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1
Kowlgi, Srinivasan Sandeep. „Etude des émetteurs radiofréquences multistandards destinés aux stations de base GSM/WCDMA/LTE“. Thesis, Paris, ENST, 2013. http://www.theses.fr/2013ENST0018/document.
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Les stations de base de télécommunications contemporaines pour les réseaux GSM / EDGE, WCDMA / HSPA et LTE sont de plus en plus complexes et à forte intensité énergétique. La solution privilégiée est un émetteur véritablement multi-standard. Modernes émetteurs des stations de base sont souvent multi-standard, en ce qu'ils peuvent supporter différentes normes ou de modes air-interface. Cependant, ce n'est pas réalisé par le fonctionnement simultané des normes différentes ou des «modes», mais par des moyens de reconfiguration, qui sont inefficaces et coûteux. Nous envisageons un émetteur entièrement multi-mode pratique capable de supporter simultanément GSM / EDGE, WCDMA / HSPA et LTE transporteurs. L'évolution des normes 3GPP vers un fonctionnement multi-mode est au stade embryonnaire. Pour contribuer à cet effort, notre travail revisite l'architecture traditionnelle de l'émetteur de station de base macro-cellule afin d'analyser et de définir les exigences de performance pour une plate-forme de radio cellulaire multi-standard. Notre analyse et la conception du système identifie également un goulot d'étranglement potentiel dans la chaîne multi-mode proposé, dont l'analyse est présentée. En conséquence, et enfin, nous proposons la conception d'un gain variable analogique modulateur en quadrature qui contourne le goulot d'étranglement, en soulignant la portée pour le développement futur et la validation de ce travail. Ce travail apporte également en avant quelques problèmes au niveau du système et met également en lumière les défis dans le fonctionnement des stations de base multi-standardContemporary telecommunication Base-Stations for GSM/EDGE, WCDMA/HSPA and LTE are increasingly complex and energy intensive. The favoured solution is a truly multi-standard transmitter known as a single Radio Access Network (single-RAN). Modern base station transmitters are often multi-standard, in that they can support different air-interface standards or modes. However, this is achieved not through concurrent operation of the different standards or 'modes', but by means of reconfiguration, which is inefficient and expensive. We envision a practical, fully multi-mode transmitter capable of simultaneously supporting GSM/EDGE, WCDMA/HSPA and LTE carriers. The evolution of 3GPP standards towards multi-mode operation is in the nascent stage. To contribute to this effort, our work revisits the architecture of the traditional macro-cell Base-Station transmitter in order to analyse and define performance requirements for a multi-standard cellular radio platform. Our system analysis and design also identifies a potential bottleneck in the proposed multi-mode chain, for which analysis is presented. Consequently and lastly, we propose the conceptual design of a variable-gain Analog Quadrature Modulator that bypasses the bottleneck, highlighting scope for future development and validation of this work. This work also brings forth some system-level issues and also highlights challenges in the operation of multi-standard Base-Stations. Some of these include multi-mode signal crest-factor reduction, carrier-to-carrier interference mitigation, per-carrier power-control, etc
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Kowlgi, Srinivasan Sandeep. „Etude des émetteurs radiofréquences multistandards destinés aux stations de base GSM/WCDMA/LTE“. Electronic Thesis or Diss., Paris, ENST, 2013. http://www.theses.fr/2013ENST0018.
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Les stations de base de télécommunications contemporaines pour les réseaux GSM / EDGE, WCDMA / HSPA et LTE sont de plus en plus complexes et à forte intensité énergétique. La solution privilégiée est un émetteur véritablement multi-standard. Modernes émetteurs des stations de base sont souvent multi-standard, en ce qu'ils peuvent supporter différentes normes ou de modes air-interface. Cependant, ce n'est pas réalisé par le fonctionnement simultané des normes différentes ou des «modes», mais par des moyens de reconfiguration, qui sont inefficaces et coûteux. Nous envisageons un émetteur entièrement multi-mode pratique capable de supporter simultanément GSM / EDGE, WCDMA / HSPA et LTE transporteurs. L'évolution des normes 3GPP vers un fonctionnement multi-mode est au stade embryonnaire. Pour contribuer à cet effort, notre travail revisite l'architecture traditionnelle de l'émetteur de station de base macro-cellule afin d'analyser et de définir les exigences de performance pour une plate-forme de radio cellulaire multi-standard. Notre analyse et la conception du système identifie également un goulot d'étranglement potentiel dans la chaîne multi-mode proposé, dont l'analyse est présentée. En conséquence, et enfin, nous proposons la conception d'un gain variable analogique modulateur en quadrature qui contourne le goulot d'étranglement, en soulignant la portée pour le développement futur et la validation de ce travail. Ce travail apporte également en avant quelques problèmes au niveau du système et met également en lumière les défis dans le fonctionnement des stations de base multi-standardContemporary telecommunication Base-Stations for GSM/EDGE, WCDMA/HSPA and LTE are increasingly complex and energy intensive. The favoured solution is a truly multi-standard transmitter known as a single Radio Access Network (single-RAN). Modern base station transmitters are often multi-standard, in that they can support different air-interface standards or modes. However, this is achieved not through concurrent operation of the different standards or 'modes', but by means of reconfiguration, which is inefficient and expensive. We envision a practical, fully multi-mode transmitter capable of simultaneously supporting GSM/EDGE, WCDMA/HSPA and LTE carriers. The evolution of 3GPP standards towards multi-mode operation is in the nascent stage. To contribute to this effort, our work revisits the architecture of the traditional macro-cell Base-Station transmitter in order to analyse and define performance requirements for a multi-standard cellular radio platform. Our system analysis and design also identifies a potential bottleneck in the proposed multi-mode chain, for which analysis is presented. Consequently and lastly, we propose the conceptual design of a variable-gain Analog Quadrature Modulator that bypasses the bottleneck, highlighting scope for future development and validation of this work. This work also brings forth some system-level issues and also highlights challenges in the operation of multi-standard Base-Stations. Some of these include multi-mode signal crest-factor reduction, carrier-to-carrier interference mitigation, per-carrier power-control, etc
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Zaraket, Elie. „Réalisation d’une 'méta-peau' récupératrice d’énergie électromagnétique pour des applications WBAN“. Electronic Thesis or Diss., Bordeaux, 2025. http://www.theses.fr/2025BORD0035.
