Infrared cameras can directly measure the apparent temperature of objects, providing thermal imaging. However, the raw output from most infrared cameras suffers from a strong, often limiting noise source called nonuniformity. Manufacturing imperfections in infrared focal planes lead to high pixel-to-pixel sensitivity to electronic bias, focal plane temperature, and other effects. In turn, different pixels within the focal plane array give a drastically different electronic response to the same irradiance. The resulting imagery can only provide useful thermal imaging after a nonuniformity calibration has been performed. Traditionally, these calibrations are performed by momentarily blocking the field of view with a flat temperature plate or blackbody cavity. However because the pattern is a coupling of manufactured sensitivities with operational variations, periodic recalibration is required, sometimes on the order of tens of seconds. A class of computational methods called Scene-Based Nonuniformity Correction (SBNUC) has been researched for over 20 years where the nonuniformity calibration is estimated in digital processing by analysis of the video stream in the presence of camera motion. The most sophisticated SBNUC methods can completely and robustly eliminate the high-spatial frequency component of nonuniformity with only an initial reference calibration or potentially no physical calibration. I will demonstrate a novel algorithm that advances these SBNUC techniques to support all spatial frequencies of nonuniformity correction. Long-wave infrared microgrid polarimeters are a class of camera that incorporate a microscale per-pixel wire-grid polarizer directly affixed to each pixel of the focal plane. These cameras have the capability of simultaneously measuring thermal imagery and polarization in a robust integrated package with no moving parts. I will describe the necessary adaptations of my SBNUC method to operate on this class of sensor as well as demonstrate SBNUC performance in LWIR polarimetry video collected on the UA mall.

A regulação da expressão gênica é vital para todos os organismos se adaptarem rapidamente às mudanças ambientais. Estes mecanismos adaptativos são altamente complexos e a maioria deles não está completamente esclarecida. O fosfato inorgânico (Pi), um nutriente essencial para todos os organismos, é requerido em importantes processos celulares como a biosíntese de ácidos nucléicos e a sinalização metabólica. O sistema de aquisição de Pi no fungo filamentoso Neurospora crassa inclui pelo menos quatro genes regulatórios: nuc-2, preg, pgov e nuc-1. Em condições limitantes de Pi, NUC- 2, uma proteína com domínio de repetição de anquirina, inibe o funcionamento do complexo PREG-PGOV, ativando assim o fator de transcrição NUC-1 e a expressão de genes envolvidos na captação de fosfato, como fosfatases, fosfato permeases e nucleases. Visando entender a funcionalidade do gene nuc-2 na regulação da expressão gênica em resposta aos níveis de Pi exógeno, foram construídas duas bibliotecas de subtração de cDNA entre as linhagens selvagem St.L.74A e nuc-2A de N. crassa, cultivadas em Pilimitante. Obtivemos 52 transcritos induzidos e 16 reprimidos pela proteína NUC-2. A categorização funcional destas sequências revelou genes envolvidos em diversos processos celulares, como transporte, regulação transcricional, transdução de sinal, metabolismo, síntese protéica e desenvolvimento. Entre os genes modulados negativamente pela proteína NUC-2, foi identificado um gene que codifica a proteína MAK-2 (mitogen-activated protein kinase-2), envolvida em vias de sinalização intracelular. O papel funcional deste gene no monitoramento do Pi extracelular foi avaliado por microarranjos de oligonucleotídeos, comparando as linhagens selvagem e mutante mak-2, cultivadas em baixa concentração de Pi. Foram identificados 4.214 genes regulados pela proteína MAK- 2, dentre eles a ciclina codificada pelo gene preg. Além disto, genes regulados em função da concentração de Pi foram identificados, mostrando o envolvimento de 