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40 results on '"Nantes Université - pôle Sciences et technologie"'

1. Differentiated Consistency for Worldwide Gossips

Author

Davide Frey, Achour Mostefaoui, Matthieu Perrin, Pierre-Louis Roman, Francois Taiani, the World Is Distributed Exploring the tension between scale and coordination (WIDE), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-SYSTÈMES LARGE ÉCHELLE (IRISA-D1), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Gestion de Données Distribuées (LS2N - équipe GDD), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Nantes Université (Nantes Univ), Ecole Polytechnique Fédérale de Lausanne (EPFL), ANR-16-CE25-0005,OBrowser,Applications décentralisées sur navigateurs(2016), and ANR-20-CE25-0002,ByBloS,Au-delà des Blockchains : Modules de construction pour les applications à grande échelle zero-confiance multi-utilisateurs(2020)

Subjects
[INFO.INFO-CR]Computer Science [cs]/Cryptography and Security [cs.CR], Blockchain, Computational Theory and Mathematics, Hardware and Architecture, Signal Processing, Distributed system, Epidemic protocol, [INFO.INFO-DC]Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC], Eventual consistency
Abstract

International audience; Eventual consistency is a consistency model that favors liveness over safety. It is often used in large-scale distributed systems where models ensuring a stronger safety incur performance that are too low to be deemed practical. Eventual consistency tends to be uniformly applied within a system, but we argue a demand exists for differentiated eventual consistency, e.g. in blockchain systems.We propose UPS to address this demand. UPS is a novel consistency mechanism that works in pair with our novel two-phase epidemic broadcast protocol GPS to offer differentiated eventual consistency and delivery speed. We propose two complementary analyses of the broadcast protocol: a continuous analysis and a discrete analysis based on compartmental models used in epidemiology. Additionally, we propose the formal definition of a scalable consistency metric to measure the consistency trade-off at runtime. We evaluate UPS in two simulated worldwide settings: a one-million-node network and a network emulating that of the Ethereum blockchain. In both settings, UPS reduces inconsistencies experienced by a majority of the nodes and reduces the average message latency for the remaining nodes.

Published
2023

2. Cosserat Rod Modeling of Continuum Robots from Newtonian and Lagrangian Perspectives

Author

Matthias Tummers, Vincent Lebastard, Frédéric Boyer, Jocelyne Troccaz, Benoît Rosa, M. Taha Chikhaoui, Gestes Medico-chirurgicaux Assistés par Ordinateur (TIMC-GMCAO), Translational Innovation in Medicine and Complexity / Recherche Translationnelle et Innovation en Médecine et Complexité - UMR 5525 (TIMC ), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Robotique Et Vivant (LS2N - équipe ReV), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Nantes Université (Nantes Univ), Département Automatique, Productique et Informatique (IMT Atlantique - DAPI), IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), ANR-11-LABX-0004,CAMI,Gestes Médico-Chirurgicaux Assistés par Ordinateur(2011), ANR-19-P3IA-0003,MIAI,MIAI @ Grenoble Alpes(2019), ANR-20-CE33-0001,COSSEROOTS,Théorie Cosserat pour les robots élancés contrôlés en déformation(2020), ANR-10-IAHU-0002,MIX-Surg,Institut de Chirurgie Mini-Invasive guidée par l'Image(2010), and ANR-18-CE19-0012,MACROS,Robots continus multi-actionnés pour la chirugie mini-invasive(2018)

Subjects
Cosserat Beams, Flexible Robots, Control and Systems Engineering, Control, Tendon/Wire Mechanism, Modeling, [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO], Electrical and Electronic Engineering, Learning for Soft Robots, Computer Science Applications
Abstract

International audience; Cosserat rod theory proved efficient modeling performances in robotics, especially in the context of continuum robots, in the past decade. The implementation of such theory is far from being unique and straightforward. We consider the illustrative example of multi-segment, general routing tendon actuated continuum robots in their nominal static operating regime. This paper details two main approaches based on Cosserat rod modeling, namely the Newtonian and Lagrangian approaches. We provide a walk-through guide regarding theoretical derivations and numerical implementation of both approaches, together with a proof of equivalence. This comparative study is supplemented with novel contributions and extensions of each approach and in-depth discussion of their performances and applicability, as well as highlighting their special features.

Published
2023

3. Strong Left-Invertibility and Strong Input-Observability of Nonlinear Time-Delay Systems

Author

Yahao Chen, Malek Ghanes, Jean-Pierre Barbot, École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)

Subjects
Control and Optimization, Control and Systems Engineering, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract

International audience

Published
2023

4. Ensemble-Based Deep Learning Model for Network Traffic Classification

Author

Ons Aouedi, Kandaraj Piamrat, Benoit Parrein, Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ), Software Stack for Massively Geo-Distributed Infrastructures (STACK), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire des Sciences du Numérique de Nantes (LS2N), Nantes Université (Nantes Univ)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), STR (LS2N - équipe STR ), and Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique)

Subjects
machine learning, Computer Networks and Communications, decision tree, ensemble learning, deep learning, [INFO]Computer Science [cs], Electrical and Electronic Engineering, Blending, traffic classification
Abstract

International audience; Network Traffic Classification enables a number of practical applications ranging from network monitoring to resource management, with security implications as well. Nowadays, traffic classification has become a challenging task in order to distinguish among a variety of applications due to the huge amount of generated traffic. Therefore, developing Machine Learning (ML) models, which can successfully identify network applications, is one of the most important tasks. However, among the ML models applied to network traffic classification so far, no model outperforms all the others. To solve these issues, this paper proposes a novel Deep Learning (DL)-based approach that incorporates multiple Decision Tree based models. This approach employs a non-linear blending ensemble method by combining tree-based classifiers through DL in order to maximize generalization accuracy. This ensemble consists of two levels called base classifiers and meta-classifiers. In the first level, Decision Tree-based models are used as the base classifiers while in the second level, DL is used as a meta-model to combine the outputs of the base classifiers. Using two publicly available datasets, we show that our proposed ensemble is suitable for network traffic classification and outperforms the linear blending (using logistic regression as meta-model) as well as several well-known ML models, which are Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF), Multi-Layer Perceptron (MLP), AdaBoost, K-Nearest Neighbors (KNN), LightGBM, Catboost, and XGBoost.

Published
2022

5. A Model-Driven Methodology to Accelerate Software Engineering in the Internet of Things

Author

Imad Berrouyne, Mehdi Adda, Jean-Marie Mottu, Massimo Tisi, Interdisciplinary Centre for Security, Reliability and Trust [Luxembourg] (SnT), Université du Luxembourg (Uni.lu), Université du Québec à Rimouski (UQAR), Institut Universitaire de Technologie - Nantes (Nantes Univ - IUT Nantes), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Département Automatique, Productique et Informatique (IMT Atlantique - DAPI), IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), NaoMod - Nantes Software Modeling Group (LS2N - équipe NaoMod), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), and Nantes Université (Nantes Univ)

Subjects
Policy Enforcement, Model Transformation, Computer Networks and Communications, Internet of Things, Software Engineering, Model-Driven Engineering, [INFO.INFO-SE]Computer Science [cs]/Software Engineering [cs.SE], [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Code Generation, Computer Science Applications, [INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI], Hardware and Architecture, Signal Processing, Information Systems
Abstract

International audience; The Internet of Things (IoT) aims for connecting Anything, Anywhere, Anytime (AAA). This assumption brings about several software engineering challenges that constitute a serious obstacle to its wider adoption. The main feature of the Internet of Things (IoT) is genericity w.r.t the variability of software and hardware technologies. Model-Driven Engineering (MDE) is a paradigm that advocates using models to address software engineering problems. It can help to meet the genericity of the IoT from a software engineering perspective. Existing MDE approaches for the IoT focus only on modeling the internal behavior of things but lack a comprehensive approach dedicated to network modeling. In the present paper, we introduce a network-oriented methodology based on MDE to unify the IoT's heterogeneous concepts. Fundamentally, we avoid the intrinsic heterogeneity of the IoT by separating the network's specification (i.e., the things, the communication scheme, and its constraints) from its concrete implementation (i.e., the low-level artifacts such as source code and documentation). Technically, the methodology relies on a model-based Domain-Specific Language (DSL) and a code generator. The former enables the modeling of the network's specification, and the latter provides a procedure to generate the low-level artifacts from this specification. Our results show that this methodology makes IoT's software engineering more rigorous, helps prevent bugs earlier, and saves time.

