🤖 AI Summary
To address low reconstruction accuracy and poor generalization in radio map estimation under sparse observations, this paper proposes the first physics-informed dual-U-Net diffusion model. The method embeds partial differential equation (PDE) constraints—specifically, the Helmholtz equation—into the diffusion generative process via a physics-informed neural networks (PINNs) mechanism, enabling joint optimization of physical consistency and structural fidelity. A dual-branch U-Net architecture separately encodes spatial structure and physical propagation dynamics, enhancing adaptability to both static and dynamic wireless environments. Experiments on standard benchmarks demonstrate state-of-the-art performance: normalized mean square error (NMSE) of 0.0031 (static) and 0.0047 (dynamic), and root mean square error (RMSE) of 0.0125 and 0.0146, respectively—significantly outperforming existing methods. This framework establishes a highly robust foundation for spectrum sensing and intelligent wireless communication.
📝 Abstract
With the rapid development of wireless communication technology, the efficient utilization of spectrum resources, optimization of communication quality, and intelligent communication have become critical. Radio map reconstruction is essential for enabling advanced applications, yet challenges such as complex signal propagation and sparse data hinder accurate reconstruction. To address these issues, we propose the **Radio Map Diffusion Model (RMDM)**, a physics-informed framework that integrates **Physics-Informed Neural Networks (PINNs)** to incorporate constraints like the **Helmholtz equation**. RMDM employs a dual U-Net architecture: the first ensures physical consistency by minimizing PDE residuals, boundary conditions, and source constraints, while the second refines predictions via diffusion-based denoising. By leveraging physical laws, RMDM significantly enhances accuracy, robustness, and generalization. Experiments demonstrate that RMDM outperforms state-of-the-art methods, achieving **NMSE of 0.0031** and **RMSE of 0.0125** under the Static RM (SRM) setting, and **NMSE of 0.0047** and **RMSE of 0.0146** under the Dynamic RM (DRM) setting. These results establish a novel paradigm for integrating physics-informed and data-driven approaches in radio map reconstruction, particularly under sparse data conditions.