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User Subgrouping in Scalable Cell-Free Massive MIMO Multicasting Systems
(VDE, 2024-09-09) de la Fuente, Alejandro; Femenias, Guillem; Riera-Palou, Felip; Interdonato, Giovanni
Cell-free massive multiple-input multiple-output (CF-mMIMO) is a breakthrough technology for beyond-5G systems, designed to significantly boost the energy and spectral efficiencies of future mobile networks while ensuring a consistent quality of service for all users. Additionally, multicasting has gained considerable attention recently because physical-layer multicasting offers an efficient method for simultaneously serving multiple users with identical service demands by sharing radio resources. Typically, multicast services are delivered either via unicast transmissions or a single multicast transmission. This work, however, introduces a novel subgroup-centric multicast CF-mMIMO framework that divides users into several multicast subgroups based on the similarities in their spatial channel characteristics. This approach allows for efficient sharing of the pilot sequences used for channel estimation and the precoding filters used for data transmission. The proposed framework employs two scalable precoding strategies: centralized improved partial MMSE (IP-MMSE) and distributed conjugate beamforming (CB). Numerical results show that for scenarios where users are uniformly distributed across the service area, unicast transmissions using centralized IP-MMSE precoding are optimal. However, in cases where users are spatially clustered, multicast subgrouping significantly improves the sum spectral efficiency (SE) of the multicast service compared to both unicast and single multicast transmission. Notably, in clustered scenarios, distributed CB precoding outperforms IP-MMSE in terms of per-user SE, making it the best solution for delivering multicast content.
High diagnostic quality ECG compression and CS signal reconstruction in body sensor networks
(IEEE, 2016) Chidean, Mihaela I.; Barquero-Pérez, Óscar; Zhang, Qi; Jacobsen, Rune Hylsberg; Caamaño, Antonio J
Compression of electrocardiograms (ECG) in wireless environments, with diagnostic quality, has shown limited potential. This lack of quality preservation, using Wavelet Transform (WT), is due to the fact that the multiple levels of detail that can be achieved in the time domain are not exploited. In the present work, we propose to fully exploit the wavelet capability to operate at different levels of signal detail at different time scales. WT with an appropriate Compressed Sensing (CS) matrix is used in the electrode nodes of body sensor networks to encode and compress the ECG. Then, the signal is reconstructed using a basis pursuit denoise algorithm. Preservation of the diagnostic quality by means of standardized metrics is then tested for multiple wavelet bases and levels. High quality ECGs from 50 healthy patients are used to statistically show that diagnostic quality preservation is possible even at high compression rates. In these cases suitable ECG wavelets are required.
Estrategias comunicativas para la arquitectura: del storyboard al reel de Instagram
(Iniciativa Digital Politècnica Oficina de Publicacions Acadèmiques Digitals de la UPC, 2024-11-08) Martín López, Lucía; De Jorge Huertas, Virginia
Este ejercicio de la asignatura de CRPA tiene como objetivo que el estudiantado aprenda a utilizar los medios de expresión gráfica arquitectónica como herramienta para la comunicación y la narración del proyecto en función de su uso. Busca con ello, a través de una coreografía de dibujos combinados con transiciones, contar a los más jóvenes de manera dinámica un proyecto de arquitectura. Para ello se utilizan dos instrumentos, el storyboard para sincronizar los ritmos visuales de las secuencias con un orden narrativo y el reel de Instagram que permite el acercamiento al mundo cinético. En este texto se presentan dos tablas analíticas de los storyboards y de los reels entregados que tienen una doble función. Por un lado, ayudan a que los estudiantes sean conscientes de lo que comunican y como lo comunican y, por otro lado, sirven como rúbrica de autoevaluación guiándolos en el proceso de desarrollo del ejercicio en el paso de lo analítico a lo digital.
First Principles Formulation of the Local Functionalization over Time in Two-Dimensional Materials
(2024-10-03) Alvarez, A. L.
