Pub Date : 2026-01-05DOI: 10.1016/j.sigpro.2026.110491
Chengxin Yang , Benoit Champagne , Wei Yi
This paper addresses the optimization problem of transmit beamforming design for area surveillance and multi-target tracking (MTT) in a colocated multiple-input multiple-output (C-MIMO) radar system. We first establish the relationship between the detection probability and the predictive Cramér-Rao lower bound (PCRLB) as performance metrics, and the transmit signal correlation matrix as the design variable. The surveillance area, defined as a circular sector bounded by a polar angle and the intersecting arc, is divided into independent smaller sectors, each corresponding to a different illumination direction of the C-MIMO radar. To maximize the efficient utilization of power resources, we then aim to maximize the number of simultaneously illuminated sectors while achieving desired detection probability and target tracking accuracy. Given that the formulated optimization problem is an intractable non-convex mixed-integer nonlinear problem, we propose a beamforming algorithm based on Quality of Service (QoS) to solve it efficiently. Simulation results indicate that the proposed algorithm is capable of effectively maximizing the illuminated area while consistently meeting the specified detection probability and MTT accuracy requirements.
{"title":"Transmit beamforming design for area surveillance and multi-target tracking in colocated MIMO radar","authors":"Chengxin Yang , Benoit Champagne , Wei Yi","doi":"10.1016/j.sigpro.2026.110491","DOIUrl":"10.1016/j.sigpro.2026.110491","url":null,"abstract":"<div><div>This paper addresses the optimization problem of transmit beamforming design for area surveillance and multi-target tracking (MTT) in a colocated multiple-input multiple-output (C-MIMO) radar system. We first establish the relationship between the detection probability and the predictive Cramér-Rao lower bound (PCRLB) as performance metrics, and the transmit signal correlation matrix as the design variable. The surveillance area, defined as a circular sector bounded by a polar angle and the intersecting arc, is divided into independent smaller sectors, each corresponding to a different illumination direction of the C-MIMO radar. To maximize the efficient utilization of power resources, we then aim to maximize the number of simultaneously illuminated sectors while achieving desired detection probability and target tracking accuracy. Given that the formulated optimization problem is an intractable non-convex mixed-integer nonlinear problem, we propose a beamforming algorithm based on Quality of Service (QoS) to solve it efficiently. Simulation results indicate that the proposed algorithm is capable of effectively maximizing the illuminated area while consistently meeting the specified detection probability and MTT accuracy requirements.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110491"},"PeriodicalIF":3.6,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978342","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}
Pub Date : 2026-01-03DOI: 10.1016/j.sigpro.2026.110487
Kunlong Zhao , Jilu Jin , Xueqin Luo , Gongping Huang , Jingdong Chen , Jacob Benesty
Differential microphone arrays (DMAs) are recognized for their highly directive broadband beampatterns and have attracted significant interest in the design of compact microphone arrays. It has been shown that increasing the number of microphones in a DMA can improve array performance. However, when applying DMAs to embedded systems, this creates challenges due to the increased number of parameters, higher computational complexity, and the need to maintain the array’s robustness. To address these challenges, this paper presents a method for designing robust low-rank (LR) differential beamformers. Initially, we extend traditional differential beamforming by introducing an LR differential beamforming framework, which represents a long filter as the Kronecker product of two sets of shorter filters, significantly reducing both the number of parameters and computational complexity. Next, we derive robust designs for the two sets of shorter filters by maximizing the directivity factor (DF) subject to a white noise gain (WNG) constraint, or by maximizing the WNG subject to a DF constraint. This results in two types of LR differential beamformers that achieve the desired DF or WNG levels. The optimization problems are formulated and transformed into quadratic eigenvalue problems (QEPs), leading to closed-form solutions for both the WNG-constrained and DF-constrained LR differential beamformers. Simulation results demonstrate the effectiveness of the proposed method, confirming its robustness and enhanced computational efficiency.
{"title":"Design of Low-Rank differential beamformers with constrained directivity or robustness","authors":"Kunlong Zhao , Jilu Jin , Xueqin Luo , Gongping Huang , Jingdong Chen , Jacob Benesty","doi":"10.1016/j.sigpro.2026.110487","DOIUrl":"10.1016/j.sigpro.2026.110487","url":null,"abstract":"<div><div>Differential microphone arrays (DMAs) are recognized for their highly directive broadband beampatterns and have attracted significant interest in the design of compact microphone arrays. It has been shown that increasing the number of microphones in a DMA can improve array performance. However, when applying DMAs to embedded systems, this creates challenges due to the increased number of parameters, higher computational complexity, and the need to maintain the array’s robustness. To address these challenges, this paper presents a method for designing robust low-rank (LR) differential beamformers. Initially, we extend traditional differential beamforming by introducing an LR differential beamforming framework, which represents a long filter as the Kronecker product of two sets of shorter filters, significantly reducing both the number of parameters and computational complexity. Next, we derive robust designs for the two sets of shorter filters by maximizing the directivity factor (DF) subject to a white noise gain (WNG) constraint, or by maximizing the WNG subject to a DF constraint. This results in two types of LR differential beamformers that achieve the desired DF or WNG levels. The optimization problems are formulated and transformed into quadratic eigenvalue problems (QEPs), leading to closed-form solutions for both the WNG-constrained and DF-constrained LR differential beamformers. Simulation results demonstrate the effectiveness of the proposed method, confirming its robustness and enhanced computational efficiency.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110487"},"PeriodicalIF":3.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927621","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}
Pub Date : 2026-01-03DOI: 10.1016/j.sigpro.2025.110479
Srihari P V, Anik Kumar Paul, Bharath Bhikkaji
This paper considers the Federated learning (FL) in a stochastic approximation (SA) framework. Here, each client i trains a local model using its dataset and periodically transmits the model parameters to a central server, where they are aggregated into a global model parameter and sent back. The clients continue their training by re-initializing their local models with the global model parameters.
Prior works typically assumed constant (and often identical) step sizes (learning rates) across clients for model training. As a consequence the aggregated model converges only in expectation. In this work, client-specific tapering step sizes are used. The global model is shown to track an ODE with a forcing function equal to the weighted sum of the negative gradients of the individual clients. The weights being the limiting ratios of the step sizes, where . Unlike the constant step sizes, the convergence here is with probability one.
In this framework, the clients with the larger p(i) exert a greater influence on the global model than those with smaller p(i), which can be used to favor clients that have rare and uncommon data. Numerical experiments were conducted to validate the convergence and demonstrate the choice of step-sizes for regulating the influence of the clients.
{"title":"Federated learning: A stochastic approximation approach","authors":"Srihari P V, Anik Kumar Paul, Bharath Bhikkaji","doi":"10.1016/j.sigpro.2025.110479","DOIUrl":"10.1016/j.sigpro.2025.110479","url":null,"abstract":"<div><div>This paper considers the Federated learning (FL) in a stochastic approximation (SA) framework. Here, each client <em>i</em> trains a local model using its dataset <span><math><msup><mi>D</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup></math></span> and periodically transmits the model parameters <span><math><msubsup><mi>w</mi><mi>n</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup></math></span> to a central server, where they are aggregated into a global model parameter <span><math><msub><mover><mi>w</mi><mo>¯</mo></mover><mi>n</mi></msub></math></span> and sent back. The clients continue their training by re-initializing their local models with the global model parameters.</div><div>Prior works typically assumed constant (and often identical) step sizes (learning rates) across clients for model training. As a consequence the aggregated model converges only in expectation. In this work, client-specific tapering step sizes <span><math><msubsup><mi>a</mi><mi>n</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup></math></span> are used. The global model is shown to track an ODE with a forcing function equal to the weighted sum of the negative gradients of the individual clients. The weights being the limiting ratios <span><math><mrow><msup><mi>p</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msup><mo>=</mo><msub><mi>lim</mi><mrow><mi>n</mi><mo>→</mo><mi>∞</mi></mrow></msub><mfrac><msubsup><mi>a</mi><mi>n</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup><msubsup><mi>a</mi><mi>n</mi><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msubsup></mfrac></mrow></math></span> of the step sizes, where <span><math><mrow><msubsup><mi>a</mi><mi>n</mi><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msubsup><mo>≥</mo><msubsup><mi>a</mi><mi>n</mi><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup><mo>,</mo><mo>∀</mo><mi>n</mi></mrow></math></span>. Unlike the constant step sizes, the convergence here is with probability one.</div><div>In this framework, the clients with the larger <em>p</em><sup>(<em>i</em>)</sup> exert a greater influence on the global model than those with smaller <em>p</em><sup>(<em>i</em>)</sup>, which can be used to favor clients that have rare and uncommon data. Numerical experiments were conducted to validate the convergence and demonstrate the choice of step-sizes for regulating the influence of the clients.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110479"},"PeriodicalIF":3.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927505","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}
