Search Results for author: Geert Leus

Found 33 papers, 4 papers with code

Optimal Pilot Design for OTFS in Linear Time-Varying Channels

no code implementations28 Mar 2024 Ids van der Werf, Richard Heusdens, Richard C. Hendriks, Geert Leus

This paper investigates the positioning of the pilot symbols, as well as the power distribution between the pilot and the communication symbols in the OTFS modulation scheme.

A Generalization of the Convolution Theorem and its Connections to Non-Stationarity and the Graph Frequency Domain

1 code implementation28 Dec 2023 Alberto Natali, Geert Leus

In this paper, we present a novel convolution theorem which encompasses the well known convolution theorem in (graph) signal processing as well as the one related to time-varying filters.

Learning graphs and simplicial complexes from data

no code implementations16 Dec 2023 Andrei Buciulea, Elvin Isufi, Geert Leus, Antonio G. Marques

Graphs are widely used to represent complex information and signal domains with irregular support.

Sensor Selection using the Two-Target Cramér-Rao Bound for Angle of Arrival Estimation

no code implementations31 Jul 2023 Costas A. Kokke, Mario Coutiño, Laura Anitori, Richard Heusdens, Geert Leus

Sensor selection is a useful method to help reduce data throughput, as well as computational, power, and hardware requirements, while still maintaining acceptable performance.

Deep-Learning-Aided Alternating Least Squares for Tensor CP Decomposition and Its Application to Massive MIMO Channel Estimation

no code implementations23 May 2023 Xiao Gong, Wei Chen, Bo Ai, Geert Leus

To achieve accurate and low-latency channel estimation, good and fast CP decomposition algorithms are desired.

Graph Signal Processing: History, Development, Impact, and Outlook

no code implementations21 Mar 2023 Geert Leus, Antonio G. Marques, José M. F. Moura, Antonio Ortega, David I Shuman

Graph signal processing (GSP) generalizes signal processing (SP) tasks to signals living on non-Euclidean domains whose structure can be captured by a weighted graph.

Graph Learning

Super-Resolution Harmonic Retrieval of Non-Circular Signals

no code implementations17 Jan 2023 Yu Zhang, Yue Wang, Zhi Tian, Geert Leus, Gong Zhang

This paper proposes a super-resolution harmonic retrieval method for uncorrelated strictly non-circular signals, whose covariance and pseudo-covariance present Toeplitz and Hankel structures, respectively.

Retrieval Super-Resolution

Blind Polynomial Regression

no code implementations21 Oct 2022 Alberto Natali, Geert Leus

Fitting a polynomial to observed data is an ubiquitous task in many signal processing and machine learning tasks, such as interpolation and prediction.

regression

Joint Ranging and Phase Offset Estimation for Multiple Drones using ADS-B Signatures

no code implementations12 Jul 2022 Mostafa Mohammadkarimi, Geert Leus, Raj Thilak Rajan

While the proposed estimator can estimate the range of multiple drones with a single receive antenna, a larger number of drones can be supported with higher accuracy by the use of multiple antennas at the receiver.

Combinatorial Optimization

Structured Sensing Matrix Design for In-sector Compressed mmWave Channel Estimation

no code implementations23 May 2022 Hamed Masoumi, Nitin Jonathan Myers, Geert Leus, Sander Wahls, Michel Verhaegen

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.

Simplicial Convolutional Filters

no code implementations27 Jan 2022 Maosheng Yang, Elvin Isufi, Michael T. Schaub, Geert Leus

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.

Learning Time-Varying Graphs from Online Data

no code implementations21 Oct 2021 Alberto Natali, Elvin Isufi, Mario Coutino, Geert Leus

This work proposes an algorithmic framework to learn time-varying graphs from online data.

Graph Learning

Simplicial Convolutional Neural Networks

no code implementations6 Oct 2021 Maosheng Yang, Elvin Isufi, Geert Leus

Graphs can model networked data by representing them as nodes and their pairwise relationships as edges.

Link Prediction

Finite Impulse Response Filters for Simplicial Complexes

no code implementations23 Mar 2021 Maosheng Yang, Elvin Isufi, Michael T. Schaub, Geert Leus

In this paper, we study linear filters to process signals defined on simplicial complexes, i. e., signals defined on nodes, edges, triangles, etc.

Denoising

Online Time-Varying Topology Identification via Prediction-Correction Algorithms

no code implementations22 Oct 2020 Alberto Natali, Mario Coutino, Elvin Isufi, Geert Leus

Signal processing and machine learning algorithms for data supported over graphs, require the knowledge of the graph topology.