Electric field-assisted covalent functionalization of graphene and other two-dimensional (2D) materials provides robustness and positional control, two crucial features when activating biosensor platforms. In particular, local anodic oxidation was proven on graphene at the nanoscale since 2008. However, it was not until 2019 that it was demonstrated to have massive application potential, scaling up to hundreds of m2 in less than one second. [1] These are sizes required by typical commercial biosensors based on field-effect transistors. Thus, a suitable formulation of the oxidation expansion over time is relevant to control and predict the oxidized spot size on the active biosensor regions. For that purpose, the incorporation of oxyanions at the edge of the oxidized zone has been formulated by applying Boltzmann statistics, what includes physical magnitudes such as the energetic barrier and its dependency on radius and applied voltage. As a result, a function t(r) describing inversely the increase of the spot radius (r) along time (t), is provided. The unknown energetic barrier for incorporation of oxyanions, and its dependency on radius, may be determined by fitting the model to the available experimental data. On the other hand, a simple multilayer stack including the relevant components (oxidized and 2D semiconductor layers, substrate and metallic contacts) is proposed, where 2D materials are considered as thin films. Under this approach, the Poisson equation has been solved self-consistently by finite element calculations, to obtain electrical magnitudes such as electric field throughout the structure, and the potential drop from the wetting layer to the active material near the edge of the oxidized region. This potential decrease aligns with the potential barrier reduction along the spot radius obtained from fitting the experimental curves, confirming the predictive nature of this model either for graphene or alternative 2D Materials. [1] S. J. Quesada et al., Small, 15 (2019), 1902817.
User subgrouping in multicast massive MIMO over spatially correlated rayleigh fading channels
(Institute of Electrical and Electronics Engineers, 2021-06-14) de la Fuente, Alejandro; Interdonato, Giovanni; Araniti, Giuseppe
Massive multiple-input-multiple-output (MaMIMO) multicasting has received significant attention over the last years. MaMIMO is a key enabler of 5G systems to achieve the extremely demanding data rates of upcoming services. Multicast in the physical layer is an efficient way of serving multiple users, simultaneously demanding the same service and sharing radio resources. This work proposes a subgrouping strategy of multicast users based on their spatial channel characteristics to improve the channel estimation and precoding processes. We employ max-min fairness (MMF) power allocation strategy to maximize the minimum spectral efficiency (SE) of the multicast service. Additionally, we explore the combination of spatial multiplexing with orthogonal (time/frequency) multiple access. By varying the number of antennas at the base station (BS) and users’ spatial distribution, we also provide the optimal subgroup configuration that maximizes the spectral efficiency per subgroup. Finally, we show that serving the multicast users into two orthogonal time/frequency intervals offers better performance than only relying on spatial multiplexing.
FSS-Backed Reflectarray for Millimeter-Wave 5G Applications at the 28 GHz band
(2023-06) Soroka, Roman; Martinez-de-Rioja, Eduardo; Arboleya, Ana; Encinar, José Antonio
This contribution presents the design of a 30x30-element reflectarray antenna backed by a frequency selective surface (FSS) for millimeter-wave 5G applications at the 28 GHz band. The proposed FSS-backed reflectarray works identically to a conventional metal-backed reflectarray in the 28 GHz band, where it can be used to enhance millimeter-wave coverage. However, in other bands of 5G, such as sub-6 GHz and 39 GHz, the antenna behaves as a transparent structure, suppressing the specular reflections of impinging signals.
Dual-Band and Dual-Polarized Reflectarray for Intelligent Reflecting Surface Applications in Millimeter-Wave 5G
(Institute of Electrical and Electronics Engineers, 2023-03) Cordente, Felipe; Martinez-de-Rioja, Eduardo; Arboleya, Ana; Encinar, José Antonio
In this work, a dual-band and dual-polarized reflectarray is proposed for non-tunable Intelligent Reflecting Surfaces (IRS) in millimeter-wave 5G. The reflectarray unit-cell has a dual-layer configuration, where the printed elements on each layer are designed to provide the required phase shifts at a different operating frequency (lower layer elements for 28 GHz and upper layer elements for 39 GHz). A 20 cm x 20 cm reflectarray panel has been designed to produce a collimated beam in dual-linear polarization at the 28 GHz and 39 GHz bands simultaneously. The proposed concept can be used to design passive IRS panels (without tunability) with dual-band operation, which can be used to improve coverage of dead zones or avoid obstacles that block direct communication links in millimeter-wave 5G networks.
