{"title":"Reinforcing Localization Credibility Through Convex Optimization","authors":"Slavisa Tomic;Marko Beko;Yakubu Tsado;Bamidele Adebisi;Abiola Oladipo","doi":"10.1109/LSP.2025.3601835","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601835","url":null,"abstract":"This work proposes a novel approach to reinforce localization security in wireless networks in the presence of malicious nodes that are able to manipulate (spoof) radio measurements. It substitutes the original measurement model by another one containing an auxiliary variance dilation parameter that disguises corrupted radio links into ones with large noise variances. This allows for relaxing the non-convex maximum likelihood estimator (MLE) into a semidefinite programming (SDP) problem by applying convex-concave programming (CCP) procedure. The proposed SDP solution simultaneously outputs target location and attacker detection estimates, eliminating the need for further application of sophisticated detectors. Numerical results corroborate excellent performance of the proposed method in terms of localization accuracy and show that its detection rates are highly competitive with the state of the art.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3445-3449"},"PeriodicalIF":3.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11134586","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Matrix-Based Signal Reconstruction and Narrowband Interference Suppression in DSSS Systems","authors":"Yuan Liu;Zhenguo Liu;Xuanang Mao;Chuxin Tang","doi":"10.1109/LSP.2025.3601850","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601850","url":null,"abstract":"Spectrum congestion and malicious interference exacerbate narrowband interference (NBI) in wideband direct sequence spread spectrum (DSSS) systems. To address this, we propose a matrix-based signal reconstruction and NBI suppression method using the MBSBL-FM algorithm. By exploiting row and column correlations and block structure information, the proposed approach enhances signal recovery and NBI recognition. We establish a relationship between hyperparameters and signal power, introducing an objective suppression criterion. Additionally, we analyze NBI tolerance to improve practical applicability. Simulations confirm its effectiveness in reconstructing signals, reducing sampling rate requirements, and maintaining robust performance under NBI. The proposed principle can also be extended to other types of spread spectrum (SS) systems.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3400-3404"},"PeriodicalIF":3.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926876","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":"CTrans-SegDiff: CTransfomer-Based Diffusion Model for Ultrasound Image Segmentation","authors":"Yuzhu Cao;Jizhao Liu;Liping Wang;Jing Lian","doi":"10.1109/LSP.2025.3601987","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601987","url":null,"abstract":"Deep generative models, particularly diffusion probabilistic models, have recently shown promise in medical ultrasound image segmentation due to their powerful denoising and detail restoration capabilities. However, most existing generative models focus primarily on image enhancement, with limited consideration for segmentation-specific challenges. To address this, we propose CTrans-SegDiff, a novel segmentation framework that integrates a denoising diffusion probabilistic model with a Transformer-enhanced dynamic conditioning mechanism. Specifically, we design a dual-channel dynamic conditioning module to jointly capture lesion-specific semantics and global contextual dependencies, and a Gaussian Distribution Fusion Module (GDFM) to harmonize the fusion of conditioning features with diffusion-encoded representations. Extensive experiments on two ultrasound datasets demonstrate that our method effectively suppresses noise, enhances structural clarity, and achieves superior segmentation performance compared to existing approaches.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3505-3509"},"PeriodicalIF":3.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061833","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}
Bingfeng He;Li Zhu;Junhua Li;Andrzej Cichocki;Wanzeng Kong
{"title":"Dual-Brain EEG Decoding for Target Detection via Joint Learning in Shared and Private Spaces","authors":"Bingfeng He;Li Zhu;Junhua Li;Andrzej Cichocki;Wanzeng Kong","doi":"10.1109/LSP.2025.3601978","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601978","url":null,"abstract":"Hyperscanning enables simultaneous electroencephalography (EEG) recording from multiple individuals, facilitating collaborative brain activity to reduce individual biases and enhance the reliability of decision-making. The decoding of such collaborative paradigm tasks has traditionally relied solely on simple fusion methods based on each individual brain activity, without incorporating cross-brain coupling information. Inspired by social interaction studies on enhanced inter-brain synchrony in collaborative tasks using hyperscanning, we propose a joint learning framework for dual-brain target