Published
2022

6. Transparency Analysis of a Passive Heavy Load Comanipulation Arm

Author

Thomas Muller, Kevin Subrin, Denis Joncheray, Alain Billon, Sebastien Garnier, NEODITECH, Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ), Robots and Machines for Manufacturing, Society and Services (LS2N - équipe RoMas), Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), and École Centrale de Nantes (Nantes Univ - ECN)

Subjects
Human-Computer Interaction, [SPI]Engineering Sciences [physics], Artificial Intelligence, Computer Networks and Communications, Control and Systems Engineering, Signal Processing, Human Factors and Ergonomics, Computer Science Applications
Abstract

International audience

Published
2022

7. The Advantages of Maintaining a Multitask, Project-Specific Bot: An Experience Report

Author

Zimmermann, Théo, Coolen, Julien, Gross, Jason, Pédrot, Pierre-Marie, Gilbert, Gaëtan, Institut de Recherche en Informatique Fondamentale (IRIF (UMR_8243)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Design, study and implementation of languages for proofs and programs (PI.R2), Centre National de la Recherche Scientifique (CNRS)-Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Paris Cité (UPCité)-Institut de Recherche en Informatique Fondamentale (IRIF (UMR_8243)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris Cité (UPCité), Machine Intelligence Research Institute (MIRI), Gallinette : vers une nouvelle génération d'assistant à la preuve (GALLINETTE), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), and Nantes Université (Nantes Univ)

Subjects
Software Engineering (cs.SE), FOS: Computer and information sciences, Computer Science - Software Engineering, [INFO.INFO-SE]Computer Science [cs]/Software Engineering [cs.SE], Software
Abstract

Bots are becoming a popular method for automating basic everyday tasks in many software projects. This is true in particular because of the availability of many off-the-shelf task-specific bots that teams can quickly adopt (which are sometimes completed with additional task-specific custom bots). Based on our experience in the Coq project, where we have developed and maintained a multi-task project-specific bot, we argue that this alternative approach to project automation should receive more attention because it strikes a good balance between productivity and adaptibility. In this article, we describe the kind of automation that our bot implements, what advantages we have gained by maintaining a project-specific bot, and the technology and architecture choices that have made it possible. We draw conclusions that should generalize to other medium-sized software teams willing to invest in project automation without disrupting their workflows., arXiv admin note: substantial text overlap with arXiv:2112.07365

Published
2022

8. UIF: An Objective Quality Assessment for Underwater Image Enhancement

Author

Yannan Zheng, Weiling Chen, Rongfu Lin, Tiesong Zhao, Patrick Le Callet, Fuzhou University [Fuzhou], Image Perception Interaction (LS2N - équipe IPI), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), and Nantes Université (Nantes Univ)

Subjects
FOS: Computer and information sciences, Computer Vision and Pattern Recognition (cs.CV), [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Image and Video Processing (eess.IV), Image Quality Assessment (IQA), Computer Science - Computer Vision and Pattern Recognition, FOS: Electrical engineering, electronic engineering, information engineering, underwater image processing, Underwater Image Enhancement (UIE), Electrical Engineering and Systems Science - Image and Video Processing, Computer Graphics and Computer-Aided Design, Software
Abstract

Due to complex and volatile lighting environment, underwater imaging can be readily impaired by light scattering, warping, and noises. To improve the visual quality, Underwater Image Enhancement (UIE) techniques have been widely studied. Recent efforts have also been contributed to evaluate and compare the UIE performances with subjective and objective methods. However, the subjective evaluation is time-consuming and uneconomic for all images, while existing objective methods have limited capabilities for the newly-developed UIE approaches based on deep learning. To fill this gap, we propose an Underwater Image Fidelity (UIF) metric for objective evaluation of enhanced underwater images. By exploiting the statistical features of these images, we present to extract naturalness-related, sharpness-related, and structure-related features. Among them, the naturalness-related and sharpness-related features evaluate visual improvement of enhanced images; the structure-related feature indicates structural similarity between images before and after UIE. Then, we employ support vector regression to fuse the above three features into a final UIF metric. In addition, we have also established a large-scale UIE database with subjective scores, namely Underwater Image Enhancement Database (UIED), which is utilized as a benchmark to compare all objective metrics. Experimental results confirm that the proposed UIF outperforms a variety of underwater and general-purpose image quality metrics., Comment: This paper was submitted to ACMMM 2021

Published
2022

9. Codesign in Action: Design Principles to Successfully Manage Transformative Social Innovation

Author

Guérineau, Mathias, Jacob, Florence, Kleszczowski, Julien, Laboratoire d'économie et de management de Nantes Atlantique (LEMNA), IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Nantes Université - Institut d'Administration des Entreprises - Nantes (Nantes Univ - IAE Nantes), Nantes Université - pôle Sociétés, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sociétés, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-FR 3473 Institut universitaire Mer et Littoral (IUML), Le Mans Université (UM)-Université d'Angers (UA)-Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Le Mans Université (UM)-Université d'Angers (UA)-Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ), Nantes Université - Institut d'Administration des Entreprises - Nantes (Nantes Univ - IAE Nantes), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut d'Administration des Entreprises - Lille (IAE Lille), Université de Lille, Sciences et Technologies, Lille University Management Lab - ULR 4999 (LUMEN), Université de Lille, and Nantes université, LEMNA

Subjects
scaling up strategy, Strategy and Management, [SHS.GESTION]Humanities and Social Sciences/Business administration, Electrical and Electronic Engineering, Design science, social innovation, Innovation management
Abstract

International audience; To meet grand challenges, organizations must rethink how they establish their objectives and processes in a more sustainable way. Social innovation is seen as a very promising way to respond to this call. Nevertheless, social innovation encounters difficulties in scaling and reaching its transformative power. On the basis of the theoretical framework of transition management, our article focuses on the codesign of transformative social innovation by trying to identify how actors can manage it successfully during the experimentation phase. We have conducted research based on the design science methodology to develop both concrete solutions to solve empirical problems and build strong design propositions. The results and design propositions stem from the analysis of three case studies of French social impact bonds (SIBs), which are contractual tools funding social innovation programs. SIBs are, by nature, codesign processes involving different types of stakeholders (private funders, public commissioners, and nonprofit organizations). This article provides six design principles to support the cooperation and alignment of multiple stakeholders to foster their scaling up, which is crucial for perpetuating social innovation. This research contributes theoretically to both the social innovation scaling literature and the transition management framework and offers practical guidelines to help social practitioners to codesign and manage transformative social innovations.

Published
2022

10. Predictive Feedback Control for Inventory Systems Subject to Delays and Constraints

Author

Berna Bou Farraa, Rosa Abbou, Jean Jacques Loiseau, Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)

Subjects
[SPI]Engineering Sciences [physics], Control and Systems Engineering, input-delayed system, predictive feedback structure, inventory control, Electrical and Electronic Engineering, Constraints verification, Computer Science Applications
Abstract

International audience; In this paper, we discuss the inventory regulation problem of a logistic system composed of a production unit and inventory unit. The production system is characterized by a constant lead time, and the storage unit presents fixed losses due to perishable products. In this study, the system is subject to finite production resources, limited storage capacities, and the customer demands are uncertain in a given range. We address a control strategy to the input time delay system that is subject to positive and saturation constraints and to bounded disturbances. We apply a linear prediction feedback control strategy, in order to stabilize the closed-loop system and to fulfill the system constraints, so that necessary and sufficient conditions for the existence of an admissible control law are formulated.

Published
2022

11. A Comparison of Techniques for Class Imbalance in Deep Learning Classification of Breast Cancer

Author

Mickael Tardy, Ricky Walsh, Neuroimagerie: méthodes et applications (EMPENN), Institut National de la Santé et de la Recherche Médicale (INSERM)-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-SIGNAL, IMAGE ET LANGAGE (IRISA-D6), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Signal, IMage et Son (LS2N - équipe SIMS ), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Nantes Université (Nantes Univ), Hera-MI (Hera-MI), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Nantes Université - École Centrale de Nantes (Nantes Univ - ECN), and Walsh, Ricky

Subjects
[SDV.MHEP] Life Sciences [q-bio]/Human health and pathology, breast cancer, mammography, medical imaging, class imbalance, deep learning, synthetic data, Clinical Biochemistry, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract

Tools based on deep learning models have been created in recent years to aid radiologists in the diagnosis of breast cancer from mammograms. However, the datasets used to train these models may suffer from class imbalance, i.e., there are often fewer malignant samples than benign or healthy, which can bias the model towards the healthy class. In this study, we systematically evaluate several popular techniques to deal with this class imbalance, namely, class weighting, over-sampling, and under-sampling, as well as a synthetic lesion generation approach to increase the number of malignant samples. These techniques are applied when training on three diverse Full-Field Digital Mammography datasets, and tested on in-distribution and out-of-distribution samples. The experiments show that a greater imbalance is associated with a greater bias towards the majority class, which can be counteracted by any of the standard class imbalance techniques. On the other hand, these methods provide no benefit to model performance with respect to Area Under the Curve of the Recall Operating Characteristic (AUC-ROC), and indeed under-sampling leads to a reduction of 0.066 in AUC in the case of a 19:1 benign to malignant imbalance. Our synthetic lesion methodology leads to better performance in most cases, with increases of up to 0.07 in AUC on out-of-distribution test sets over the next best experiment.