3.174 transcritos. Os resultados obtidos neste trabalho revelam novos aspectos moleculares envolvidos na adaptação à disponibilidade de Pi extracelular, sugerindo que o gene mak-2 constitui um novo componente da via de sinalização e monitoramento de fosfato em N. crassa. / Gene expression regulation is crucial for all organisms to rapidly adapt to environmental changes. These adaptive mechanisms are highly complex and most of them have not been completely elucidated. The inorganic phosphate (Pi), an essential nutrient for all organisms, is required for important cellular processes, such as nucleic acids biosynthesis and metabolic signaling. The Pi acquisition system in the filamentous fungus Neurospora crassa includes at least four regulatory genes: nuc-2, preg, pgov and nuc-1. Under limiting Pi conditions, NUC-2, an ankyrin-like repeat protein, inhibits the functioning of the PREG-PGOV complex, allowing the activation of the transcription factor NUC-1 and the expression of genes involved in phosphate acquisition, such as phosphatases, phosphate permeases and nucleases. Aiming at a better comprehension of the nuc-2 functionality in gene expression regulation in response to exogenous Pi levels, two cDNA subtraction libraries were constructed comparing N. crassa wild type St.L.74A and nuc-2A strains, grown under Pi starvation. We obtained 52 NUC-2 up- and 16 downregulated genes. Functional categorization of these sequences revealed genes involved in several cellular processes, such as cellular transport, transcriptional regulation, metabolism, protein synthesis and development. Among the NUC-2 negatively modulated genes, we identified the MAK-2 (mitogen-activated protein kinase-2) protein coding gene, involved in the intracellular signaling pathway. The functional role of this gene in the extracellular Pi sensing was evaluated by oligonucleotide microarrays, comparing wild type and mak-2 strains responses under Pi starvation. We identified 4.214 MAK-2 regulated genes, among them the cyclin coding gene, preg. Furthermore, 3.174 genes regulated in response to Pi levels were identified. In a nutshell, the results obtained in this work reveal novel molecular aspects of the adaptation to extracellular Pi availability, suggesting that the mak-2 gene constitutes a novel component of the N. crassa phosphate sensing and signaling pathway.

A regulação da expressão gênica é vital para todos os organismos se adaptarem rapidamente às mudanças ambientais. Estes mecanismos adaptativos são altamente complexos e a maioria deles não está completamente esclarecida. O fosfato inorgânico (Pi), um nutriente essencial para todos os organismos, é requerido em importantes processos celulares como a biosíntese de ácidos nucléicos e a sinalização metabólica. O sistema de aquisição de Pi no fungo filamentoso Neurospora crassa inclui pelo menos quatro genes regulatórios: nuc-2, preg, pgov e nuc-1. Em condições limitantes de Pi, NUC- 2, uma proteína com domínio de repetição de anquirina, inibe o funcionamento do complexo PREG-PGOV, ativando assim o fator de transcrição NUC-1 e a expressão de genes envolvidos na captação de fosfato, como fosfatases, fosfato permeases e nucleases. Visando entender a funcionalidade do gene nuc-2 na regulação da expressão gênica em resposta aos níveis de Pi exógeno, foram construídas duas bibliotecas de subtração de cDNA entre as linhagens selvagem St.L.74A e nuc-2A de N. crassa, cultivadas em Pilimitante. Obtivemos 52 transcritos induzidos e 16 reprimidos pela proteína NUC-2. A categorização funcional destas sequências revelou genes envolvidos em diversos processos celulares, como transporte, regulação transcricional, transdução de sinal, metabolismo, síntese protéica e desenvolvimento. Entre os genes modulados negativamente pela proteína NUC-2, foi identificado um gene que codifica a proteína MAK-2 (mitogen-activated protein kinase-2), envolvida em vias de sinalização intracelular. O papel funcional deste gene no monitoramento do Pi extracelular foi avaliado por microarranjos de oligonucleotídeos, comparando as linhagens selvagem e mutante mak-2, cultivadas em baixa concentração de Pi. Foram identificados 4.214 genes regulados pela proteína MAK- 2, dentre eles a ciclina codificada pelo gene preg. Além disto, genes regulados em função da concentração de Pi foram identificados, mostrando o envolvimento de 3.174 transcritos. Os resultados obtidos neste trabalho revelam novos aspectos moleculares envolvidos na adaptação à disponibilidade de Pi extracelular, sugerindo que o gene mak-2 constitui um novo componente da via de sinalização e monitoramento de fosfato em N. crassa. / Gene expression regulation is crucial for all organisms to rapidly adapt to environmental changes. These adaptive mechanisms are highly complex and most of them have not been completely elucidated. The inorganic phosphate (Pi), an essential nutrient for all organisms, is required for important cellular processes, such as nucleic acids biosynthesis and metabolic signaling. The Pi acquisition system in the filamentous fungus Neurospora crassa includes at least four regulatory genes: nuc-2, preg, pgov and nuc-1. Under limiting Pi conditions, NUC-2, an ankyrin-like repeat protein, inhibits the functioning of the PREG-PGOV complex, allowing the activation of the transcription factor NUC-1 and the expression of genes involved in phosphate acquisition, such as phosphatases, phosphate permeases and nucleases. Aiming at a better comprehension of the nuc-2 functionality in gene expression regulation in response to exogenous Pi levels, two cDNA subtraction libraries were constructed comparing N. crassa wild type St.L.74A and nuc-2A strains, grown under Pi starvation. We obtained 52 NUC-2 up- and 16 downregulated genes. Functional categorization of these sequences revealed genes involved in several cellular processes, such as cellular transport, transcriptional regulation, metabolism, protein synthesis and development. Among the NUC-2 negatively modulated genes, we identified the MAK-2 (mitogen-activated protein kinase-2) protein coding gene, involved in the intracellular signaling pathway. The functional role of this gene in the extracellular Pi sensing was evaluated by oligonucleotide microarrays, comparing wild type and mak-2 strains responses under Pi starvation. We identified 4.214 MAK-2 regulated genes, among them the cyclin coding gene, preg. Furthermore, 3.174 genes regulated in response to Pi levels were identified. In a nutshell, the results obtained in this work reveal novel molecular aspects of the adaptation to extracellular Pi availability, suggesting that the mak-2 gene constitutes a novel component of the N. crassa phosphate sensing and signaling pathway.

No description available.

Staphylococcus aureus belongs to the normal flora. Many healthy people are colonized by the bacterium mainly in the nose but also on the skin and on other mucous membranes without showing symptoms. After damage to the skin, the bacterium can enter the wound and cause infections. Methicillin-resistant S. aureus (MRSA) is resistant to b-lactam antibiotics such as penicillin and methicillin. The gene that gives resistance characteristic of MRSA is the mecA-gene. MRSA strains are spread in both hospitals and in the community, and it is important to identify these bacteria with rapid and sensitive methods. In this study, Taq Man RT-qPCR was compared with SYBR Green RT-qPCR (LightCycler480, Roche) to explore which method had the best sensitivity with the least working hours. In addition, Bullet for automated DNA extraction and CAS 1200 ™ for automated pipetting of the samples were evaluated. Twelve patient isolates and 232 patient samples for MRSA screening were included in the study. The results showed that the primers were of major importance for the outcome of the amplification. It was also shown that the Ct-values were clearly lower when the Bullet, CAS 1200 ™ and LightCycler480 were combined compared with manual DNA extraction, manual pipetting and the Rotor-Gene 6000. In future, the former method will be used by the laboratory when screening patient samples for MRSA.