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Les progrès récents dans le domaine des technologies biomédicales et de la santé connectée ont considérablement accéléré le développement de dispositifs flexibles et portables pour une surveillance continue de la santé. Le marché de l'Internet des Objets Médicaux (IoMT) devrait connaître une croissance rapide avec un taux annuel de 38.5% entre 2024 et 2032, largement porté par les Réseaux de Capteurs Corporels Sans Fil (WBAN). Cependant, la conception de dispositifs IoT portables, miniaturisés et biocompatibles, capables de fonctionner de manière autonome, reste un défi majeur, en particulier pour les capteurs physiologiques. Cette thèse propose le développement d’un système portable de récupération d'énergie sous la forme d’un dispositif appliqué sur la peau, destiné à la surveillance de l'état physiologique. L’un des principaux défis de ce travail réside dans l’impact du corps humain sur les performances des antennes, qui sont directement influencées lorsqu’elles sont positionnées sur la peau. Les Conducteurs Magnétiques Artificiels (AMC) apparaissent comme une solution prometteuse en tant que réflecteurs pour des antennes à faible profil fonctionnant dans les bandes GSM et WiFi. Grâce à leurs propriétés de réflexion à phase nulle, les AMCs permettent d’améliorer les performances des antennes tout en éliminant la nécessité d’un plan de masse volumineux de type quart d’onde. Les tests expérimentaux réalisés sur une antenne à double bande équipée d’un AMC ont démontré une distorsion minimale des performances pour les applications WBAN. Enfin, l’intégration d’un convertisseur RF-DC permet à la rectenna de fonctionner comme un collecteur d’énergie portable et autonome, tout en fournissant une tension redressée de 1V à environ -17.5 dBm, ce qui est suffisant pour alimenter certains capteurs physiologiquesRecent advancements in remote healthcare and biomedical technologies are rapidly accelerating the development of flexible, wearable devices for continuous health monitoring. The Internet of Medical Things (IoMT) market is projected to grow at a Compound Annual Growth Rate (CAGR) of 38.5% between 2024 and 2032, with Wireless Body Area Networks (WBAN) serving as a critical driver of this growth. Thus far, the expansion of IoT devices has faced challenges in designing wearable, miniaturized, and biocompatible prototypes with power-autonomous operation for physiological sensors. Therefore, this thesis aims to develop a wearable Energy-Harvesting (EH) system, in the form of a skin-applied device, designed for monitoring physiological conditions. The primary challenge of this research is the impact of the human body on the antenna system's performance when positioned directly on the skin. The body absorbs part of the radiation, which significantly reduces the efficiency of the EH system. In this context, Artificial Magnetic Conductors (AMC)s present a promising solution as reflectors for low-profile antennas, in the GSM and WiFi bands. By leveraging their inherent zero-phase reflection properties, AMCs improve antenna performance while eliminating the need for a bulky quarter-wave backplane. The real-world tests of the dual-band AMC-backed antenna showed minimal performance distortion for WBAN applications. Finally, the integration of a designed RF-to-DC converter enables the rectenna to function as an autonomous wearable energy harvester, providing a rectified voltage of 1V at approximately -17.5 dBm, suitable for powering certain physiological sensors
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Colin, Elizabeth. „Architecture reconfigurable pour la numérisation du signal radio de récepteurs mobiles multistandards“. Paris, ENST, 2003. http://www.theses.fr/2003ENST0040.
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L'explosion de la téléphonie cellulaire et des normes de communications mobiles de couverture réduite (Wide, Local, Personal Area Networks, WAN, LAN et PAN), motivent de nombreuses études avec des approches très différentes. C'est dans ce contexte que s'inscrit ce travail de thèse qui propose une architecture reconfigurable pour la numérisation du signal radio de récepteurs mobiles multistandards. La première phase du travail cherche à déterminer la chaîne la mieux adaptée à la réception de différentes normes. Les récepteurs à conversion directe sont particulièrement adaptés à cette application car ils allient forte intégration et implémentation multi-standard. La deuxième phase propose une architecture reconfigurable GSM/UMTS pour la bande de base analogique. La troisième phase présente une méthode qui permet de définir un cahier de charges à partir des spécifications techniques d'une norme pour les différents blocs de la bande de base analogique. Cette méthode met en évidence les compromis entre les différentes fonctions. La quatrième décrit un convertisseur analogique-numérique GSM/UMTS et enfin, la conception d'un filtre anti-repliement GSM/UMTSThe mobile communications evolution requires receivers architectures ablle to process existing standards facilities, emerging services, and applications related to tne next generations. This Ph. D. Thesis presents a Reconfiguable Architecture for Analog-to-Digital Conversion of Multistandard Mobile RF receiver signals. It proposes the architecture best suited to handle various mobile standards. Homodyne receivers are particularly adapted because they combine strong integration and multistandard implementation. It presents an anlog baseband reconfigurable GSM/UMTS architectureIt shows a method to define specifications for each analog baseband block from the standard technical specifications. This method highlights the trade-off between the performed functions. It describes a GSM/UMTS analog-to-digital converter and finally, the design of a GSM/UMTS antialiasing filter
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Colin, Elizabeth. „Architecture reconfigurable pour la numérisation du signal radio de récepteurs mobiles multi-standards“. Phd thesis, Télécom ParisTech, 2003. http://pastel.archives-ouvertes.fr/pastel-00000856.
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L'explosion de la téléphonie cellulaire et le déferlement de normes de communication mobiles de couverture réduite (Wide, Local, Personal Area Networks, WAN, LAN et PAN), motivent de nombreuses études avec des approches très différentes. C'est dans ce contexte que s'inscrit ce travail de thèse qui propose une architecture reconfigurable pour la numérisation du signal radio de récepteurs mobiles multistandards. De la transition progressive du GSM vers l'UMTS en Europe découle le besoin de terminaux bi-mode GSM/UMTS dans un futur proche. Pour cette raison nous avons appliqué cette étude à ces deux normes. La première phase du travail cherche à déterminer la chaîne la mieux adaptée à la réception de différentes normes. Les récepteurs à conversion directe ou homodynes sont particulièrement adaptés à cette application car ils allient forte intégration et implémentation multi-standard. Mais la flexibilité d'un tel système impose des contraintes sévères pour le traitement analogique en bande de base. En effet, la bande de réception dans son intégralité (60MHz pour l'UMTS) se retrouve en bande de base. La deuxième phase propose une architecture reconfigurable GSM/UMTS pour la bande de base analogique. Une fois l'architecture du récepteur choisie, nous avons défini les fonctions assurées par le traitement du signal en bande de base ainsi que les blocs qui la constituent. Puis nous avons déduit l'architecture qui répond le mieux au cahier des charges fixé, notamment en ce qui concerne la reconfigurabilité. Nous avons privilégié une architecture qui nous permette de réutiliser telle quelle ou de reconfigurer, le maximum de blocs afin qu'ils servent aussi bien pour le GSM que pour l'UMTS. La troisième phase présente une méthode qui permet de définir un cahier de charges à partir des spécifications techniques d'une norme, pour les différents blocs de la bande de base analogique, à savoir amplificateurs à gain variable, filtre anti-repliement et convertisseur analogique-numérique. Ceci sera fait en termes de dynamique et de linéarité pour tous les éléments de la bande de base. Pour les filtres, nous définirons en plus leurs gabarits. Cette méthode met en évidence les compromis entre les fonctions de filtrage anti-repliement, conversion analogique - numérique et amplification à gain variable. La quatrième décrit un convertisseur analogique-numérique GSM/UMTS et enfin, la conception d'un filtre anti-repliement reconfigurable GSM/UMTS. Lors de cette phase du travail notre réflexion s'est portée sur le degré de reconfigurabilité de ce bloc et sur la recherche du meilleur compromis entre flexibilité, performance et surface. Enfin, une conclusion récapitule les principaux résultats obtenus et présente les perspectives.