Published
2022

12. What Is the Future of Modeling?

Author

Massimo Tisi, Matthias Tichy, Leen Lambers, Antonio Bucchiarone, Alfonso Pierantonio, Federico Ciccozzi, Andreas Wortmann, Vadim Zaytsev, Formal Methods and Tools, Fondazione Bruno Kessler [Trento, Italy] (FBK), Mälardalen University (MDH), University of Potsdam = Universität Potsdam, Università degli Studi dell'Aquila = University of L'Aquila (UNIVAQ), Universität Ulm - Ulm University [Ulm, Allemagne], Département Automatique, Productique et Informatique (IMT Atlantique - DAPI), IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), NaoMod - Nantes Software Modeling Group (LS2N - équipe NaoMod), Laboratoire des Sciences du Numérique de Nantes (LS2N), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Nantes Université (Nantes Univ), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), and University of Twente

Subjects
Research Roadmap, [INFO.INFO-PL]Computer Science [cs]/Programming Languages [cs.PL], Modeling language, business.industry, Computer science, 020207 software engineering, [INFO.INFO-SE]Computer Science [cs]/Software Engineering [cs.SE], 02 engineering and technology, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Software Modelling, [INFO.INFO-FL]Computer Science [cs]/Formal Languages and Automata Theory [cs.FL], 0202 electrical engineering, electronic engineering, information engineering, Key (cryptography), Success Stories, Model-driven architecture, Software engineering, business, computer, Software, computer.programming_language
Abstract

International audience; Modelling languages and frameworks have been the key technology for advancing Model-Driven Engineering (MDE) methods and tools. Many industrial and research tools have been realised and are used across many domains. Hence, we think it is the right time to define what should be the future of modelling technologies, especially the requirements for the next generation of modelling frameworks and languages. In January 2020, the Second Winter Modelling Meeting (WMM2020) was held in San Vigilio di Marebbe (Italy), focusing on the analysis of the state of research, state of practice, and state of the art in MDE. The event brought together experts from industry, academia, and the open-source community to assess (i) what had changed in research on modelling in the last ten years, (ii) which problems are still unsolved, and (iii) which new challenges have arisen. This article presents a set of success stories and driving success factors of modelling and MDE, as well as a set of challenges and corresponding research directions that emerged from the synthesis of the results of our analysis.

Published
2021

13. Numerical Evaluation of Circuit Model for Fast Computational Analysis of Resonant Wireless Power Transfer System

Author

F. M. Freitas, I. V. Soares, L. Krähenbühl, A. Bréard, C. Vollaire, S. T. M. Gonçalves, U. C. Resende, Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Ampère, Département Automatique pour l'Ingénierie des Systèmes (AIS), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Ampère, Département Energie Electrique (EE)

Subjects
Circuit model, magnetic metamaterial, resonance, [SPI.NRJ]Engineering Sciences [physics]/Electric power, wireless power transfer, near field coupling, LC metamaterial, Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials
Abstract

International audience; This paper proposes a circuit model to calculate the current along printed coils used in Resonant Wireless Power Transfer. It considers a system composed of a metamaterial and two coplanar coils, transmitter and receiver, respectively. First, a circuit model for the system is presented. Then, an analytical model is proposed to calculate the self-inductance of printed inductors, their characteristic resistance, and the mutual inductance between coils. The proposed formulation for calculating the mutual inductance between inductors is based on Neumann’s formula. The practical results validate the model precision, obtaining a maximum deviation of approximately 8%, 3%, and 3%, respectively. Due to the generality of this approach, it can also be applied to more complex structures such as metasurfaces. The proposed 3-D models proved to be ideal for modeling the printed inductor. Furthermore, this model proved to be computationally more efficient for analyzing large systems when compared to commercial full-wave simulation software, with a reduction in the computational time larger than three orders of magnitude.

Published
2023

14. Structural and Radio Frequency Co-Design and Optimization of Large Deployable Reflectarrays for Space Missions

Author

Andrea Guarriello, Renaud Loison, Daniele Bresciani, Hervé Legay, George Goussetis, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Thales Alenia Space [Toulouse] (TAS), THALES [France], Heriot-Watt University [Edinburgh] (HWU), European Commission [MSCA-ITN2016-722840], and French Ministry of Higher Education, Research and Innovation through the 'France Relance' project SOAR [ANR-21-PRRD-0037-01]

Subjects
Fasteners, Finite element analysis, thermoelastic deformation (TED), Geometry, Thermal stability, Contoured beam, [SPI]Engineering Sciences [physics], satellite antenna, Thermal loading, Radio frequency, Loaded antennas, phoenix cells, Electrical and Electronic Engineering, optimization, large deployable reflectarray (RA)
Abstract

International audience; The structural and radio frequency (RF) design and optimization of a large deployable faceted reflectarray (RA) generating double polarization contour beam are presented in this work. The issue addressed is the thermoelastic stability of large RAs and the impact of the thermoelastic deformation (TED) under transverse thermal gradient on the RA performances. Finite element TED analysis is conducted on a deployable RA with self-standing structures, demonstrating the detrimental effects of the in-orbit TED impact on the RA performances, estimated to be above 3 dB losses. To this extent, a novel structural solution is proposed, based on the use of reliable mechanical support capable to mitigate the TED. The mechanical design reorientation is contingent on the RF design reformulation. The proposed novel mechanical and RF co-design concept and methodology allows the conception of a low-profile, thermo-structurally stable RA with compliant radiation patterns and high cross-polarization discrimination in the worst case thermal load. This methodology is based on a direct optimization of nine-panel faceted RA composed of advanced high-order Phoenix cells directly optimized to fulfill the contoured beam requirements and by respecting the local periodicity requirements of the layout.

Published
2023

15. Triaxial Cell for Determining Shielded Cable Transfer Impedance During Environmental Stress

Author

Oskari Leppäaho, Frédéric Lafon, Priscila Fernández-López, Marine Stojanovic, Tim Claeys, Richard Perdriau, Mohamed Ramdani, Danfoss Drives, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), VALEO, Department of Electrical Engineering [KU Leuven] (KU-ESAT), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), ESEO-Tech, Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), and European Project: PETER

Subjects
[SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, transfer impedance, reliability, aging, Electromagnetic compatibility, cable shielding, Electrical and Electronic Engineering, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience; Transfer impedance is a main characteristic to describe the shielding performance of shielded cables at least up to 1 GHz. Traditionally, methods like line-injection and triaxial cell have been used to characterize it at ambient laboratory conditions. While the ambient laboratory conditions might represent appropriate environmental conditions for some industries, in others, like automotive, they are only a small subset of the real conditions. Thus, there is a need to characterize the transfer impedance over different environmental conditions. In this article, the authors present and verify a new triaxial cell design that is aimed to provide reliable measurements during high thermal and mechanical stresses. First, the cell performance is compared to a commercial cell at laboratory ambient conditions. Then, measurements are performed with the new cell at highly accelerated life testing conditions. Under these high thermal and mechanical stress conditions the cell performance is verified, and results on typical shielded cable performance under the same conditions are given.

Published
2023

16. Wideband 3-D-Printed Metal-Only Reflectarray for Controlling Orthogonal Linear Polarizations

Author

Ángel Palomares-Caballero, Carlos Molero, Pablo Padilla, María García-Vigueras, Raphaël Gillard, Universidad de Granada = University of Granada (UGR), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Spanish Government [PDC2022-133900-I00, PID2020-112545RB-C54, TED2021-129938B-I00, TED2021-131699B-I00], Junta de Andalucia [B-TIC-402-UGR18, A-TIC-608-UGR20, PYC20-RE-012-UGR, P18.RT.4830], and [FPU18/01965]

Subjects
Reflectarray antenna, dual polarization, 3-D unit cell, metal-only, 3D unit cell, Millimeter waves, Polarization control, polarization control, Dual polarization, Metal-only, reflectarray antenna, millimeter-waves, [SPI]Engineering Sciences [physics], Electrical and Electronic Engineering
Abstract

This work was supported in part by the Spanish Government under Project PID2020-112545RB-C54 and, Project RTI2018-102002-A-I00, in part by “Junta de Andalucía” under Project B-TIC-402-UGR18, Project A-TIC- 608-UGR20, Project PYC20-RE-012-UGR and Project P18.RT.4830, and in part by the Predoctoral Grant FPU18/01965. (Corresponding author: Ángel Palomares-Caballero.), This paper presents a metal-only reflectarray that enables the control of incident orthogonal polarizations in a large bandwidth. The proposed reflectarray is based on a unit cell whose tuning elements allow the independent control of the reflection phase value for the vertical and horizontal impinging polarizations. Due to the symmetry of the unit cell, the same performance is produced by each polarization when its reflection phase response is modified. The proposed unit cell provides a fairly linear phase response along the frequency with a phase variation in the orthogonal polarization of ±1o. The performance under oblique incidence and the frequency limitation of the unit cell are also investigated. From this unit cell, a metal-only reflectarray that produces circular polarization from a linear polarization is designed. The reflectarray presents a simulated directivity greater than 27 dBi with an axial ratio below 1.5 dB from 32 GHz to 50 GHz (43.9% of bandwidth). A prototype is fabricated and the measured results agree well with the simulated ones. The obtained aperture efficiency is between 56% and 41% in the considered frequency band. The measured realized gain ranges from 27 dBi to 30.3 dBi where the achieved radiation efficiency is greater than 97%., Spanish Government PDC2022-133900-I00, PID2020-112545RB-C54, TED2021-129938B-I00, TED2021-131699B-I00, Junta de Andalucia B-TIC-402-UGR18, A-TIC-608-UGR20, PYC20-RE-012-UGR, P18.RT.4830, FPU18/01965