Made available in DSpace on 2014-12-17T14:06:58Z (GMT). No. of bitstreams: 1 LuizCFS.pdf: 3453741 bytes, checksum: a917d4da21cccce053bc103345ba7ee6 (MD5) Previous issue date: 2008-07-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This research is about the use of the coconut?s endocarp (nucifera linn) and the waste of derivatives of wood and furniture as raw material to technological use. In that sense, the lignocellulosic waste is used for manufacture of homogeneous wood sheet agglomerate (LHWS) and lignocellulosic load which take part of a polymeric composite with fiber glass E (GFRP-WC). In the manufacturing of the homogeneous wood sheet agglomerate (LHWS), it was used mamona?s resin as waste s agglutinating element. The plates were taken up in a hydraulic press engine, heated, with temperature control, where they were manufactured for different percentage of waste wood and coconuts nuc?fera linn. Physical tests were conducted to determine the absorption of water, density, damp grade (in two hours and twenty-four hours), swelling thickness (in two hours and twenty-four hours), and mechanical tests to evaluate the parallel tensile strength (internal stick) and bending and the static (steady) flexural. The physical test?s results indicate that the LHWS can be classified as bonded wood plate of high-density and with highly water resistant. In the mechanical tests it was possible to establish that LHWS presents different characteristics when submitted to uniaxial tensile and to the static (steady) flexural, since brittle and elasticity module had a variation according to the amount of dry endocarp used to manufacture each trace of LHWS. The GFRP-WC was industrially manufactured by a hand-lay-up process where the fiber glass E was used as reinforcement the lignocellul?sic?s waste as load. The matrix was made with ortofitalic unsaturated polyester resin. Physical and mechanical tests were performed in presence of saturated humidity and dry. The results indicated good performance of the GFRP-WC, as traction as in flexion in three points. The presence of water influenced the modules obtained in the flexural and tensile but there were no significant alteration in the properties analyzed. As for the fracture, the analysis showed that the effects are more harmful in the presence of damp, under the action of loading tested, but despite this, the fracture was well defined starting in the external parts and spreading to the internal regions when one when it reaches the hybrid load / Na presente pesquisam-se a utiliza??o do endocarpo do cocos nuc?fera linn e o res?duo de derivados de madeira e de m?veis como mat?ria-prima para uso tecnol?gico. Nesse sentido, usam-se esses res?duos lignocelul?sico na fabrica??o de chapa de madeira aglomerada homog?nea (CHMC) e, como carga, em comp?sito polim?rico refor?ado com fibra de vidro E (PHFV-MC). Na fabrica??o da chapa de madeira aglomerada homog?nea (CHMC) usou-se a resina ? base de mamona como elemento aglutinante dos res?duos. As chapas foram conformadas em uma prensa hidr?ulica aquecida com controle de temperatura, onde as mesmas foram fabricadas para diferentes percentuais dos res?duos de madeira e do cocos nuc?fera linn. Foram realizados ensaios f?sicos para a determina??o de absor??o de ?gua, densidade, do teor de umidade (em duas horas e vinte e quatro horas), inchamento de espessura (em duas horas e vinte e quatro horas), e ensaios mec?nicos para a determina??o da resist?ncia ? tra??o paralela (ades?o interna) e o ensaio de flex?o est?tica. Os resultados obtidos nos ensaios f?sicos indicam que a CHMC pode ser classificada como chapa de madeira aglomerada de alta densidade e que suporta bem a presen?a de ?gua. Nos ensaios mec?nicos foi poss?vel constatar que a CHMC apresenta caracter?sticas distintas quando submetida ? for?a de tra??o uniaxial e ? flex?o est?tica, uma vez que os m?dulos de ruptura e de elasticidade variaram em fun??o da quantidade do endocarpo seco usado para fabricar cada tra?o da CHMC. A PHFV-MC foi fabricada industrialmente por meio do processo hand-lay-up onde a fibra de vidro-E foi usada como refor?o e os res?duos lignocelul?sicos, como carga. A matriz foi ? base de resina poli?ster ortofit?lica insaturada. Foram realizados ensaios f?sicos e mec?nicos em presen?a de umidade saturada e a seco. Os resultados indicaram um bom desempenho da PHFV-MC, tanto na tra??o quanto na flex?o em tr?s pontos. A presen?a de ?gua influenciou os m?dulos obtidos na flex?o e na tra??o, mas n?o alterou significativamente as propriedades analisadas. Quanto ? fratura, a an?lise mostrou que os efeitos s?o mais danosos em presen?a da umidade, sob a a??o dos carregamentos analisados, mas, apesar disto, a fratura se mostrou bastante caracterizada, iniciando nas regi?es externas e se propagando para as regi?es internas quando atinge a carga h?brida

