82 research outputs found

    Mobile Communication Networks and Digital Television Broadcasting Systems in the Same Frequency Bands – Advanced Co-Existence Scenarios

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    The increasing demand for wireless multimedia services provided by modern communication systems with stable services is a key feature of advanced markets. On the other hand, these systems can many times operate in a neighboring or in the same frequency bands. Therefore, numerous unwanted co-existence scenarios can occur. The aim of this paper is to summarize our results which were achieved during exploration and measurement of the co-existences between still used and upcoming mobile networks (from GSM to LTE) and digital terrestrial television broadcasting (DVB) systems. For all of these measurements and their evaluation universal measurement testbed has been proposed and used. Results presented in this paper are a significant part of our activities in work package WP5 in the ENIAC JU project “Agile RF Transceivers and Front-Ends for Future Smart Multi-Standard Communications Applications (ARTEMOS)”

    DVB-T2: The Second Generation of Terrestrial Digital Video Broadcasting System

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    This paper provides a review of the second generation of terrestrial digital video broadcasting standard (DVB-T2). DVB-T2 is the evolution of DVB-T and, together with DVB-S2 and DVB-C2, inaugurated a new transition from the firstgeneration digital broadcasting systems, similar to the transition from analog-to-digital systems. In this paper, the most relevant features of DVB-T2 are explained in detail, along with their benefits and trade-offs. This paper also presents a comprehensive review of the laboratory and field trial results available so far. Especial emphasis is placed in the results of the measurements carried out to test the mobile reception and the novel technologies as multiple input single output and time frequency slicing.This work was supported in part by the University of the Basque Country UPV/EHU under Grant UFI 11/30, in part by the Basque Government under Grants IT-683-13 and SAIOTEK, and in part by the Spanish Ministry of Economy and Competitiveness Project HEDYT-GBB under Grant TEC2012-33302.Eizmendi, I.; Velez, M.; Gómez Barquero, D.; Morgade, J.; Baena Lecuyer, V.; Slimani, M.; Zoellner, J. (2014). DVB-T2: The Second Generation of Terrestrial Digital Video Broadcasting System. IEEE Transactions on Broadcasting. 60(2):258-271. https://doi.org/10.1109/TBC.2014.2312811S25827160

    DVB-NGH: the Next Generation of Digital Broadcast Services to Handheld Devices

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    This paper reviews the main technical solutions adopted by the next-generation mobile broadcasting standard DVB-NGH, the handheld evolution of the second-generation digital terrestrial TV standard DVB-T2. The main new technical elements introduced with respect to DVB-T2 are: layered video coding with multiple physical layer pipes, time-frequency slicing, full support of an IP transport layer with a dedicated protocol stack, header compression mechanisms for both IP and MPEG-2 TS packets, new low-density parity check coding rates for the data path (down to 1/5), nonuniform constellations for 64 Quadrature Amplitude Modulation (QAM) and 256QAM, 4-D rotated constellations for Quadrature Phase Shift Keying (QPSK), improved time interleaving in terms of zapping time, end-to-end latency and memory consumption, improved physical layer signaling in terms of robustness, capacity and overhead, a novel distributed multiple input single output transmit diversity scheme for single-frequency networks (SFNs), and efficient provisioning of local content in SFNs. All these technological solutions, together with the high performance of DVB-T2, make DVB-NGH a real next-generation mobile multimedia broadcasting technology. In fact, DVB-NGH can be regarded the first third-generation broadcasting system because it allows for the possibility of using multiple input multiple output antenna schemes to overcome the Shannon limit of single antenna wireless communications. Furthermore, DVB-NGH also allows the deployment of an optional satellite component forming a hybrid terrestrial-satellite network topology to improve the coverage in rural areas where the installation of terrestrial networks could be uneconomical.Gómez Barquero, D.; Douillard, C.; Moss, P.; Mignone, V. (2014). DVB-NGH: the Next Generation of Digital Broadcast Services to Handheld Devices. IEEE Transactions on Broadcasting. 60(2):246-257. doi:10.1109/TBC.2014.2313073S24625760