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Paiva, João Manuel Lima. „Análise da QoS na perspectiva do utilizador dos serviços mais comuns em sistemas celulares GSM e UMTS“. Master's thesis, Universidade de Aveiro, 2007. http://hdl.handle.net/10773/1877.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesO aparecimento da tecnologia GSM mudou significativamente o panorama das telecomunicações. Desde que surgiram as primeiras redes comerciais,em 1991, o número de utilizadores tem aumentado continuamente. Mais recentemente, os sistemas celulares de terceira geração, entre osquais o UMTS, vieram colmatar algumas insuficiências do GSM aopermitirem acessos de alto débito para suporte de serviços de banda larga,tais como, acesso à Internet e aplicações multimédia. Actualmente, face às elevadas taxas de penetração e de utilização dos sistemas GSM e UMTS, a qualidade de serviço na perspectiva do utilizador assume-se como uma das principais vantagens competitivas dosoperadores presentes no mercado.Cada vez mais os consumidores procuram nos serviços simplicidade de utilização e qualidade superior, ininterruptamente e em qualquer lugar. Nesta dissertação são definidos indicadores de qualidade de serviço eperfis de medida que permitem avaliar o desempenho dos serviços de telefonia (voz e videotelefonia), mensagens (SMS e MMS) e dados (HTTPbrowsing, FTP upload/download e E-Mail send/receive) suportados em sistemas de comunicações móveis GSM e UMTS. Para validação dos indicadores de desempenho e perfis de medida,apresentam-se os resultados de uma análise aos serviços de telefonia, mensagens e dados, de dois operadores GSM/UMTS portugueses. ABSTRACT: The advent of GSM has changed significantly the telecommunications landscape. Since the launch of the first commercial network, in 1991,the number of subscribers has increased continuously. More recently, third generation cellular systems, in particular UMTS, went beyond GSM limitations, leveraging high-speed access and broadband services, such as internet and multimedia applications. Nowadays, due to high penetration and usage of GSM and UMTS systems, the quality of service built upon the user’s point of view is one ofcornerstones where operators seek to take competitive advantages. Consumers increasingly search for ease-of-use and superior quality, anytime and anywhere. This dissertation provides quality of service indicators and measurement profiles that allow a performance evaluation, on telephony (voice and video), messaging (SMS and MMS) and data (HTTP browsing, FTPupload/download and E-mail send/receive) services, of the GSM and UMTS mobile communications systems. To validate the performance indicators and the measurement profiles, the results of an analysis on telephony, messaging and data services,of two Portuguese GSM/UMTS operators, are provided.
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Bachhav, Pramod. „Explicit memory inclusion for efficient artificial bandwidth extension“. Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS492.
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La plupart des algorithmes ABE exploitent les informations contextuelles ou la mémoire capturée via l'utilisation de caractéristiques statiques ou dynamiques extraites de trames de parole voisines. L'utilisation de la mémoire entraîne des caractéristiques dimensionnelles plus élevées et une complexité informatique accrue. Lorsque les informations provenant de trames de prévisualisation sont également utilisées, la latence augmente également. Les travaux antérieurs montrent l'avantage pour ABE d'exploiter la mémoire sous la forme d'entités dynamiques avec un modèle de régression standard. Même dans ce cas, la littérature manque d'une analyse quantitative de l'avantage relatif de l'inclusion de mémoire explicite. La recherche présentée dans cette thèse évalue dans quelle mesure la mémoire explicite est utile et rapporte en outre un certain nombre de techniques différentes qui permettent son inclusion sans augmentation significative de la latence et de la complexité de calcul. Les avantages sont démontrés à la fois par une analyse quantitative avec une mesure basée sur la théorie de l'information et par des tests d'écoute subjectifs. Les principales contributions concernent la préservation de l'efficacité des calculs grâce à l'utilisation de la réduction de dimensionnalité sous la forme d'une analyse en composantes principales, d'auto-encodeurs superposés semi-supervisés et d'auto-encodeurs variationnels conditionnels. Les deux dernières techniques optimisent la réduction de la dimensionnalité pour offrir une performance ABE supérieureMost ABE algorithms exploit contextual information or memory captured via the use of static or dynamic features extracted from neighbouring speech frames. The use of memory leads to higher dimensional features and increased computational complexity. When information from look-ahead frames is also utilised, then latency also increases. Past work points toward the benefit to ABE of exploiting memory in the form of dynamic features with a standard regression model. Even so, the literature is missing a quantitative analysis of the relative benefit of explicit memory inclusion. The research presented in this thesis assesses the degree to which explicit memory is of benefit and furthermore reports a number of different techniques that allow for its inclusion without significant increases to latency and computational complexity. Benefits are shown through both a quantitative analysis with an information-theoretic measure and subjective listening tests. Key contributions relate to the preservation of computational efficiency through the use of dimensionality reduction in the form of principal component analysis, semisupervised stacked autoencoders and conditional variational auto-encoders. The two latter techniques optimise dimensionality reduction to deliver superior ABE performance
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Park, Yunseo. „Direct Conversion RF Front-End Implementation for Ultra-Wideband (UWB) and GSM/WCDMA Dual-Band Applications in Silicon-Based Technologies“. Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7563.
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This dissertation focuses on wideband circuit design and implementation issues up to 10GHz based on the direct conversion architecture in the CMOS and SiGe BiCMOS technologies. The dissertation consists of two parts: One, implementation of a RF front-end receiver for an ultra-wideband system and, two, implementation of a local oscillation (LO) signal for a GSM/WCDMA multiband application. For emerging ultra-wideband (UWB) applications, the key active components in the RF front-end receiver were designed and implemented in 0.18um SiGe BiCMOS process. The design of LNA, which is the critical circuit block for both systems, was analyzed in terms of noise, linearity and group delay variation over an extemely wide bandwidth. Measurements are demonstrated for an energy-thrifty UWB receiver based on an MB-OFDM system covering the full FCC-allowed UWB frequency range.
For multiband applications such as a GSM/WCDMA dual-band application, the design of wideband VCO and various frequency generation blocks are investigated as alternatives for implementation of direct conversion architecture. In order to reduce DC-offset and LO pulling phenomena that degrade performance in a typical direct conversion scheme, an innovative fractional LO signal generator was implemented in a standard CMOS process. A simple analysis is provided for the loop dynamics and operating range of the design as well as for the measured results of the factional LO signal generator.
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Otárola, Correa Diego Antonio, und Gonzales Frank Campos. „Modernización de la red de acceso de un operador móvil para el caso de Lima Metropolitana“. Bachelor's thesis, Universidad Ricardo Palma, 2015. http://cybertesis.urp.edu.pe/handle/urp/1277.