Dual-Band Reflectarray-Based Electromagnetic Skin to Provide Millimeter-Wave Coverage in the 28/60-GHz Bands
(Institute of Electrical and Electronics Engineers, 2024-03) Vallejo, Jorge; Martinez-de-Rioja, Eduardo; Arboleya, Ana
In this contribution, a low-profile dual-band smart electromagnetic skin (SES) is proposed to improve wireless communications in millimeter-wave 5G. The SES is based on a single-layer reflectarray panel that can operate simultaneously at the 28 and 60 GHz bands. The reflectarray unit-cell consists of a central lower frequency element which is surrounded by four higher frequency elements. The SES has been designed to provide a different coverage for each frequency (i.e., two separate beams with different pointing directions). A beamforming technique has been applied to broaden the beams in azimuth and achieve a wider coverage. The proposed device can be used to enable wireless communications in millimeter-wave 5G by providing enhanced coverage in nonline-of-sight (NLOS) scenarios.
Superficies Reflectoras de Doble Banda para Proporcionar Cobertura en Redes 5G de Ondas Milimétricas
(Comité Organizador y Científico XXXIX Simposio Nacional de la Unión Científica Internacional de Radio, URSI 2024. Escuela Politécnica de Cuenca. Universidad de Castilla-La Mancha, 2024-09) Martinez-de-Rioja, Eduardo; Vallejo, Jorge; Arboleya, Ana; Varela, Fernando, R.; Fontá, Celia
In this contribution, two designs of dual-band reflectarray surfaces are proposed for coverage-enhancing applications in millimeter-wave 5G networks. The first design is based on a two-layer reflectarray panel with simultaneous operation at 28 and 39 GHz, which is able to generate two independent collimated beams in dual polarization (one beam at each frequency). The second design is based on a single-layer reflectarray that operates at 28 and 60 GHz. In this case, a beamforming technique has been applied to broaden the beams in the azimuth plane, in order to cover a wider angular range. The proposed reflectarrays can be used to enable wireless communications in millimeter-wave networks, providing coverage of blind zones in both indoor and outdoor scenarios.
Robotic Arm-based Antenna Measurement System
(Institute of Electrical and Electronics Engineers AP-S/URSI, 2024-07) Fontá, Celia; R. Varela, Fernando; Arboleya, Ana; Martinez-de-Rioja, Eduardo
An in house robotic arm-based antenna measurement system is presented. The need for a flexible measurement system to work at millimeter-wave bands (mmW) is the main motivation of this work. At the moment the system is programmed to perform planar acquisitions of 80mm×80mm up to 67 GHz. Post-processing techniques in order to reduce the effect of the non-anechoic environment and acquisition time have also been implemented. The system has been validated by means of measurements in the K-band with very good agreement with reference measurement performed in a spherical range in anechoic chamber.
Dual-Polarized Reflectarray for Coverage-Enhancing Applications in sub-THz 6G Networks
(2024 4th URSI Atlantic Radio Science Meeting, AT-RASC 2024, 2024-05) Feito-Rojo, Alejandro; Palací, Jesús; Martinez-de-Rioja, Eduardo; Arboleya, Ana
This contribution presents the design and simulation results of a dual-polarized reflectarray antenna for coverageenhancing applications in sub-THz 6G communication networks. A 68 mm x 68 mm reflectarray panel, comprising a planar array of 40 x 40 cells, has been designed to produce two independent beams in orthogonal linear polarizations at 100 GHz, in order to cover two different regions of mobile users. The beams have been broadened by the application of a beamforming technique to cover a wider angular region. The proposed design procedure can be applied to design passive reflectarrays for operation as base station antennas or reflecting intelligent surfaces, capable of improving wireless coverage in future sub-THz 6G systems.
