Advanced Layered Divsion Multiplexing Technologies for Next-Gen Broadcast

Tesis por compendioDesde comienzos del siglo XXI, los sistemas de radiodifusión terrestre han sido culpados de un uso ineficiente del espectro asignado. Para aumentar la eficiencia espectral, los organismos de estandarización de TV digital comenzaron a desarrollar la evolución técnica de los sistemas de TDT de primera generación. Entre otros, uno de los objetivos principales de los sistemas de TDT de próxima generación (DVB-T2 y ATSC 3.0) es proporcionar simultáneamente servicios de TV a dispositivos móviles y fijos. El principal inconveniente de esta entrega simultánea son los diferentes requisitos de cada condición de recepción. Para abordar estas limitaciones, se han considerado diferentes técnicas de multiplexación. Mientras que DVB-T2 acomete la entrega simultánea de los dos servicios mediante TDM, ATSC 3.0 adoptó la Multiplexación por División en Capas (LDM). LDM puede superar a TDM y a FDM al aprovechar la relación de Protección de Error Desigual (UEP), ya que ambos servicios, llamados capas, utilizan todos los recursos de frecuencia y tiempo con diferentes niveles de potencia. En el lado del receptor, se distinguen dos implementaciones, de acuerdo con la capa a decodificar. Los receptores móviles solo están destinados a obtener la capa superior, conocida como Core Layer (CL). Para no aumentar su complejidad en comparación con los receptores de capa única, la capa inferior, conocida como Enhanced Layer (EL), es tratada como un ruido adicional en la decodificación. Los receptores fijos aumentan su complejidad, ya que deben realizar un proceso de Cancelación de Interferencia (SIC) sobre la CL para obtener la EL. Para limitar la complejidad adicional de los receptores fijos, las capas de LDM en ATSC 3.0 están configuradas con diferentes capacidades de corrección, pero comparten el resto de bloques de la capa física, incluido el TIL, el PP, el tamaño de FFT, y el GI. Esta disertación investiga tecnologías avanzadas para optimizar el rendimiento de LDM. Primero se propone una optimización del proceso de demapeo para las dos capas de LDM. El algoritmo propuesto logra un aumento de capacidad, al tener en cuenta la forma de la EL en el proceso de demapeo de la CL. Sin embargo, el número de distancias Euclidianas a computar puede aumentar significativamente, conduciendo no solo a receptores fijos más complejos, sino también a receptores móviles más complejos. A continuación, se determina la configuración de piloto ATSC 3.0 más adecuada para LDM. Teniendo en cuenta que las dos capas comparten el mismo PP, surge una contrapartida entre la densidad de pilotos (CL) y la redundancia sobre los datos (EL). A partir de los resultados de rendimiento, se recomienda el uso de un PP no muy denso, ya que ya han sido diseñados para hacer frente a ecos largos y altas velocidades. La amplitud piloto óptima depende del estimador de canal en los receptores (ej., se recomienda la amplitud mínima para una implementación Wiener, mientras que la máxima para una implementación FFT). También se investiga la potencial transmisión conjunta de LDM con tres tecnologías avanzadas adoptadas en ATSC 3.0: las tecnologías de agregación MultiRF, los esquemas de MISO distribuido y los de MIMO colocalizado. Se estudian los potenciales casos de uso, los aspectos de implementación del transmisor y el receptor, y las ganancias de rendimiento de las configuraciones conjuntas para las dos capas de LDM. Las restricciones adicionales de combinar LDM con las tecnologías avanzadas se consideran admisibles, ya que las mayores demandas ya están contempladas en ATSC 3.0 (ej., una segunda cadena de recepción). Se obtienen ganancias significativas en condiciones de recepción peatonal gracias a la diversidad en frecuencia proporcionada por las tecnologías MultiRF. La conjunción de LDM con esquemas de MISO proporciona ganancias de rendimiento significativas en redes SFN para la capa fija con el esquema de Alamouti.Since the beginning of the 21st century, terrestrial broadcasting systems have been blamed of an inefficient use of the allocated spectrum. To increase the spectral efficiency, digital television Standards Developing Organizations settled to develop the technical evolution of the first-generation DTT systems. Among others, a primary goal of next-generation DTT systems (DVB-T2 and ATSC 3.0) is to simultaneously provide TV services to mobile and fixed devices. The major drawback of this simultaneous delivery is the different requirement of each reception condition. To address these constraints different multiplexing techniques have been considered. While DVB-T2 fulfilled the simultaneous delivery of the two services by TDM, ATSC 3.0 adopted the LDM technology. LDM can outperform TDM and FDM by taking advantage of the UEP ratio, as both services, namely layers, utilize all the frequency and time resources with different power levels. At receiver side, two implementations are distinguished, according to the intended layer. Mobile receivers are only intended to obtain the upper layer, known as CL. In order not to increase their complexity compared to single layer receivers, the lower layer, known as EL is treated as an additional noise on the CL decoding. Fixed receivers, increase their complexity, as they should performed a SIC process on the CL for getting the EL. To limit the additional complexity of fixed receivers, the LDM layers in ATSC 3.0 are configured with different error correction capabilities, but share the rest of physical layer parameters, including the TIL, the PP, the FFT size, and the GI. This dissertation investigates advanced technologies to optimize the LDM performance. A demapping optimization for the two LDM layers is first proposed. A capacity increase is achieved by the proposed algorithm, which takes into account