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La presente tesina titulada “Modernización de la red de acceso de un operador móvil para el caso de Lima Metropolitana” expone una propuesta para un operador que tiene como objetivo poder incrementar su cobertura de servicio de segunda y cuarta generación, para esto se definen conceptos teóricos en base a lo que son las tecnologías de telefonía móvil celular de tipo GSM, UMTS y LTE y se compararan con las características técnicas de los equipos que se plantean usar demostrándose que estos pueden optimizar la red de acceso del operador en cobertura y funcionamiento para brindar un mejor servicio en base a 2G y 4G. Para lograr el objetivo propuesto, esta tesina describe el diseño y dimensionamiento de proyecto, pasos para su ejecución, especificaciones técnicas de los equipos, procedimiento para la puesta en servicio y resultados en base a pruebas del servicio y KPI.
The current thesis entitled “Modernización de la red de acceso de un operador móvil para el caso de Lima Metropolitana” exposes a proposal for a mobile operator that has as a target increase their second and fourth generator coverage. For achieve this we have to defined theoric concepts based on the mobile telecommunication technology GSM, UMTS and LTE and compare with the features of equipment proposed to use proving that the coverage and performance of the access network of the operator can be improved for provide a better 2G and 4G service. For achieve this target proposed, this thesis describes the design and sizing of Project, steps for execution, technical features of equipment, on air procedure and results base on the testing service and KPI.
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Ahmed, Mamun. „Adaptive Sub band GSC Beam forming using Linear Microphone-Array for Noise Reduction/Speech Enhancement“. Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-6174.
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This project presents the description, design and the implementation of a 4-channel microphone array that is an adaptive sub-band generalized side lobe canceller (GSC) beam former uses for video conferencing, hands-free telephony etc, in a noisy environment for speech enhancement as well as noise suppression. The side lobe canceller evaluated with both Least Mean Square (LMS) and Normalized Least Mean Square (NLMS) adaptation. A testing structure is presented; which involves a linear 4-microphone array connected to collect the data. Tests were done using one target signal source and one noise source. In each microphone’s, data were collected via fractional time delay filtering then it is divided into sub-bands and applied GSC to each of the subsequent sub-bands. The overall Signal to Noise Ratio (SNR) improvement is determined from the main signal and noise input and output powers, with signal-only and noise-only as the input to the GSC. The NLMS algorithm significantly improves the speech quality with noise suppression levels up to 13 dB while LMS algorithm is giving up to 10 dB. All of the processing for this thesis is implemented on a computer using MATLAB and validated by considering different SNR measure under various types of blocking matrix, different step sizes, different noise locations and variable SNR with noise.Mamun Ahmed E-mail: mamuncse99cuet@yahoo.com
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Queiroz, Eduardo Martinelli Galvão de. „Algoritmo de alocação dinâmica de largura de faixa para redes de comunicação móvel celular“. Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18155/tde-20062008-100444/.
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O crescente aumento da demanda de tráfego nas redes celulares vem aumentando a necessidade de uma melhor utilização dos recursos do sistema, já que sua expansão é custosa. Nas estações rádio base (ERB), a disponibilidade de largura de faixa de freqüências é limitada e desta maneira, em uma rede de comunicação móvel celular, o controle de admissão de chamadas exerce grande influência no desempenho do sistema, pois determina a utilização de banda das ERBs e se uma determinada quantidade de recursos (banda) será alocado ou não para uma determinada chamada. O desempenho da rede pode ser atrelado a determinados parâmetros, como a probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de chamadas handoff e a utilização de banda da rede. Este trabalho propõe um controle de admissão de chamadas que, no atendimento de uma chamada, faz o empréstimo de banda de chamadas em andamento na célula no caso de banda insuficiente. O sistema adota um mecanismo heurístico que determina a banda disponível para novas chamadas conforme os valores de certos parâmetros do sistema. O empréstimo de banda é realizado em chamadas em andamento nas células até níveis mínimos estabelecidos para cada tipo de chamada, que se diferenciam pelas necessidades de banda de cada uma. O algoritmo foi aplicado às bandas e características de uma rede de terceira geração (3G), que possui chamadas de voz, videoconferência, interação multimídia, e-mail, downloads e transferência de arquivos e a uma rede GSM/GPRS (global system for mobile communications/ general packet radio service), que possui chamadas de voz e de dados. Os resultados mostram melhorias na probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de handoff e na utilização de banda do sistema.The recent growth in traffic loads in cellular networks has seen the need for a better use of system resources as its expansion is expensive. In the base transceiver station (BTS), the bandwidth availability is limited. Thus, in cellular networks the call admission control greatly influences the system performance because it determines the bandwidth use of the BTSs and if an amount of resources will or will not be allocated to a call. The network performance can be evaluated by parameters such as blocking probability of new calls, dropping probability of handoff calls and bandwidth use. This work proposes a call admission control that carries out the bandwidth borrowing when a call arrives and there is not enough bandwidth. The system makes use of a heuristic mechanism that determines the available bandwidth for the new calls according to some parameter values of the system. The bandwidth borrowing is applied to the cell ongoing calls until the minimum levels for each type are met. The algorithm was applied to the bandwidths and characteristics of a third generation cellular network, which supports voice calls, videoconference, multimedia interaction, e-mails, downloads and file transfers. It was also applied to a GSM/GPRS (global system for mobile communications/ general packet radio service), which supports voice and data calls. The results show improvements in the blocking probability of new calls, dropping probability of handoff calls and in the bandwidth use of the system.
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NOBRE, ISABELA CUNHA MAIA. „ON THE PROTECTION OF FIXED SERVICE RECEIVERS FROM THE INTERFERENCE GENERATED BY NON-GSO SATELLITE SYSTEMS OPERATING IN THE 3.7-4.2 GHZ BAND“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=32037@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Neste trabalho, os limites atuais de densidade de fluxo de potência do Artigo 21 do Regulamento de Radiocomunicações da UIT para sistemas não-GEO operando na banda 3.7-4.2 GHz são analizados. Estes limtes visam proteger os receptores do Serviço Fixo Terrestre, operando na mesma faixa de frequência, das interferências produzidas por sistemas de satélites não geoestacionários. A análise foi motivada pela Resolução 157 [1] da Conferência Mundial de Radiocomunicações de 2015, que reconheceu a necessidade de uma revisão do Artigo 21 para que sistemas não-GEO possam operar nestas faixas de frequências assegurando, ao mesmo tempo, que os serviços primários existentes continuem protegidos. Na análise, cinco estruturas de constelações de satélites não-GEO do tipo Walker Delta, adequadamente escolhidas, foram consideradas. Resultados mostraram que os atuais limtes de pfd podem impor restrições indevidas aos sistemas não-GEO operando nesta faixa. Assim, uma metodologia para investigar uma máscara limitante de pfd mais adequada é apresentada. A aplicação desta metodologia leva a uma máscara alternativa que se aproxima dos limites atuais de pfd para satélites geoestacionários quando o número de satélites no sistema interferente não-GEO é igual a um. Uma avaliação da máscara de pfd proposta mostra que ela não impõe restrições desnecessárias aos sistemas de satélites não-GEO. Isto, junto a outros fatos, indica que os limites de pfd propostos são, de fato, muito mais adequados do que os atuais.