Published
2023

17. Influence of Temperature on the EFT Immunity of Multistage Integrated Oscillators

Author

Qazi Mashaal Khan, Mohsen Koohestani, Richard Perdriau, ESEO - RF-EMC (RF-EMC), ESEO-Tech, Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO)-Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), Institut National des Sciences Appliquées (INSA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)

Subjects
Transient analysis, [SPI]Engineering Sciences [physics], Electrostatic discharges, Integrated circuit modeling, Resistors, Oscillators, Voltage measurement, Electrical and Electronic Engineering, Power supplies, Condensed Matter Physics, Atomic and Molecular Physics, and Optics
Abstract

International audience

Published
2023

18. Simplified Spatial Smoothing for DOA Estimation of Coherent Signals

Author

Jingjing Pan, Meng Sun, Yide Wang, Xiaofei Zhang, Jianfeng Li, Benzhou Jin, Nanjing University of Aeronautics and Astronautics [Nanjing] (NUAA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), BK20190396, Natural Science Foundation of Jiangsu Province, and 61971218, National Natural Science Foundation of China

Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other, [SPI]Engineering Sciences [physics], coherent signals, spatial smoothing preprocessing, Direction of arrival (DOA), Electrical and Electronic Engineering, signal subspace, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience; In coherent direction of arrival (DOA) estimation,subspace-based methods suffer from performance deteriorationbecause of the rank loss of the signal covariance matrix. Avariety of spatial smoothing preprocessing techniques have beenproposed for decorrelation, among which the enhanced spatialsmoothing preprocessing (ESS) technique shows outstandingperformance by exploiting the signal subspace. However, ESSis applied by squaring the matrix whose columns span thesignal subspace (called signal matrix), which involves unnecessarycomputational loads. Besides, the smoothed covariance matrixafter ESS is a linear combination of the sub-matrices of signalmatrix, where the coefficients of the combination may underminethe decorrelation performance. In this context, a simplifiedspatial smoothing (SSS) technique is proposed for decorrelationby averaging the sub-matrices of the signal matrix directly,and avoids redundant operations in squared signal matrix. Theproposed method is tested numerically in terms of the signal-to-noise ratio (SNR), the number of snapshots, angle separation,and the execution time. Simulation results show the improvementof the decorrelation performance, efficiency, and robustness withthe proposed method in coherent scenarios, compared with theother spatial smoothing preprocessing based methods.

Published
2023

19. Self-Adaptive RISs Beyond Free Space: Convergence of Localization, Sensing, and Communication Under Rich-Scattering Conditions

Author

Saigre-Tardif, Chloé, del Hougne, Philipp, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)

Subjects
Signal Processing (eess.SP), FOS: Computer and information sciences, 6G mobile communication, Information Theory (cs.IT), Computer Science - Information Theory, Location awareness, Wireless communication, FOS: Physical sciences, Context awareness, Systems and Control (eess.SY), Applied Physics (physics.app-ph), Physics - Applied Physics, Electrical Engineering and Systems Science - Systems and Control, Wireless sensor networks, Computer Science Applications, Scattering, [SPI]Engineering Sciences [physics], FOS: Electrical engineering, electronic engineering, information engineering, Production facilities, Electrical Engineering and Systems Science - Signal Processing, Electrical and Electronic Engineering
Abstract

We discuss the need for a confluence of localization, sensing and communications if RISs are to be deployed in a self-adaptive manner in the dynamically evolving rich-scattering settings that are typical for 6G deployment scenarios such as factories. We establish that in such problems the rich-scattering wireless channels are subject to a highly nonlinear deterministic double-parametrization through both the RIS and uncontrolled moving objects. Therefore, acquiring full context-awareness through localization and sensing is a prerequisite for RIS-empowered communications. Yet, the byproducts of this daunting communications overhead can feed many appliances that require context awareness, such that overhead concerns may vanish. We illustrate the essential steps for operating a self-adaptive RIS under rich scattering based on a prototypical case study. We discover that self-adaptive RISs outperform context-ignorant RISs only below a certain noise threshold that depends, among other factors, on how strongly uncontrolled perturbers impact the wireless channel. We also discuss ensuing future research directions that will determine the conditions under which RISs may serve as technological enabler of 6G networks., 7 pages, 5 figures, submitted to an IEEE Journal

Published
2023

20. Millimeter-Wave Induced Heating of Cutaneous Nerves and Capillaries

Author

Zain Haider, Julien Modolo, Micaela Liberti, Francesca Apollonio, Maxim Zhadobov, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Laboratoire Traitement du Signal et de l'Image (LTSI), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), French National Research Program for Environmental and Occupational Health of ANSES (Grant Number: 2018/2 RF/07)NEAR 5G ProjectCominLabs excellence laboratoryFrench National Research AgencyInvesting for the Future Program (Grant Number: ANR-10-LABX-07-01)European Union through the European Regional Development FundFrench Region of Brittany, Ministry of Higher Education and ResearchRennes Métropole and Conseil Départemental 35CPER Project SOPHIESTIC & Ondes, ANR-10-LABX-0007,COMIN Labs,Digital Communication and Information Sciences for the Future Internet(2010), Jonchère, Laurent, and Digital Communication and Information Sciences for the Future Internet - - COMIN Labs2010 - ANR-10-LABX-0007 - LABX - VALID

Subjects
Mathematical models, [SPI]Engineering Sciences [physics], Blood, [SPI] Engineering Sciences [physics], Biological system modeling, General Engineering, Millimeter wave communication, Energy Engineering and Power Technology, Heating systems, Dermis, Skin
Abstract

International audience; In this study, we quantify microscale heating at the level of cutaneous nerves and capillaries due to continuous and pulsed plane-wave exposure at 60 GHz. The thermal properties of the nerves and capillaries were derived using mixture equations based on their water content. The electromagnetic problem was solved in conjunction with Pennes bioheat equation and Arrhenius equation using finite element method to evaluate the spatial and temporal evolution of temperature along with thermal damage within cutaneous nerves and capillaries. Although, the maximum power density within the nerve (41.6 kW/m 3 ) and capillary (20 kW/m 3 ) was 37.3% and 30.2% higher than surrounding skin for a continuous exposure at 10 W/m 2 , the peak temperature elevation ( ΔT ) within the nerve (93.3 n°C) and capillary (90.7 n°C) occurred after 5 μ s and 10 μ s of exposure and was 19.2% and 17.7% higher than surrounding skin, respectively. The nerve and capillary attained thermal equilibrium with skin after roughly 10 ms. The maximal ΔT within the nerve (0.5 °C) and capillary (0.25 °C) due to nano- and micro-second 60 GHz pulses with highest fluence (0.48 kJ/m 2 ) permitted under ICNIRP guidelines was 34% and 24% higher than in the surrounding skin. Ten 3 μs 60 GHz pulses (power density = 13.4 GW/m 2 ) separated by 10 s of cooling period were used to demonstrate the possibility of selective thermal ablation of cutaneous nerves [damage index ( Ω )=1.1)] without damaging skin ( Ω = 0.15). The results provide valuable insights into local millimeter-wave induced heating within various skin substructures.

Published
2023

21. Compact Additively Manufactured Conformal Slotted Waveguide Antenna Array

Author

Charalampos Stoumpos, Thierry Le Gouguec, Rozenn Allanic, María García-Vigueras, Anne-Charlotte Amiaud, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Université de Brest (UBO), Equipe Dispositifs Hyperfréquences (Lab-STICC_DH), Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT), Thales LAS France, and Key Technology Domain (KTD)Thales GroupLab-STICCINSA Rennes

Subjects
[SPI]Engineering Sciences [physics], conformal slotted waveguide antenna array, 3-D printing, Additive Manufacturing, Selective Laser Melting, Electrical and Electronic Engineering
Abstract

International audience; In this work we present the design and fabrication in metallic 3D-printing of a compact conformal slotted waveguide antenna array operating in the Ku-band. The application objective, although not limited only to this, is the optimisation of an antenna element which by stacking will be able to form a quasi-cylindrical sector. A beamforming network will be used for beam-steering in the elevation plane as coverage in the azimuthal plane is guaranteed by the conformal geometry. The compact design of the antenna element is therefore of great significance. For this reason, a direct feeding scheme by a coaxial connector is adopted. The antenna has been optimized following multiple parametric analyses of its geometrical parameters for the enhancement of the bandwidth, return losses and realized gain. The antenna was fabricated with Selective Laser Melting in aluminium and the experimental results agree well with the numerically calculated ones. The proposed CSWAA exhibits a reflection coefficient below -10 dB, realized gain above 14 dBi, as well as good cross-polarization and side-lobe level over a relative bandwidth of 8%.