detection that integrates a shared space construction module and shared feature-guided module. The shared space construction module incorporates brain-to-brain coupling analysis to identify cross-brain synchrony, and further integrates shared and private features through a multi-head fusion mechanism for joint representation learning in shared feature-guided module. Experimental results show an average 10% improvement in balanced accuracy across 12 participant groups compared to traditional single-brain approaches, with some groups achieving up to a 5% gain over state-of-the-art (SOTA) methods. Notably, higher-performing groups exhibit stronger inter-brain coupling and more synchronized target-related responses. These findings advance the development of collaborative brain-computer interface (BCI) systems for more robust and effective target detection.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3500-3504"},"PeriodicalIF":3.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078640","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 Simple Yet Robust Nonlinear Function for Low-Light Image Enhancement Task","authors":"A. Razafindratovolahy;Y. Rao","doi":"10.1109/LSP.2025.3602001","DOIUrl":"https://doi.org/10.1109/LSP.2025.3602001","url":null,"abstract":"We present a novel, parameter-free nonlinear transformation for low-light image enhancement that operates directly on individual pixel values. This simple yet powerful function requires no prior knowledge or external tuning, and enhances image brightness and contrast by leveraging only the input image itself. When applied iteratively, the method achieves optimal results after just three applications. Despite its minimalism, our approach outperforms recent state-of-the-art methods on benchmarks. This highlights the potential of simple signal processing operations for emergent enhancement, and suggests directions for theoretical analysis, integration with deep learning, and deployment in real-world vision systems.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3370-3374"},"PeriodicalIF":3.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909406","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":"Spectrally Sharpened Two Channel Graph Filter Bank and Its Polyphase Structure","authors":"David B. Tay","doi":"10.1109/LSP.2025.3601560","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601560","url":null,"abstract":"Graph filter banks allow for the spectral analysis of signals defined over graph domains. We consider the construction of two channel biorthogonal filter banks with outputs that are critically sampled. A method that sharpens the frequency response of an existing filter bank will be presented. The method is based on the use of sharpening kernels, and an analytical technique for constructing the kernels will be developed. Polyphase analysis of the sharpened filters will be performed, and the relationship between the original and sharpened polyphase structures will be derived. The polyphase structure allows the filter bank to be implemented efficiently using lifting steps. We will show that the number of lifting steps of the sharpened structure is unchanged, compared to the original structure. Application to nonlinear approximation of images will also be considered.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3470-3474"},"PeriodicalIF":3.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057461","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}
Jiaqi Nie;Ben Yang;Zhiyuan Xue;Xuetao Zhang;Fei Wang
{"title":"Correntropy-Induced Hypergraph Spectral Clustering With Discrete Optimization","authors":"Jiaqi Nie;Ben Yang;Zhiyuan Xue;Xuetao Zhang;Fei Wang","doi":"10.1109/LSP.2025.3601523","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601523","url":null,"abstract":"Hypergraph clustering has garnered considerable attention in complex learning tasks due to its powerful capacity for modeling high-order relationships among samples. Nevertheless, existing methods encounter two fundamental challenges: 1) The need for an additional discretization step following low-dimensional spectral embedding, which introduces a suboptimal mismatch between continuous embeddings and discrete cluster assignments, thereby impairing clustering performance; and 2) the susceptibility to diverse and complex noise are commonly present in real-world scenarios, which significantly compromises clustering robustness. To address these issues, we propose a novel correntropy-induced hypergraph spectral clustering (CIHSC) model. Different from current spectral clustering methods, CIHSC integrates a correntropy-based framework to enable direct discrete spectral decomposition on hypergraphs, eliminating the need for post discretization and thereby enhancing clustering fidelity and robustness. To effectively address the non-convex optimization arising from the correntropy-induced objective, we develop a half-quadratic optimization strategy tailored to the CIHSC model. Extensive experiments conducted on both real-world and noise-contaminated datasets demonstrate that CIHSC consistently outperforms state-of-the-art clustering methods in terms of performance and robustness.