Reflectarray de doble banda y polarización dual para redes 5G de ondas milimétricas
(Comité Organizador y Científico XXXVIII Simposio Nacional de la Unión Científica Internacional de Radio, URSI23. Universidad de Extremadura, 2023-09) Cordente, Felipe; Martinez-de-Rioja, Eduardo; Arboleya, Ana; Encinar, José Antonio
In this contribution, a dual-band reflectarray that operates at 28 and 39 GHz is proposed for millimeter-wave 5G applications. The unit-cell of the reflectarray is based on a dual-layer configuration, where the printed elements on each layer are used to control the phase shift introduced at each operating frequency. A 20 cm x 20 cm reflectarray is designed to generate a collimated beam in dual-linear polarization (Horizontal and Vertical) simultaneously at 28 and 39 GHz. The proposed technology can be applied to design passive intelligent reflecting surfaces (IRS) with dual-band operation, which can be used in millimeter-wave 5G networks to improve the coverage of dead zones or avoid the obstacles that block direct point-to-point communications links.
Moral reflection with video games: An approach through spontaneous play with Papers, Please.
(IATED Digital library., 2021) Cabellos, Beatriz; Sánchez, Daniel L.; Marín-Rubio, Kevin; Pozo, Juan Ignacio
Research on moral learning with video games (VG), for a long time, has focused on their connection with violent or antisocial behavior. However, there are more and more designs and suggestions about how VG can promote ethics and pro-social learning (Darvasi, 2016). Games with social, political, or moral conflict topics are on the rise, and this is an issue that should interest us as educators, taking into account the rates of their use for entertainment in the youth population. Despite increasing demand and enthusiasm for these VG, the scientific evidence of their benefits is scarce. As de Aldama & Pozo (2020) note, the difference may be found when playing with an epistemic goal -aimed at building reflection and knowledge-, in contrast with following the game’s aims of leisure. In this study, we analyze, basing on the Social Intuitionist Model developed by Haidt (2001), whether the spontaneous play of "Papers, please" (Lucas Pope, 2013) activates moral intuitions and if they are followed by an explicit reflection about them. This VG is highly acclaimed for its treatment of ethical conflicts in immigration, international relationships, and totalitarianism, in which the player portrays an immigration officer tasked with examining documents and deciding upon authorization or denial of access to the country. We have turned to comments about the game on Steam to see if the speech of players shows terms and structures linked to different moral assessments. In this study, we have prepared category analysis, applied with the Nvivo software, where we identified references to each of the five moral foundations (Care/Harm, Fairness/Cheating, Loyalty/Betrayal, Authority/Subversion, Sanctity/Degradation) proposed by Haidt (2004). We also analyzed whether conflicts between foundations are identified, and to which topics and emotions are the most linked. Provisional results point to low degrees and frequencies of moral reflection, with a high tendency to resolve moral conflict according to the dynamics and immediate rewards of the game. These potential results are similar to some studies that have already observed these VG may be counterproductive on their own to pursue education projects for peace and justice, even though their design and topics appear to be coherent with the learning objectives. Therefore, we propose that for VG are useful to develop pro-social behavior, reflection guided by an epistemic goal must be encouraged. Thus, we must put our efforts into designing scaffoldings and educational interventions that favor the reflection on the situations which reproduce in them.