the underlying layer shape in the demapping process. Nevertheless, the number of Euclidean distances to be computed can be significantly increased, contributing to not only more complex fixed receivers, but also more complex mobile receivers. Next, the most suitable ATSC 3.0 pilot configuration for LDM is determined. Considering the two layers share the same PP a trade-off between pilot density (CL) and data overhead (EL) arises. From the performance results, it is recommended the use of a not very dense PP, as they have been already designed to cope with long echoes and high speeds. The optimum pilot amplitude depends on the channel estimator at receivers (e.g. the minimum amplitude is recommended for a Wiener implementation, while the maximum for a FFT implementation). The potential combination of LDM with three advanced technologies that have been adopted in ATSC 3.0 is also investigated: MultiRF technologies, distributed MISO schemes, and co-located MIMO schemes. The potential use cases, the transmitter and receiver implementations, and the performance gains of the joint configurations are studied for the two LDM layers. The additional constraints of combining LDM with the advanced technologies is considered admissible, as the greatest demands (e.g. a second receiving chain) are already contemplated in ATSC 3.0. Significant gains are found for the mobile layer at pedestrian reception conditions thanks to the frequency diversity provided by MultiRF technologies. The conjunction of LDM with distributed MISO schemes provides significant performance gains on SFNs for the fixed layer with Alamouti scheme. Last, considering the complexity in the mobile receivers and the CL performance, the recommended joint configuration is MISO in the CL and MIMO in the EL.Des de començaments del segle XXI, els sistemes de radiodifusió terrestre han sigut culpats d'un ús ineficient de l'espectre assignat. Per a augmentar l'eficiència espectral, els organismes d'estandardització de TV digital van començar a desenvolupar l'evolució tècnica dels sistemes de TDT de primera generació. Entre altres, un dels objectius principals dels sistemes de TDT de pròxima generació (DVB-T2 i el ATSC 3.0) és proporcionar simultàniament serveis de TV a dispositius mòbils i fixos. El principal inconvenient d'aquest lliurament simultani són els diferents requisits de cada condició de recepció. Per a abordar aquestes limitacions, s'han considerat diferents tècniques de multiplexació. Mentre que DVB-T2 escomet el lliurament simultani dels dos serveis mitjançant TDM, ATSC 3.0 va adoptar la Multiplexació per Divisió en Capes (LDM). LDM pot superar a TDM i a FDM en aprofitar la relació de Protecció d'Error Desigual (UEP), ja que tots dos serveis, cridats capes, utilitzen tots els recursos de freqüència i temps amb diferents nivells de potència. En el costat del receptor, es distingeixen dues implementacions, d'acord amb la capa a decodificar. Els receptors mòbils solament estan destinats a obtenir la capa superior, coneguda com Core Layer (CL). Per a no augmentar la seua complexitat en comparació amb els receptors de capa única, la capa inferior, coneguda com Enhanced Layer (EL), és tractada com un soroll addicional en la decodificació. Els receptors fixos augmenten la seua complexitat, ja que han de realitzar un procés de Cancel·lació d'Interferència (SIC) sobre la CL per a obtenir l'EL. Per a limitar la complexitat addicional dels receptors fixos, les capes de LDM en ATSC 3.0 estan configurades amb diferents capacitats de correcció, però comparteixen la resta de blocs de la capa física, inclòs el TIL, el PP, la grandària de FFT i el GI. Aquesta dissertació investiga tecnologies avançades per a optimitzar el rendiment de LDM. Primer es proposa una optimització del procés de demapeo per a les dues capes de LDM. L'algoritme proposat aconsegueix un augment de capacitat, en tenir en compte la forma de l'EL en el procés de demapeo de la CL. No obstant açò, el nombre de distàncies Euclidianes a computar pot augmentar significativament, conduint NO sols a receptors fixos més complexos, sinó també a receptors mòbils més complexos. A continuació, es determina la configuració de pilot ATSC 3.0 més adequada per a LDM. Tenint en compte que les dues capes comparteixen el mateix PP, es produeix una contrapartida entre la densitat de pilots (CL) i la redundància sobre les dades (EL). A partir dels resultats de rendiment, es recomana l'ús d'un PP no gaire dens, ja que ja han sigut dissenyats per a fer front a ecos llargs i altes velocitats. L'amplitud pilot òptima depèn de l'estimador de canal en els receptors (ex., es recomana l'amplitud mínima per a una implementació Wiener, mentre que la màxima per a una implementació FFT). També s'investiga la potencial transmissió conjunta de LDM amb tres tecnologies avançades adoptades en ATSC 3.0: les tecnologies d'agregació de MultiRF, els esquemes de MISO distribuït i els de MIMO colocalitzat. S'estudien els potencials casos d'ús, els principals aspectes d'implementació del transmissor i el receptor, i els guanys de rendiment de les configuracions conjuntes per a les dues capes de LDM. Les restriccions addicionals de combinar LDM amb les tecnologies avançades es consideren admissibles, ja que les majors demandes ja estan contemplades en ATSC 3.0 (ex., una segona cadena de recepció). S'obtenen guanys significatius per a la capa mòbil en condicions de recepció per als vianants gràcies a la diversitat en freqüència proporcionada per les tecnologies MultiRF. La conjunció de LDM amb esquemes MISO distribuïts proporciona guanys de rendiment significatius en xarxes SFN per a la capa fixa amb l'esquema d'Alamouti.Garro Crevillén, E. (2018). Advanced Layered Divsion Multiplexing Technologies for Next-Gen Broadcast [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/105559TESISCompendi