In this work, the current power-flux density limits in Article 21 of the ITU-R Radio Regulations for non-GSO systems operating in the 3.7-4.2 GHz band are analyzed. These limits aim the protection of Fixed Service receivers, operating in the same frequency band, from the interference produced by non-GSO satellite systems. The analysis was motivated by Resolution 157 [1] of the World Radiocommunication Conference 2015, that recognized the need for a revision of Article 21 with a view to enabling non-GSO systems to operate in these FSS frequency bands while ensuring that existing primary services are protected. In the analysis, five different Walker Delta type satellite constellation structures, adequately chosen, were considered. Results have shown that the current pfd limits may impose undue constraints to non-GSO systems operating in this band. Therefore, a methodology to investigate a more adequate pfd limiting mask is presented. The application of this methodology leads to an alternative mask that approaches the current pfd limits for the geostationary satellites when the number of satellites in the non-GSO interfering system is equal to one. An evaluation of the proposed pfd mask shows that it does not impose unnecessary constraints to the non-GSO satellite systems. This, along with other facts, indicates that the proposed pfd limits are, indeed, much more adequate than the current ones.
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Vehovský, Radek. „Vliv uživatele na miniaturní antény v mobilních aplikacích“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219972.
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This master’s thesis deals with user influence on miniature antennas in mobile application. Electrically small antennas including fundamental performance properties and limitations are introduced in the theoretical section of this thesis. This section also deals with microstrip antennas and their common types. The accent is on PIFA antennas, their typical constructions and methods of miniaturization. In the practical section, dual-band PIFA antenna for operation at frequencies of systems GSM900 and GSM1800 is designed with the assistance of electromagnetic field simulator CST Microwave Studio. On this type of antenna, the user influence on impedance matching and radiation pattern in data mode (the user is typing message or browsing with the phone) is investigated. For this purpose the hand phantom, corresponding to author’s right hand, was made from agar based material. For typical position of human hand is designed matching network, which eliminate the user influence and ensure correct function of antenna.
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Barros, Fabien de. „Conception, Réalisation et Caractérisation de papiers fonctionnels pour des applications de filtrage électromagnétique“. Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT118/document.
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Le brouillard électromagnétique dans lequel nous vivons en permanence estaujourd’hui montré du doigt car, outre les risques sanitaires qu’il pourrait engendrer, illimite l’usage de certaines technologies. L’importance des interférences entre réseauxsans fil, ou la peur du piratage sur ces mêmes réseaux, en sont deux exemples. Cetravail de thèse vise à développer un nouveau moyen de protection contre certaines deces ondes électromagnétiques. Plus spécifiquement, ce travail se focalise sur unetechnologie capable de filtrer uniquement les ondes WiFi et GSM à travers de grandessurfaces d’une habitation, comme un mur. Pour ce faire, la fonctionnalisation d’uncomposant standard des bâtiments, le papier-peint, a été étudié.L’utilisation de surfaces sélectives en fréquence a été retenue. Ces motifs sontdirectement imprimés sur du papier à l’aide d’encre conductrice et de la techniqued’impression flexographique. L’étude s’est également portée sur la réalisation de motifsde filtrage innovants. Les résultats de simulation montrent qu’ils sont capables de filtrerdeux ou trois bandes, qu’ils sont quasiment insensibles à la polarisation et à l’angled’incidence dans une plage allant de 0° à ± 80°. Le travail a ensuite permis dedémontrer la faisabilité pratique de ce concept aux stades laboratoire et industriel.Ensuite, nous avons démontré expérimentalement l’efficacité de ce concept dans lesbandes WiFi. La transmission atteint alors -30 dB. Enfin, une validation expérimentaledu produit en situation réelle a été menée, à savoir la pose du papier-peint sur du plâtre,du bois, l’influence de la colle ou encore la pose d’une couche de papier-peint décoratifpar-dessus le produit.En conclusion, les résultats pratiques obtenus confirment les résultats théoriquesestimés et, permettent à ce nouveau concept, appelé métapapier, d’être suffisammentefficace pour permettre la réduction des ondes WiFi ou GSMThe electromagnetic smog in which we live today is nowadays a real issue because it limits the use of certain technologies and also because there are some potential health risks associated with it, even if the latter is still a controversial subject. The importance of the interferences between wireless networks or the possibility of data hacking on the same networks are two examples. The aim of this thesis is to develop a new way to protect buildings against some of these electromagnetic waves. More specifically, this work focuses on a technology able to filter only the WiFi and the GSM waves through large areas of a home, like a wall for example. To do this, the functionalization of a standard component of buildings, the wallpaper, was studied. The use of frequency selective surface (FSS) was chosen. These patterns are printed directly on paper with a conductive ink printing technology: the flexography. The study also focuses on the realization of innovative filter designs. Simulation results show that these novel FSS are able to filter two or three bands. They are almost insensitive to the polarization and to the angle of incidence in the range of 0° to ±80°. The realization feasibility of this concept in a laboratory or in industrial conditions was demonstrated. Next, an experimental demonstration of this concept in the WiFi bands was carried out. In this context, the transmission coefficient was reached -30 dB. Finally, an experimental validation of the product in real conditions of use was conducted, namely the wallpaper was put over plasterboards or over wood panels. Also, the influence of the glue on the general performances and the placement of a decorative wallpaper over the FSS wallpaper were studied. In conclusion, the practical results obtained confirm and validate the theoretical predictions of this new concept, called metapaper, and show that the practical realizations are efficient enough to allow the reduction of WiFi or GSM signals
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Chuang, Yu-Chou, und 莊彧宙. „ANTENNA COVERING GSM/WLANAND GPS BANDS“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/74557488103834876560.
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碩士大同大學
通訊工程研究所
97
In this thesis, design and implementation of a U-shaped strip-slot antenna covering GSM/WLAN/Bluetooth and GPS bands are proposed. The total antenna size is 100 x 40 mm. It is modified from a symmetrical self-complementary strip-slot structure. However, one leg of the U-shaped slot is extended to the rim of the printed circuit board. It is investigated that this extension makes the antenna also be well-matched at GPS band. Without this extension, the antenna cannot work at this band.
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Wu, Chia-Hao, und 吳家豪. „Antenna Design for RFID and GSM Band Applications“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/45305542420256754815.
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碩士國立臺灣海洋大學
電機工程學系
96
In this thesis we have proposed a design which can be used as RFID reader system. The design is based on the integration of a network feed line onto a planar antenna. The network was constructed of passive components and when combining with the planer antenna demonstrated improved operational characteristics (CP axial ratio bandwidth of the circularly polarized antenna and cross-polarization) of the planar antenna. By constructing slots on a planar antenna and combining with the 90 degree phase shift character of a Wilkinson power divider, a circularly polarized wide bandwidth antenna in the frequency range of 800-900 MHz has been constructed. Through the use of a Wilkinson power divider in the design, the 3 dB axial ratio bandwidth showed improvement over that of a single feed circularly polarized antenna and at the same time, the new design is more compact. We have also proposed, by exploiting the high gain and directional character of Yagi antenna, a Yagi-type antenna on a PCB board fed by a coplanar waveguide. The design can be used as communication antenna for the combined omni-directional 900 MHz GSM and 2.4 GHz RFID with end-fire pattern system. Since the operated frequency is at 900 MHz, the antenna structure is implemented by feeding a coplanar waveguide into a meander line. The 2.4 GHz band is generated by frequency multiplication of the 900 MHz band. The radiation pattern of the Yagi-type antenna depends on the separation, length, and the quantity of the radiating elements. The gain of GSM band is about 0~1 dBi and the gain of RFID band is about 2~3 dBi.