Topology-Aware Joint Graph Filter and Edge Weight Identification for Network Processes

no code implementations7 Jul 2020 Alberto Natali, Mario Coutino, Geert Leus

Therefore, in this paper, we focus on the joint identification of coefficients and graph weights defining the graph filter that best models the observed input/output network data.

How Does Momentum Help Frank Wolfe?

no code implementations19 Jun 2020 Bingcong Li, Mario Coutino, Georgios B. Giannakis, Geert Leus

We unveil the connections between Frank Wolfe (FW) type algorithms and the momentum in Accelerated Gradient Methods (AGM).

Submodularity in Action: From Machine Learning to Signal Processing Applications

no code implementations17 Jun 2020 Ehsan Tohidi, Rouhollah Amiri, Mario Coutino, David Gesbert, Geert Leus, Amin Karbasi

We introduce a variety of submodular-friendly applications, and elucidate the relation of submodularity to convexity and concavity which enables efficient optimization.

BIG-bench Machine Learning

Forecasting Multi-Dimensional Processes over Graphs

no code implementations17 Apr 2020 Alberto Natali, Elvin Isufi, Geert Leus

The forecasting of multi-variate time processes through graph-based techniques has recently been addressed under the graph signal processing framework.

Time Series Time Series Analysis

Graphs, Convolutions, and Neural Networks: From Graph Filters to Graph Neural Networks

1 code implementation8 Mar 2020 Fernando Gama, Elvin Isufi, Geert Leus, Alejandro Ribeiro

We also introduce GNN extensions using edge-varying and autoregressive moving average graph filters and discuss their properties.

Recommendation Systems

Online Graph-Adaptive Learning with Scalability and Privacy

no code implementations3 Dec 2018 Yanning Shen, Geert Leus, Georgios B. Giannakis

Moreover, new nodes can emerge over time, which can necessitate real-time evaluation of their nodal attributes.

Sampling and Reconstruction of Signals on Product Graphs

2 code implementations30 Jun 2018 Guillermo Ortiz-Jiménez, Mario Coutino, Sundeep Prabhakar Chepuri, Geert Leus

In this paper, we consider the problem of subsampling and reconstruction of signals that reside on the vertices of a product graph, such as sensor network time series, genomic signals, or product ratings in a social network.

Active Learning Recommendation Systems +2

Sparse Sampling for Inverse Problems with Tensors

2 code implementations28 Jun 2018 Guillermo Ortiz-Jiménez, Mario Coutino, Sundeep Prabhakar Chepuri, Geert Leus

We consider the problem of designing sparse sampling strategies for multidomain signals, which can be represented using tensors that admit a known multilinear decomposition.

Information Theory Signal Processing Information Theory

MIMO Graph Filters for Convolutional Neural Networks

no code implementations6 Mar 2018 Fernando Gama, Antonio G. Marques, Alejandro Ribeiro, Geert Leus

Superior performance and ease of implementation have fostered the adoption of Convolutional Neural Networks (CNNs) for a wide array of inference and reconstruction tasks.

Convolutional Neural Networks Via Node-Varying Graph Filters

no code implementations27 Oct 2017 Fernando Gama, Geert Leus, Antonio G. Marques, Alejandro Ribeiro

Convolutional neural networks (CNNs) are being applied to an increasing number of problems and fields due to their superior performance in classification and regression tasks.

Adaptive Graph Signal Processing: Algorithms and Optimal Sampling Strategies

no code implementations12 Sep 2017 Paolo Di Lorenzo, Paolo Banelli, Elvin Isufi, Sergio Barbarossa, Geert Leus

Numerical simulations carried out over both synthetic and real data illustrate the good performance of the proposed sampling and reconstruction strategies for (possibly distributed) adaptive learning of signals defined over graphs.

Graph Sampling

Learning Sparse Graphs Under Smoothness Prior

no code implementations12 Sep 2016 Sundeep Prabhakar Chepuri, Sijia Liu, Geert Leus, Alfred O. Hero III

Given the noisy data, we show that the joint sparse graph learning and denoising problem can be simplified to designing only the sparse edge selection vector, which can be solved using convex optimization.

Denoising Graph Learning

Autoregressive Moving Average Graph Filtering

no code implementations14 Feb 2016 Elvin Isufi, Andreas Loukas, Andrea Simonetto, Geert Leus

We design a family of autoregressive moving average (ARMA) recursions, which (i) are able to approximate any desired graph frequency response, and (ii) give exact solutions for tasks such as graph signal denoising and interpolation.

Denoising Philosophy

Compressed Sensing for Block-Sparse Smooth Signals

no code implementations10 Sep 2013 Shahzad Gishkori, Geert Leus

We present reconstruction algorithms for smooth signals with block sparsity from their compressed measurements.

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