eTwinning como escenario de aprendizaje competencial y de compromiso con los Objetivos de Desarrollo Sostenible en las aulas universitarias: integración en la formación del profesorado universitaria
(Dykinson, 2022) Hervás-Escobar, Aránzazu; Martín Lope, Mercedes
El nuevo planteamiento educativo revela la urgencia de repensar los objetivos, replantear los contenidos e innovar en las metodologías; reorientar todo ello a la consecución de la cooperación internacional y al cuidado del medio ambiente. El profesorado se presenta imprescindible para el desarrollo y logro de estas metas y su formación se descubre como la palanca esencial para afrontar los retos que plantea la sociedad actual. El II Congreso Internacional Educare+Educere (2022) propone un espacio de encuentro, debate y discusión en torno a experiencias y buenas prácticas educativas encaminadas a la formación integral de los docentes. Los trabajos de investigación expuestos surgen de las prioridades enunciadas en el Espacio Europeo de Educación Superior: desde la igualdad, la inclusión, la innovación, el multilingüismo, el uso de las tecnologías o las prácticas STEAM nos acercamos a las realidades y exigencias formativas del siglo XXI. En este encuentro adquiere especial protagonismo la presentación de la Red Iberoamericana de Formación del Profesorado, comunidad educativa que propone entre sus fines potenciar la internacionalización formativa y aumentar el prestigio del Grado y Postgrado de Educación y de la carrera docente.
Criterios lingüísticos para la creación de signos sin correspondencia con el español.
(2017) Vera Villaverde, Francisco
Compendio de criterios lingüísticos a tener en cuenta para crear términos que no tienen su correspondencia con el español.
Proyecto Cuentacuentos y normalización lingüística: comunicación oral - signada - escrita.
(CNLSE, 2015) Vera Villaverde, Francisco; Sibón Macarro, Teresa G.; Salvador Rosa, Aurora; Delgado Jiménez, M. Mar; Barreiro Galera, Belén; Hervías Ortega, Araceli; González Manjón, Daniel
Describimos la elaboración de un prototipo de cuentacuentos, creado como recurso para favorecer la convivencia de tres códigos de la lengua española (oral, signado, escrito) sobre los parámetros de la educación inclusiva. Desde la realidad de la lengua de signos española y el desarrollo de habilidades comunicativas sobre la lengua y la literatura españolas, en la cuentística encontramos una forma de expresión literaria que bien podemos adaptar al aprendizaje de un segundo código –oral/ signado/ escrito– puente hacia la lectoescritura y fuente de estrategias con base en la literacidad: Presenta acciones insólitas, extrañas y perturbadoras, provoca fuertes emociones, capta la atención de los alumnos que se involucra en el proceso de aprendizaje, agudiza la comprensión discursiva, estimula la producción y percepción comunicativa –recreada sobre recursos TICs–. Describimos los pasos alcanzados en nuestra propuesta para la creación de recurso didáctico en an¬droid, y proponemos opciones de mejora.
Análisis de propuestas didácticas sobre El Quijote a través del análisis de la versión subtitulada en la edición en signotexto de la CNSE.
(Asociación Europea de Profesores de Español, 2016) Vera Villaverde, Francisco; Sibón Macarro, Teresa G.; Cruz Troyano, Regina
Enlazando con las reflexiones presentadas en el Coloquio AEPE (Cracovia, 2016) sobre el desarrollo de las habilidades comunicativas escritas en español para hablantes signantes, queremos presentar un análisis de propuestas didácticas sobre El Quijote en este año que conmemoramos el cuarto centenario de la muerte de Miguel de Cervantes Saavedra. De la mano de esta adaptación de El Quijote de Anna Obiols y Joan Subirana, nos acercamos a la edición de este clásico de nuestra literatura publicado por la Fundación de la Confederación Nacional de Sordos Españoles para la supresión de barreras en la comunicación, en 2009. Según se describe en su página este material “está compuesto por el libro Las aventuras de Don Quijote y un DVD interactivo “Acercando el Quijote a la infancia sorda” con el cuento totalmente accesible en lengua de signos española, subtitulado y voz en off. La obra está adaptada para dos grupos de edad: de 3 a 6 años, y de 6 a 8 años e incluye además actividades para facilitar a los más pequeños la comprensión del texto y extras con actividades adicionales para el fomento de la lectura. Otras tantas versiones se han editado de El Quijote interpretadas en Lengua de Signos. En nuestro análisis, describimos cómo es el camino para llegar a estos productos y cuál es su rendimiento como recurso didáctico. Queremos no solo brindar un merecido homenaje a nuestro internacional autor, -don Miguel de Cervantes-, con la interpretación en Lengua de Signos Española 399 de un Clásico, sino también descubrir en este tipo de ediciones una aplicación del multiculturalismo implícito en los materiales didácticos para hablantes signantes y para los oyentes que quieran participar de estos aprendizajes.