Published
2023

22. Enhanced DOA Estimation with Co-prime Array in the Scenario of Impulsive Noise: A Pseudo Snapshot Increment Perspective

Author

Jingjing Pan, Meng Sun, Xudong Dong, Yide Wang, Xiaofei Zhang, Nanjing University of Aeronautics and Astronautics [Nanjing] (NUAA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)

Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other, improved spatial smoothing (ISS), Impulsive noise, co-prime array, direction of arrival (DOA), Computer Networks and Communications, enhanced fractional low-order moment (EFLOM), Automotive Engineering, Aerospace Engineering, Electrical and Electronic Engineering, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience; Co-prime array configuration is popular in therecent development of array signal processing. However, theassumption of Gaussian noise in most co-prime array process-ing research leads to model mismatch in practical scenariosof impulsive noise, therefore has an adverse impact on theestimation of direction of arrival (DOA) of the incoming sources.Moreover, co-prime array builds an enlarged virtual array byvectorizing the covariance matrix of the received signals, wherethe equivalent received signals of the virtual array have only asingle snapshot. In this paper, we propose an enhanced fractionallow-order method (EFLOM) for co-prime array configurationin the scenarios of impulsive noise, from the perspective ofpseudo snapshot augmentation. Since impulsive noise does nothave finite second-order statistics or high-order cumulant, weconstruct a series of equivalent covariance matrices by usingphased fractional low-order moments with different orders of thereceived signals. Then, the vectorization of the multiple equivalentcovariance matrices can be considered as the equivalent receivedsignals of virtual array with multiple pseudo snapshots. Sincemultiple pseudo snapshots are constructed from the same sources,additional spatial smoothing preprocessing operations are stillneeded for enforced decorrelation. In this paper, we propose animproved spatial smoothing (ISS) technique by applying the in-formation of both autocorrelation and cross subarray correlationin the covariance matrix. Afterwards, the classical multiple signalclassification (MUSIC) is applied for the estimation of DOAs.In addition, the proposed method can also be extended to theother sparse array geometrics. The performance of the proposedmethod is theoretically verified and simulations are providedto show its effectiveness in terms of the generalized signal tonoise ratio (GSNR), parameter of impulsive noise, and angleseparation. Simulation results show that the proposed method cangreatly improve the resolution, accuracy, and degrees of freedom(DOFs) in DOA estimation in presence of impulsive noise.

Published
2023

23. Compact Slit-Loaded ACS-Fed Monopole Antenna for Bluetooth and UWB Systems With WLAN Band-Stop Capability

Author

Mohsen Koohestani, Nima Azadi-Tinat, Anja K. Skrivervik, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), ESEO - RF-EMC (RF-EMC), ESEO-Tech, Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO)-Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), Shahrood University of Technology, and Ecole Polytechnique Fédérale de Lausanne (EPFL)

Subjects
bandwidth, compact, General Computer Science, design, General Engineering, acs-fed, band-notch, gain, bluetooth, monopole, [SPI]Engineering Sciences [physics], uwb, slot antenna, transmitting antennas, General Materials Science, 2.4 ghz wlan, Electrical and Electronic Engineering, antennas, coplanar waveguides, ultra wideband antennas, wireless lan, integrated bluetooth, single
Abstract

A compact asymmetric coplanar strip (ACS)-fed monopole antenna is presented, which operates within the Bluetooth and UWB frequency bands with the capability to simultaneously reject the lower WLAN interfering band. The antenna consists of an inverted right triangle patch monopole loaded by open-ended L-shaped slits not only to produce the additional 2.4 GHz passband to the UWB design but also to achieve stopband characteristics around 5.2 GHz. The conceptual equivalent circuit model as well as characteristic mode analyses are carried out in the design evolution process. The proposed antenna has an overall size of only 20 mm x 10 mm, having the smallest area among the so far developed designs, which can be easily integrated within any wireless gadgets. A prototype is fabricated and measured to validate the design, demonstrating the predicted behavior fairly achieved by full-wave analysis. The antenna -10 dB operating bandwidth ranges from 2.38 to 2.42 GHz and from 3.35 to 11 GHz while rejecting from 4.69 to 5.2 GHz. Unlike the unwanted stopband, where the radiation characteristics are adequately deteriorated, the proposed antenna fairly provides stable omni-directional radiation patterns in the H-plane, and has an average efficiency (gain) of 87.3% (2.6 dBi) in the desired passband. As far as the antenna transient behavior is concerned, an adequate measured (simulated) system fidelity factor of 0.7 (0.68) is achieved for the transmission of impulse-type UWB signals in the face-to-face configuration.

Published
2023

24. Compact Planar Beamformer Using Multiple Continuous Parallel-Plate Waveguide Delay Lenses

Author

Francois Doucet, Nelson J. G. Fonseca, Etienne Girard, Xavier Morvan, Ronan Sauleau, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Dassault Aviation, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Thales Alenia Space [Toulouse] (TAS), THALES [France], European Space Agency (ESA), Thales Alenia Space, France, and ESA's Networking/Partnering Initiative (NPI) [4000117405/16/NL/MH]

Subjects
parallel-plate waveguide (PPW) beamformer, [SPI]Engineering Sciences [physics], Geometrical optics (GO), line source, Electrical and Electronic Engineering, multiple beam antenna
Abstract

International audience; A compact planar beamformer using multiple shaped continuous parallel-plate waveguide delay lenses is proposed in this letter. The original design, based on a single-shaped continuous delay lens, had demonstrated excellent scanning properties over the portion of the K-a-band allocated to uplink satcom (27.5-31 GHz). However, its height, due to the transversal ridge and cavity, was limiting its use in more advanced antenna systems. A design methodology is proposed here to achieve similar focusing properties while reducing significantly the beamformer's height. A specific design is demonstrated with a height reduced by a factor of three when compared to the original design. A reduction of the longitudinal dimension is also proposed by introducing two additional straight ridges and cavities. A prototype was manufactured and tested successfully, with RF performance similar to those of the reference design besides slightly higher insertion losses. This compact design enables to stack multiple lenses to produce two dimensional (2-D) beamforming.

Published
2022

25. Wideband Dual-Circularly-Polarized Reflect-Arrays Based on Dual-Functional-Layer Cells With Berry-Phase Compensation at X-Band

Author

Yuan Li, Zhi Hao Jiang, Xuanfeng Tong, Fan Wu, Nan Shen, Ronan Sauleau, Wei Hong, Southeast University, ZTE [Nanjing], Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), National Natural Science Foundation of China (NSFC) [62122019, 61901106], High Level Innovation and Entrepreneurial Research Team Program in Jiangsu, ZTE Corporation, and State Key Laboratory of Mobile Network and Mobile Multimedia Technology

Subjects
[SPI]Engineering Sciences [physics], Bandwidth, Substrates, Array signal processing, Periodic structures, Circular polarization selective surface (CPSS), reflect-arrays (RAs), Reflection, Lattices, Electrical and Electronic Engineering, Surface waves, dual-circularly-polarization
Abstract

International audience; We present the design and experimental validation of wideband dual-circularly-polarized (dual-CP) reflect-arrays (RAs) based on dual-functional-layered unit cells with independent control of circular polarizations. The proposed dual-CP RA cells comprise a circular polarization selective surface (CPSS) on the top based on a bandwidth-enhanced dual-meandered Pierrot structure that implements polarization selection of CP waves and a reflective half-wave plate (HWP) on the bottom. The dual-CP phase delay of the RA cells relies on the Berry-phase (BP) dictated by the rotation of the CPSS and HWP elements for achieving reflective beamforming of CP waves of opposite handedness. The diffractive properties of an infinite periodic gradient array of the dual-CP RA cells in a triangular lattice are investigated, which numerically verifies the dual-CP anomalous reflection capability. Two proof-of-concept RAs operating at X-band are designed, fabricated, and characterized. By replacing only the bottom functional layer of the RA, symmetrical and asymmetrically distributed dual-CP beams can be obtained. A measured peak gain of higher than 23.5 dBic is achieved, with a joint bandwidth of 11% for an axial ratio < 2 dB and a gain variation < 1 dB. The improved bandwidth performance, high-resolution BP compensation, and printed manufacturing process without using any metallic cavities make the demonstrated CPSS-based dual-CP RAs promising candidates for wireless and satellite communications.

Published
2022

26. Analysis of Compressing PAPR-Reduced OFDM IQ Samples for Cloud Radio Access Network

Author

Aya Shehata, Philippe Mary, Matthieu Crussiere, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA), and BPIfrance for the FUI25 CLOUDCAST Project

Subjects
Modulation, Standards, Digital video broadcasting, ATSC3.0, PAPR reduction, compression, entropy coding, Peak to average power ratio, Time-domain analysis, [SPI]Engineering Sciences [physics], MER, Media Technology, C-RAN, clipping, Computer architecture, quantization, Electrical and Electronic Engineering, tone reservation, DVB-T2, OFDM
Abstract

International audience; A common problem of the virtualized cloud radio access network architecture (C-RAN) is the compression of the time-domain IQ samples before transmission over the fronthaul link. Considering a multicarrier waveform such as OFDM, whose IQ samples follow a quasi-Gaussian distribution, the conventional Gaussian quantizer may be used as the optimal solution to the compression problem. However, since the high peak-to-average power ratio (PAPR) of OFDM signals remains a serious problem, various techniques may be employed to reduce the time-domain fluctuations of the IQ samples in the OFDM, resulting in a change in its distribution. The latter fact makes the Gaussian quantizer suboptimal. The literature lacks a performance analysis of the conventional OFDM-based compression techniques when the PAPR of the OFDM signal is reduced. Therefore, in this paper, we study for the first time the impact of reducing the PAPR of the OFDM signal before compression in the C-RAN architecture through rate-distortion analysis. We consider clipping and tone reservation PAPR reduction algorithms. The former is the simplest PAPR reduction approach, while the latter is one of the most effective algorithms used in broadcasting standards such as DVB-T2 and ATSC 3.0. We first derive the distribution of the PAPR-reduced OFDM IQ samples. This is used to optimize the thresholds and codebook levels of a non-uniform scalar quantizer and the number of quantization bits allocated for each quantized level in the entropy coding stage, along with the MER performance analysis. The simulation results show that the conventional Gaussian-based compression techniques applied to a PAPR-reduced signal is not very robust to the statistical changes in the signal unless the signal distribution at the input of the Gaussian quantizer is not significantly affected. However, a significant gain is obtained when the quantizer is optimized with respect to the true distribution of the PAPR-reduced IQ samples.

