4 research outputs found

    Time Diversity in Mobile DVB-T2 Systems

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    DVB-T2 implements a very flexible time interleaving that allows multiple tradeoffs in terms of time diversity, latency and power saving. In this paper, we study in detail these tradeoffs in the context of mobile reception. Together with time diversity, we also investigate the impact of reduced time de-interleaving memory and Alamouti-based MISO in the mobile reception of DVB-T2 services. In addition, we propose the utilization of upper layer FEC protection in order to overcome the limitations of the DVB-T2 physical layer for the provision of long time interleaving, and enable fast zapping. The performance is evaluated by means of simulations in mobile channels that include the presence of fast fading and shadowing in the received signal. © 2010 IEEE.Manuscript received October 13, 2010; revised April 22, 2011; accepted May 11, 2011. Date of publication July 25, 2011; date of current version August 24, 2011. This work was supported in part by the Spanish Ministry of Industry, Tourism, and Commerce under the Celtic project Enabling Next-Generation Networks for Broadcast Services ENGINES (TSI-020400-2010-108). The work of D. Gozalvez was supported by the FPU Grant AP2008-03293 of the Spanish Ministry of Education.Gozálvez Serrano, D.; Gómez Barquero, D.; Vargas, D.; Cardona Marcet, N. (2011). Time Diversity in Mobile DVB-T2 Systems. IEEE Transactions on Broadcasting. 57(3):617-628. doi:10.1109/TBC.2011.2161189S61762857

    D6.3 Intermediate system evaluation results

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    The overall purpose of METIS is to develop a 5G system concept that fulfil s the requirements of the beyond-2020 connected information society and to extend today’s wireless communication systems for new usage cases. First, in this deliverable an updated view on the overall METIS 5G system concept is presented. Thereafter, simulation results for the most promising technology components supporting the METIS 5G system concept are reported. Finally, s imulation results are presented for one relevant aspect of each Horizontal Topic: Direct Device - to - Device Communication, Massive Machine Communication, Moving Networks, Ultra - Dense Networks, and Ultra - Reliable Communication.Popovski, P.; Mange, G.; Fertl, P.; Gozálvez - Serrano, D.; Droste, H.; Bayer, N.; Roos, A.... (2014). D6.3 Intermediate system evaluation results. http://hdl.handle.net/10251/7676

    African and Latin American family reunifications in Mediterranean Spain: dynamics and socio-demographic structures

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    Los extranjeros autorizados en 2006-2009 a residir en España por motivos de reagrupación familiar, muestran la importancia que ha alcanzado esta forma de inmigración en el total de nuevos extranjeros empadronados. La investigación se basa en una encuesta específica a reagrupantes africanos y latinoamericanos, que también informan sobre sus familiares reagrupados, hayan utilizado, o no, las leyes de reagrupación. Africanos y latinoamericanos ofrecen dinámicas y estructuras sociodemográficas muy diferentes, a resultas, entre otras causas, de la antigüedad de sus flujos, su fecundidad, su dominio del idioma español, su nivel de instrucción, sus posibilidades de ingresos, su estructura por sexo y edad, tamaño de las familias reagrupadas, etc. Se ofrece información para los dos colectivos continentales y para los subgrupos familiares —reagrupantes, cónyuges, hijos, progenitores y otros familiares—, y se utilizan escalas del conjunto estudiado y de ámbitos territoriales —Cataluña litoral, Comunidad Valenciana, Murcia-Almería—. Los africanos concentran los aspectos estructurales más negativos —idioma español, instrucción, ingresos,…—, pero también son los que declaran intenciones más firmes y generalizadas de permanencia en España. Las conclusiones orientan sobre el futuro de estos flujos.The amount of foreigners authorised to live in Spain as residents between 2006 and 2009 due to family reunification reflects the significance of this type of immigration in the number of new registered foreigners. This research is based on a specific survey carried out on Africans and Latin Americans, who also provide information on the family members who have joined them here, in accordance with reunification laws or not. Africans and Latin Americans have very different dynamics and socio-demographic structures due, amongst other reasons, to the antiquity of their flows, their fertility rates, their command of Spanish, their level of education, their possibility of income, their structure by sex and age, the size of the reunited families, etc. Information is provided on both continental groups and family subgroups —those who reunite the family, spouses, children, parents and other family members— using scales for the group studied and for the geographical area —coastal Catalonia, the Region of Valencia, Murcia and Almeria—. Africans report the most negative structural aspects —Spanish language, education, income, etc.—; nevertheless it is this group that claim to have more firm and generalised intentions of staying in Spain. The conclusions in this paper give an indication of future flows for these two groups.Investigación realizada dentro del Proyecto «La reagrupación familiar de los inmigrantes africanos y latinoamericanos en la España mediterránea», Ref. CSO2008-01796, financiado por el Ministerio de Ciencia e Innovación

    Seroprevalence and immunological memory against SARS-CoV-2 in lung cancer patients : the SOLID study

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    At present, we did not find any articles that studied seroprevalence and its persistence several months later in lung cancer patients in the setting of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Most patients with coronavirus disease 2019 (COVID-19) go on to develop antibodies (Abs) against viral proteins. However, it is not known how long these Abs last nor whether cancer treatments could affect the duration of immune response. This prospective, longitudinal, multicenter serological study in the setting of SARS-CoV-2 infection was carried out in 50 Spanish hospitals. Eligibility criterion was the diagnosis of any lung cancer. The determination of anti-SARS-CoV-2 IgG Abs was performed by qualitative immuno-enzymatic assay using enzyme-linked immunosorbent assay (ELISA) kit from NovaLisa whose Abs target the recombinant antigen N of the nucleocapsid of SARS-CoV-2. The first Ab determination was performed between April 21 and June 3, 2020. The second Ab determination was performed in all previously seropositive patients, between September 10 and November 20, 2020. Study objectives were to prospectively determine seroprevalence in unselected lung cancer patients during the first wave of the pandemic; the persistence of immunity; protection or lack thereof against reinfection; and the influence of treatments on maintenance or loss of immunity. Of 1,500 patients, 128 were seropositive, overall prevalence of 8.5% seropositivity [95% confidence interval (CI): 7.2-10.1%]. Seventy-five percent were in active cancer treatment. Forty-seven point seven percent of IgG positive participants had experienced a symptomatic illness suspected of being infected with SARS-CoV-2 (95% CI: 38.8-56.6%). A second determination was performed on average 4.5 months later [interquartile range (IQR), 4.0-5.0 months] and obtained for 104 of the initially seropositive patients (81%), it could not be obtained in 24 patients, the majority due to death caused by disease progression (73%). In the second determination, IgG was not detected in 30.8% of patients. The severity of the infection, the need for hospitalization (P=0.032) and the presence of symptoms at diagnosis (P=0.02) were associated with persistence of immunity in the second determination. No variables or treatments received were associated with Abs loss. Immunity against SARS-CoV-2 does not appear to be compromised by treatment and persists beyond 4 months. Neither do mortality rates appear to be particularly high in this unselected population. ClinicalTrials.gov identifier: NCT04407143
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