MIMO Scattered Pilot Performance and Optimization for ATSC 3.0

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] ATSC 3.0 is the latest digital terrestrial television (DTT) standard, and it allows a higher spectral efficiency and/or a transmission robustness with multiple-input multiple-output (MIMO) technology compared to existing DTT standards. Regarding MIMO channel estimation, two pilot encoding algorithms known as Walsh-Hadamard encoding and Null Pilot encoding are possible in ATSC 3.0. The two MIMO pilot algorithms are standardized so as to have the same pilot positions and the same pilot boosting as single-input single-output, and the optimum pilot configuration has not been fully evaluated for MIMO. This paper focuses on the performance evaluation and optimization of the pilot boosting and the pilot patterns for two MIMO pilot encoding algorithms in ATSC 3.0 using physical layer simulations. This paper provides a great benefit to broadcasters to select the MIMO pilot configuration including pilot boosting, pilot pattern, and pilot encoding algorithm that better suits their service requirements. Several channel interpolation algorithms have been taken into account as a typical receiver implementation in both fixed SFN reception and mobile reception.This work was supported in part by the Ministry of Economy and Competitiveness of Spain under Grant TEC2014-56483-R, and in part by the European FEDER Fund.Shitomi, T.; Garro, E.; Murayama, K.; Gomez-Barquero, D. (2018). MIMO Scattered Pilot Performance and Optimization for ATSC 3.0. IEEE Transactions on Broadcasting. 64(2):188-200. https://doi.org/10.1109/TBC.2017.2755262S18820064

Effect of temperature, pH and NaCl on nisin activity against <i>Lactobacillus fructivorans</i>