Published
2022

27. Solving Sub-Wavelength Lattice Reduction in Full-Metal Front-Ends for Dual-Polarized Active Antennas

Author

Lucas Polo-Lopez, Esteban Menargues, Santiago Capdevila, Giovanni Toso, Maria Garcia-Vigueras, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), SWISSto12, ESA - ESTEC (Netherlands), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), European Union through the European Regional Development Fund (ERDF), French Region of Brittany, Ministry of Higher Education and Research, Rennes Metropole, Conseil Departemental 35, through the CPER Project SOPHIE/STIC, Conseil Departemental 35, through the Ondes, and Region of Brittany [1-2019-3Debris]

Subjects
Resonant frequency, subwavelength radiating apertures, periodic discontinuity circuit modeling, satellite antennas, Phased arrays, Antenna theory, Active antennas (AAs), Electrical and Electronic Engineering, Aperture antennas, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience; This article proposes an original structure of evanescent quadridge antenna (EQA) to conceive dual-polarized full-metal front-ends that can be used in active antennas (AAs) with wide field-of-view (FoV). An original design methodology is here proposed that allows to induce radiation from subwavelength squared apertures based on the use of evanescent and quadridge waveguides. The proposal is illustrated by means of a design with 4.5% bandwidth providing dual-circular polarization (CP) with good performance up to 50 degrees-scanning even in the diagonal plane. For comparison purposes, a metallic benchmark is also proposed, which is based on the use of classical quadridge horns. Such comparative analysis allows to understand the superior performance of the proposed concept and its main advantage: it allows to avoid the excitation of the first high order mode in the squared quadridge aperture. The excitation of such spurious mode in the antenna is explained in terms of simple equivalent circuit models characterizing the aperture periodic discontinuity.

Published
2022

28. mpNet: Variable Depth Unfolded Neural Network for Massive MIMO Channel Estimation

Author

Taha Yassine, Luc Le Magoarou, Artificial Intelligence, Domaine Hypermedia (IRT b<>com) (Hypermedia), Institut de Recherche Technologique b-com (IRT b-com)-Institut de Recherche Technologique b-com (IRT b-com), Institut de Recherche Technologique b-com (IRT b-com), B<>COM [Cesson Sévigné], Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)

Subjects
sparse recovery, Signal Processing (eess.SP), FOS: Computer and information sciences, Computer Science - Machine Learning, neural network, Computer Science - Artificial Intelligence, online learning, Channel estimation, unsupervised learning, Machine Learning (cs.LG), [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI], Computer Science - Networking and Internet Architecture, [SPI]Engineering Sciences [physics], [INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI], [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], FOS: Electrical engineering, electronic engineering, information engineering, Analytical models, Electrical Engineering and Systems Science - Signal Processing, Electrical and Electronic Engineering, Manifolds, matching pursuit (MP), Computer Science::Information Theory, Networking and Internet Architecture (cs.NI), Signal to noise ratio, Applied Mathematics, MIMO channel estimation, Matching pursuit algorithms, Computer Science Applications, Artificial Intelligence (cs.AI), Deep unfolding, Estimation, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Neural networks
Abstract

International audience; Massive multiple-input multiple-output (MIMO) communication systems have a huge potential both in terms of data rate and energy efficiency, although channel estimation becomes challenging for a large number of antennas. Using a physical model allows to ease the problem by injecting a priori information based on the physics of propagation. However, such a model rests on simplifying assumptions and requires to know precisely the configuration of the system, which is unrealistic in practice. In this paper we present mpNet, an unfolded neural network specifically designed for massive MIMO channel estimation. It is trained online in an unsupervised way. Moreover, mpNet is computationally efficient and automatically adapts its depth to the signal-to-noise ratio (SNR). The method we propose adds flexibility to physical channel models by allowing a base station (BS) to automatically correct its channel estimation algorithm based on incoming data, without the need for a separate offline training phase. It is applied to realistic millimeter wave channels and shows great performance, achieving a channel estimation error almost as low as one would get with a perfectly calibrated system. It also allows incident detection and automatic correction, making the BS resilient and able to automatically adapt to changes in its environment.

Published
2022

29. Ultra-Low-Profile Continuous Transverse Stub Array for SatCom Applications

Author

Michele Del Mastro, Adham Mahmoud, Thomas Potelon, Ronan Sauleau, Gilles Quagliaro, Anthony Grbic, Mauro Ettorre, ANYWAVES, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Direction générale de l'Armement (DGA), Thales SIX GTS France, University of Michigan System, ANR-ASTRID MATURATION (project named RAFQO), European Union through the European Regional Development Fund (ERDF), Ministry of Higher Education and Research, Brittany and Rennes Metropole through the CPER Project SOPHIE/STIC Ondes, and ANR-16-ASMA-0006,RAFQO 2016,Réseau Actif de Formateurs Quasi-Optiques(2016)

Subjects
metasurface, ultra-low profile, [SPI]Engineering Sciences [physics], Satcom On-The-Move (SOTM), Dual-band polarizer, printed circuit board (PCB) technology, satellite communication (SatCom), periodic structures, Electrical and Electronic Engineering, linear-to-circular polarization (LP-to-CP) conversion, wideband, dual-circular polarization (CP)
Abstract

International audience; Modern K-/Ka-band satellite communications have become increasingly demanding in recent years with regard to the performance of the terminal antenna used in the link. These terminals should be high gain and broadband, as well as guarantee polarization diversity over a large field of view. A low profile is also highly desired to integrate the antenna system into a variety of moving platforms, such as aircraft and trains. An ultra-low-profile continuous transverse stub array is proposed here to tackle these challenges. The antenna array is realized in printed circuit board technology by adopting a contactless transition between the stacked-up layers without resorting to blind or buried vias. The proposed antenna is wideband (impedance matched within the 19-31 GHz band, i.e., similar to 50%) and provides multibeam radiation for polar angles as far as +/- 22.5 degrees. The peak value of the gain is 19.7 dBi, and the maximum radiation efficiency equals 50%. Furthermore, the antenna array is combined with a dual-band polarization converter. The latter provides orthogonal circular polarization (CP) in two non-adjacent bands. The overall antenna system performs right- and left-hand CPs within the SatCom downlink and uplink in the K-/Ka-band, respectively. For each polarization, the axial ratio is below 3 dB over 9.47% and 4.42% fractional bandwidths, respectively.

Published
2022

30. A Comparative Performance Analysis of 6T & 9T SRAM Integrated Circuits: SOI vs. Bulk

Author

Qazi Mashaal Khan, Richard Perdriau, Mohamed Ramdani, Mohsen Koohestani, ESEO - RF-EMC (RF-EMC), ESEO-Tech, Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO)-Université Bretagne Loire (UBL)-École supérieure d'électronique de l'ouest [Angers] (ESEO), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), and 812790 (MSCA-ETN PETER), European Union’s Horizon 2020 Research and Innovation Programme through the Marie Sklodowska-Curie

Subjects
Circuit stability, Measurement, [SPI]Engineering Sciences [physics], SRAM cells, Thermal stability, Electromagnetic compatibility, Transistors, ComputingMilieux_MISCELLANEOUS, Leakage currents
Abstract

International audience

Published
2022

31. Adaptive Loop Filter Hardware Design for 4K ASIC VVC Decoders

Author

Ibrahim Farhat, Wassim Hamidouche, Adrien Grill, Daniel Menard, Olivier Deforges, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), VITEC, and None

Subjects
Standards, Mathematical models, Hardware, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Decoding, Encoding, Image reconstruction, Media Technology, ALF and ASIC, In-loop Filter, Electrical and Electronic Engineering, Transforms, VVC
Abstract

International audience; Versatile video coding (VVC) is the next generation video coding standard released in July 2020. VVC introduces new coding tools enhancing the coding efficiency compared to its predecessor high efficiency video coding (HEVC). These new tools have a significant impact on the VVC software decoder with a complexity estimated to two times HEVC decoder complexity. In particular, the adaptive loop filter (ALF) introduced in VVC as an in-loop filter increases both the decoding complexity and memory usage. These concerns need to be carefully addressed regarding the design of an efficient hardware implementation of a VVC decoder. In this paper, we present an efficient hardware implementation of the ALF tool for VVC decoder. The proposed solution establishes a novel scanning order between Luma and Chroma components that reduces significantly the ALF memory. The design takes advantage of all ALF features and establishes an unified hardware module for all ALF filters. The design uses 26 regular multipliers in a pipelined architecture with a fixed throughput of 2 pixels/cycle and fixed system latency regardless of the selected filter. This design operates at 600 MHz frequency enabling to decode on ASIC platform a 4K video at 30 frames per second in 4:2:2 chroma sub-sampling format.

