Coupled Oscillator Phased Antenna Array Element for Phase Shifter-less Beam Steering

La rápida expansión de las comunicaciones inalámbricas y la creciente demanda de ancho de banda están acelerando el desarrollo de tecnologías que operan a altas frecuencias. Para dar solución al canal de propagación hostil que estas bandas de frequencia sufren, los arrays de antenas suscitan un creciente interés, pues son capaces de producir un haz dirigible con alta directividad. Los esquemas de conformado de haz convencionales utilizan componentes costosos y voluminosos, y los arrays basados en phase-shifters, que representan la técnica más extendida actualmente, están perdiendo popularidad de cara a futuras aplicaciones, en las cuales la rentabilidad y eficiencia están siendo altamente impulsadas. Este trabajo de final de máster describe el diseño de un elemento de un array, que forma el elemento básico de un array de conformado de haz que no utiliza phase shifters. Operando a 2.45 GHz, la arquitectura de beam-forming propuesta en este documento utiliza una técnica de acoplo entre osciladores operando bajo el fenómeno de injection locking para controlar la distribución de fase en el array.The ubiquity of modern wireless communications and the huge and ever-growing demand of data bandwidth are accelerating the development of technologies operating at higher frequencies. To overcome the hostile propagation channel that these frequencies face, a lot of attention has been put on antenna arrays, which produce high directivity with steerable beam direction. Conventional beam-forming schemes rely on bulky and costly components, and traditional phase shifter-based arrays, which account for the currently most widespread beam-forming technique, are losing popularity for future applications, where system cost-effectiveness is strongly embraced. This master¿s dissertation covers the design of an array element, that forms the basic antenna element of a phase-shifterless beamsteering antenna array operating at 2.45 GHz. The beam-forming architecture proposed in this document presents a nearest-neighbor coupling technique between oscillators operating under the injection locking phenomenom to control the phase distribution in the array.Montero Bayo, L. (2018). Coupled Oscillator Phased Antenna Array Element for Phase Shifter-less Beam Steering. http://hdl.handle.net/10251/109364TFG

Diseño de antenas de banda ancha para aplicaciones de microondas

This report covers the description and development of the Master Thesis "Wideband antenna design for microwave applications", in which is analyzed the state of the art of wireless communications and communications industry needs with regard to antennas and their expected features in the future. This document details the design process of a wideband antenna through theoretical analysis and practical application of the Theory of Characteristic Modes. Designed antenna performs a wide bandwidth in which radiation pattern and impedance stability are guaranteed, whilst it provides polarization diversity for MIMO implementations.La presente memoria abarca la descripción y desarrollo del Trabajo Fin de Máster "Diseño de antenas de banda ancha para aplicaciones de microondas", consistente en un análisis del estado del arte de las comunicaciones inalámbricas y de las necesidades de la industria de las comunicaciones con respecto a las antenas y las características que se espera de ellas en un futuro. Este documento detalla el proceso de diseño de una antena de banda ancha a través del estudio teórico y aplicación práctica de la Teoría de Modos Característicos. La antena diseñada posee un gran ancho de banda que garantiza la estabilidad tanto en impedancia como en diagrama de radiación, a la vez que proporciona diversidad en polarización para su aplicación en sistemas MIMO.Montero Bayo, L. (2017). Diseño de antenas de banda ancha para aplicaciones de microondas. http://hdl.handle.net/10251/91710TFG

