vehicle (UAV)-enabled secure communication and sensing (SCS) scheme for an air-to-ground integrated sensing and communication (ISAC) system, in which a dual-functional source UAV and jamming UAV collaborate to enhance both the secure communication and target sensing performance. From a perspective of hybrid monostatitc-bistatic radar, the jamming UAV maneuvers to aid the source UAV to detect multiple ground targets by emitting artificial noise, meanwhile interfering with the ground eavesdropper. Residual interference is considered to reflect the effects of imperfect successive interference cancellation (SIC) on the receive signal-plus-interference-to-noise ratios, which results in a degraded system performance. To maximize the average secrecy rate (ASR), the dual-UAV trajectory and dual-UAV beamforming are jointly optimized subject to the transmit power budget, UAV maneuvering constraint, and sensing requirements. To tackle the highly complicated non-convex ASR maximization problem, the dual-UAV trajectory and dual-UAV beamforming are optimized for the secure communication (SC) purpose and the SCS purpose, sequentially. In the SC phase, a block coordinate descent algorithm is proposed to optimize the dual-UAV trajectory and dual-UAV beamforming iteratively, using the trust-region successive convex approximation (SCA) and semidefinite relaxation (SDR) techniques. Then, a weighted distance minimization problem is formulated to determine the dual-UAV maneuvering positions suitable for the SCS purpose, which is solved by a heuristic greedy algorithm, followed by the joint optimization of source beamforming and jamming beamforming.

Figures (10)

• Figure 1: Dual-UAV-enabled A2G-ISAC system model
• Figure 2: UAV trajectories obtained by different schemes.
• Figure 3: Selected time slot indices for target sensing.
• Figure 4: Secrecy rate at each time slot.
• Figure 5: Sum secrecy rate versus task period duration.