Pub Date : 2026-01-03DOI: 10.1016/j.sigpro.2026.110490
Khadija Omar Mohammed, Liping Du, Yueyun Chen
Effective spectrum sensing in fading environments faces challenges due to correlated noise, strong multipath effects, and complex non-linear dependencies among received signals. Traditional eigenvalue-based detectors often assume independence or capture only limited forms of dependence, which reduces reliability in realistic conditions. This study proposes an Adaptive Joint Metric Detection Algorithm (AJMDA) that integrates both independent and dependency eigenvalue statistics into a unified framework. The independent metric represents the signal energy through the sum of eigenvalues, while the dependency metric captures the statistical structure using copula modeling with the Cramér–von Mises (CVM) goodness-of-fit test. An adaptive weighting factor balances these two metrics, and a generalized extreme value (GEV) model provides analytical threshold estimation. Simulation results under Rayleigh fading show that AJMDA significantly improves detection performance over classical energy detectors, eigenvalue-based GOF tests, and copula-only methods. At –15 dB SNR, the proposed detectors achieve a 45–50% higher detection probability, and at –10 dB SNR, they maintain a 20–60% gain, depending on the baseline. In ROC analysis, AJMDA achieves 10–25% higher performance at low-to-moderate false-alarm levels, approaching the ideal vertical ROC curve.
衰落环境下的有效频谱感知面临着相关噪声、强多径效应和接收信号之间复杂的非线性依赖关系的挑战。传统的基于特征值的检测器通常假设独立性或只捕获有限形式的依赖性,这降低了现实条件下的可靠性。本文提出了一种自适应联合度量检测算法(AJMDA),该算法将独立和依赖特征值统计集成到一个统一的框架中。独立度量通过特征值的和表示信号能量,而依赖度量使用与cram - von Mises (CVM)拟合优度检验的copula建模来捕获统计结构。自适应加权因子平衡这两个度量,广义极值(GEV)模型提供分析阈值估计。Rayleigh衰落下的仿真结果表明,与经典能量检测器、基于特征值的GOF测试和纯copula方法相比,AJMDA检测性能有显著提高。在-15 dB信噪比下,所提出的检测器实现了45-50%的高检测概率,在-10 dB信噪比下,它们保持了20-60%的增益,具体取决于基线。在ROC分析中,AJMDA在中低虚警水平下的性能提高了10-25%,接近理想的垂直ROC曲线。
{"title":"Adaptive joint-metric detection algorithm for efficient spectrum sensing: A deep-water case study","authors":"Khadija Omar Mohammed, Liping Du, Yueyun Chen","doi":"10.1016/j.sigpro.2026.110490","DOIUrl":"10.1016/j.sigpro.2026.110490","url":null,"abstract":"<div><div>Effective spectrum sensing in fading environments faces challenges due to correlated noise, strong multipath effects, and complex non-linear dependencies among received signals. Traditional eigenvalue-based detectors often assume independence or capture only limited forms of dependence, which reduces reliability in realistic conditions. This study proposes an Adaptive Joint Metric Detection Algorithm (AJMDA) that integrates both independent and dependency eigenvalue statistics into a unified framework. The independent metric represents the signal energy through the sum of eigenvalues, while the dependency metric captures the statistical structure using copula modeling with the Cramér–von Mises (CVM) goodness-of-fit test. An adaptive weighting factor balances these two metrics, and a generalized extreme value (GEV) model provides analytical threshold estimation. Simulation results under Rayleigh fading show that AJMDA significantly improves detection performance over classical energy detectors, eigenvalue-based GOF tests, and copula-only methods. At –15 dB SNR, the proposed detectors achieve a 45–50% higher detection probability, and at –10 dB SNR, they maintain a 20–60% gain, depending on the baseline. In ROC analysis, AJMDA achieves 10–25% higher performance <span><math><mrow><msub><mi>P</mi><mi>d</mi></msub><mspace></mspace></mrow></math></span>at low-to-moderate false-alarm levels, approaching the ideal vertical ROC curve.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110490"},"PeriodicalIF":3.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927509","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}
Pub Date : 2026-01-02DOI: 10.1016/j.sigpro.2025.110463
Meng-Qi Wang, Xiao-Heng Chang
This paper studies the problem of non-fragile H∞ control for uncertain bilinear systems with the quantized control input. The research focus lies in designing the controller by fully considering the influence of various uncertainties in the actual system on the system performance, as well as the situation where the system input is quantized, to ensure that the closed-loop control system to have the specified H∞ performance index. By introducing the Lyapnov function and applying the Linear Matrix Inequality (LMI) method, the complex system stability conditions are transformed into easily solvable LMI problems, and the design conditions of the H∞ controller to ensure the stability of the continuous-time bilinear system with uncertain are derived. It can be clear seen from the simulation experiments that the designed H∞ controller can effectively deal with the system uncertainties and signal quantization problems, verifying the effectiveness of the design method proposed in this paper.