Utilización de Sistemas Móviles para Aplicaciones de Docencia

[EN] A system developed for the assessment of online tests using mobile devices such as smarphones, tablets and laptops, will be presented in this document. This system is a webapp, developed in PHP, with a mobile interface based in HTML, CSS and JavaScript. The questions can be created using the available tools in platforms like PoliformaT (Sakai), Moodle, Respondus and any other platform adapted to IMS-QTI standard. Using the email and an identification code of each student, will make possible for them to access a test via email, that will be answered in a graphic interface adapted to the device from which the test is being done. The teacher, then, has the possibility to see the answers in real time and visualize statistics. Assessment will be automatized, and the scores can be exported using standard formats ( spreadsheets compatible with Sakai and Padrino) for its specific use within the UPV[ES] En este documento se presentará un sistema desarrollado para la realización y evaluación de encuestas en aulas de forma online, utilizando dispositivos móviles como teléfonos, tabletas y ordenadores portátiles. El sistema consta de una aplicación web, desarrollada en PHP, y un interfaz móvil basado en HTML, CSS y JavaScript. Las preguntas y cuestiones de las encuestas se pueden crear utilizando las herramientas disponibles en plataformas como PoliformaT (Sakai), Moodle, Respondus y otras similares que utilicen el estándar IMS-QTI. A partir de los correos electrónicos de los alumnos y su código de identificación, se podrá acceder a los tests generar exámenes o encuestas, que se envían por correo electrónico, y que se responden con un interfaz gráfico adaptado al dispositivo desde el que se accede. El profesor dispone de las respuestas en tiempo real, y puede presentar las estadísticas de las mismas. Las calificaciones obtenidas se pueden exportar utilizando formatos estándar (hoja de cálculo o ficheros compatibles con Sakai y padrino) para su uso específico en la UPV.Ferrando Bataller, M.; Montero Bayo, L. (2015). Utilización de Sistemas Móviles para Aplicaciones de Docencia. En In-Red 2015 - CONGRESO NACIONAL DE INNOVACIÓN EDUCATIVA Y DE DOCENCIA EN RED. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2015.2015.1525OC

Beam management for vehicle-to-vehicle (V2V) communications in millimeter wave 5G

Cooperative, Connected and Automated Mobility (CCAM) is expected to leverage the full potential of wireless communications. With the growing adoption of 5G and its support for Vehicle-to-Everything (V2X) communications, beamformed vehicular communications at millimeter-wave (mmWave) bands are expected to enable the most demanding connected driving applications. Beamformed V2X links present the challenge of beam management in such a fast-changing scenario. This paper goes through the practical limitations of the 5G V2X stack to support successful beamforming procedures. Two beam management strategies are proposed. Both strategies are evaluated in terms of power performance, beam recovery time and channel usage. The results suggest that significant differences apply when the beam is more frequently updated, whereas little improvement is seen by increasing the size of the beamset. Also, the selection of a proper strategy is shown to be important to alleviate the channel from overheads, and substantial differences in required signaling can be seen depending on the beam-tracking approach.This work was partly funded by the Spanish Comisión Interministerial de Ciencia y Tecnología under projects TEC2013-47360- C3-1-P, TEC2016-78028-C3-1-P and MDM2016-0600, and Catalan Research Group 2017 SGR 219. The Spanish Ministry of Education (FPU17/05561) and Generalitat de Catalunya DI programme (2018- DI-084) also contribute with predoctoral grants for the authors.Peer ReviewedPostprint (published version

Multi-antenna 3D pattern design for millimeter-wave vehicular communications

The transformation of the automotive industry towards ubiquitous connection of vehicles with all kind of external agents (V2X) motivates the use of a wide range of frequencies for several applications. Millimeter-wave (mmWave) connectivity represents a paramount research field in which adequate geometries of antenna arrays must be provided to be integrated in modern vehicles, so 5G-V2X can be fully exploited in the Frequency Range 2 (FR2) band. This paper presents an approach to design mmWave vehicular multi-antenna systems with beamforming capabilities considering the practical limitations of their usage in real vehicular environments. The study considers both the influence of the vehicle itself at radiation pattern level and the impact of the urban traffic on physical layer parameters. Connectivity parameters such as Signal-to-Interference-plus-Noise Ratio (SINR) and outage probability are optimized based on the array topology. A shaped beam in the vertical plane based on three preset radiating elements is proven to be robust enough against self-scattering effects on the vehicle body. Regarding the horizontal geometry, four panels on the roof's edges provide good coverage and link quality. The number of horizontal antennas per panel tightly depends on the required values of the link quality metrics, potentially leading to a non-uniform geometry between sides and front or back panels.This work was partly funded by the Spanish Ministerio de Economía y Competitividad under the projects PID2019-107885GB- C31 and MDM2016-0600, the Catalan Research Group 2017 SGR 219, and “Industrial Doctorate” programme (2018-DI-084). The Spanish Ministry of Education contributes via a predoctoral grant to the first author (FPU17/05561).Peer ReviewedPostprint (published version

Adaptive beamwidth optimization under Doppler ICI and positioning errors at mmWave bands