<p>This thesis describes and evaluates a number of algorithms for reducing fixed pattern noise in image sequences. Fixed pattern noise is the dominantnoise component for many infrared detector systems, perceived as a superimposed pattern that is approximately constant for all image frames. </p><p>Primarily, methods based on estimation of the movement between individual image frames are studied. Using scene-matching techniques, global motion between frames can be successfully registered with sub-pixel accuracy. This allows each scene pixel to be traced along a path of individual detector elements. Assuming a static scene, differences in pixel intensities are caused by fixed pattern noise that can be estimated and removed. </p><p>The algorithms have been tested by using real image data from existing infrared imaging systems with good results. The tests include both a two-dimensional focal plane array detector and a linear scanning one-dimensional detector, in different scene conditions.</p>

This thesis describes and evaluates a number of algorithms for reducing fixed pattern noise in image sequences. Fixed pattern noise is the dominantnoise component for many infrared detector systems, perceived as a superimposed pattern that is approximately constant for all image frames. Primarily, methods based on estimation of the movement between individual image frames are studied. Using scene-matching techniques, global motion between frames can be successfully registered with sub-pixel accuracy. This allows each scene pixel to be traced along a path of individual detector elements. Assuming a static scene, differences in pixel intensities are caused by fixed pattern noise that can be estimated and removed. The algorithms have been tested by using real image data from existing infrared imaging systems with good results. The tests include both a two-dimensional focal plane array detector and a linear scanning one-dimensional detector, in different scene conditions.

Submitted by Marta Toyoda (1144061@mackenzie.br) on 2018-02-08T20:32:01Z No. of bitstreams: 2 GEORGE HENRIQUE MARANHÃO GARCIA DE OLIVEIRA.pdf: 3162275 bytes, checksum: 7e4e2ff4fcb19dbee94fa8f9ac1a5a69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-04-03T15:10:51Z (GMT) No. of bitstreams: 2 GEORGE HENRIQUE MARANHÃO GARCIA DE OLIVEIRA.pdf: 3162275 bytes, checksum: 7e4e2ff4fcb19dbee94fa8f9ac1a5a69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-03T15:10:51Z (GMT). No. of bitstreams: 2 GEORGE HENRIQUE MARANHÃO GARCIA DE OLIVEIRA.pdf: 3162275 bytes, checksum: 7e4e2ff4fcb19dbee94fa8f9ac1a5a69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-06 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Fundo Mackenzie de Pesquisa / This work presents the characteristics of the ISDB-TB, adopted in Brazil as part of Digital TV Brazilian System (SBTVD) and the challenges and needed adaptations for the next digital TV generations. It also shows the historic of SDR, physical layer LDM, NUC modulations and error correction code LDPC technologies. Their advantages are demonstrated in terms of eficient use of spectrum, robustness and increase of transmission rate. A digital communication system with this technologies was proposed, allowing the compatibility with the ISDB-TB system. The focus of this work are the stages of coding and modulation in the LDM lower layer, enabling better performance of this technique in the ISDB-TB system. This implementation was performed with the software GNU Radio Companion and the use of the C ++ language. / Este trabalho apresenta as características do ISDB-TB, adotado no Brasil como parte do Sistema Brasileiro de TV Digital (SBTVD) e os desafios e adaptações necessárias para as próximas gerações da TV digital. O trabalho também mostra o histórico das tecnologias SDR, camada física LDM, modulações NUC e código corretor de erro LDPC. Suas vantagens de utilização são demonstradas em termos de sua eficiência espectral, robustez e do aumento da taxa de dados transmitida. Um sistema de comunicação digital unindo estas tecnologias é proposto, permitindo a compatibilidade com o sistema ISDB-TB. O foco deste trabalho são as etapas de codificação e modulação da camada inferior do LDM, permitindo maior desempenho desta técnica no sistema ISDB-TB. Esta implementação foi realizada com o software GNU Radio Companion e o uso da linguagem C++.