{"title":"Non-fragile H∞ control of uncertain bilinear systems with signal quantization","authors":"Meng-Qi Wang, Xiao-Heng Chang","doi":"10.1016/j.sigpro.2025.110463","DOIUrl":"10.1016/j.sigpro.2025.110463","url":null,"abstract":"<div><div>This paper studies the problem of non-fragile <em>H</em><sub>∞</sub> control for uncertain bilinear systems with the quantized control input. The research focus lies in designing the controller by fully considering the influence of various uncertainties in the actual system on the system performance, as well as the situation where the system input is quantized, to ensure that the closed-loop control system to have the specified <em>H</em><sub>∞</sub> performance index. By introducing the Lyapnov function and applying the Linear Matrix Inequality (LMI) method, the complex system stability conditions are transformed into easily solvable LMI problems, and the design conditions of the <em>H</em><sub>∞</sub> controller to ensure the stability of the continuous-time bilinear system with uncertain are derived. It can be clear seen from the simulation experiments that the designed <em>H</em><sub>∞</sub> controller can effectively deal with the system uncertainties and signal quantization problems, verifying the effectiveness of the design method proposed in this paper.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110463"},"PeriodicalIF":3.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927506","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}
Pub Date : 2026-01-02DOI: 10.1016/j.sigpro.2026.110488
Zehua Sun, Shuli Sun
This paper is focused on the issue of distributed recursive linear fusion estimation in multi-sensor multi-rate linear discrete-time stochastic systems with non-Gaussian noises. The asynchronous sampling system is transformed into a synchronous sampling system through the pseudo-observation method. First, local filter in the minimum error entropy criterion is obtained at each sensor. Then, a distributed recursive linear fusion filter without feedback in the linear unbiased minimum variance criterion is presented based on local filters from all sensors. Estimation error cross-covariance matrices between local filters are derived. The proposed fusion filter is more accurate than the matrix-weighted fusion filter from local filters. Finally, to further improve the estimation accuracy, a distributed recursive linear fusion filter with feedback is presented, which avoids calculating cross-covariance matrices. The effectiveness of fusion algorithms is verified by simulations.
{"title":"Distributed recursive linear fusion estimation for multi-sensor multi-rate systems with non-Gaussian noises","authors":"Zehua Sun, Shuli Sun","doi":"10.1016/j.sigpro.2026.110488","DOIUrl":"10.1016/j.sigpro.2026.110488","url":null,"abstract":"<div><div>This paper is focused on the issue of distributed recursive linear fusion estimation in multi-sensor multi-rate linear discrete-time stochastic systems with non-Gaussian noises. The asynchronous sampling system is transformed into a synchronous sampling system through the pseudo-observation method. First, local filter in the minimum error entropy criterion is obtained at each sensor. Then, a distributed recursive linear fusion filter without feedback in the linear unbiased minimum variance criterion is presented based on local filters from all sensors. Estimation error cross-covariance matrices between local filters are derived. The proposed fusion filter is more accurate than the matrix-weighted fusion filter from local filters. Finally, to further improve the estimation accuracy, a distributed recursive linear fusion filter with feedback is presented, which avoids calculating cross-covariance matrices. The effectiveness of fusion algorithms is verified by simulations.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110488"},"PeriodicalIF":3.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927504","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}
In practical engineering settings, operating conditions are seldom ideal: input signals are corrupted by noise, desired signals suffer interference, and measurements can be unanticipated truncated. These nonidealities reduce the effectiveness of standard adaptive algorithms and can lead to biased or unstable results. To address these challenges, this paper proposes a robust method called the unanticipated truncation-constrained least total logistic distance metric (UT-CLTLDM). The method combines a maximum likelihood approach with an expectation-maximization framework and a least total squares strategy to handle both input noise and signal truncation effectively. Simulation results show that the proposed algorithm achieves superior estimation accuracy and faster convergence compared to existing methods. Its effectiveness is further validated using chaotic input signals from Chua’s circuit model.
