Martin Willame;Gilles Monnoyer;Hasan Can Yildirim;François Horlin;Jérôme Louveaux
{"title":"Multi Target Localization With Block Orthogonal Least Squares for Multistatic MIMO Radars","authors":"Martin Willame;Gilles Monnoyer;Hasan Can Yildirim;François Horlin;Jérôme Louveaux","doi":"10.1109/LSP.2025.3565168","DOIUrl":"https://doi.org/10.1109/LSP.2025.3565168","url":null,"abstract":"Recently, there has been a growing interest in multistatic radar configurations to improve the localization of multiple targets. Theoretically, the maximum likelihood (ML) approach enables to fuse the information provided by each radar pair to localize the different targets. However, it involves a multi-dimensional search process whose complexity exponentially grows with the number of targets. Consequently, heuristic methods, notably including the block orthogonal matching pursuit (BOMP), have been used in the multistatic radar context to approach the ML estimation greedily. Interestingly, the more accurate block orthogonal least squares (BOLS) method has not been studied in this context because the performance improvement is usually low in regard to its computational complexity. In this work, we investigate the application of BOLS to an angle-based localization of multiple targets using a multistatic multiple-input and multiple-output (MIMO) radar. First, an efficient implementation of BOLS is presented reducing its computational complexity. Then, using Monte Carlo simulations, we show evidence of the significant advantage of this efficient implementation of BOLS over BOMP in this scenario featuring highly correlated signals. The impact of radar parameters on the localization root mean square error and on the computational complexity of both algorithms is studied.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1990-1994"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distributed Secure State Estimation Against Stealthy Attacks","authors":"Yan Yu;Wen Yang;Hongbo Yuan;Longyu Li;Chao Yang","doi":"10.1109/LSP.2025.3564886","DOIUrl":"https://doi.org/10.1109/LSP.2025.3564886","url":null,"abstract":"This paper investigates the issue of False Data Injection (FDI) attacks within distributed state estimation. In the network, each sensor transmits its state estimate to neighboring nodes. Based on the detection variables inherent to distributed systems, we construct a covert attack strategy to bypass data detectors and degrade the estimation performance of the system. Furthermore, we propose an enhanced stealthy attack strategy, which aims to prevent interference from the attacks of neighboring edges that otherwise counteract against each other. To improve the detection rate of attacks, a detector with a dynamic coding strategy is designed to secure data transmission. The destructiveness of the stealthy attacks and the effectiveness of the detection mechanism are demonstrated through numerical examples.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1930-1934"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Instantaneous Frequency Estimation via Ridge Detection in Polynomial Time and Space","authors":"Igor Djurović","doi":"10.1109/LSP.2025.3564882","DOIUrl":"https://doi.org/10.1109/LSP.2025.3564882","url":null,"abstract":"Application of ridge detection algorithms to various transforms and problems in time-frequency (TF) analysis has become increasingly widespread with notable application in the instantaneous frequency (IF) estimation. Metaheuristic techniques, such as simulated annealing algorithms, are commonly employed for ridge detection. In this letter, we demonstrate that ridge detection can be achieved using an instance of the Viterbi algorithm (VA). This implementation ensures a global optimum with polynomial time and space complexity. The proposed ridge detection IF estimator is compared to an alternative approach based on the VA.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1975-1979"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Conditional Diffusion Model for Skeleton-Based Gesture Recognition With Severe Occlusions","authors":"Jinting Liu;Minggang Gan;Yao Du;Keyi Guan;Jia Guo","doi":"10.1109/LSP.2025.3563445","DOIUrl":"https://doi.org/10.1109/LSP.2025.3563445","url":null,"abstract":"In the field of skeleton-based gesture recognition, occlusion remains a significant challenge, significantly degrading performance when key joints are occluded or disturbed. To tackle this issue, we propose DiffTrans, a practical conditional diffusion model for occlusion recognition, which enables skeleton-based gesture recognition under high occlusion by generating more likely samples. This study addresses the hand skeleton occlusion problem by framing it as a conditional denoising problem, where unoccluded data serve as observations and occluded data as repair targets. We employ a conditional diffusion model to impute the missing skeleton data and the DSTANet model, which is based on the transformer, to learn the skeleton feature representations. Research results show that the DiffTrans outperforms existing methods under various occlusion modes, maintaining high performance even in scenarios with a high missing rate.