153 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

    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

    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

    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

    Utjecaj LTE sustava zasnovanog na kognitivnoj radio tehnologiji na DVB-T2 sustav zasnovan na metodi diverzifikacije

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    In recent years, the development of advanced wireless communication systems has been rapidly progressing. In Europe, the 2nd Generation Terrestrial Digital Video Broadcasting (DVB-T2) and Long-Term Evolution (LTE) are the most promising techniques to provide multimedia services efficiently (in flexible quality and with high spectrum efficiency). The purpose of this work is to explore possible influences of the LTE {uplink services}, using cognitive radio (CR) technology, on the area which is covered by DVB-T2 services. In the case of DVB-T2, both single-input single-output (SISO) and multiple-input single-output (MISO) transmission techniques are considered. The defined coexistence scenarios are measured with an appropriate measurement testbed. The performance of the received TV signal is evaluated on its physical layer (PHY) level. The obtained results allow better understand the influence of LTE system on DVB-T2 which is using diversity technique in the same RF channel (co-channel coexistence). One of the main results is that there are the same requirements on the Forward Error Correction (FEC) decoding process in the DVB-T2 receiver, when power imbalances between TV transmitters (an both SISO and MISO modes) are considered at the interfering LTE signal. This finding was also proved by analysis of variance (ANOVA).U posljednje vrijeme se znatno ubrzao razvoj naprednih bežičnih komunikacijskih sustava. U Europi metode prijenosa signala zasnovane na DVB-T2 (eng. 2nd Generation Terrestrial Digital Video Broadcasting) i LTE (eng. Long-Term Evolution) metodama najviše obećavaju u području učinkovitog pružanja multimedijalnih usluga (s prilagodivom kvalitetom i s visokom učinkovitosti spektra). U ovom radu je razmotrena mogućnost korištenja LTE signala uzlazne veze, uz korištenje kognitivne radio tehnologije, u području pokrivenom DVB-T2 signalom. Razmotrene su metode prijenosa DVB-T2 signala s jednim ulazom i jednim izlazom (eng. Single-Input Single-Output, SISO) te više ulaza i jednim izlazom (eng. Multiple-Input Single-Output, MISO). Definirani su scenariji koegzistencije i isti su izmjereni korištenjem prikladnog mjernog ispitnog stola. Kvaliteta primljenog TV signala je evaluirana na fizičkom sloju. Prikupljeni rezultati omogućuju bolje razumijevanje utjecaja LTE sustava na DVB-T2 koji koristi metodu diverzifikacije u istom radio-frekvencijskom kanalu (koegzistencija susjednog kanala). Jedan od glavnih rezultata je postojanje istih zahtjeva na proces dekodiranja s ispravljanjem pogrešaka u prijemniku (eng. Forward Error Correction) DVB-T2 prijemnika kada se neravnoteža snaga između TV predajnika (MISO i SISO režimi rada) uzima u obzir na interferirajućem LTE signalu. Navedeni rezultat potvrđen je analizom varijance

    Interference Analysis Between Digital Terrestrial Television (DTT) and 4G LTE Mobile Networks in the Digital Dividend Bands

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    With the introduction of digital terrestrial television (DTT) and the analogue television switch-off, terrestrial broadcast spectrum in the UHF band is being released for mobile communications, in particular for fourth generation (4G) long term evolution (LTE) mobile services. This spectrum is known as digital dividend. An impending problem when deploying 4G LTE mobile networks in the digital dividend bands is that interferences may appear in the adjacent radio frequency channels used for DTT. In this paper, we analyze the adjacent coexistence of DTT and 4G LTE networks in the digital dividend bands at 700 MHz and 800 MHz. A generic framework is adopted such that results can be easily extrapolated to different scenarios and bands. Results are presented as a function of the guard band between technologies, for both LTE uplink and downlink adjacent to the DTT signals, and for fixed outdoor and portable indoor DTT reception. Also, the effect of using anti-LTE filters is studied.This work was supported by the Spectrum Regulator of Colombia ANE (Agencia Nacional del Espectro).Ribadeneira Ramírez, JA.; Martínez, G.; Gómez Barquero, D.; Cardona, N. (2016). Interference Analysis Between Digital Terrestrial Television (DTT) and 4G LTE Mobile Networks in the Digital Dividend Bands. IEEE Transactions on Broadcasting. 62(1):24-34. doi:10.1109/TBC.2015.2492465S243462

    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

    Layered Division Multiplexing With Multi-Radio-Frequency Channel Technologies

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    "(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works.")The advanced television system committee (ATSC) is to release the next-generation U.S. digital terrestrial television standard, known as ATSC 3.0. Layered division multiplexing (LDM) is one of the new physical layer technologies included in the standard, which enables the efficient provision of mobile and fixed services by superposing two independent signals with different power levels. ATSC 3.0 has also adopted a novel transmission technique known as channel bonding (CB), which splits the data of a service into two sub-streams that are modulated and transmitted over two radio-frequency (RF) channels. This paper investigates the potential use cases, implementation aspects, and performance advantages, for combining LDM with CB and also with the multi-RF channel technology time frequency slicing (TFS) introduced in digital video broadcasting - terrestrial second generation (DVB-T2) (as an informative annex) and digital video broadcasting - next generation handheld (DVB-NGH) which allows distributing the data of a service across two or more RF channels by means of time slicing and frequency hopping.Parts of this paper have been published in the Proceedings of the IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, Ghent, Belgium, in 2015. This work was supported by the ICT Research and Development Program of MSIP/IITP. [R0101-15-294, Development of Service and Transmission Technology for Convergent Realistic Broadcast.]Garro Crevillén, E.; Gimenez Gandia, JJ.; Park, SI.; Gómez Barquero, D. (2016). Layered Division Multiplexing With Multi-Radio-Frequency Channel Technologies. IEEE Transactions on Broadcasting. 62(2):365-374. doi:10.1109/TBC.2015.2492474S36537462
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