The aim of this work was to determine the influence of pH, sodium chloride concentration and the combination of different temperatures and periods of exposure on the antimicrobial activity against Lactobacillus fructivorans. Turbidity of the different system conditions was monitored in order to establish the microorganism growth. The effect of temperatures ranging from 60 to 120ºC during periods of 10 to 60 minutes was evaluated. Nisin activity was only changed by temperatures ranging from 100 to 120ºC, in several exposure times. A pH range between 3.5 and 7 was tested. The highest inhibitory effect was recorded for neutral pH and lightly acidic conditions. Sodium chloride concentrations studied were 1 and 2 % w/v. The latter value helped to enhance the inhibitory effect of the bacteriocin. These results show the influence that the studied factors exert on nisin activity against L. fructivorans and suggest that they have to be taken into account when nisin is to be used as a biopreservative in food.El presente trabajo tuvo como objetivo determinar la influencia del pH, concentración de cloruro de sodio y la combinación de diferentes temperaturas y períodos de exposición sobre la actividad antimicrobiana de nisina s obre una bacteria alterante Lactobacillus fructivorans. El crecimiento del microorganismo bajo diferentes condiciones fue determinado por la presencia de turbidez. Se evaluó el efecto de la temperatura en un rango de 60 a 120ºC durante períodos de 10 a 60 minutos. La actividad de la nisina fue afectada solamente por temperaturas de 100 y 120ºC, a cualquier tiempo de exposición considerado. Los ensayos se realizaron con un rango de pH entre 3,5 y 7. El mayor efecto inhibitorio fue a pH neutro y levemente ácido. Las concentraciones de cloruro de sodio fueron de 1 y 2% p/v. Sólo a la mayor concentración se ve un incremento en la actividad inhibitoria de la bacteriocina. Estos resultados muestran la influencia que los factores estudiados ejercen sobre la actividad de la bacteriocina frente a L. fructivorans e indican que tales factores deben ser tenidos en cuenta cuando la nisina sea usada en la preservación de alimentos.Centro de Investigación y Desarrollo en Ciencias Aplicada

Microfabricated Otto chip device for surface plasmon resonance based optical sensing

Surface plasmon resonance (SPR) based sensors are usually designed using the Kretschmann prism coupling configuration in which an input beam couples with a surface plasmon through a thin metal film. This is generally preferred by sensor developers for building planar devices instead of the Otto prism coupling configuration, which, for efficient coupling, requires the metal surface to be maintained at a distance on the order of the wavelength from the input prism surface. In this paper, we report on the microfabrication and characterization of an Otto chip device, which is suitable for applications of the SPR effect in gas sensing and biosensing

Sugar Content and Sources in Commercial Infant Cereals in Spain

Instant infant cereals reconstituted with infant formula are the first complementary food for most Spanish infants. The main aim is to provide information on sugars in the formulation of infant cereals. Product information was collected from department stores, supermarkets, and pharmacies and completed with data from brand websites. A portion of the samples was selected for total sugars determination using the HPLC and Luff-Schoorl methods. The information regarding a total of 120 milk-free instant infant cereals marketed in Spain from 12 companies was summarized. The mean of total sugars was 23 +/- 9 g/100 g (25-42%), providing 24% of the calories. Most of porridges are prepared with partially hydrolyzed flours providing free sugars (glucose and maltose). The most commonly added sugar is sucrose. A total of 43.3% of products contain added sucrose, and 16.7% contain fruits. Infant cereals analyzed with added sugars can have a sugar content similar to that found in products without added sugars. Consistent differences were found in sugars content between assayed methods and this label information. Although the European legislation of infant cereals establishes values for added sugars, the labeling reflects the content of total sugars, but not that of added sugars

Information-Theoretic Analysis and Performance Evaluation of Optimal Demappers for Multi-Layer Broadcast Systems

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] Multi-layer broadcast systems distribute services across time and frequency domain by means of power-division multiplexing. Successive interference cancelation is required, in general, in order to extract the content of all services. For a low-complexity implementation, the receiver can obtain the strongest (top-layer) signal assuming underlying signals to behave like thermal noise. The thermal noise assumption may not be valid under certain conditions and a more accurate characterization of the interference could bring improved performance. This paper analyzes the validity of the noise-like assumption considering the power ratio between signals and the required carrier-to-noise ratio for error-free reception. The main contribution of the paper is the proposal of a demapping algorithm that exploits the knowledge of the constellation of underlying signals. Generalized mutual information, performance evaluation, and complexity analysis are provided with the additive white Gaussian noise-like assumptions and with the proposed alternative in order to assess the potential performance improvements that can be achieved.This work was supported by in part by the Ministerio de Educacion y Ciencia, Spain under Grant TEC2014-56483-R, and in part by the European FEDER Funds.Garro, E.; Gimenez Gandia, JJ.; Klenner, P.; Gomez-Barquero, D. (2018). Information-Theoretic Analysis and Performance Evaluation of Optimal Demappers for Multi-Layer Broadcast Systems. IEEE Transactions on Broadcasting. 64(4):781-790. https://doi.org/10.1109/TBC.2018.2799300S78179064