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1970-1974"},"PeriodicalIF":3.2,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Convex Combination-Based Distributed Momentum Methods Over Directed Graphs","authors":"Siyuan Huang;Juan Gao;Qiao-Li Dong;Cuijie Zhang","doi":"10.1109/LSP.2025.3563722","DOIUrl":"https://doi.org/10.1109/LSP.2025.3563722","url":null,"abstract":"In this article, we introduce a convex combination-based distributed momentum method (CDM) for solving distributed optimization to minimize a sum of smooth and strongly convex local objective functions over directed graphs. The proposed method integrates the convex combination, row- and column-stochastic weights, and the adapt-then-combination rule. By selecting different parameters, it can be reduced to other distributed momentum methods, such as the parametric distributed momentum. CDM converges to the optimal solution at a global <italic>R-</i>linear rate for any smooth and strongly convex function when the step-size and momentum coefficient satisfy some bounded conditions. Numerical results for some distributed optimization problems demonstrate that CDM yields a performance that is superior to that of the state-of-the-art methods.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1835-1839"},"PeriodicalIF":3.2,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jingsheng Qian;Hangjie Yi;Honggang Liu;Xuanyu Jin;Wanzeng Kong
{"title":"QELDBA: Query-Efficient and Low Distortion Black-Box Attack for Brainprint Recognition","authors":"Jingsheng Qian;Hangjie Yi;Honggang Liu;Xuanyu Jin;Wanzeng Kong","doi":"10.1109/LSP.2025.3563446","DOIUrl":"https://doi.org/10.1109/LSP.2025.3563446","url":null,"abstract":"While various deep learning techniques for electroencephalogram (EEG)-based brainprint recognition have achieved considerable success, these models remain vulnerable to adversarial attacks. However, existing black-box attack methods suffer from an inherent trade-off between query efficiency and distortion level. To address this challenge and further investigate the security risks of brainprint recognition systems in real-world black-box scenarios, we propose a query-efficient, low-distortion black-box attack method that targets the high-frequency components of EEG signals. Our approach innovatively selects sparse sampling points to estimate more accurate gradient information and leverages historical gradients to guide the prioritization of important points, thereby accelerating the attack process. The perturbations are applied in the high-frequency domain of the EEG signal to enhance stealth and effectiveness. Extensive experiments under black-box settings demonstrate that our method achieves state-of-the-art performance across two datasets and four models. Compared to existing methods, our approach significantly improves attack success rates while reducing the number of queries and minimizing distortion to imperceptible levels, thus achieving a superior balance between query efficiency and perturbation stealth.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"2020-2024"},"PeriodicalIF":3.2,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144099972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Asynchronous Voice Anonymization by Learning From Speaker-Adversarial Speech","authors":"Rui Wang;Liping Chen;Kong Aik Lee;Zhen-Hua Ling","doi":"10.1109/LSP.2025.3563306","DOIUrl":"https://doi.org/10.1109/LSP.2025.3563306","url":null,"abstract":"This letter focuses on asynchronous voice anonymization, wherein machine-discernible speaker attributes in a speech utterance are obscured while human perception is preserved. We propose to transfer the voice-protection capability of speaker-adversarial speech to speaker embedding, thereby facilitating the modification of speaker embedding extracted from original speech to generate anonymized speech. Experiments conducted on the LibriSpeech dataset demonstrated that compared to the speaker-adversarial utterances, the generated anonymized speech demonstrates improved transferability and voice-protection capability. Furthermore, the proposed method enhances the human perception preservation capability of anonymized speech within the generative asynchronous voice anonymization framework.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1905-1909"},"PeriodicalIF":3.2,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yao Chen;Jiabao Wang;Peichao Wang;Rui Zhang;Yang Li
