Dissertations / Theses: 'UWB'

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Santhanam, Manisundaram. "UWB technology and its application." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Data- och elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-16970.

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Despite the fact ultra-wideband (UWB) technology has been around for over 30 years, there is a newfound excitement about its potential for communications. With the advantageous qualities of multipath immunity and low power spectral density, researchers are examining fundamental questions about UWB communication systems. Majorly the whole report gives a complete picture about properties of UWB signal and its advantages and disadvantages, generation of the UWB pulse using various techniques, Modulation scheme, Test bed, applications, UWB regulations. The report mainly concerns with the survey about various techniques and also its comparison of generating UWB pulses using various components. There is a general description on various modulation and demodulation scheme that are relevant to UWB technology and its various applications concerning different fields. This report clearly explains how UWB is far better than RFID and difference between active and passive RFID and its communication protocol, message format. Clear explanation about advantage of higher operating frequencies and low power spectral density. Properties of UWB pulse gives clear idea why we go for UWB and in near future lot of applications will discover. Generation of UWB is a tedious process and in this report readers can understand the various method of generation its advantages and its drawbacks. Modulation and demodulation scheme gives clear idea about how UWB are modulated and demodulated as well as its probability of error and in which situation which modulation is suitable. By using future testbed concept, smaller size UWB chip will be designed and used in various application efficiently. Application gives clear idea about how to take advantage of various properties.

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Voinot, Stanislas. "Analyse et développement d'un système de communication radio fréquence ULB à faible consommation." Université Joseph Fourier (Grenoble), 2008. http://www.theses.fr/2008GRE10098.

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La technologie ULB (Ultra Large Bande) Radio a été développée au milieu des années quatre-vingt -dix. C'est une technologie à très large étalement de spectre (de plusieurs GHz). Enfévrier 2002, la FCC (Federal Communications Commission), après des études de compatibilité électromagnétique, a donné un avis favorable à l'utilisation de l'ULB Radio. Ceci a montré une intensification des travaux de recherches et de développement dans ce domaine. La thèse a été orientée vers l'étude de l'ULB, comme technologie d'accès radio, pour des réseaux locaux mobiles à courte portée (JO m) et à débit moyen (-lMb/s). Ces réseaux peuvent être considérés comme une alternative aux systèmes existants du type Bluetooth, DECT ou IEEE 802. 11 b, sans pour autant être limités par l'utilisation de bandes spectrales prédéfinies. Les puissances autorisées à l'émission par les législations étant très faibles, des modulations ont été développées pour permettre le maximum de puissance à l'émission, tout en conservant une structure simple à mettre en œuvre. A partir de ces modulations, le travail a consisté à simuler et à développer différentes structures de front-end radio ULB, en vue d'une intégration sur silicium. Les études et les architectures de télécommunications menées ont été intégrées sur des dispositifs submicroniques. Des collaborations ont été obtenues avec des producteurs de circuits intégrés, et des fournisseurs d'antennes
The wireless UWB technology developed in the middle 90. It is a technology with broad spread spectrum (several GHz). Ln February 2002 the FCC (Federal Communications Commission) after studying electromagnetic compatibility, gave a favorable opinion to the use of the ULB Radio. This showed an intensification of research and development in this field. The thesis has been oriented towards the study of the ULB as radio access technology for LANs mobile short-range (JO meters) and medium rate (- 1 Mb / s). These networks are considered as an alternative to the existing systems of the type Bluetooth, DECT or IEEE 802. 11b, but they are not limited by the use of predefined spectral bands. The powers authorized by the legislation are very low. A modulation method has been developed to provide maximum transmitted power with a simple receiver structure. The modulation method was simulated. A RF front end has designed and implemented as a single integrated circuit

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Ramos, Sparrow Oswaldo. "Modélisation et conception d’un récepteur non cohérent ultra large bande pour les communications ULB radio impulsionnelle dans la bande 3-5 GHz." Thesis, Nice, 2014. http://www.theses.fr/2014NICE4091/document.

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Ce travail de recherche est basé sur la technologie Ultra Large Bande (ULB), en particulier pour des applications bas débit (standard IEEE 802.15.4) tels que les réseaux de capteurs, les transmissions WPAN ou encore WBAN. La modélisation et la conception d’un récepteur non cohérent ULB pour les communications radio impulsionnelles ont été réalisées. Un des facteurs les plus importants dans les communications ULB est la sensibilité du récepteur, qui détermine la portée de transmission maximale. Un autre facteur aussi important est la consommation d’énergie qui influence directement la durée de vie de la source d’alimentation (batterie). Dans ce contexte, nous présentons dans le chapitre I une introduction sur la technologie ULB et ses diverses applications. Le chapitre II présente la modélisation au niveau système ainsi que d’une étude comparative des récepteurs non cohérents basés sur la détection d’énergie et la pseudo-Détection d’énergie. Dans le chapitre III sont présentés la méthode de conception et de réalisation d’un récepteur non cohérent ULB dans la bande de 3-5 GHz, ainsi que les résultats de mesure et ses performances en termes de sensibilité et de consommation d’énergie. Finalement, le chapitre IV présente une étude théorique sur les différents modes de fonctionnement du transistor MOS afin de mieux comprendre le fonctionnement de chaque bloc du récepteur. Cela permet de proposer de nouvelles architectures pour la détection d’énergie. Enfin, à partir de ces études nous réalisons l’optimisation du récepteur en termes de sensibilité et de consommation d’énergie
This research is based on Ultra Wide Band (UWB) technology, in particularly for low-Rate applications such as sensor network, WPAN and WBAN (for the standard IEEE 802.15.4). The model and design of a non coherent receiver for UWB impulse radio communications has been completed. One of the most important factors in the UWB communications is the receiver sensitivity which determines the maximum transmission range. Another important factor is the energy consumption that determines the lifetime of the power source (battery). In this context, we present in Chapter I an introduction to UWB technology and its different applications. Chapter II deals with a modeling at the system level of non-Coherent receivers as well as a comparative study based on the energy detection and pseudo energy detection. In Chapter III is presented the method of design and implementation of a non-Coherent UWB receiver in the band of 3-5 GHz, as well as measurement results and performance in terms of sensitivity and power consumption. Finally, Chapter IV presents a theoretical study on the different modes of operation of the MOS transistor to understand the operation of each block of the receiver. This allows us to show the new architectures for energy detection and perform the optimization of receiver in terms of sensitivity and power consumption

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Gao, Xiangjian. "UWB Indoor Localization System." Thesis, The George Washington University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10813674.

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This thesis report has introduced the UWB Indoor Localization System. In the beginning, this thesis report has explained the Indoor Localization System and presented existing techniques (such as Wi-Fi and Bluetooth) to construct an Indoor Localization System. Then, this thesis report has discussed the Ultra Wideband Radio fundamentals to analyze its construction and operating mechanism. During the transmission, the UWB signals will pass an additive white Gaussian noise channel with multipath effects, which cause errors in the values of bits. This thesis report has studied different solutions (such as Modulation Methods and Rake Receiver) to improve the bit error rate in different situations (such as Multipath-free AWGN channel). Next, this thesis report utilizes the UWB Radio fundamentals to show and compare different positioning algorithms (such as TOA and AOA). This thesis report focuses on TOA algorithm. For TOA algorithm, this thesis report has analyzed the IEEE UWB standards and the UWB Radio fundamentals to present and compare different types of receivers. Finally, this thesis report has studied algorithms (such as WLS) to solve non-linear equations to find the position of a mobile station with NLOS effects. In this thesis report, an algorithm (removing excess delay) has been used to mitigate NLOS effects with the simulation based on IEEE 802.15.4a channels. The simulation results are shown in chapter 12, and the average positioning error is around 7 cm.