Scattered Pilot Performance and Optimization for ATSC 3.0

[EN] The next-generation U.S. digital terrestrial television (DTT) standard ATSC 3.0 is the most flexible DTT standard ever developed, outperforming the state-of-the-art digital video broadcasting-terrestrial 2nd generation (DVB-T2) standard. This higher flexibility allows broadcasters to select the configuration that better suits the coverage and capacity requirements per service. Regarding the selection of pilot patterns, whereas DVB-T2 provides eight different patterns with a unique pilot amplitude, ATSC 3.0 expands up to 16, with five different amplitudes per pattern. This paper focuses on the pilot pattern and amplitude performance and optimization for time and power multiplexing modes, time division multiplexing and layered division multiplexing (LDM), respectively, of ATSC 3.0. The selection of the optimum pilot configuration is not straightforward. On the one hand, the pilots must be sufficiently dense to follow channel fluctuations. On the other hand, as long as pilot density is increased, more data overhead is introduced. Moreover, this selection is particularly essential in LDM mode, because the LDM implementation in ATSC 3.0 requires that both layers share all the waveform parameters, including pilot pattern configuration. In addition, there is an error proportional to the channel estimate of the top layer that affects to the lower layer performance.This work was supported in part by the Institute for Information and Communications Technology (IITP) by the Korea Government (MSIP) (Development of Service and Transmission Technology for Convergent Realistic Broadcast) under Grant R0101-15-294, and in part by the Ministerio de Educación y Ciencia, Spain, by European FEDER Funds under Grant TEC2014-56483-R.Garro, E.; Gimenez, JJ.; Park, SI.; Gomez-Barquero, D. (2017). Scattered Pilot Performance and Optimization for ATSC 3.0. IEEE Transactions on Broadcasting. 63(1):282-292. https://doi.org/10.1109/TBC.2016.2630304S28229263

A Multivariate QSAR Study on the Anticonvulsant Activity of Acetamido-N-Benzylacetamide Derivatives. Influence of Different Molecular Descriptors

A quantitative structure activity relationship analysis was applied to a library of 51 benzylacetamide derivatives with anticonvulsant activity. The molecular structures of 51 compounds were optimized with the Semiempirical Method PM6 (Parametric Method-6) included in the MOPAC2009 software. The optimized structures of all the examined compounds were represented by 1497 DRAGON-type descriptors. Using multiple linear regression (MLR), the influence of constitutional, topological, electronic, physicochemical and quantum molecular descriptors on the activity was investigated. The validation of models were performed through the leave-one-out cross technique in conjunction with external validation. From different types of molecular descriptors, six new QSAR models were developed. The models using 0D descriptors (constitutional descriptors) and quantum descriptors do not have high statistical quality. The combination of 2D and 3D descriptors produce a model of high predictive quality (Rcal= 0.888; Scal= 0.195; Rval= 0.814; Sval=0.431; Rloo=0.867; Sloo=0.212). Results show the important role of electronic and topologic features of molecules on their anticonvulsant activity in relative to constitutional parameters.Fil: Garro Martinez, Juan Ceferino. Universidad Nacional de San Luis. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Estrada, Mario Rinaldo. Universidad Nacional de San Luis. Departamento de Química; ArgentinaFil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentin

Layered Division Multiplexing With Multi-Radio-Frequency Channel Technologies

"(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

Conformation-independent QSPR approach for the soil sorption coefficient of heterogeneous compounds

We predict the soil sorption coefficient for a heterogeneous set of 643 organic non-ionic compounds by means of Quantitative Structure-Property Relationships (QSPR). A conformation-independent representation of the chemical structure is established. The 17,538molecular descriptors derived with PaDEL and EPI Suite softwares are simultaneously analyzed through linear regressions obtained with the Replacement Method variable subset selection technique. The best predictive three-descriptors QSPR is developed on a reduced training set of 93 chemicals, having an acceptable predictive capability on 550 test set compounds. We also establish a model with a single optimal descriptor derived from CORAL freeware. The present approach compares fairly well with a previously reported one that uses Dragon descriptors.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada