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He, Y. (author), Coutino, Mario (author), Isufi, E. (author), Leus, G.J.T. (author)In this work, we focus on partitioning dynamic graphs with two types of nodes (bi-colored), though not necessarily bipartite graphs. They commonly appear in communication network applications, e.g., one color being base stations, the other users, and the dynamic process being the varying connection status between base stations and moving...conference paper 2022
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Zhang, Yu (author), Wang, Yue (author), Tian, Zhi (author), Leus, G.J.T. (author), Zhang, Gong (author)This paper develops an efficient solution for super-resolution two-dimensional (2D) harmonic retrieval from multiple measurement vectors (MMV). Given the sample covariance matrix constructed from the MMV, a gridless compressed sensing approach is proposed based on the atomic norm minimization (ANM). In the approach, our key step is to perform...journal article 2022
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Masoumi, H. (author), Myers, N.J. (author), Leus, G.J.T. (author), Wahls, S. (author), Verhaegen, M.H.G. (author)Fast millimeter wave (mmWave) channel estimation techniques based on compressed sensing (CS) suffer from low signal-to-noise ratio (SNR) in the channel measurements, due to the use of wide beams. To address this problem, we develop an in-sector CS-based mmWave channel estimation technique that focuses energy on a sector in the angle domain....conference paper 2022
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Sharma, Shubham (author), Hari, K.V.S. (author), Leus, G.J.T. (author)Variable density sampling of the k-space in MRI is an integral part of trajectory design. It has been observed that data-driven trajectory design methods provide a better image reconstruction as compared to trajectories obtained from a fixed or a parametric density function. In this paper, a data-driven strategy has been proposed to obtain non...conference paper 2022
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Romero, Daniel (author), Viet, Pham Q. (author), Leus, G.J.T. (author)Mobile base stations on board unmanned aerial vehicles (UAVs) promise to deliver connectivity to those areas where the terrestrial infrastructure is overloaded, damaged, or absent. A fundamental problem in this context involves determining a minimal set of locations in 3D space where such aerial base stations (ABSs) must be deployed to provide...conference paper 2022
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Hu, Yuyang (author), Brown, Michael (author), Doğan, D. (author), Leus, G.J.T. (author), Kruizinga, P. (author), Van Der Steen, Antonius F.W. (author), Bosch, Johannes G. (author)We intend to develop an ultrasound compressive imaging device to perform carotid artery (CA) function and flow monitoring/imaging by using just a few single element transducers equipped with spatial coding masks. The spatially unique impulse responses can be exploited in compressive reconstructions. To explore the potential of different...conference paper 2022
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Fernandez-Menduina, Samuel (author), Krahmer, Felix (author), Leus, G.J.T. (author), Bhandari, Ayush (author)Conventional literature on array signal processing (ASP) is based on the "capture first, process" later philosophy and to this end, signal processing algorithms are typically decoupled from the hardware. This poses fundamental limitations because if the sensors result in information loss, the algorithms may no longer be able to achieve their...journal article 2022
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Yang, Maosheng (author), Isufi, E. (author), Schaub, Michael T. (author), Leus, G.J.T. (author)We study linear filters for processing signals supported on abstract topological spaces modeled as simplicial complexes, which may be interpreted as generalizations of graphs that account for nodes, edges, triangular faces, etc. To process such signals, we develop simplicial convolutional filters defined as matrix polynomials of the lower and...journal article 2022
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Kokke, C.A. (author), Coutino, Mario (author), Heusdens, R. (author), Leus, G.J.T. (author), Anitori, L. (author)Doppler velocity estimation in pulse-Doppler radar is done by evaluating the target returns of bursts of pulses. While this provides convenience and accuracy, it requires multiple pulses. In adaptive and cognitive radar systems, the ability to adapt on consecutive pulses, instead of bursts, brings potential performance benefits. Hence, with...conference paper 2022
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Coutino, Mario (author), Leus, G.J.T. (author)One of the main challenges of graph filters is the stability of their design. While classical graph filters allow for a stable design using optimal polynomial approximation theory, generalized graph filters tend to suffer from the ill-conditioning of the involved system matrix. This issue, accentuated for increasing graph filter orders,...journal article 2022