{"title":"Constrained least total logistic distance metric algorithm for unanticipated signal truncation","authors":"Pengwei Wen , Botao Jin , Boyang Qu , Sheng Zhang , Xuzhao Chai","doi":"10.1016/j.sigpro.2025.110478","DOIUrl":"10.1016/j.sigpro.2025.110478","url":null,"abstract":"<div><div>In practical engineering settings, operating conditions are seldom ideal: input signals are corrupted by noise, desired signals suffer interference, and measurements can be unanticipated truncated. These nonidealities reduce the effectiveness of standard adaptive algorithms and can lead to biased or unstable results. To address these challenges, this paper proposes a robust method called the unanticipated truncation-constrained least total logistic distance metric (UT-CLTLDM). The method combines a maximum likelihood approach with an expectation-maximization framework and a least total squares strategy to handle both input noise and signal truncation effectively. Simulation results show that the proposed algorithm achieves superior estimation accuracy and faster convergence compared to existing methods. Its effectiveness is further validated using chaotic input signals from Chua’s circuit model.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110478"},"PeriodicalIF":3.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927503","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}
Pub Date : 2026-01-01DOI: 10.1016/j.sigpro.2025.110483
Lin Chen , Lin Gao , Yuxuan Xia , Chaoqun Yang , Zijie Shang , Zhicheng Su , Ting Yuan , Ping Wei
This paper considers the multi-target tracking (MTT) problem under epistemic uncertainty, and such a goal is achieved by integrating possibility theory into the Poisson multi-Bernoulli mixture (PMBM) filtering framework. To do so, we first define the possibility PMBM, and then we derive the possibility PMBM filtering recursions. The resulting possibility PMBM filter preserves strong theoretical foundations of PMBM while enhancing robustness to model mismatches. In addition, we present the possibility Poisson multi-Bernoulli (PMB) filter, which is a computationally efficient approximation of the possibility PMBM filter. We also present analytical implementations of the proposed possibility PMBM and possibility PMB filters based on Gaussian mixture representation and their robustness and estimation accuracy have been demonstrated in the simulation studies.
{"title":"Possibility PMBM filter for robust multi-target tracking","authors":"Lin Chen , Lin Gao , Yuxuan Xia , Chaoqun Yang , Zijie Shang , Zhicheng Su , Ting Yuan , Ping Wei","doi":"10.1016/j.sigpro.2025.110483","DOIUrl":"10.1016/j.sigpro.2025.110483","url":null,"abstract":"<div><div>This paper considers the multi-target tracking (MTT) problem under epistemic uncertainty, and such a goal is achieved by integrating possibility theory into the Poisson multi-Bernoulli mixture (PMBM) filtering framework. To do so, we first define the possibility PMBM, and then we derive the possibility PMBM filtering recursions. The resulting possibility PMBM filter preserves strong theoretical foundations of PMBM while enhancing robustness to model mismatches. In addition, we present the possibility Poisson multi-Bernoulli (PMB) filter, which is a computationally efficient approximation of the possibility PMBM filter. We also present analytical implementations of the proposed possibility PMBM and possibility PMB filters based on Gaussian mixture representation and their robustness and estimation accuracy have been demonstrated in the simulation studies.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110483"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927508","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}
Due to the enhanced beam flexibility and improved tracking performance, the colocated multiple-input multiple-output (MIMO) radar technology has been increasingly adopted in multifunction radar (MFR) systems. The use of narrow beamwidths in high-precision radar systems increases the likelihood of missed illuminations, violating conventional tracking assumptions and challenging existing beam scheduling methods. In order to address the narrow-beam problem, a Gaussian mixture (GM) filtering method is proposed, which refines the target state distribution using the information obtained from missed detections. Based on the proposed filter, a beam steering strategy is introduced to enable rapid target localization. To predict the tracking performance for multitarget tracking (MTT) with narrow beamwidths, the multiple hypothesis posterior Cramér-Rao lower bound (MH-PCRLB) is derived. Taking advantage of the proposed MH-PCRLB, the narrow-beam scheduling problem is formulated as a mathematical optimization. Simulation results demonstrate the superior performance of the proposed filtering method, beam steering strategy and the beam scheduling approach.