Nowadays, the digital terrestrial television (DTT) market is characterized by the high capacity needed for high definition TV services. There is a need for an efficient use of the broadcast spectrum, which requires new technologies to guarantee increased capacities. Non-Uniform Constellations (NUC) arise as one of the most innovative techniques to approach those requirements. NUCs reduce the gap between uniform Gray-labelled Quadrature Amplitude Modulation (QAM) constellations and the theoretical unconstrained Shannon limit. With these constellations, symbols are optimized in both in-phase (I) and quadrature (Q) components by means of signal geometrical shaping, considering a certain signal-to-noise ratio (SNR) and channel model. There are two types of NUC, one-dimensional and two-dimensional NUCs (1D-NUC and 2D-NUC, respectively). 1D-NUCs maintain the squared shape from QAM, but relaxing the distribution between constellation symbols in a single component, with non-uniform distance between them. These constellations provide better SNR performance than QAM, without any demapping complexity increase. 2D-NUCs also relax the square shape constraint, allowing to optimize the symbol positions in both dimensions, thus achieving higher capacity gains and lower SNR requirements. However, the use of 2D-NUCs implies a higher demapping complexity, since a 2D-demapper is needed, i.e. I and Q components cannot be separated. In this dissertation, NUCs are analyzed from both transmit and receive point of views, using either single-input single-output (SISO) or multiple-input multiple-output (MIMO) antenna configurations. In SISO transmissions, 1D-NUCs and 2D-NUCs are optimized for a wide range of SNRs and different constellation orders. The optimization of rotated 2D-NUCs is also investigated. Even though the demapping complexity is not increased, the SNR gain of these constellations is not significant. The highest rotation gain is obtained for low-order constellations and high SNRs. However, with multi-RF techniques, the SNR gain is drastically increased, since I and Q components are transmitted in different RF channels. In this thesis, multi-RF gains of NUCs with and without rotation are provided for some representative scenarios. At the receiver, two different implementation bottlenecks are explored. First, the demapping complexity of all considered constellations is analyzed. Afterwards, two complexity reduction algorithms for 2D-NUCs are proposed. Both algorithms drastically reduce the number of distances to compute. Moreover, both are finally combined in a single demapper. Quantization of NUCs is also explored in this dissertation, since LLR values and I/Q components are modified when using these constellations, compared to traditional QAM constellations. A new algorithm that is based on the optimization of the quantizer levels for a particular constellation is proposed. The use of NUCs in multi-antenna communications is also investigated. It includes the optimization in one or two antennas, the use of power imbalance, the cross-polar discrimination (XPD) between receive antennas, or the use of different demappers. Assuming different values for the parameters evaluated, new Multi-Antenna Non-Uniform Constellations (MA-NUC) are obtained by means of a particularized re-optimization process, specific for MIMO. At the receiver, an extended demapping complexity analysis is performed, where it is shown that the use of 2D-NUCs in MIMO extremely increases the demapping complexity. As an alternative, an efficient solution for 2D-NUCs and MIMO systems based on Soft-Fixed Sphere Decoding (SFSD) is proposed. The main drawback is that SFSD demappers do not work with 2D-NUCs, since they perform a Successive Interference Cancellation (SIC) step that needs to be performed in separated I and Q components. The proposed method quantifies the closest symbol using Voronoi regions and allows SFSD demappers to work. / Hoy en día, el mercado de la