ITSep 13, 2023
Improving the Performance of R17 Type-II Codebook with Deep LearningKe Ma, Yiliang Sang, Yang Ming et al.
The Type-II codebook in Release 17 (R17) exploits the angular-delay-domain partial reciprocity between uplink and downlink channels to select part of angular-delay-domain ports for measuring and feeding back the downlink channel state information (CSI), where the performance of existing deep learning enhanced CSI feedback methods is limited due to the deficiency of sparse structures. To address this issue, we propose two new perspectives of adopting deep learning to improve the R17 Type-II codebook. Firstly, considering the low signal-to-noise ratio of uplink channels, deep learning is utilized to accurately select the dominant angular-delay-domain ports, where the focal loss is harnessed to solve the class imbalance problem. Secondly, we propose to adopt deep learning to reconstruct the downlink CSI based on the feedback of the R17 Type-II codebook at the base station, where the information of sparse structures can be effectively leveraged. Besides, a weighted shortcut module is designed to facilitate the accurate reconstruction. Simulation results demonstrate that our proposed methods could improve the sum rate performance compared with its traditional R17 Type-II codebook and deep learning benchmarks.
IVMay 1
Unsupervised Denoising of Real Clinical Low Dose Liver CT with Perceptual Attention NetworksJingxi Pu, Tonghua Liu, Zhilin Guan et al.
With the development of deep learning, medical image processing has been widely used to assist clinical research. This paper focuses on the denoising problem of low-dose computed tomography using deep learning. Although low-dose computed tomography reduces radiation exposure to patients, it also introduces more noise, which may interfere with visual interpretation by physicians and affect diagnostic results. To address this problem, inspired by Cycle-GAN for unsupervised learning, this paper proposes an end-to-end unsupervised low-dose computed tomography denoising framework. The proposed framework combines a U-Net structure for multi-scale feature extraction, an attention mechanism for feature fusion, and a residual network for feature transformation. It also introduces perceptual loss to improve the network for the characteristics of medical images. In addition, we construct a real low-dose computed tomography dataset and design a large number of comparative experiments to validate the proposed method, using both image-based evaluation metrics and medical evaluation criteria. Compared with classical methods, the main advantage of this paper is that it addresses the limitation that real clinical data cannot be directly used for supervised learning, while still achieving excellent performance. The experimental results are also professionally evaluated by imaging physicians and meet clinical needs.
IVJul 9, 2025
Multi-omic Prognosis of Alzheimer's Disease with Asymmetric Cross-Modal Cross-Attention NetworkYang Ming, Jiang Shi Zhong, Zhou Su Juan
Alzheimer's Disease (AD) is an irreversible neurodegenerative disease characterized by progressive cognitive decline as its main symptom. In the research field of deep learning-assisted diagnosis of AD, traditional convolutional neural networks and simple feature concatenation methods fail to effectively utilize the complementary information between multimodal data, and the simple feature concatenation approach is prone to cause the loss of key information during the process of modal fusion. In recent years, the development of deep learning technology has brought new possibilities for solving the problem of how to effectively fuse multimodal features. This paper proposes a novel deep learning algorithm framework to assist medical professionals in AD diagnosis. By fusing medical multi-view information such as brain fluorodeoxyglucose positron emission tomography (PET), magnetic resonance imaging (MRI), genetic data, and clinical data, it can accurately detect the presence of AD, Mild Cognitive Impairment (MCI), and Cognitively Normal (CN). The innovation of the algorithm lies in the use of an asymmetric cross-modal cross-attention mechanism, which can effectively capture the key information features of the interactions between different data modal features. This paper compares the asymmetric cross-modal cross-attention mechanism with the traditional algorithm frameworks of unimodal and multimodal deep learning models for AD diagnosis, and evaluates the importance of the asymmetric cross-modal cross-attention mechanism. The algorithm model achieves an accuracy of 94.88% on the test set.
ITMay 14, 2023
Deep Learning Empowered Type-II Codebook: New Paradigm for Enhancing CSI FeedbackKe Ma, Yiliang Sang, Yang Ming et al.
Deep learning based channel state information (CSI) feedback in frequency division duplex systems has drawn much attention in both academia and industry. In this paper, we focus on integrating the Type-II codebook in the beyond fifth-generation (B5G) wireless systems with deep learning to enhance the performance of CSI feedback. In contrast to its counterpart in Release 16, the Type-II codebook in Release 17 (R17) exploits the angular-delay-domain partial reciprocity between uplink and downlink channels and selects part of angular-delay-domain ports for measuring and feeding back the downlink CSI, where the performance of the conventional deep learning methods is limited due to the deficiency of sparse structures. To address this issue, we propose the new paradigm of adopting deep learning to improve the performance of R17 Type-II codebook. Firstly, considering the relatively low signal-to-noise ratio of uplink channels, deep learning is utilized to refine the selection of the dominant angular-delay-domain ports, where the focal loss is harnessed to solve the class imbalance problem. Secondly, we propose to reconstruct the downlink CSI by way of deep learning based on the feedback of R17 Type-II codebook at the base station, where the information of sparse structures can be effectively leveraged. Finally, a weighted shortcut module is designed to facilitate the accurate reconstruction, and a two-stage loss function with the combination of the mean squared error and sum rate is proposed for adapting to actual multi-user scenarios. Simulation results demonstrate that our proposed angular-delay-domain port selection and CSI reconstruction paradigm can improve the sum rate performance by more than 10% compared with the traditional R17 Type-II codebook and deep learning benchmarks.