    A software based DVB-T2 time frequency slicing evaluation framework

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    DVB-T2 is the second generation terrestrial broadcast system developed within the DVB consortium. Based on multi-carrier transmission OFDM, DVB-T2 introduces many innovative tools offering high flexibility to broadcasters. Among many other new techniques DVB-T2 defines an optional Time-Frequency-Slicing (TFS) profile. In TFS slices of a PLP are sent over multiple and non necessarily adjacent RF frequency channels. This technique provides a gain associated to propagation diversity, as well as an intrinsic multiplexation gain. Following a software defined radio approach this paper presents a flexible DVB-T2 Time Frequency Slicing evaluation framework built to study the practical performance of DVB-T2 Time Frequency Slicing configurations under realistic channel scenarios. The paper focuses on the diversity gain associated to propagation diversity

    Modified classification of Gram-stained vaginal smears to predict spontaneous preterm birth : a prospective cohort study

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    In a prospective cohort study, we assessed the predictive value of a modified vaginal smear scoring method to identify risk for spontaneous preterm birth

    Combined Time, Frecuency and Space Diversity in Multimedia Mobile Broadcasting Systems

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    El uso combinado de diversidad en el dominio temporal, frecuencial y espacial constituye una valiosa herramienta para mejorar la recepción de servicios de difusión móviles. Gracias a la mejora conseguida por las técnicas de diversidad es posible extender la cobertura de los servicios móviles además de reducir la infraestructura de red. La presente tesis investiga el uso de técnicas de diversidad para la provisión de servicios móviles en la familia europea de sistemas de difusión terrestres estandarizada por el prpoyecto DVB (Digital Video Broadcasting). Esto incluye la primera y segunda generación de sistemas DVB-T (Terrestrial), DVB-NGH (Handheld), y DVB-T2 (Terrestrial 2nd generation), así como el sistema de siguiente generación DVB-NGH. No obstante, el estudio llevado a cabo en la tesis es genérico y puede aplicarse a futuras evoluciones de estándares como el japonés ISDB-T o el americano ATSC. Las investigaciones realizadas dentro del contexto de DVB-T, DVB-H y DVBT2 tienen como objetivo la transmisión simultánea de servicios fijos y móviles en redes terrestres. Esta Convergencia puede facilitar la introducción de servicios móviles de TB debido a la reutilización de espectro, contenido e infraestructura. De acuerdo a los resultados, la incorporación de entrelazado temporal en la capa física para diversidad temporal, y de single-input multiple-output (SIMO) para diversidad espacial, son esenciales para el rendimiento de sistemas móviles de difusión. A pesar de que las técnicas upper later FEC (UL-FEC) pueden propocionar diversidad temporal en sistemas de primera generación como DVB-T y DVB-H, requieren la transmisión de paridad adicional y no son útiles para la recepción estática. El análisis en t�ñerminos de link budjget revela que las técnicas de diversidad noson suficientes para facilitar la provision de servicios móviles en redes DVB-T y DVB-T2 planificadas para recepción fija. Sin embargo, el uso de diversidad en redes planificadas para recepción portableGozálvez Serrano, D. (2012). Combined Time, Frecuency and Space Diversity in Multimedia Mobile Broadcasting Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16273Palanci

    Reception performance studies for the evaluation and improvement of the new generation terrestrial television systems