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Kuan, Tseng Jung, und 曾榮冠. „A Direct Conversion Transceiver for Dual-Band GSM Design“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/41233697877695774887.
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碩士淡江大學
電機工程學系碩士在職專班
92
In this thesis, dual band (900/1800MHz) GSM radio module is implemented for complying with ETSI standard. The radio module employs direct conversion structure in receiver and offset phase lock loop (PLL) in transmitter, which consists of the zero-IF transceiver AD6523, multi-band synthesizer AD6524, low noise amplifier (LNA), voltage control oscillator (VCO), power amplifier (PA), transmit-receive switch, power control, balun, and regulator. The design start with link budget calculation to define circuit complied with ETSI specifications. When transmitting signal, the baseband signal is modulated to 0.3GMSK (Gaussian minimum shift keying), and through radio frequency circuit up-convert frequency to 900/1800MHz specified carrier channel. When receiving signal, RF frequency direct converter to I/Q signal. The thesis emphasizes that system of integration and measurement. For this reason, make sure RF module could conform to ETSI specifications in design circuit.
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Lin, Xin-Liang, und 林信良. „The Design and Evaluation of High Performance RFIC in GSM Band“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/58370183028176688412.
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碩士國立高雄第一科技大學
電腦與通訊工程所
92
In transceiver, the RF front end is the most remarkable part in system, which decides channel utilization, distance of transmission, communication quality and receiver’s sensitivity. Therefore, the high performance of RF module will affect total solutions. In this thesis, two RF integrated circuits (RFIC) have been designed using a 0.5-mµCMOS technology and 0.35-BiCMOS technology, and simulated by ADS (Advance Design System). The compact RFIC is composed of LNA, Mixer [1]-[2]and input/output matching impedance based on the optimum design for the model inductance. We also have first derived the model inductance, and then optimized design of the LNA, Mixer and matching circuits by the CMOS process technology. The results have been shown a low noise with a forward gain of 17dB for a RFIC in 2.4GHz and wideband in ±100MHz. Moreover, the results also have been showed a low noise with a forward gain of 12dB for a RFIC in 1.5GHz and wideband in ±300MHz. Simulating and Modeling applications are good strategies in the processes technologies of the BiCMOS devices, which it will be developed. And then we have the optimum conditions for the device structures and the processes technology will be obtained. Device characteristics of the BiCMOS are used, such as the noise figure, channel interference, output power, and power efficiency characteristics will be studied. The relationship of the device characteristics to the requirements of the advanced wireless communication systems will also be correlated. A high performance of the compact RFIC for our design can be measured and simulated by the QPSK and USB mode compatible transceiver platform. In future, we propose to develop the new GaAs-based high-frequency devices and use the modeling inductance technologies for the advanced wireless communication applications.
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Lee, Wen-yi, und 李文毅. „Design and Implementation Dual-band Coupler for GSM/ISM Amplifier Application“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/08326549097765662801.
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碩士逢甲大學
資訊電機工程碩士在職專班
96
This thesis presents two kinds of miniature technology to reduce the size of traditional type dual-band branch-line coupler and to match one or more amplifier with its coupler characteristic to complete the dual band balance amplifier design and implementation for GSM/ISM application. Firstly SIR structure will reduce the area of traditional type dual-band branch line form 100% to 49%.Secondly T-shape and SIR structures the area of traditional type dual-band branch line will reduce to 28%. Especially , T-shape and SIR structure not only have the effect of compact-size but also be able to satisfied system specifications ,which band-width can reached 100MHz(∠S21 -∠S31 within 90°±1°). The frequency of these two compact-size branch-line couplers are designed at 0.9GHz & 2.4 GHz and fabricated on a FR-4 copper clad laminate ( ; =0.022 ; thickness=0.8mm ; metal thickness=0.02mm). Finally, the measurements result area reduction, single planar and one time implementation. Additionally, without lumped component, bonding- wires and via-holes the waste of manufacture will be reduce. In the end , a balance amplifier by using the miniaturized coupler to reach the dual band property, and research in the miniaturized circuit and balance amplifier applications.
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Wu, Jing-yi, und 吳進義. „Design of Planar Dual-band Hand-held Antennas For GSM Systems“. Thesis, 1998. http://ndltd.ncl.edu.tw/handle/89416152234150724394.
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碩士國立臺灣大學
電機工程學系研究所
86
As far as modern personal communication is concerned, a nifty, lightweight an d multi-functioned mobile phone is always competitive. In this work, we propos ed and carefully examined a miniaturized dual band planar antenna which is des igned to be operated at both 900 and 1800 MHz for mobile phones. For the desig n purpose, a simple and easily understood design procedure is also proposed in contrast to those of the reported inverted-F antennas. Specifically, a dual b and planar antenna that meets the specifications of GSM standard is purposed. In practice, this antenna shall be further improved to be used in the versatil e wireless communication environment.
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Chen, Bin-yi, und 陳秉毅. „Study of Power Amplifier Module for GSM/DCS Quad-Band Cell Phone“. Thesis, 2013. http://ndltd.ncl.edu.tw/handle/71594846951855070711.
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碩士義守大學
電機工程學系
101
In this thesis a compact and cost effective power amplifier (PA) module for GSM/DCS Quad-Band cell phone was designed and fabricated. This module combines three various chips. One works as a quad-band PA for GSM/DCS system and was fabricated on GaAs HBT substrate. Another one is a SP7T switch which is used to separate the paths of signals such as transmission and receiving signals for GSM and DCS, respectively. The SP7T switch was fabricated on GaAs pHEMT substrate. The third chip is mixed logic controller IC which is fabricated with CMOS process. The controller circuit provides the required signal to control the SP7T switch and also gives the base D.C.bias voltage to power amplifier so that the PA output power can be regulated. The design principle and architecture of each chips, simulation and measurement techniques were discussed in detail. The measurement results show a good consistence with simulation and the performance of the PA module nearly meet the specification of a commercial product.
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Chang, Chia-wei, und 張家瑋. „Design of GSM Dual-Band Pass Microstrip Filters Using Open-Loop Resonators“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/70187977262428358090.
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碩士國立成功大學
電機工程學系碩博士班
97
To produce a dual-band pass microstrip filter, a circuit designer must understand determine the location that suppression oscillation frequencies of resonators and takes place and the coupling structure of resonators, and next have to overcomesolve the match problem of dual bands in the input and output ends. In order to solve the match problem, an effective design method using a quarter-wavelength impedance converter and a correlation formula of external quality factor is proposed in this study. The uniform impedance square resonator is used to design the double-frequency dual-band filter. The study showed that the even-mode impedance can be changed freely. Finally, a folding method was used to change the structure of the resonator. Analysis of the coupling coefficients was performed. The results showed that the behavior of the stop band of the circuit could be improved by adding extra transmission zero point. The proposed structure could effectively reduce the area of the circuit and promote the performance of the circuit. To realize the folding dual-band filters, the FR4 boards and the Al2O3 boards were used. The experiments showed that both the integer and non-integer second harmonics could be excited successfully and the effective area was reduced by 45%.
