Sistemas de comunicaciones móviles : segunda, tercera y cuarta generación

El libro Sistemas de Comunicaciones Móviles-Segunda, Tercera y Cuarta Generación- se centra en el estudio de los sistemas de comunicaciones móviles modernos. En el primer capítulo se realiza una introducción en la que se explican las características generales de los sistemas de comunicaciones móviles. En el segundo capítulo se explica el sistema de segunda generación (2G) de GSM; este estándar fue desarrollado en Europa y fue en su tiempo el sistema más utilizado en el mundo. En este capítulo también se explica la evolución de GSM hacia la tercera generación. En el tercer capítulo se explica el sistema de Red Móvil Privada (PMR) TETRA; este sistema es ampliamente utilizado por servicios de seguridad y emergencia así como por compañías privadas y consorcios públicos. En el siguiente capítulo se muestran las características de los sistemas de tercera generación (3G) y se explica especialmente el sistema UMTS y sus sistemas de mejora (HSDPA, HSUPA y HSPA+). El capítulo se completa con la explicación del sistema de 3G americano CDMA-2000. Finalmente, en el capítulo quinto se explica el sistema de cuarta generación (4G) denominado LTE y su sistema de mejora LTE-Advanced

Sistemas de comunicaciones móviles : caracterización del canal móvil

El libro Sistemas de Comunicaciones Móviles-Caracterización del Canal Móvil- se centra en el estudio del canal inalámbrico que posibilita la comunicación entre una estación base y un usuario móvil. El libro muestra cómo se realiza el mencionado estudio tanto desde un punto de vista teórico como práctico. En primer lugar se muestra la caracterización del canal en Gran Escala. Posteriormente, se muestran las funciones de transferencia y tipos de desvanecimiento que permiten el análisis del canal en Pequeña Escala. Parte de este análisis se basa en el estudio de los parámetros del canal móvil extraídos de las funciones de transferencia. El libro se completa con la explicación de distintos sistemas de medida y de una serie de modelos de propagaciónalgunos de los cuales también pueden ser utilizados en el análisis de radioenlaces. Los sistemas de medida posibilitan la medición de la potencia recibida y las pérdidas del canal, de las funciones de transferencia y en último término de sus parámetros mientras que los modelos de propagación permiten la evaluación de la pérdida básica de propagación

Using the Uniform Theory of Diffraction to Analyze Radio Wave Propagation along Urban Street Canyons for Device-to-Device Communication

This paper examines the propagation of radio waves in so-called urban street canyons through formulations based on Geometrical Optics (GO) and the Uniform Theory of Diffraction (UTD). As this type of environment comprises a street flanked by tall buildings more or less equally spaced on both sides (creating a canyon-like morphology), estimating the attenuation that radio signals may experience in these scenarios is crucial to the planning of urban device-to-device (D2D) wireless communication. In this sense, the results obtained through the analysis based on GO/UTD (in the horizontal plane containing the transmitter and receiver) are validated by a comparison with experimental measurements, showing good agreement. This work demonstrates how the use of GO/UTD-based formulations can contribute to a simpler and computationally more efficient planning of D2D mobile communication systems in which the considered propagation environment can be modeled as an urban street canyon comprising rectangular and equispaced buildings.This work was supported by the Ministerio de Ciencia e Innovación, Spain, under Grant PID2019-107885GB-C33. Partial funding for open access charge: Universidad de Málag

Traffic noise mitigation using single and double barrier caps of different shapes for an extended frequency range

The primary function of noise barriers is to shield inhabitants of affected areas from excessive noise generated by road traffic. To enhance the performance of noise barriers while simultaneously adhering to height restrictions, the attachment of structures (caps) of different shapes to the tops of conventional screens can be considered. These caps can significantly impact the diffracted sound energy, thereby increasing the desired global acoustic losses. This work presents a comprehensive study of the acoustic performance of noise barriers with single and double attached caps of different shapes through a calculation of their insertion losses (IL). This study comprehensively addresses and compares different types, sizes, combinations, and numbers of noise barrier caps for different scenarios (including sloping and absorbent grounds) and sources (“car” and “ambulance”) for an extended frequency band up to 10 kHz. To the best of the authors’ knowledge, this is a range that has not previously been analyzed. A variety of different cap shapes were considered including cylinders, rectangles, trapezoids, and Y/T-shaped forms. To calculate the IL, an innovative and fast uniform theory of diffraction (UTD)-based method developed by the authors was applied in all simulations. The results showed that the Y-shaped single and double barrier caps were, in general, the most effective at increasing IL without raising the height of the barrier, thereby successfully managing the aesthetic impact. The results also showed how the consideration of sloping and absorbent floors could also contribute to improved noise abatement.This work was funded by the Ministerio de Ciencia e Innovación, Spain (TEC2016-78028-C3-2-P and PID2019-107885GB-C33), and by the European Fonds Européen de Développement Économique et Régional (FEDER) funds

On the Contribution of Dense Multipath Components in an Intrawagon Environment for 5G mmW Massive MIMO Channels

© 2019 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] In this letter, the dependence of the specular multipath components (SMC) and dense multipath components (DMC) to the interuser spatial correlation and sum-rate capacity of a massive multiuser multiple-input--multiple-output (MU-MIMO) setup is evaluated from measurements conducted inside an underground subway wagon at the 25-40 GHz candidate frequency bands for 5G systems. The radio channel consists in a 7 7 uniform rectangular array (URA) acting as access point for eight users uniformly distributed in the wagon. The DMC power ratio is observed to be distance- and frequency-dependent as the SMC and DMC exhibit different propagation mechanisms. Remarkably, it is reported that the interuser spatial correlation computed with DMC offers the best favorable propagation for a massive MIMO setup, whereas SMC contribute to the users correlation. Hence, correlation is found to be strongly dependent on the DMC ratio frequency characteristics. In addition, better interuser correlation and sum-rate capacity values are obtained as the frequency is increased. These results highlight the need to include DMC in 5G massive MIMO channel models and emulators to improve their accuracy at the system level.This work was supported in part by MINECO, Spain, under the National Projects TEC2016-78028-C3-2-P and TEC2017-86779-C2-2-R and in part by the ELSAT2020 OS4 SMARTIES program co-financed by the European Union with the European Regional Development Fund, the French state, and the Hauts de France Region Council.Challita, F.; Rodrigo Peñarrocha, VM.; Rubio Arjona, L.; Reig, J.; Juan-Llácer, L.; Pascual-García, J.; Molina-García-Pardo, J.... (2019). On the Contribution of Dense Multipath Components in an Intrawagon Environment for 5G mmW Massive MIMO Channels. IEEE Antennas and Wireless Propagation Letters. 18(12):2483-2487. https://doi.org/10.1109/LAWP.2019.2940831S24832487181

Aplicabilidad de modelos teóricos de propagación para entorno urbano en la estimación de las pérdidas a 3.5 GHz en plantaciones de cítricos

[EN] Agriculture 4.0 represents a considerable increase in the number of sensors, as well as the appearance of new wireless technologies, which will mean the need to efficiently planning radio communication systems in agricultural environments. In this work, the applicability of the WalfischBertoni and the Ikegami propagation models that have been used to estimate propagation losses in urban environments, has been studied in citrus plantations. The similarities and differences of the profiles between the transmitter and the receiver, have been analyzed to identify the dominant propagation mechanisms in each case: buildings, in urban environments, and trees, in citrus plantations, assuming that the height of the transmitter is above the height of the trees and the height of the receiver below them. The propagation losses estimated by the models have been compared with the measurements carried out at the 3.5GHz frequency (one of the 5G bands) in a lemon plantation after the fruit was collected. Under these conditions, it has been observed how the slope of the regression line of the measurements has a value of 2.7, far from that obtained by the Walfisch-Bertoni model and closer to the one estimated by the Ikegami model. Furthermore, when analyzing the error between the theoretical and the measured losses, a standard deviation of 6.39dB is observed for the Walfisch-Bertoni model and 4.91dB for the Ikegami model.Este trabajo ha sido financiado por la Comunidad Autónoma de la Región de Murcia a través del proyecto 20804/PI/18 de la convocatoria de Ayudas a proyectos para el desarrollo de investigación científica y técnica por grupos competitivos, incluida en el Programa Regional de Fomento de la Investigación (Plan de Actuación 2019) de la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia y por el Ministerio de Economía y Competitividad MINECO, Spain (TEC2016-78028-C3-2-P).Juan-Llácer, L.; Párraga Riquelme, D.; Martínez-Inglés, MT.; Molina García-Pardo, JM.; Rodríguez, JV.; Pascual-García, J.; Antonino Daviu, E.... (2020). Aplicabilidad de modelos teóricos de propagación para entorno urbano en la estimación de las pérdidas a 3.5 GHz en plantaciones de cítricos. Universidad de Málaga. 1-4. http://hdl.handle.net/10251/178553S1

Análisis de las pérdidas de propagación medidas en una plantación de cítricos en las bandas de 1800 MHz, 2100 MHz, 3.5 GHz y 28 GHz en una situación de LoS

[EN] Agriculture 4.0 is going to represent a massive deployment of sensors, so efficient planning of radiocommunication systems in this type of environment will be necessary. In this work, the measured path loss in a LoS situation, with the transmitter and receiver heights below the trees height, at a citrus plantation in the 1800MHz, 2100MHz, 3.5GHz and 28GHz frequency bands using the FI (Floating Intercept) and the CI (Close-In reference) models has been analyzed. It has been observed that from 3.5GHz, the slope of the FI model also represents the propagation exponent (PLE). Furthermore, a guiding effect (PLE less than 2) has been observed in the 1800MHz and 2100MHz bands, not in the 3.5GHz and 28GHz bands, in which the PLE is practically equal to 2 (free space). Finally, the analysis of the polarization reveals that the standard deviation of the measured values with respect to the values obtained from the models is greater for horizontal than vertical polarization in the 1800MHz and 2100MHz frequency bands.Este trabajo ha sido financiado por la Comunidad Autónoma de la Región de Murcia a través del proyecto 20804/PI/18 de la convocatoria de Ayudas a proyectos para el desarrollo de investigación científica y técnica por grupos competitivos, incluida en el Programa Regional de Fomento de la Investigación (Plan de Actuación 2019) de la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia y por el Ministerio de Economía y Competitividad MINECO (PID2019-107885GB-C33).Juan-Llácer, L.; Martínez Rubiola, L.; Molina-García-Pardo, JM.; Martínez-Inglés, MT.; Rodríguez, J.; Pascual-García, J.; Cabedo Fabres, M.... (2021). Análisis de las pérdidas de propagación medidas en una plantación de cítricos en las bandas de 1800 MHz, 2100 MHz, 3.5 GHz y 28 GHz en una situación de LoS. Íñigo Cuiñas Gómez. 1-4. http://hdl.handle.net/10251/1910861