televisión digital terrestre (TDT) está caracterizado por la alta capacidad requerida para transmitir servicios de televisión de alta definición y el espectro disponible. Es necesario por tanto un uso eficiente del espectro radioeléctrico, el cual requiere nuevas tecnologías para garantizar mayores capacidades. Las constelaciones no-uniformes (NUC) emergen como una de las técnicas más innovadoras para abordar tales requerimientos. Las NUC reducen el espacio existente entre las constelaciones uniformes QAM y el límite teórico de Shannon. Con estas constelaciones, los símbolos se optimizan en ambas componentes fase (I) y cuadratura (Q) mediante técnicas geométricas de modelado de la señal, considerando un nivel señal a ruido (SNR) concreto y un modelo de canal específico. Hay dos tipos de NUC, unidimensionales y bidimensionales (1D-NUC y 2D-NUC, respectivamente). Las 1D-NUC mantienen la forma cuadrada de las QAM, pero permiten cambiar la distribución entre los símbolos en una componente concreta, teniendo una distancia no uniforme entre ellos. Estas constelaciones proporcionan un mejor rendimiento SNR que QAM, sin ningún incremento en la complejidad en el demapper. Las 2D-NUC también permiten cambiar la forma cuadrada de la constelación, permitiendo optimizar los símbolos en ambas dimensiones y por tanto obteniendo mayores ganancias en capacidad y menores requerimientos en SNR. Sin embargo, el uso de 2D-NUCs implica una mayor complejidad en el receptor. En esta tesis se analizan las NUC desde el punto de vista tanto de transmisión como de recepción, utilizando bien configuraciones con una antena (SISO) o con múltiples antenas (MIMO). En transmisiones SISO, se han optimizado 1D-NUCs para un rango amplio de distintas SNR y varios órdenes de constelación. También se ha investigado la optimización de 2D-NUCs rotadas. Aunque la complejidad no aumenta, la ganancia SNR de estas constelaciones no es significativa. La mayor ganancia por rotación se obtiene para bajos órdenes de constelación y altas SNR. Sin embargo, utilizando técnicas multi-RF, la ganancia aumenta drásticamente puesto que las componentes I y Q se transmiten en distintos canales RF. En esta tesis, se han estudiado varias ganancias multi-RF representativas de las NUC, con o sin rotación. En el receptor, se han identificado dos cuellos de botella diferentes en la implementación. Primero, se ha analizado la complejidad en el receptor para todas las constelaciones consideradas y, posteriormente, se proponen dos algoritmos para reducir la complejidad con 2D-NUCs. Además, los dos pueden combinarse en un único demapper. También se ha explorado la cuantización de estas constelaciones, ya que tanto los valores LLR como las componentes I/Q se ven modificados, comparando con constelaciones QAM tradicionales. Además, se ha propuesto un algoritmo que se basa en la optimización para diferentes niveles de cuantización, para una NUC concreta. Igualmente, se ha investigado en detalle el uso de NUCs en MIMO. Se ha incluido la optimización en una sola o en dos antenas, el uso de un desbalance de potencia, factores de discriminación entre antenas receptoras (XPD), o el uso de distintos demappers. Asumiendo distintos valores, se han obtenido nuevas constelaciones multi-antena (MA-NUC) gracias a un nuevo proceso de re-optimización específico para MIMO. En el receptor, se ha extendido el análisis de complejidad en el demapper, la cual se incrementa enormemente con el uso de 2D-NUCs y sistemas MIMO. Como alternativa, se propone una solución basada en el algoritmo Soft-Fixed Sphere Decoding (SFSD). El principal problema es que estos demappers no funcionan con 2D-NUCs, puesto que necesitan de un paso adicional en el que las componentes I y Q necesitan separarse. El método propuesto cuantifica el símbolo más cercano utilizando las regiones de Voronoi, permitiendo el uso de este tipo de receptor. / Actualment, el mercat de la televisió digital terrestre (TDT) està caracteritzat per l'alta