Performance comparison of interference alignment algorithms in an energy harvesting scenario

Proceeding of: 12th IEEE/IET International Symposium on Communication Systems, Networks and Digital Signal Processing, (CSNDSP), 20-22, July 2020, (Online).Energy-efficient interference alignment (IA) algorithms that simultaneously satisfy continuous coverage and green communications requirements are an open problem in 5G cellular networks. IA is one of the most promising techniques to eliminate interference. However, a recent assumption in green communications is to utilize interference signals as an energy supply for electronic devices. In this scenario, simultaneous wireless information and power transfer (SWIPT) schemes are a common technique to harvest energy from wireless signals. This paper addresses a performance comparison of different IA algorithms to guarantee the best trade-off between sum-rate and the amount of harvested energy, with an in-depth analysis.This work has received funding from the European Union (EU) Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ETN TeamUp5G, grant agreement No. 813391. Also, this work has been supported in part by the Spanish National Project TERESA-ADA, funded by (MINECO/AEI/FEDER, UE) under grant TEC2017-90093-C3-2-R

Optimal sensing policy for energy harvesting cognitive radio systems

Energy harvesting (EH) emerges as a novel technology to promote green energy policies. Based on Cognitive Radio (CR) paradigm, nodes are designed to operate with harvested energy from radio frequency signals. CR-EH systems state several strategies based on sensing and access policies to maximize throughput and protect primary users from interference, simultaneously. However, reported solutions do not consider to maximize detection performance to detect spectrum holes which represent a major drawback whenever available energy is not efficiently used. In this concern, this paper addresses optimal sensing policies based on energy harvesting schemes to maximize probability of detection of available spectrum. These novel policies may be incorporated to previous reported solutions to maximize performance. Optimal processing scheduling schemes are proposed for offline and online scenarios based on convex optimization theory, Dynamic Programming (DP) algorithm and heuristic solutions (Constant Power and Greedy policies). Performance of proposed policies are validated by simulations for common detection techniques such as Matched Filter (MF), Quadrature Matched Filter (QMF) and Energy Detector (ED). As a result, it is shown that the best detection scheme theoretically addressed by MF, does not always perform better than the poorest detection scheme, given by the ED, in an energy harvesting scenario.This work has received funding from the European Union (EU) Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie ETN TeamUp5G, grant agreement No. 813391. Also, this work has been supported in part by the Spanish National Project TERESA-ADA, funded by (MINECO/AEI/FEDER, UE) under grant TEC2017-90093-C3-2-R

Hardware Evaluation of Interference Alignment Algorithms Using USRPs for Beyond 5G Networks

Proceedings of the 20th IEEE Region 8 EUROCON Conference, EUROCON 2023, 6-8 July 2023, Turín, ItalyNetwork densification is a key technology to achieve the spectral efficiency (SE) expected in 5G wireless networks and beyond. However, the proximity between transmitters and receivers increases the interference levels, becoming a major drawback. To overcome this problem, several interference management techniques have been proposed to increase the signal-to-interference-plus-noise ratio (SINR). Interference alignment (IA) algorithms have been extensively studied due to their capability to achieve optimal degrees of freedom (DoFs) in interference channels (ICs). Nevertheless, most of the works are limited to a purely theoretical analysis based on non-realistic assumptions such as perfect channel state information (CSI) and the synchronization of all nodes in the network. To the best of our knowledge, only a few articles address the IA implementation using reconfigurable hardware. To cover this lack, this paper proposes a practical design of the IA algorithm based on the SINR maximization, known as MAX-SINR, considering a multi-user IC. Each transmitter and receiver is implemented on the National Instruments USRP-2942. A practical solution for the channel estimation and synchronization stages in an IC, that are usually omitted in theoretical works, is developed. The performance of the proposed implementation is shown in terms of the SINR gain, SE, and bit error rate (BER). Unlike previous works, all the results are based on real measurements providing valuable insights into the performance of IA algorithms.This work has received funding from the European Union (EU) Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ETN TeamUp5G, grant agreement No. 813391. Also, this work has been partially funded by the Spanish National project IRENE-EARTH (PID2020- 115323RB-C33 / AEI / 10.13039/501100011033