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3280-3284"},"PeriodicalIF":3.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144909103","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":"Prompt-Based Cross-Modal Feature Alignment for Weakly Supervised IFER","authors":"Hanqin Shi;Xiaofeng Kang;Jiaxiang Wang;Aihua Zheng;Wenjuan Cheng","doi":"10.1109/LSP.2025.3601513","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601513","url":null,"abstract":"Infrared Facial Expression Recognition (IFER) encounters challenges in data acquisition and annotation under low-light conditions, making fully supervised training difficult. Although pre-trained Vision-Language Models (VLMs) can enhance generalization for downstream tasks, their insufficient attention modeling in cross-domain scenarios leads to ineffective local semantic correlation. To address this, we propose a Prompt-based Cross-modal feature Alignment (PCA) method that improves weakly supervised IFER performance by leveraging RGB facial expression data. The PCA framework comprises two key components: (1) a Cross-modal Prompt Transfer (CPT) strategy that integrates category-specific information to distinguish expressions, and (2) an Image-Guided Alignment (IGA) module that achieves feature alignment using dual-domain feature banks. Experimental results on two benchmark datasets demonstrate that our method significantly outperforms current state-of-the-art approaches, confirming its effectiveness and superiority.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3410-3414"},"PeriodicalIF":3.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926877","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":"Hybrid Cooperative Relative Localization for Urban Vehicles Based on Vehicle-to-Vehicle Communication","authors":"Qijie Li;Zhi Xiong;Chenfa Shi;Tianxv Wu;Jun Xiong","doi":"10.1109/LSP.2025.3601515","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601515","url":null,"abstract":"Accurate vehicle localization is crucial for urban vehicles. We propose a hybrid Gaussian variational message passing (HGVMP) scheme for cooperative relative localization. First, we propose a Gaussian variational message passing (GVMP) framework for state estimation of global navigation satellite system (GNSS) and vehicle-to-vehicle (V2V) observations from multiple vehicles, which puts the messages in GVMP in closed Gaussian form to ensure the stability and efficiency of estimation. In addition, we integrate GVMP with inertial navigation system (INS) via the extended kalman filter (EKF), which makes full use of the inertial information of INS to improve the system’s localization accuracy and stability in dynamic and complex environments. Our experimental results show that in simulated GNSS signal blocked urban environment, the proposed HGVMP achieves a 32.19% improvement in localization accuracy compared to the cooperative localization extended kalman filter (CL-EKF), and the computational efficiency improves by 93.78% over the nonparametric belief propagation (NBP) method.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3380-3384"},"PeriodicalIF":3.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914270","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}
Jianqiang Xu;Yulai Cong;Junyuan Deng;Fei Zeng;Mingcheng Dai
{"title":"Continual NeRF-Based 3D ISAR Imaging With Multilevel Distillation","authors":"Jianqiang Xu;Yulai Cong;Junyuan Deng;Fei Zeng;Mingcheng Dai","doi":"10.1109/LSP.2025.3601535","DOIUrl":"https://doi.org/10.1109/LSP.2025.3601535","url":null,"abstract":"In 3D inverse synthetic aperture radar (ISAR) imaging of space targets, radar neural radiance fields (i.e., ISAR-NeRF) is an important research direction. However, a significant yet unexplored problem is its deployment in continual learning scenarios, where gradual 3D imaging is expected since target ISAR images often emerge sequentially. To address this issue, this letter proposes a new continual 3D ISAR imaging method, named CL-ISAR-NeRF. Specifically, CL-ISAR-NeRF leverages a multilevel distillation mechanism to simultaneously replay pixel, field, and feature-levels information, to alleviate the forgetting of previously learned knowledge. In addition, an efficient memory selection strategy is designed to enrich the diversity of line-of-sight (LOS) when selecting replayed data, which improves imaging performance and further enhances the stability and plasticity of the method. In order to evaluate the proposed method in continual learning settings, we design a realistic simulation scenario in which the trajectories of space targets are calculated by the Simplified General Perturbations-4 (SGP4) model. The comparative experiments with classic continual learning methods demonstrate the superior performance and robustness of CL-ISAR-NeRF.","PeriodicalId":13154,"journal":{"name":"IEEE Signal Processing Letters","volume":"32 ","pages":"3495-3499"},"PeriodicalIF":3.9,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078643","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}