{"title":"Vision Mamba Distillation for Low-Resolution Fine-Grained Image Classification","authors":"Yao Chen;Jiabao Wang;Peichao Wang;Rui Zhang;Yang Li","doi":"10.1109/LSP.2025.3563441","DOIUrl":"https://doi.org/10.1109/LSP.2025.3563441","url":null,"abstract":"Low-resolution fine-grained image classification has recently made significant progress, largely thanks to the super-resolution techniques and knowledge distillation methods. However, these approaches lead to an exponential increase in the number of parameters and computational complexity of models. In order to solve this problem, in this letter, we propose a Vision Mamba Distillation (ViMD) approach to enhance the effectiveness and efficiency of low-resolution fine-grained image classification. Concretely, a lightweight super-resolution vision Mamba classification network (SRVM-Net) is proposed to improve its capability for extracting visual features by redesigning the classification sub-network with Mamba modeling. Moreover, we design a novel multi-level Mamba knowledge distillation loss to boost the performance. The loss can transfer prior knowledge obtained from a High-resolution Vision Mamba classification Network (HRVM-Net) as a teacher into the proposed SRVM-Net as a student. Extensive experiments on seven public fine-grained classification datasets related to benchmarks confirm our ViMD achieves a new state-of-the-art performance. While having higher accuracy, ViMD outperforms similar methods with fewer parameters and FLOPs, which is more suitable for embedded device applications.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1965-1969"},"PeriodicalIF":3.2,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Complex Singular Spectrum Analysis Leveraging Adaptive Taper Windows for Enhancing Mode Reconstruction From Multivariate Signals","authors":"Jialiang Gu;Kevin Hung;Bingo Wing-Kuen Ling;Daniel Hung-Kay Chow;Yang Zhou","doi":"10.1109/LSP.2025.3562823","DOIUrl":"https://doi.org/10.1109/LSP.2025.3562823","url":null,"abstract":"In this letter, a generic extension of complex singular spectrum analysis (CSSA), referred to as GC-SSA, is proposed to enhance mode reconstruction from multivariate signals. This is achieved by introducing adaptive taper windows for CSSA. Specifically, we formulate an optimization problem related to window design for specific multivariate signals, and then employ an iterative algorithm to optimize the coefficients of the taper windows. GC-SSA using optimized taper windows can decompose multivariate signals and perfectly reconstruct time-varying modes that have maximally concentrated energy. Numerical simulations were demonstrated to validate the effectiveness of the proposed method in mode reconstruction compared to other multivariate signal processing methods.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1820-1824"},"PeriodicalIF":3.2,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ASSMark: Dual Defense Against Speech Synthesis Attack via Adversarial Robust Watermarking","authors":"Yulin He;Hongxia Wang;Yiqin Qiu;Hao Cao","doi":"10.1109/LSP.2025.3562817","DOIUrl":"https://doi.org/10.1109/LSP.2025.3562817","url":null,"abstract":"Given the widespread dissemination of digital audio and the advancements in speech synthesis technologies, protecting audio copyright has become a critical issue. Although watermarks play an important role in copyright verification and forensic analysis, they are insufficient to proactively defend against malicious speech synthesis. To address this issue, we introduce a novel adversarial speech synthesis watermarking mechanism (ASSMark), which simultaneously traces the audio copyright and disrupts the speech synthesis models by embedding robust adversarial watermarks in a one-time manner. Specifically, we design a unified training framework that models the embedding of watermarks and adversarial perturbations as collaborative tasks. This approach allows for the fine-tuning of any robust watermark into an adversarial watermark, resulting in watermarked audio that can effectively defend against unauthorized speech synthesis attacks. Experimental results demonstrate that ASSMark achieves over 90% protection rate even to unknown black-box models. Compared to simplistic two-step protection methods, it not only effectively resists synthesis attacks but also achieves superior watermark extraction accuracy and speech quality, offering an outstanding solution for protecting audio copyright.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"1870-1874"},"PeriodicalIF":3.2,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143929842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}