The growing trends towards massive antenna arrays with focusing capabilities has enabled the use of higher frequencies at the cost of more complex systems. In the particular case of vehicular communications, millimeter-wave (mmWave) communications are expected to unleash a set of advanced use cases with stringent spectrum needs. However, dealing with very directive patterns and high frequencies entail additional challenges such as beam misalignment and Doppler effect. This paper presents a beam optimization procedure for vehicle-to-network (V2N) systems in which a base station communicates with high-speed users. Aided by the a priori knowledge of the vehicle location, the base station is able to estimate the average signal-to-interference-plus-noise ratio (SINR) until the next beam refresh considering the positioning accuracy and the Doppler inter-carrier interference (ICI). The estimation includes the antenna beamwidth, which can be optimized to maximize the achievable throughput. The numerical results indicate that the SINR can be significantly enhanced compared to beam sweeping with identical hierarchical codebooks while reducing the probability of outage.This work was partly funded by the Spanish Ministerio de Economía y Competitividad under the projects PID2019-107885GB- C31 and MDM2016-0600, the Catalan Research Group 2017 SGR 219, and “Industrial Doctorate” programme of the Agència de Gestió d’Ajuts Universitaris i de Recerca (2018-DI-084). The Spanish Ministerio de Universidades contributes via a predoctoral grant to the first author (FPU17/05561).Peer ReviewedPostprint (published version

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Utilización de Sistemas Móviles para Aplicaciones Avanzadas de Docencia

La presente memoria abarca la descripción y desarrollo del Trabajo Fin de Grado “Utili- zación de Sistemas Móviles para Aplicaciones Avanzadas de Docencia”, consistente en un análisis de la situación actual de todos los aspectos que relacionan la docencia moderna con los servicios de Internet, centrándose principalmente en la adaptación de éstos al entorno móvil y en su estandarización. Además, se detalla el proceso de desarrollo de una aplicación web, llamada “UPVtest”, diseñada con el objetivo de proporcionar un valor añadido a la realización de cuestionarios al alumnado de la Universidad Politécnica de Valencia, y enfocada a mejorar la interacti- vidad de los contenidos evaluativos en el aula, apoyándose en la ya extendida implantación de los dispositivos móviles como punto de partida.Montero Bayo, L. (2015). Utilización de Sistemas Móviles para Aplicaciones Avanzadas de Docencia. http://hdl.handle.net/10251/78894.Archivo delegad

Study on beamforming V2I scenarios for sub-6 GHz and mmWave channels

The study of the wireless channel between a hybrid massive MIMO Base Station (BS) and a vehicular platform is proposed. Several multi-antenna geometries and MIMO architectures in both vehicle and BS are numerically modeled and compared. Different metrics are used for the assessment of the system performance, including channel capacity, in two frequency bands, sub-6 GHz (5.9 GHz) and millimeter-wave (mmWave) (26 GHz), under different propagation conditions. The use of beamforming techniques on the vehicle side is compared to conventional SISO and MIMO solutions. In the urban scenario used in the study, a 45° beamwidth circular array is able to enhance the single monopole performance up to 157% in capacity, and outperform MIMO 4×4 in most situations.This work was supported by the Spanish Comision Interministerial de Ciencia y Tecnología (CICYT) under projects TEC2016-78028-C3-1-P, MDM2016-0600, and Catalan Research Group 2017 SGR 219. The Spanish Ministry of Education contributes via a doctoral grant to the first author (FPU17/05561).Peer ReviewedPostprint (author's final draft

Millimeter-wave MIMO array measurement system for imaging and channel characterization

Millimeter-wave band offer unique characteristicsto obtain good spatial position and resolution of certain type oftargets. The aim of this paper is to study a near-field focusingtechnique applied to the imaging of different geometries, from ananalytical, numerical and experimental point of view. Millimeter-wave band scattering simulations are performed and comparedwith imaging reconstruction of experimental measurements,using a particular set-up and scenario. This work is a first stepto contribute to the growing need of sensing the environment andsurrounding objects of moving devices, such as new generationvehicles, in a clear and robust way with respect to other formsof sensing.This work was supported by the Spanish Ministry of Education and Science under projects 2019-107885GB-C31,TEC2016-78028-C3-1-P, TEC2016-78028-C3-2-P, TEC2016-78028-C3-3-P, MDM2016-0600, the Catalan Research Group 2017 SGR 219 and by the European FEDER funds. The Spanish Ministry of Education contributes via apredoctoral grant to the first author (FPU17/05561).Peer ReviewedPostprint (published version