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Zhang, Yu (author), Wang, Yue (author), Tian, Zhi (author), Leus, G.J.T. (author), Zhang, Gong (author)This paper proposes an efficient direction of departure (DOD) and direction of arrival (DOA) estimation method for multi-input multi-output (MIMO) systems. For uncorrelated scenarios, the redundancy of the covariance matrix is first exploited by establishing its concise representation through redundancy reduction, which transforms the...journal article 2022
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Yang, Maosheng (author), Isufi, E. (author), Leus, G.J.T. (author)Graphs can model networked data by representing them as nodes and their pairwise relationships as edges. Recently, signal processing and neural networks have been extended to process and learn from data on graphs, with achievements in tasks like graph signal reconstruction, graph or node classifications, and link prediction. However, these...conference paper 2022
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Hagenaars, Erik (author), Pandharipande, Ashish (author), Murthy, Abhishek (author), Leus, G.J.T. (author)People-counting data can be used in building-control systems to improve comfort and in space management applications to optimize building space. In this work, we consider a combi-sensor with a single-pixel thermopile and passive infrared sensor for people counting. We first develop a thermopile signal model for object temperature measurements...journal article 2021
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Wang, F. (author), Leus, G.J.T. (author)In this paper we consider the problem of joint wideband spectrum sensing and direction-of-arrival (DoA) estimation, where a number of uncorrelated narrowband sources spread over a wide frequency band impinge on a sparse linear array (SLA). To overcome the sampling rate bottleneck for wideband spectrum sensing, we rely on sub-Nyquist sampling for...conference paper 2021
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Yang, Maosheng (author), Isufi, E. (author), Schaub, Michael T. (author), Leus, G.J.T. (author)In this paper, we study linear filters to process signals defined on simplicial complexes, i.e., signals defined on nodes, edges, triangles, etc. of a simplicial complex, thereby generalizing filtering operations for graph signals. We propose a finite impulse response filter based on the Hodge Laplacian, and demonstrate how this filter can be...conference paper 2021
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Natali, A. (author), Isufi, E. (author), Coutino, Mario (author), Leus, G.J.T. (author)Topology identification is an important problem across many disciplines, since it reveals pairwise interactions among entities and can be used to interpret graph data. In many scenarios, however, this (unknown) topology is time-varying, rendering the problem even harder. In this paper, we focus on a time-varying version of the structural...conference paper 2021
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Wang, F. (author), Tian, Zhi (author), Leus, G.J.T. (author), Fang, Jun (author)In this paper, we study the problem of wideband direction of arrival (DoA) estimation with sparse linear arrays (SLAs), where a number of uncorrelated wideband signals impinge on an SLA and the data is collected from multiple frequency bins. To boost the performance and perform underdetermined DoA estimation, the difference co-array response...journal article 2021
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Yang, Maosheng (author), Coutino, Mario (author), Leus, G.J.T. (author), Isufi, E. (author)A critical task in graph signal processing is to estimate the true signal from noisy observations over a subset of nodes, also known as the reconstruction problem. In this paper, we propose a node-adaptive regularization for graph signal reconstruction, which surmounts the conventional Tikhonov regularization, giving rise to more degrees of...journal article 2021
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Doğan, D. (author), Kruizinga, P. (author), Bosch, Johannes G. (author), Leus, G.J.T. (author)Ultrasound imaging of the vasculature has major significance for the detection of cardiovascular diseases and cancer. However, limited spatial resolution or long acquisition times of existing techniques limit the visualization of the microvascular structures. Enforcing sparsity in the underlying vasculature as well as exploiting statistical...conference paper 2021
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Natali, A. (author), Coutino, Mario (author), Isufi, E. (author), Leus, G.J.T. (author)Signal processing and machine learning algorithms for data sup-ported over graphs, require the knowledge of the graph topology. Unless this information is given by the physics of the problem (e.g., water supply networks, power grids), the topology has to be learned from data. Topology identification is a challenging task, as the problem is often...conference paper 2021