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Hsia, Tung-Liang, und 夏同良. „Multi-Band Antenna Design for Mobile Phone on LTE/GSM/WLAN Operations“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/48035405970736956256.
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碩士國立高雄大學
電機工程學系碩士班
103
This study direction focuses on multi-band antenna used for mobile phone. The main structure of the antenna is planar monopole antenna with parasitic elements。 Proposed design antenna is operating at LTE 700/900/1800/2300/2500 (698~787 , 900 ,1800 , 2300 ~ 2400, 2500 ~ 2690 MHz), GSM 850/900 (824 ~ 960 MHz), DCS 1800 (17100 ~ 1880 MHz), PCS 1900 (1850 ~ 1990 MHz), UMTS 2100 (1920 ~ 2170 MHz), WLAN 2400 (2400 ~ 2480MHz) and Bluetooth (2400~2483.5MHz)。 The planar monopole antenna coupled with parasitic elements excites two fundamental modes. By adjusting the parameters of the planar monopole and the ground plane, the antenna can operate multi-band frequency .This antenna can be used for LTE/WLAN/GSM applications. The overall dimension of antenna is within 50×120×0.8 mm3 area, with antenna area of 37×19 mm2 and planar structure。
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He, Cheng-Wei, und 何丞偉. „A DUAL-BAND CMOS RF FRONT-END DESIGN FOR GSM AND WCDMA APPLICATIONS“. Thesis, 2002. http://ndltd.ncl.edu.tw/handle/18140730991076278060.
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碩士大同大學
電機工程研究所
90
This thesis presents a highly integrated dual-band RF front-end for GSM 900 MHz and WCDMA 2 GHz systems. The front-end is designed to be used in a direct-conversion architecture with 0.25 um CMOS processes. The direct-conversion receiver includes two single-ended low noise amplifiers (LNA), a single-ended-to-differential converter, and quadrature mixers. The front-end can use the same devices in the signal path except the LNA input transistors. The LNA in GSM mode has gain 25 dB, NF (Noise Figure) 2.8 dB, input third order intercept point(IIP3) -14 dBm, and 47.8 mW power consumption. The LNA in WCDMA mode has gain 23.5 dB, NF (Noise Figure) 2.5 dB, IIP3 -14 dBm, and 58 mW power consumption. The mixer designed as doubled-balanced one with NF 10 dB, conversion gain 9 dB, IIP3 -10 dBm, and 5 mW power consumption. The schematics of the front-end are all simulated by Agilent EDA (Electronic Design Automatic)-ADS (Advanced Design System) with TSMC 0.25 um RF CMOS 2.5V technology.
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Hwang, Hwong-Wen, und 黃鴻文. „Design and Performance Evaluation for Phase Locked Loops with Multi-channel in GSM band“. Thesis, 2003. http://ndltd.ncl.edu.tw/handle/64477962770776605571.
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碩士國立高雄第一科技大學
電腦與通訊工程所
91
This thesis conducts a high performance of Phase Locked Loops (PLLs) in GSM band. It is assumed that the modulated technology to send data with high frequency but it can not transmit as long distance in wireless environment and the demodulation technology in receiver, is restored original data from RF front-end to baseband. From the wireless system, the channel band limited, we should be to solve the band limited by the multiplex technology only. In the wireless communication, we must have a high stable local oscillator as show in conventional super heterodyne to restore the original data. In this thesis, we have been studied and implemented the high performance Phase Locked Loops, which will be to replace the local oscillator in wireless communication system. For the results, we first have a program control with single chip as 8051 to control the channel band, and then to get the short locked time and the low phase noise for our optimum design. For short locked time, we assume that the system is no noise interference to calculate as following mathematical model and simulate by matlab. In addition, we get the transient response by the unit step input for first order and second order loop filter as frequency response. Then, it is easy to solve the discussion results: (1)Can find the phase locked still as PLLs work normally. (2)Can find the optimum parameter for PLLs as short locked time. For the low noise, we can assume that the system is a linear to analyze the equivalent block diagram and to get the total response for PLLs. In our study, we realize the multi-channel for PLLs with IC SP8853 and meet the specification of GSM. We have the results by simulation with the wireless platform and results show an excellent performance. In particular, we get an optimum design flow to t fast realization for low cost and non-complexity.
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LIN, CHUN-CHENG, und 林春成. „Planar Wide-Band Unsymmetry Semicircle Antenna for GSM 1800/UMTS 2100 4G LTE Applications“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/69597512194118515783.
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27
Chang, Yu-Fang, und 張毓芳. „Design and Implementation of Miniaturized Dual-band Branch Line Coupler for WiMAX and GSM Application“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/31418558367174449649.
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碩士逢甲大學
通訊工程所
97
In this thesis, the miniaturized branch-line coupler with dual-band for WiMAX and GSM application will be designed and implemented. It must have the characteristics of compact size and dual-band. In order to accord with the characteristics of dual-band, wide-band and small size, we propose several kinds of reducing size method in this research, and will apply it to the dual-band coupler. Furthermore, without any implementation of lumped elements, bonding wires, and via holes is proposed. The requirement of bandwidth is a big problem. We add capacitance to increase the bandwidth. In addition, use of coupling between line and line to make the phase become more and more flat. Above circuits have good agreement between simulation and measurement results. We will realize above couplers with PCB technology. Because of the consideration of exact phase different, high stability in the substrate and low cost, RO4003 is the best choice. It is suitable for couplers designing.
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You, Jia-Hui, und 尤嘉暉. „GSM(1.8GHz)/WLAN(2.4GHz) Dual-Band Low-Voltage LNA Design With A Switchable Inductive Load“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/14945426177111785503.