¿Cómo mejorar las reflexiones sobre la lectoescritura desde los saberes lingüísticos entre alumnado sordo?
(Universidad de Cádiz, 2017) Sibón Macarro, Teresa G.; Vera Villaverde, Francisco; Picado Sánchez, Manuel J.
Con un enfoque comunicativo-funcional, y un punto de vista inclusivo e integrador, replanteamos las variables de la comunicación visual y auditiva en el acceso a la escritura avanzada, escritura formal. El Libro Blanco (Fundación CNSE) sigue sin ver aplicación, aunque las leyes posibiliten su implantación en las aulas (cfr. 11/2011, de 5 de diciembre). Ante la falta de concreciones en el desarrollo normativo sobre dificultades o estrategias para el desarrollo de habilidades comunicativas escritas, para el acceso a la lectoescritura de las personas sordas, pretendemos generar propuestas para cimentar un andamiaje constructivo. Nos hemos basado en el premio de innovación metodológica obtenido por Manuel J. Picado Sánchez y en las reflexiones sobre la Lengua de Signos que ofrece Paco Vera Villaverde en Centro Superior de Lenguas Modernas. En el I Congreso Internacional sobre Escritura y Sordera (Jerez, febrero de 2017), varias participantes abordaron estas cuestiones en sus ponencias. Es conveniente que los docentes reconozcan las lagunas en las estrategias de enseñanza/ aprendizaje del proceso lectoescritor, siendo palpables estas dificultades en personas con deficiencia auditiva (D.A.) Los recursos visuales sugieren un cambio metodológico, e invitan a que la lengua de signos se convierta en protagonista del acceso al texto escrito; con ello relega el método fonético de sesgo oral por los cauces naturales de la lengua de signos (2). Construimos puentes de comunicación con la certeza de que la escritura contribuye a la organización del pensamiento y de que en todos los países del mundo la escritura se constituye en la forma de expresión compartida entre comunicantes auditivos y visuales. El enriquecimiento cultural se cimienta sobre la suma de todo aquel aporte esos saberes que amplíen nuestras experiencias y nuestros conocimientos. Los textos visuales y los textos en tinta han de hermanarse en la creación de los recursos [audio] visuales.
Gamificación educativa en tiempo de la IA
(2024-10-17) Borrás-Gené, Oriol
Acercar a los asistentes el concepto de gamificación en el ámbito educativo y cómo podemos hacer uso de las herramientas de Inteligencia Artificial para ayudarnos a aplicarla.
A High-Throughput Deployable Antenna based on Not-Aligned Reflectarray Panels
(2024 IEEE International Symposium on Antennas and Propagation and ITNC-USNC-URSI Radio Science Metting, 2024-07-19) Imaz Lueje, Borja; Martinez-de-Rioja, Daniel; Rodríguez Pino, Marcos; Arrebola Baena, Manuel
This contribution describes a deployable large multi-faceted reflectarray to be embarked in different aerospace vehicles. The structure comprises several low-profile panels that are assembled to follow an equivalent parabolic reflector. An example of this antenna concept is designed to operate in Ka-band and dual-linear polarization. It provides high-gain, low-losses, and a bandwidth significantly higher than the one achieved with a conventional deployable reflectarray. Therefore, the proposed antenna exhibits high-throughput performance with integrability with the vehicle platform. Such features are of particular interest for space missions and some terrestrial communications.

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