{"title":"Simultaneous multiple high-precision beam scheduling for multitarget tracking","authors":"Honghao Guang, Ratnasingham Tharmarasa, Thia Kirubarajan","doi":"10.1016/j.sigpro.2025.110486","DOIUrl":"10.1016/j.sigpro.2025.110486","url":null,"abstract":"<div><div>Due to the enhanced beam flexibility and improved tracking performance, the colocated multiple-input multiple-output (MIMO) radar technology has been increasingly adopted in multifunction radar (MFR) systems. The use of narrow beamwidths in high-precision radar systems increases the likelihood of missed illuminations, violating conventional tracking assumptions and challenging existing beam scheduling methods. In order to address the narrow-beam problem, a Gaussian mixture (GM) filtering method is proposed, which refines the target state distribution using the information obtained from missed detections. Based on the proposed filter, a beam steering strategy is introduced to enable rapid target localization. To predict the tracking performance for multitarget tracking (MTT) with narrow beamwidths, the multiple hypothesis posterior Cramér-Rao lower bound (MH-PCRLB) is derived. Taking advantage of the proposed MH-PCRLB, the narrow-beam scheduling problem is formulated as a mathematical optimization. Simulation results demonstrate the superior performance of the proposed filtering method, beam steering strategy and the beam scheduling approach.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110486"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927510","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}
Pub Date : 2026-01-01DOI: 10.1016/j.sigpro.2025.110482
Saulo Cardoso Barreto, Julien Flamant, Sebastian Miron, David Brie
Matrix-valued images appear in many applications, ranging from polarimetric remote sensing to medical imaging. Such images can be represented as 4th-order tensors, where the first two dimensions correspond to spatial variables and the last two encode the matrix feature in each pixel. To efficiently analyze, decompose, and process these images, this paper considers the block-block terms decomposition (2BTD), a versatile low-rank tensor decomposition model that extends bilinear matrix factorization to 4th-order tensors by representing the latter as the sum of outer products of low-rank matrix blocks. Low-rank assumptions allow for a significantly reduced number of parameters to be estimated and enable the enforcement of key physical constraints on matrix sources. We establish both necessary and sufficient conditions for the uniqueness of the 2BTD model. To enable the use of 2BTD in covariance matrix-valued imaging, we develop an optimization framework that allows efficient handling of non-negativity and symmetry constraints together with low-rank assumptions on matrix blocks. Numerical experiments on synthetic and real data from Diffusion Tensor Imaging (DTI) illustrate the potential of the 2BTD model in matrix-valued imaging, as well as its effectiveness in practical settings.
{"title":"Tensor block-block terms decomposition for matrix-valued imaging applications","authors":"Saulo Cardoso Barreto, Julien Flamant, Sebastian Miron, David Brie","doi":"10.1016/j.sigpro.2025.110482","DOIUrl":"10.1016/j.sigpro.2025.110482","url":null,"abstract":"<div><div>Matrix-valued images appear in many applications, ranging from polarimetric remote sensing to medical imaging. Such images can be represented as 4th-order tensors, where the first two dimensions correspond to spatial variables and the last two encode the matrix feature in each pixel. To efficiently analyze, decompose, and process these images, this paper considers the block-block terms decomposition (2BTD), a versatile low-rank tensor decomposition model that extends bilinear matrix factorization to 4th-order tensors by representing the latter as the sum of outer products of low-rank matrix blocks. Low-rank assumptions allow for a significantly reduced number of parameters to be estimated and enable the enforcement of key physical constraints on matrix sources. We establish both necessary and sufficient conditions for the uniqueness of the 2BTD model. To enable the use of 2BTD in covariance matrix-valued imaging, we develop an optimization framework that allows efficient handling of non-negativity and symmetry constraints together with low-rank assumptions on matrix blocks. Numerical experiments on synthetic and real data from Diffusion Tensor Imaging (DTI) illustrate the potential of the 2BTD model in matrix-valued imaging, as well as its effectiveness in practical settings.</div></div>","PeriodicalId":49523,"journal":{"name":"Signal Processing","volume":"243 ","pages":"Article 110482"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927507","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}