Cooperative ISAC Network for Off-Grid Imaging-based Low-Altitude Surveillance
Journal:
arXiv
Published Date:
May 5, 2025
Abstract
The low-altitude economy has emerged as a critical focus for future economic
development, emphasizing the urgent need for flight activity surveillance
utilizing the existing sensing capabilities of mobile cellular networks.
Traditional monostatic or localization-based sensing methods, however,
encounter challenges in fusing sensing results and matching channel parameters.
To address these challenges, we propose an innovative approach that directly
draws the radio images of the low-altitude space, leveraging its inherent
sparsity with compressed sensing (CS)-based algorithms and the cooperation of
multiple base stations. Furthermore, recognizing that unmanned aerial vehicles
(UAVs) are randomly distributed in space, we introduce a physics-embedded
learning method to overcome off-grid issues inherent in CS-based models.
Additionally, an online hard example mining method is incorporated into the
design of the loss function, enabling the network to adaptively concentrate on
the samples bearing significant discrepancy with the ground truth, thereby
enhancing its ability to detect the rare UAVs within the expansive low-altitude
space. Simulation results demonstrate the effectiveness of the imaging-based
low-altitude surveillance approach, with the proposed physics-embedded learning
algorithm significantly outperforming traditional CS-based methods under
off-grid conditions.