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    270 p.La industria de la TV ha experimentado grandes cambios en las últimas décadas. Las expectativas cada vez mayores de los espectadores y la reducción del espectro disponible para los servicios de TV han provocado la necesidad de sistemas más robustos de Televisión Digital Terrestre (TDT).El primer intento de cumplir estos requisitos es el estándar europeo DVB-T2 (2009). La publicación de un nuevo estándar significa el inicio de un proceso de evaluación del rendimiento del mismo mediante, por ejemplo, estudios de cobertura u obtención de valores de umbral de relación señal / ruido (SNR). Al inicio de esta tesis, este proceso estaba casi terminado para recepción fija y móvil. Sin embargo, la recepción en interiores no se había estudiado en detalle. Por esta razón, esta tesis completa la evaluación de DVB-T2 en interiores y define una nueva metodología de evaluación optimizada para este escenario.A pesar de que DVB-T2 emplea tecnologías muy avanzadas, el sistema se definió hace casi diez años y desde entonces han aparecido nuevas técnicas avanzadas, como por ejemplo nuevos códigos de corrección de errores o la nueva técnica de multiplexación por división en capas (LDM). Estas nuevas técnicas tampoco han sido evaluadas en entornos de interior, por lo que esta tesis incluye el análisis de las mismas evaluando su idoneidad para mejorar el rendimiento de DVB-T2. Además, se ha comprobado que los algoritmos tradicionales de los receptores TDT no están optimizados para los nuevos escenarios en los que se consideran las señales multicapa y recepción móvil. Por esta razón, se han propuesto nuevos algoritmos para mejorar la recepción en este tipo de situaciones.El último intento de hacer frente a los altos requisitos actuales de TDT es el estándar americano ATSC 3.0 (2016). Al igual que con DVB-T2, se necesita proceso completo de evaluación del sistema. Por ello, en esta tesis se han realizado simulaciones y pruebas de laboratorio para completar el estudio de rendimiento de ATSC 3.0 en diferentes escenarios

    MIMO for DVB-NGH, the next generation mobile TV broadcasting

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    DVB-NGH (Digital Video Broadcasting - Next Generation Handheld) is the next generation technology for mobile TV broadcasting, which has been developed by the DVB project with the most advanced transmission technologies. DVB-NGH is the first broadcasting standard to incorporate multiple-input multiple-output (MIMO) as the key technology to overcome the Shannon limit of single antenna communications. MIMO techniques can be used to improve the robustness of the transmitted signal by exploiting the spatial diversity of the MIMO channel, but also to achieve increased data rates through spatial multiplexing. This article describes the benefits of MIMO that motivated its incorporation in DVB-NGH, reviews the MIMO schemes adopted, and discusses some aspects related to the deployment of MIMO networks in DVB-NGH. The article also provides a feature comparison with the multi-antenna techniques for 3GGP's LTE/LTE-Advanced for cellular networks. Finally, physical layer simulation results calibrated within the DVB-NGH standardization process are provided to illustrate the gain of MIMO for the next generation of mobile TV broadcasting.Vargas Paredero, DE.; Gozálvez Serrano, D.; Gómez Barquero, D.; Cardona Marcet, N. (2013). MIMO for DVB-NGH, the next generation mobile TV broadcasting. IEEE Communications Magazine. 51(7):130-137. doi:10.1109/MCOM.2013.6553689S13013751

    Time Frequency Slicing for Future Digital Terrestrial Broadcasting Networks

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    “© © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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.”Time Frequency Slicing (TFS) is a novel transmission technique for the future of terrestrial broadcasting. TFS breaks with the traditional transmission of TV services over single RF channels.With TFS, services are distributed across several channels by frequency hopping and time-slicing. The bundling of several RF channels into a TFS multiplex provides important advantages. A capacity gain is obtained due to a more efficient statistical multiplexing of video content since more services can be encoded in parallel. Improved frequency diversity also provides a coverage gain since signal imbalances between RF channels can be smoothed. Enhanced robustness against static and time varying interferences can also be achieved. TFS was described, although not implemented, for DVB-T2 and was fully adopted in DVB-NGH. At present, it is proposed for a future evolution of DVB-T2 and will also be considered in the ongoing ATSC 3.0 standard. This paper investigates the potential advantages of TFS by means of field measurements as well as simulations and discusses practical implementation aspects and requirements regarding transmission and reception. Results demonstrate the interesting advantages of TFS to improve both coverage and spectral efficiency, which addresses the future necessity of a more efficient DTT spectrum usage.Gimenez Gandia, JJ.; Stare, E.; Bergsmark, S.; Gómez Barquero, D. (2014). Time Frequency Slicing for Future Digital Terrestrial Broadcasting Networks. IEEE Transactions on Broadcasting. 60(2):227-238. doi:10.1109/TBC.2014.2315766S22723860
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