capacitat requerida per a transmetre servicis de televisió d'alta definició i l'espectre disponible. És necessari per tant un ús eficient de l'espectre radioelèctric, el qual requereix noves tecnologies per a garantir majors capacitats i millors servicis. Les constel·lacions no-uniformes (NUC) emergeixen com una de les tècniques més innovadores en els sistemes de televisió de següent generació per a abordar tals requeriments. Les NUC redueixen l'espai existent entre les constel·lacions uniformes QAM i el límit teòric de Shannon. Amb estes constel·lacions, els símbols s'optimitzen en ambdós components fase (I) i quadratura (Q) per mitjà de tècniques geomètriques de modelatge del senyal, considerant un nivell senyal a soroll (SNR) concret i un model de canal específic. Hi ha dos tipus de NUC, unidimensionals i bidimensionals (1D-NUC i 2D-NUC, respectivament). 1D-NUCs mantenen la forma quadrada de les QAM, però permet canviar la distribució entre els símbols en una component concreta, tenint una distància no uniforme entre ells. Estes constel·lacions proporcionen un millor rendiment SNR que QAM, sense cap increment en la complexitat al demapper. 2D-NUC també canvien la forma quadrada de la constel·lació, permetent optimitzar els símbols en ambdós dimensions i per tant obtenint majors guanys en capacitat i menors requeriments en SNR. No obstant això, l'ús de 2D-NUCs implica una major complexitat en el receptor, ja que es necessita un demapper 2D, on les components I i Q no poden ser separades. En esta tesi s'analitzen les NUC des del punt de vista tant de transmissió com de recepció, utilitzant bé configuracions amb una antena (SISO) o amb múltiples antenes (MIMO). En transmissions SISO, s'han optimitzat 1D-NUCs, per a un rang ampli de distintes SNR i diferents ordes de constel·lació. També s'ha investigat l'optimització de 2D-NUCs rotades. Encara que la complexitat no augmenta, el guany SNR d'estes constel·lacions no és significativa. El major guany per rotació s'obté per a baixos ordes de constel·lació i altes SNR. No obstant això, utilitzant tècniques multi-RF, el guany augmenta dràsticament ja que les components I i Q es transmeten en distints canals RF. En esta tesi, s'ha estudiat el guany multi-RF de les NUC, amb o sense rotació. En el receptor, s'han identificat dos colls de botella diferents en la implementació. Primer, s'ha analitzat la complexitat en el receptor per a totes les constel·lacions considerades i, posteriorment, es proposen dos algoritmes per a reduir la complexitat amb 2D-NUCs. Ambdós algoritmes redueixen dràsticament el nombre de distàncies. A més, els dos poden combinar-se en un únic demapper. També s'ha explorat la quantització d'estes constel·lacions, ja que tant els valors LLR com les components I/Q es veuen modificats, comparant amb constel·lacions QAM tradicionals. A més, s'ha proposat un algoritme que es basa en l'optimització per a diferents nivells de quantització, per a una NUC concreta. Igualment, s'ha investigat en detall l'ús de NUCs en MIMO. S'ha inclòs l'optimització en una sola o en dos antenes, l'ús d'un desbalanç de potència, factors de discriminació entre antenes receptores (XPD), o l'ús de distints demappers. Assumint distints valors, s'han obtingut noves constel·lacions multi-antena (MA-NUC) gràcies a un nou procés de re-optimització específic per a MIMO. En el receptor, s'ha modificat l'anàlisi de complexitat al demapper, la qual s'incrementa enormement amb l'ús de 2D-NUCs i sistemes MIMO. Com a alternativa, es proposa una solució basada en l'algoritme Soft-Fixed Sphere Decoding (SFSD) . El principal problema és que estos demappers no funcionen amb 2D-NUCs, ja que necessiten d'un pas addicional en què les components I i Q necessiten separar-se. El mètode proposat quantifica el símbol més pròxim utilitzan / Fuentes Muela, M. (2017). Non-Uniform Constellations for Next-Generation Digital Terrestrial Broadcast Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84743 / TESIS