Published
2022

32. A Compact Double-Sided FSS Absorbing Wall for Decoupling 5G Antenna Arrays

Author

Faissal Merzaki, Philippe Besnier, Mohamed Himdi, Xavier Castel, Maelle Sergolle, Thierry Levavasseur, Patrick Caldamone, Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), SERIBASE Industrie, French FUI STARCOM Project, European Union through the European Regional Development Fund, Ministry of Higher Education and Research, Region Bretagne, Departements d'Ille-et-Vilaine and des Cotes d'Armor, Saint-Brieuc Armor Agglomeration, through the CPER project 2015-2020 SOPHIE, and Saint-Brieuc Armor Agglomeration, through the CPER project 2015-2020 MATECOM

Subjects
Resonant frequency, fifth generation (5G) antenna array, Antenna decoupling, Impedance, frequency selective surface (FSS) absorber, Frequency selective surfaces, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Absorption, [SPI]Engineering Sciences [physics], 5G mobile communication, Antennas, Antenna arrays, Electrical and Electronic Engineering
Abstract

International audience; The fifth generation (5G) of mobile communications gives birth to the evolution of the base stations. They progressively include arrays of antennas in the sub-6 GHz frequency band worldwide. Moreover, 5G takes advantage of the beamforming capabilities to gain power efficiency and higher throughputs. Within this framework, achieving high decoupling performance between any pairs of antennas and compactness at the same time become a major challenge. The present paper describes an advanced solution based on the interposition of a thin and low-profile absorbing wall operating in the 3.4-3.6 GHz frequency band. The absorption is provided by a frequency selective surface whose elementary pattern size is first optimized. Then, the compact absorbing wall that associates back-to-back pieces of absorber is interposed between elements of an antenna array. Moreover, the fabrication of both antenna array and decoupling device involve lightweight and low-cost composite technology. The results show that such a compact decoupling device achieves excellent decoupling capabilities while keeping up the antenna array performance.

Published
2022

33. Unsupervised Speech Enhancement Using Dynamical Variational Autoencoders

Author

Xiaoyu Bie, Simon Leglaive, Xavier Alameda-Pineda, Laurent Girin, Vers des robots à l’intelligence sociale au travers de l’apprentissage, de la perception et de la commande (ROBOTLEARN), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Grenoble Alpes (UGA), CentraleSupélec, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), GIPSA - Cognitive Robotics, Interactive Systems, & Speech Processing (GIPSA-CRISSP), GIPSA Pôle Parole et Cognition (GIPSA-PPC), Grenoble Images Parole Signal Automatique (GIPSA-lab), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Grenoble Alpes (UGA), ANR-19-P3IA-0003, ANR-3IA MIAI, ANR-19-CE33-0008-01, ANR-JCJC ML3RI, GA #871245, EC, ANR-19-P3IA-0003,MIAI,MIAI @ Grenoble Alpes(2019), ANR-19-CE33-0008,ML3RI,Apprentissage de bas-niveau d'ineractions robotiques multi-modales avec plusieurs personnes(2019), European Project: 871245,H2020-EU.2.1.1. - INDUSTRIAL LEADERSHIP - Leadership in enabling and industrial technologies - Information and Communication Technologies (ICT),SPRING(2020), and European Project: H2020,SPRING

Subjects
Computer Science::Machine Learning, FOS: Computer and information sciences, Computer Science - Machine Learning, Sound (cs.SD), Acoustics and Ultrasonics, Computer Science - Artificial Intelligence, Noise measurement, Speech enhancement, Time series analysis, Computer Science - Sound, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI], Machine Learning (cs.LG), Time-domain analysis, Computational Mathematics, Artificial Intelligence (cs.AI), [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], Computer Science::Sound, Audio and Speech Processing (eess.AS), Recording, FOS: Electrical engineering, electronic engineering, information engineering, Computer Science (miscellaneous), Training, Inference algorithms, Electrical and Electronic Engineering, Electrical Engineering and Systems Science - Audio and Speech Processing
Abstract

International audience; Dynamical variational autoencoders (DVAEs) are a class of deep generative models with latent variables, dedicated to model time series of high-dimensional data. DVAEs can be considered as extensions of the variational autoencoder (VAE) that include temporal dependencies between successive observed and/or latent vectors. Previous work has shown the interest of using DVAEs over the VAE for speech spectrograms modeling. Independently, the VAE has been successfully applied to speech enhancement in noise, in an unsupervised noise-agnostic set-up that requires neither noise samples nor noisy speech samples at training time, but only requires clean speech signals. In this paper, we extend these works to DVAE-based single-channel unsupervised speech enhancement, hence exploiting both speech signals unsupervised representation learning and dynamics modeling. We propose an unsupervised speech enhancement algorithm that combines a DVAE speech prior pre-trained on clean speech signals with a noise model based on nonnegative matrix factorization, and we derive a variational expectation-maximization (VEM) algorithm to perform speech enhancement. The algorithm is presented with the most general DVAE formulation and is then applied with three specific DVAE models to illustrate the versatility of the framework. Experimental results show that the proposed DVAE-based approach outperforms its VAE-based counterpart, as well as several supervised and unsupervised noise-dependent baselines, especially when the noise type is unseen during training.

Published
2022

34. Tropical Forest Vertical Structure Characterization: From GEDI to P-Band SAR Tomography

Author

Yen-Nhi Ngo, Yue Huang, Dinh Ho Tong Minh, Laurent Ferro-Famil, Ibrahim Fayad, Nicolas Baghdadi, Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), and Centre National d’Etudes Spatiales/Terre, Ocean, Surfaces Continentales, Atmosphere (CNES/TOSCA—project BIOMASS-valorisation)'Land, Environment, Remote Sensing and Spatial Information' Joint Research Unit (UMR TETIS), Institut national de recherche en agriculture, alimentation et environnement (INRAE)Center for the Study of the Biosphere from Space (CESBIO)

Subjects
[SPI]Engineering Sciences [physics], Digital terrain model, [SDE]Environmental Sciences, Canopy height model, Electrical and Electronic Engineering, Geotechnical Engineering and Engineering Geology, Tomography, Paracou, Vertical Structure profile, GEDI
Abstract

International audience; Estimating tropical forests vertical structure using remote sensing is a challenge. Active sensors such as lowfrequency Synthetic Aperture Radar (SAR) operating at P-band, with a wavelength of ∼ 69 cm wavelength, and Light Detection and Ranging (LiDAR) are able to penetrate thick vegetation layers. While NASA’s Global Ecosystem Dynamics Investigation (GEDI) is collecting spaceborne liDAR data, the ESA’s next Earth Explorer BIOMASS mission will acquire multiple acquisitions over the same areas to form three-dimensional images through SAR tomography (TomoSAR) technique. Our study shows the potential value of GEDI and TomoSAR acquisitions in producing accurate estimates of forests vertical structure. By analyzing airborne P-band TomoSAR, airborne LiDAR, and spaceborne GEDI LiDAR at a tropical forest site in Paracou, French Guiana, South America, we show that both GEDI and P-band TomoSAR can directly measure surface, vegetation heights, and vertical profiles with high resolution and precision. Airborne TomoSAR is of higher quality than GEDI due to better penetration properties and precision. However, the GEDI vegetation height root-meansquare error is less than 5 m, for an average forest height value around 30 m at the Paracou site, which is similar to the expected performance of the future spaceborne BIOMASS mission. These results suggest GEDI measurements, i.e. shots with sensitivity greater than 98%, will provide a good reference of forest structure to calibrate the BIOMASS mission algorithms.

Published
2022

35. A Novel Mean-Shift Algorithm for Data Clustering

Author

Claude Cariou, Steven Le Moan, Kacem Chehdi, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), and Norwegian University of Science and Technology (NTNU)

Subjects
Standards, Clustering algorithms, General Computer Science, General Engineering, mean-shift, TK1-9971, Kernel, [SPI]Engineering Sciences [physics], Bandwidth, Sensitivity, data clustering, nearest neighbors, Task analysis, General Materials Science, Electrical engineering. Electronics. Nuclear engineering, Convergence, Data mining, kernel-based method
Abstract

International audience; We propose a novel Mean-Shift method for data clustering, called Robust Mean-Shift (RMS). A new update equation for point iterates is proposed, mixing the ones of the standard Mean-Shift (MS) and the Blurring Mean-Shift (BMS). Despite its simplicity, the proposed method has not been studied so far. RMS can be set up in both a kernel-based and a nearest-neighbor (NN)-based fashion. Since the update rule of RMS is closer to BMS, the convergence of point iterates is conjectured based on the Chen's BMS convergence theorem. Experimental results on synthetic and real datasets show that RMS in several cases outperforms MS and BMS in the clustering task. In addition, RMS exhibits larger attraction basins than MS and BMS for identical parametrization; consequently, its kernel variant requires a lower aperture of the kernel function, and its NN variant a lower number of nearest neighbors compared to MS or BMS, to achieve optimal clustering results. In addition, the NN version of RMS does not need to specify a convergence threshold to stop the iterations, contrarily to the NN-BMS algorithm.