Channel sounding and indoor radio channel characteristics in the W-band

This work presents directional radio channel measurements in the W-band using a commercial versatile channel sounder based on a vector network analyzer (VNA), capable of measuring scattering parameters from 75 to 500 GHz with frequency converters. The commercial setup has been modified by increasing the distance for one of the converters using precision coaxial cables and avoiding the use of amplifiers. Firstly, initial distance-dependent single-input single-output (SISO) measurements of indoor radio channels are presented to assess the validity of the setup in the 75 110 GHz frequency band with highly directive horn antennas. Then, single-input multiple-output (SIMO) radio channels were measured at 94 GHz using one directional and one omnidirectional antenna mounted on two positioners. Initial channel characterization is presented comprising root mean square (rms) delay spread, rms angular spread, K-factor, and path loss in an indoor environment at 94 GHz.This work was supported by MINECO, Spain (TEC2013-47360-C3-2-P TEC2013-47360-C3-3-P) and by European FEDER funds.Martínez Inglés, M.; Gaillot, D.; Pascual-García, J.; Molina-García-Pardo, JM.; Rodriguez Rodriguez, JV.; Rubio Arjona, L.; Juan Llacer, L. (2016). Channel sounding and indoor radio channel characteristics in the W-band. EURASIP Journal on Wireless Communications and Networking. 30:1-8. doi:10.1186/s13638-016-0530-7S1830D Zico, Ultra-wideband and 60 GHz communications for biomedical applications. Springer. http://link.springer.com/book/10.1007%2F978-1-4614-8896-5 .L Jofre, J Romeu, S Capdevila, J Abril, E Nova, M Alonso, The “challenging” world of Terahertz radiation and imaging. Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP), 2011, pp. 3470–3475M Kawase, “Non-destructive evaluation method of pharmaceutical tablet by terahertz-time-domain spectroscopy: application to sound-alike medicines”, J. Infrared Millimeter Terahertz Waves, 34(9), 566–571KD Anderson, 94 GHz propagation in the evaporation duct. IEEE Trans. Antennas Propag. 38(5), 746–753 (1990)K Aydin, Y-M Lure, Millimeter wave scattering and propagation in rain: a computational study at 94 and 140 GHz for oblate spheroidal and spherical raindrops. IEEE Trans. Geosci. Remote Sens. 29(1), 593–601 (1991)C Gloaguen, An experiment for propagation studies at 94 GHz. Eighth Int. Conf. Antennas Propagation 1, 406–409 (1993)A Kajiwara, “Indoor propagation measurements at 94 GHz,” personal, indoor and mobile radio communications, 1995. Sixth IEEE Int. Symp PIMRC’95. Wireless Merging Inf. Superhighway 3, 1026 (1995)J Helminger, J Detlefsen, H Groll, Propagation properties of an indoor-channel at 94 GHz. Int. Conf. Microw Millimeter Wave Technol.Proc 98, 9–14 (1998)R Piesiewicz, R Geise, M Jacob, J Jemai, T Kurner, “Indoor channel measurements of point-to-point ultra broadband short range links between 75 GHz and 110 GHz”, in International Symposium Antennas and Propagation Society, 2008, pp. 1–4A Brizzi, A Pellegrini, Y Hao, “Experimental characterization of the propagation on the human torso at W band”, in Radio Science Meeting (Joint with AP-S Symposium), USNC-URSI, 2013, p. 39K Haneda, J Järveläinen, A Karttunen, M Kyro, J Putkonen, Indoor short-range radio propagation measurements At 60 and 70 GHz, in EuCAP 2014, The Hague, The Netherlands, 2014, pp. 1–4S Promwong, J Takada, Free space link budget estimation scheme for ultra wideband impulse radio with imperfect antennas. IEICE Electronics Express 1(7), 188–192 (2004)NL Johnson, S Kotz, N Balakrishnan, Continuous univariate distributions, vol. 1 (Wiley-Interscience, Hoboken, 1993)A Richter, Estimation of radio channel parameters: models and algorithms (Dr.-Ing. dissertation, TU Ilmenau, Ilmenau, Germany, 2005

CIBERER: Spanish national network for research on rare diseases: A highly productive collaborative initiative

13 páginas,1 figura, 3 tablas, 1 apéndice. Se extraen los autores pertenecientes a The CIBERER network que trabajan en Centros del CSIC del Appendix ACIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research.This study has been funded by Instituto de Salud Carlos III (ISCIII) and Spanish Ministry of Science and InnovationPeer reviewe

Modulación de amplitud (AM) en el dominio de la frecuencia

Se explica la modulación de amplitud (AM) en el dominio del tiempo tanto de forma teórica como práctica