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碩士國立成功大學
電機工程學系碩博士班
96
Recently years, in the century of speedy development wireless communication, this tendency that the mobile phone have communication and network is more and more important. Developing SOP (System on Package) and SOC (System on chip) is the mainstream. However, the receiver that having GSM and WLAN standards has been height concerned. For this receiver, if using a direct conversion structure, we need the low noise amplifier that operates in different frequency, amplify the signal of GSM and WLAN form antenna respectively. The direct way is to integrate two LNA’s for GSM and WLAN respectively. However, the chip area consumption will be increased and thus the cost increases. For the cost down reason, it becomes important to develop a re-configurable LNA circuit that can provide the frequency either in the GSM (1.8GHz) band or in the WLAN (2.4GHz) band. Moreover, by using fold-cascode structure achieve advantages of low voltage and low power. In this thesis, we try to develop the LNA1 and the LNA2 that can achieve GSM and WLAN standard at the same time. By way of switching the inductor, the operation of frequency can either in GSM band or in WLAN. In this research is fabricated in TSMC 0.18μm 1P6M CMOS process. In LNA1 structure, the average forward S21 are 13.347 dB (GSM) and 11.324 dB (WLAN), the reverse isolation S12 is under –40 dB, the S11 are –13 dB(GSM) and –20 dB (WLAN), the noise figure are 2.9 dB(GSM) and 3.4dB (WLAN), IIP3 are –6 dBm (GSM) and –1 dBm (WLAN) and the circuit power consumption is only 8.23mW. The LNA2 is designed for not to effect operation frequency of LNA1 after designing input matching of Mixer, thus added buffer designing in LNA1. In LNA2 structure, the average forward S21 are 10.893 dB (GSM) and 10.673 dB(WLAN), the reverse isolation S12 is under –60 dB, the S11 are –13 dB(GSM) and –17 dB (WLAN), the noise figure are 3.0 dB (GSM) and 3.2dB (WLAN), IIP3 are –7.2 dBm (GSM) and –5.2 dBm (WLAN) and the circuit power consumption is only 16mW. The goals of LNA1 are as followed: The first, how to do fold-cascode can operation in low voltage and in low power, moreover, let it achieve low noise at the same time. The second, how to use switch inductor change the operation frequency of LNA. The main research of LNA2 is the relation about the inter-matching of the linearity effect.
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Chen, Po-Heng, und 陳柏亨. „A Multi-band Frequency Synthesizer for GSM/DCS/WIMAX/WLAN Applications with Ripple-free Circuit“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/83308204906103044718.
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碩士國立交通大學
電子研究所
98
A fully integrated multi-band frequency synthesizer implemented in CMOS 0.18μm process with the ripple-free circuit in a single loop is presented in this thesis. The synthesizer is designed for GSM/DCS/WIMAX/WLAN (802.11a/b/g) systems applying to IQ phase based transceivers. The proposed synthesizer with ripple-free circuit can reduce the amplitude of control voltage ripple to 3.45 μ V in locking time of 13.5μs. The synthesizer performs the suppression of 31.4dB in the power spectrum of reference-spur and the peak-to-peak jitter with 74% improvement compared to conventional single loop synthesizer designs. The measurement result of the QVCO in the frequency synthesizer has the phase noise performance of -123.38dBc/Hz at offset frequency 1MHz, and the FOM is -179dBc/Hz.
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Chang, Chi-Yu, und 張啟宇. „Design of A Triple-band Antenna Switch Module for GSM Handset Application with LTCC Technology“. Thesis, 2005. http://ndltd.ncl.edu.tw/handle/08428208020882196101.
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碩士國立交通大學
電機資訊學院碩士在職專班
93
A procedure is design of an antenna switch module (ASM) with LTCC technology has been applied in GSM handset. By means of the design, the handset contributed not only to reduce the number of components, costs, and product’s weight, but also simplify the system assembly. A more detail research of antenna switch module (ASM) has been described the system is consists of diplexer, RF switches, and low pass filters. In the system, a simple’s diplexer design method has been applied, the effect factors of the transmitter loop insertion loss in both the SPDT and SP3T RF switches had been described, while elliptic-type filter to be chosen is by a simpler circuit’s structure. Utilized the electromagnetic simulation software to got the accurate simulation results, and by means of it to construct a validation system to got the system characteristics. The module is develops for EGSM/DCS/PCS triple band handset and achieved as maximum insertion loss of 1.65 dB in the transmitter loop for both EGSM and DCS/PCS transmitter band. As to the receiver loop, a maximum insertion loss of 1.5 dB had achieved for all the EGSM, DCS, and PCS receiver band. At least 30 dB high attenuation characteristics at harmonic in the transmitter loop were also obtained. An at least 20 dB isolation is achieved in both the transmitter or receiver mode.
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See, Chan H., Raed A. Abd-Alhameed, Achimugu A. Atojoko, Neil J. McEwan und Peter S. Excell. „Link Budget Maximization for a Mobile-Band Subsurface Wireless Sensor in Challenging Water Utility Environments“. 2017. http://hdl.handle.net/10454/12141.
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yesA subsurface chamber transceiver system and associated propagation channel link budget considerations for an underground wireless sensor system (UWSS) are presented: the application was a sewerage system for a water utility company. The UWSS operates over the GSM850/900, GSM1800/1900 and UMTS bands in order to operate with the standard public mobile phone system. A novel antenna was developed to minimize path loss from the underground location: a folded loop type, which is small enough to fit conveniently inside a utility manhole access chamber while giving adequate signal strength to link to mobile base stations from such a challenging environment. The electromagnetic performance was simulated and measured in both free space and in a real manhole chamber. An experimental test bed was created to determine the return loss and received signal strength with different transceiver positions below the manhole chamber access cover. Both numerical and experimental results suggested an optimum position of the unit inside the manhole, combining easy access for maintenance with viable received signal strength. This confirmed that the characteristics were adequate for incorporation in a transceiver designed to communicate with mobile base stations from underground. A field trial confirmed the successful operation of the system under severe conditions.
This work was supported partially by Yorkshire Innovation Fund, IETG Ltd. Contract, Research Development Project (RDP) and the European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424.
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Pretorius, Johann Christiaan. „Composite plaster cement-based electromagnetic wave absorber“. Diss., 2013. http://hdl.handle.net/2263/33352.
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The electromagnetic wave absorption characteristics of composite cement-based building
material have attracted much interest in recent times. Researchers have mainly focused on
the 2 GHz to 12 GHz frequency range. Mobile and wireless communication systems use
frequencies from 800 MHz upwards. The determination of characteristics such as reflection
loss, absorption, attenuation and shielding effectiveness are crucial in the evaluation
and development of these materials for the building industry. Absorption is an indication of
how much of the EMW energy enters the material. Attenuation indicates how much of the
absorbed energy is converted into other forms of energy by the material. Shielding effectiveness
(SE) is a combination of reflection loss, attenuation and multiple internal reflections
and attenuations.
This research determined these characteristics by measuring the S11 and S21 parameters
of the composite cement-based material in the GSM and WiFi frequency bands. The time domain gating function of a vector network analyser is applied to measure the reflection
from the material. The data was then used to obtain the reflection and absorption losses
in the frequency bands. The transmission loss was measured by placing the sample in the
propagation path between two antennas.
MnZn-ferrite and electrolytic manganese dioxide in powder form were evaluated as absorber
material to increase the permeability of the cement-based material to improve absorption
and attenuation capabilities to create a cost-effective practical electromagnetic wave absorber.
The compound of the cement-based material was cement, sifted river sand and filler
powder.
The results achieved in the research showed the uniqueness of electrolytic manganese dioxide
as filler in composite cement based material for electromagnetic wave shielding effectiveness
improvement. The combined measurement techniques used in this research were
uniquely used to determine the required electromagnetic wave absorption characteristics and
shielding effectiveness of 10 dB was measured in the GSM850 and GSM900 frequency
bands.Dissertation (MEng)--University of Pretoria, 2013.
gm2014
Electrical, Electronic and Computer Engineering
unrestricted