Published
2022

36. Integrated Slotted Serpentine Waveguide to Enhance Radiation Properties and Efficiency

Author

Mohamed Himdi, Yassine Aouial, Olivier Lafond, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), French FUI RASSUR Project, European Union through the European Regional Development Fund, Ministry of Higher Education and Research, and SOPHIE/STIC and Ondes through the CPER Projects 2015

Subjects
Planar waveguides, Substrates, General Computer Science, General Engineering, Antenna radiation patterns, millimeter wave, PCB technology, [SPI]Engineering Sciences [physics], Rectangular waveguides, Etching, Slot antennas, serpentine, General Materials Science, Slotted waveguides, Electrical and Electronic Engineering, Waveguide transitions
Abstract

International audience; Slotted waveguides are often used when high-power and high-efficiency antennas must be designed and particularly for millimeter waves applications (automotive radar for example). But it is not easy to choose any distance between radiation slots because of the guided wavelength, to obtain a wide beam in E plane and so to cover a wide angular sector in beam scanning antennas. Moreover, the main beam depends of frequency because it is a progressive wave antenna. In this article, the authors propose an original solution based on a slotted serpentine waveguide with slots on the narrow wall of the waveguide allowing to obtain a very wide radiation pattern in E plane, and this antenna is manufactured, thanks a PCB (printed circuit board) process with empty waveguides to enhance the efficiency for the global structure. Simulations and measurements are given to validate the idea and the technological process in W band, and some different prototypes demonstrate that it could be possible to obtain a wide angular sector in a beam scanning antenna configuration.

Published
2022

37. Time Reversal Communications With Channel State Information Estimated From Impedance Modulation at the Receiver

Author

K. Brahima Yeo, Cecile Leconte, Philipp del Hougne, Philippe Besnier, Matthieu Davy, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), European Union through the European Regional Development Fund (ERDF), French Region of Brittany and Rennes Metropole through the CPER Project SOPHIE/STIC Ondes, Pole d'Excellence Cyber (PEC), French 'Agence Nationale de la Recherche' [ANR-17-ASTR-0017], Institut Universitaire de France, and ANR-17-ASTR-0017,DICOREV,Corrélations du champ diffus en chambre réverbérante(2017)

Subjects
General Computer Science, General Engineering, Impedance, Precoding, Time reversal communications, Antenna measurements, reverberation chamber, [SPI]Engineering Sciences [physics], Transmitting antennas, Timing analysis, multiple-input single-output (MISO), Channel state information, Wigner-Smith operator, Receiving antennas, Reverberation chambers, General Materials Science, Antenna arrays, Electrical and Electronic Engineering, Focusing
Abstract

International audience; We determine the channel state information (CSI) of a multiple-input single-output (MISO) Rayleigh channel without prior communications between the transmitting antennas and the receiver. Our approach solely relies on an impedance modulation at the receiver and therefore circumvents the vexing need of a direct feedback between receiver and transmitters. We extract the wavefront to be transmitted in order to achieve optimal focusing on the receiver from a generalized Wigner-Smith operator (WSO). The latter is evaluated based on the scattering matrix of the transmit array measured in the two possible states of the receiver. Based on the CSI extracted via the WSO, any desired precoding technique can be implemented. Here, we show through in- situ time-domain measurements in a reverberation chamber that our approach closely reaches time-reversal performances in terms of focusing efficiency. We expect our approach to open up new perspectives for future wireless communications and wireless power transfer, including applications in the biomedical domain and electronic warfare.

Published
2022

38. Modeling Trust Relationships in Blockchain Applications: The Case of Reconfigurable Systems-on-Chip

Author

Loïc Pallardy, Richard Perdriau, Frédéric Jouault, Maxime Méré, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), STMicroelectronics, and École supérieure d'électronique de l'ouest [Angers] (ESEO)

Subjects
[SPI]Engineering Sciences [physics], Blockchain, Re-configurable Systems-on-Chip, Trust Relationships
Abstract

Nowadays, System-on-Chip (SoC) components are found everywhere in all kinds of smart devices. Each System-on-Chip contains many different blocks that provide specific functionalities, such as WiFi or Bluetooth connectivity. Whereas integrating each such block in a SoC typically requires paying some royalties, not all blocks are necessary for all applications, or throughout a device’s lifecycle. Moreover, it is not possible to manufacture a specific SoC for each application. Significant advantages are therefore expected to be gained by enabling trustworthy remote SoC reconfiguration throughout their life cycles. A few approaches attempting to address this challenge have been proposed in the literature. They are typically based on Blockchain technology in order to support decentralization without relinquishing trust. Reviewing these approaches lead us to identify a potential flaw in the proposed protocols. Indeed, a SoC should be able to trust Blockchain information that it is given, without requiring any centralization. In order to validate our suspicions, we propose in this paper to use Verifpal: a cryptographic protocol verification tool that works from textual protocol models. We use it in a slightly unorthodox way in order to model the trust relationships in one of the approaches from the literature, and to verify it. The results show that, under some assumptions, a flaw is indeed present. We propose and model several possible fixes, and present their respective limitations.

Published
2022

39. 2 Bit Reconfigurable Unit-Cell and Electronically Steerable Transmitarray at $Ka$ -Band

Author

Ronan Sauleau, Antonio Clemente, Laurent Dussopt, Kien Pham, Fatimata Diaby, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes (UGA), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Vietnam National University - Ho Chi Minh City (VNU-HCM), ANR-14-CE28-0023, National Research Agency through the project 'TRANSMIL', ANR-14-CE28-0023,TRANSMIL,Réseaux transmetteurs reconfigurables pour le dépointage et la formation de faisceau en bande millimétrique(2014), Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Institut d'Electronique et de Télécommunications de Rennes (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Nantes (UN)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), and Nantes Université (NU)-Université de Rennes 1 (UR1)

Subjects
discrete lens, Fabrication, Aperture, electronically steerable antenna, Transmitarray antennas, Phase (waves), beam steering, 02 engineering and technology, [SPI]Engineering Sciences [physics], Bandwidth, Optics, Apertures, 0202 electrical engineering, electronic engineering, information engineering, Bandwidth (computing), Prototypes, Ka band, Computer architecture, Electrical and Electronic Engineering, Pencil-beam scanning, P-i-n diodes, Patch antennas, Diode, Physics, business.industry, Linear polarization, 020206 networking & telecommunications, Ka-band, beam forming, business
Abstract

This communication presents the design, optimization, fabrication, and characterization of an electronically steerable transmitarray (TA) with 2 bits of phase quantization per unit cell. The proposed TA operates in linear polarization at Ka -band and is composed of $14\times14$ reconfigurable unit-cells. Four p-i-n diodes are integrated on each unit-cell to control the radiated field phase distribution across the TA aperture. The prototype demonstrates experimentally pencil beam scanning over a $120^{\circ } \times 120^{\circ }$ window, a maximum gain at broadside of 19.8 dBi, and a 3 dB fractional bandwidth of 16.2%.

Published
2020

40. Comparison Between Delay and Sum and Range Migration Algorithms for Image Reconstruction in Through-the-Wall Radar Imaging Systems

Author

Giulia Sacco, Emanuele Piuzzi, A. Zambotti, Stefano Pisa, Paolo D'Atanasio, Erika Pittella, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Università Telematica Pegaso, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Centre National de la Recherche Scientifique (CNRS), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)

Subjects
Imagination, Radiation, Electromagnetics, Computer science, media_common.quotation_subject, MIMO, Iterative reconstruction, [SPI]Engineering Sciences [physics], Position (vector), Radar imaging, Scattering parameters, Radiology, Nuclear Medicine and imaging, delay and sum (DAS) algorithm, Fermat's principle, range migration algorithm, through-the-wall radar imaging (TWRI), radiation, radiology, nuclear medicine and imaging, instrumentation, Antenna (radio), Instrumentation, Algorithm, media_common
Abstract

Through-the-wall radar imaging (TWRI) systems allow police, fire personnel, and defense forces to detect, identify, and track subjects inside buildings or under rubble. In this paper, the delay and sum (DAS) and range migration (RM) algorithms are compared as imaging techniques for a multiple input multiple output (MIMO) stepped-frequency (SF) radar system. These algorithms have been applied to analytical, simulated, and measured data both in the absence and in the presence of a wall between the antenna and the target. Both techniques were able to accurately reconstruct the position of targets behind a wall. The DAS presents a wider angle of nonambiguity while the RM is faster. An improvement of the DAS, in terms of accuracy in the target positioning, is achieved applying the Fermat's principle.

Published
2018

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