Deployment of clustered-based small cells in interference-limited dense scenarios: analysis, design and trade-offs

Network densification is one of the most promising solutions to address the high data rate demands in 5G and beyond (B5G) wireless networks while ensuring an overall adequate quality of service. In this scenario, most users experience significant interference levels from neigh-bouring mobile stations (MSs) and access points (APs) making the use of advanced interference management techniques mandatory. Clustered interference alignment (IA) has been widely pro-posed to manage the interference in densely deployed scenarios with a large number of users. Nonetheless, the setups considered in previous works are still far from the densification lev-els envisaged for 5G/B5G networks that are considered in this paper. Moreover, prior designs of clustered-IA systems relied on oversimplified channel models and/or enforced single-stream transmission. In this paper, we explore an ultradense deployment of small-cells (SCs) to pro-vide coverage in 5G/B5G wireless networks. A novel cluster design based on size-restricted k-means algorithm to divide the SCs into different clusters is proposed taking into account path loss and shadowing effects, thus providing a more realistic solution than those available in the current literature. Unlike previous works, this clustering method can also cater for spatial mul-tiplexing scenarios. Also, several design parameters such as the number of transmit antennas, multiplexed data streams, and deployed APs are analyzed in order to identify trade-offs between performance and complexity. The relationship between density of network elements per area unit and performance is investigated, thus allowing to illustrate that there is an optimal coverage area value over which the network resources should be distributed. Moreover, it is shown that the spectral-efficiency degradation due to the inter-cluster interference in ultra-dense networks (UDNs) points to the need of designing an interference management algorithm that accounts for both, intra-cluster and inter-cluster interference. Simulation results provide key insights for the deployment of small cells in interference-limited dense scenarios.This work has received funding from the European Union (EU) Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie ETN TeamUp5G, grant agreement No. 813391. We also acknowledge the Ministerio de Ciencia, Innovación y Universidades (MCIU), the Agencia Estatal de Investigacion (AEI) and the European Regional Development Funds (ERDF) for its support to the Spanish National Project TERESA (subprojects TEC2017-90093-C3-2-R and TEC2017-90093-C3-3-R).Publicad

Poner en palabras la estrategia del TIVU. Miradas, sentidos y reflexiones en torno al ingreso en la Facultad de Informática de la UNLP

Este trabajo presenta una primera aproximación sobre el proceso de cambio y transformación del Taller de Inserción a la Vida Universitaria (TIVU) y la recuperación de la voz de docentes que han participado de alguna de las actividades desarrolladas en las estrategias del ingreso. Este taller ha transitado por distintas etapas desde su inicio en pos de promover la inclusión de los nuevos estudiantes, buscando tender puentes entre los que llegan y los que están. En este sentido, el presente trabajo muestra las distintas y diversas impresiones de docentes de la FI -a modo de reflexión- en torno a pensar los modos y formas de involucrar a los diferentes sujetos institucionales en el proceso de formación de los estudiantes. Desde una reconstrucción de los diferentes momentos transitados por el TIVU se da cuenta aquí: de los cambios y modificaciones de la propuesta a lo largo de su trayectoria, planteando nuevas dinámicas e interpelaciones, conforme a las necesidades de los sujetos educativos y los contextos de la casa de estudios. A partir de entrevistas a docentes (a cargo de asignaturas de los últimos años de las carreras de la FI-UNLP), recuperamos la voz de los sujetos con el fin de conocer su experiencia en el Taller para continuar pensando la propuesta como también la estrategia de inclusión de los sujetos educativos.Trabajo publicado en Giordano, Carlos José y Morandi, Glenda (comps.). Memorias de las 2º Jornadas sobre las Prácticas Docentes en la Universidad Pública. La enseñanza universitaria a 100 años de la reforma: legados, transformaciones y compromisos. Universidad Nacional de La Plata: La Plata, 2019.Presidenci

