Abstract:Wireless world models aim to represent, predict, and reason about wireless propagation by jointly understanding physical environments and channel responses. Realizing such models in sixth-generation (6G) digital twin channels requires datasets that capture measured wireless responses and environment states under real-world propagation conditions. This paper presents WiWorld-RealData, a real-world outdoor multi-band channel and multi-modal sensing dataset collected along campus mobile routes. WiWorld-RealData provides measured channel impulse responses (CIRs) at 3.7 GHz and 6.775 GHz, together with multi-view images, panoramic images, light detection and ranging (LiDAR) point clouds, millimeter-wave (mmWave) radar records, and global navigation satellite system (GNSS) trajectories. Through unified file organization and metadata manifests, the dataset establishes sample-level correspondences among channel responses, environment observations, timestamps, route information, antenna configurations, and quality flags. The overall measurement campaign has produced 10 TB-level multi-modal field data. The current public release provides one representative dual-band route at 3.7 GHz and 6.775 GHz with complete channel-environment alignment, while the acquisition framework supports extension to more frequency bands and scenarios. A case study on environment-assisted path-loss prediction achieves a mean absolute error (MAE) of 2.02 dB and a root mean squared error (RMSE) of 2.69 dB, indicating that the aligned environment observations contain predictive information for channel variations. The dataset is available at https://scc.bupt.edu.cn/dataset-manage/datasets/44, and a ScienceDB mirror will be provided upon release.




Abstract:Partial scan is a common approach to accelerate Magnetic Resonance Imaging (MRI) data acquisition in both 2D and 3D settings. However, accurately reconstructing images from partial scan data (i.e., incomplete k-space matrices) remains challenging due to lack of an effectively global receptive field in both spatial and k-space domains. To address this problem, we propose the following: (1) a novel convolutional operator called Faster Fourier Convolution (FasterFC) to replace the two consecutive convolution operations typically used in convolutional neural networks (e.g., U-Net, ResNet). Based on the spectral convolution theorem in Fourier theory, FasterFC employs alternating kernels of size 1 in 3D case) in different domains to extend the dual-domain receptive field to the global and achieves faster calculation speed than traditional Fast Fourier Convolution (FFC). (2) A 2D accelerated MRI method, FasterFC-End-to-End-VarNet, which uses FasterFC to improve the sensitivity maps and reconstruction quality. (3) A multi-stage 3D accelerated MRI method called FasterFC-based Single-to-group Network (FAS-Net) that utilizes a single-to-group algorithm to guide k-space domain reconstruction, followed by FasterFC-based cascaded convolutional neural networks to expand the effective receptive field in the dual-domain. Experimental results on the fastMRI and Stanford MRI Data datasets demonstrate that FasterFC improves the quality of both 2D and 3D reconstruction. Moreover, FAS-Net, as a 3D high-resolution multi-coil (eight) accelerated MRI method, achieves superior reconstruction performance in both qualitative and quantitative results compared with state-of-the-art 2D and 3D methods.