Medición de la eficacia en la hemodiafiltración on-line

El objetivo de este estudio es estimar la caída del aclaramiento del dializador durante la diálisis medido por OCM y analizar los posibles factores que influyen en ello. Pacientes y métodos: Pacientes de nuestra unidad que estuvieran en tratamiento con hemodiafiltración on-line durante el mes de marzo. Conclusiones: La hemodiafiltración on-line permite tener buenos aclaramientos a lo largo dela sesión. El módulo OCM permite de forma sencilla monitorizar el aclaramiento del dializador a lo largo de la sesión.Dialisia egin bitartean dialisi makinaren argitzea jaistea, OCM bidez neurturikoa, zertan den analizatzea da azterlan honen helburua, baita horretan eragina izan lezaketen faktoreak aztertzea ere. Gure unitatean onlineko hemodiafiltrazio tratamenduan zeuden eriak aztertu genituen hilabeteko aldian. Ondorioztatu dugunez, onlineko hemodiafiltrazioak argitze egokiak izatea ahalbidetzen du saioan zehar eta OCM moduluak ahalbidetu egiten du saioan zeharreko dialisi makinaren argitzea monitorizatzea modu errazean.L'objectif de cette étude est d'estimer la chute de l'éclaircissement du dialyseur durant la dialyse mesuré par OCM et analyser les éventuels facteurs qui influent sur ce processus. Nous analysons les patients de notre unité qui ont été en traitement avec hémodiafiltration on-line durant un mois. Nous en concluons que l'hémodiafiltration on-line permet d'avoir de bons éclaircissements tout aulong de la session et le module OCM permet de monitoriser de façon simple l'éclaircissement du dialyseur tout au long de la session.The objective of this study is to estimate the fall in dialysator clarificationduring dialysis as measured by OCM and to analyse possible factors that may have an influence therein. We analysed the patients in our unit who were undergoing on-line hemodiafiltration treatment during one month. We concluded that on-linehemodiafiltration allows for good clarification throughout the session and that the OCM module allows for easy dialysator monitoring throughout the session

Ingreso e inclusión a la universidad : Aportes para pensar una experiencia educativa desde un enfoque interdisciplinario en la Facultad de Informática

¿En qué pensamos cuando planificamos y diseñamos estrategias de ingreso a la universidad? Este equipo de trabajo interdisciplinario se plantea interrogantes y procura elaborar una propuesta dinámica, ajustada permanentemente a partir de la evaluación de la experiencia anterior. Somos docentes y estudiantes que trabajamos en esta propuesta de ingreso en la Facultad de Informática (FI) de la Universidad Nacional de La Plata (UNLP), denominada Taller de Inserción a la Vida Universitaria (TIVU) y compartimos la experiencia de trabajo en este relato.Eje 2: Nuevas experiencias y trayectorias estudiantiles. Desafíos para la inclusión educativa en la universidad. Estrategias y políticas de fortalecimiento del ingreso, la permanencia y el egresoSecretaría de Asuntos Académico

Determinants of Participation in a Post-Hospitalization Physical Exercise Program for Older Adults

Background: Older patients often experience a decline in physical function and cognitive status after hospitalization. Although interventions involving physical exercise are effective in improving functional performance, participation in physical exercise interventions among older individuals is low. We aimed to identify factors that contribute to exercise refusal among post-hospitalized older patients. Methods: A cross-sectional study of recruitment data from a randomized controlled trial was conducted involving 495 hospitalized people >= 70 years old. Sociodemographic and clinical data were obtained from the Basque Public Health System database. We determined physical function with the Short Physical Performance Battery (SPPB), nutritional status with the Mini-Nutritional Assessment, frailty according to the Fried phenotype criteria, and cognitive function with the Short Portable Mental Status Questionnaire (SPMSQ). Student's t, Mann-Whitney U, or chi-squared tests were applied for bivariate analysis. Parameters significantly associated with participation were introduced in a logistic multivariate regression model. Results: Among the analyzed patients, 88.8% declined participation in the physical exercise program. Multivariate regression revealed that older age (OR: 1.13; 95% CI: 1.07-1.19), poor nutritional status (OR: 0.81; 95% CI: 0.69-0.95), and reduced home accessibility (OR: 0.27; 95% CI: 0.08-0.94) were predictors of participation refusal. Moreover, patients who declined participation had worse performance on the SPPB (P < 0.05) and its tests of balance, leg strength, and walking speed (P < 0.05). No differences were found between groups in other variables. Conclusions: This study confirms low participation of older adults in a post-hospitalization physical exercise program. Non-participation was associated with increased age, poor nutritional status, and reduced home accessibility. Our findings support the need for intervention design that accounts for these factors to increase older patient participation in beneficial exercise programs.The study was funded by the Department of Education, Language Policy and Culture (2016111138) and a Programme Contract of the Department of Health, both departments of the Government of the Basque Country, which provided financial support during the research. The funders had no role in the study design, data collection and analysis and interpretation or writing the manuscript

Differentially Deregulated MicroRNAs as Novel Biomarkers for Neoplastic Progression in Ulcerative Colitis

Introduction: Colorectal cancer (CRC) is a potentially life-threatening complication of long-standing ulcerative colitis (UC). MicroRNAs (miRNA) are epigenetic regulators that have been involved in the development of UC-associated CRC. However, their role as potential mucosal biomarkers of neoplastic progression has not been adequately studied. Methods: In this study, we analyzed the expression of 96 preselected miRNAs in human formalin-fixed and paraffin-embedded tissue of 52 case biopsies (20 normal mucosa, 20 dysplasia, and 12 UC-associated CRCs) and 50 control biopsies (10 normal mucosa, 21 sporadic adenomas, and 19 sporadic CRCs) by using Custom TaqMan Array Cards. For validation of deregulated miRNAs, we performed individual quantitative real-time polymerase chain reaction in an independent cohort of 50 cases (13 normal mucosa, 25 dysplasia, and 12 UC-associated CRCs) and 46 controls (7 normal mucosa, 19 sporadic adenomas, and 20 sporadic CRCs). Results: Sixty-four miRNAs were found to be differentially deregulated in the UC-associated CRC sequence. Eight of these miRNAs were chosen for further validation. We confirmed miR-31, -106a, and -135b to be significantly deregulated between normal mucosa and dysplasia, as well as across the UC-associated CRC sequence (all P < 0.01). Notably, these miRNAs also confirmed to have a significant differential expression compared with sporadic CRC (all P < 0.05). Discussion: UC-associated and sporadic CRCs have distinct miRNA expression patterns, and some miRNAs indicate early neoplastic progression

Performance bounds with precoding matrices compliant with standardized 5G-NR for MIMO transmission

Proceeding of: IEEE Conference on Standards for Communications and Networking (CSCN 2022), 28-30 November 2022, Thessaloniki, GreeceAdvanced multiple-input multiple-output (MIMO) beamforming techniques are crucial in 5G New Radio (NR) to achieve the expected data rate values. Therefore, the 3rd Generation Partnership Project (3GPP) has proposed a codebook-based MIMO precoding strategy to provide high diversity, array gain, and spatial multiplexing. The main goal is to obtain a tradeoff between performance, signal overhead, and complexity. The precoding matrix is selected from a set of predefined codebooks based on the knowledge that the 5G-NR base station (gNB) acquires about the channel status. In this work, a detailed study of the precoding matrix design is provided following the guidelines reported in the technical specifications 38-211 and 38-214 of the 3GPP. An analysis of the performance in terms of spectral efficiency (SE) achieved by the 5G-NR precoding matrices is illustrated for a single-user MIMO scenario. These results are contrasted against the optimal singular value decomposition (SVD) solution in order to explore the gap between the standardized precoding proposal and the optimal one. Several values of signal-to-noise ratio (SNR) and different antenna array configurations are considered. Moreover, the multiplexing gain for a different number of parallel data streams is evaluated. Numerical results show the SE bounds that can be obtained with the 5G-NR precoding matrices. These insights are of key importance for practical implementation of precoding strategies in 5G-NR systems and beyond