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Montojo-Bennassar, Juan I. "Adaptive OFDM-based UWB." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3356337.

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Thesis (Ph. D.)--University of California, San Diego, 2009.
Title from first page of PDF file (viewed July 9, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 114-118).

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Akbar, Rizwan. "Contribution à la conception d'un système de radio impulsionnelle ultra large bande intelligent." Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-00870970.

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Face à une demande sans cesse croissante de haut débit et d'adaptabilité des systèmes existants, qui à son tour se traduit par l'encombrement du spectre, le développement de nouvelles solutions dans le domaine des communications sans fil devient nécessaire afin de répondre aux exigences des applications émergentes. Parmi les innovations récentes dans ce domaine, l'ultra large bande (UWB) a suscité un vif intérêt. La radio impulsionnelle UWB (IR-UWB), qui est une solution intéressante pour réaliser des systèmes UWB, est caractérisée par la transmission des impulsions de très courte durée, occupant une largeur de bande allant jusqu'à 7,5 GHz, avec une densité spectrale de puissance extrêmement faible. Cette largeur de bande importante permet de réaliser plusieurs fonctionnalités intéressantes, telles que l'implémentation à faible complexité et à coût réduit, la possibilité de se superposer aux systèmes à bande étroite, la diversité spatiale et la localisation très précise de l'ordre centimétrique, en raison de la résolution temporelle très fine.Dans cette thèse, nous examinons certains éléments clés dans la réalisation d'un système IR-UWB intelligent. Nous avons tout d'abord proposé le concept de radio UWB cognitive à partir des similarités existantes entre l'IR-UWB et la radio cognitive. Dans sa définition la plus simple, un tel système est conscient de son environnement et s'y adapte intelligemment. Ainsi, nous avons tout d'abord focalisé notre recherché sur l'analyse de la disponibilité des ressources spectrales (spectrum sensing) et la conception d'une forme d'onde UWB adaptative, considérées comme deux étapes importantes dans la réalisation d'une radio cognitive UWB. Les algorithmes de spectrum sensing devraient fonctionner avec un minimum de connaissances a priori et détecter rapidement les utilisateurs primaires. Nous avons donc développé de tels algorithmes utilisant des résultats récents sur la théorie des matrices aléatoires, qui sont capables de fournir de bonnes performances, avec un petit nombre d'échantillons. Ensuite, nous avons proposé une méthode de conception de la forme d'onde UWB, vue comme une superposition de fonctions B-splines, dont les coefficients de pondération sont optimisés par des algorithmes génétiques. Il en résulte une forme d'onde UWB qui est spectralement efficace et peut s'adapter pour intégrer les contraintes liées à la radio cognitive. Dans la 2ème partie de cette thèse, nous nous sommes attaqués à deux autres problématiques importantes pour le fonctionnement des systèmes UWB, à savoir la synchronisation et l'estimation du canal UWB, qui est très dense en trajets multiples. Ainsi, nous avons proposé plusieurs algorithmes de synchronisation, de faible complexité et sans séquence d'apprentissage, pour les modulations BPSK et PSM, en exploitant l'orthogonalité des formes d'onde UWB ou la cyclostationnarité inhérente à la signalisation IR-UWB. Enfin, nous avons travaillé sur l'estimation du canal UWB, qui est un élément critique pour les récepteurs Rake cohérents. Ainsi, nous avons proposé une méthode d'estimation du canal basée sur une combinaison de deux approches complémentaires, le maximum de vraisemblance et la décomposition en sous-espaces orthogonaux,d'améliorer globalement les performances.

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Piratla, Dinakara Phaneendra Kumar. "Synchronization in Impulse Based Ultra Wideband Systems." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/33654.

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In Impulse Radio based Ultra Wide Band (UWB) systems, where sub-nano second pulses are used, synchronization is very challenging because of their short pulse duration and very low duty cycle.

Coherent detection of ultra wide-band signals requires complex channel estimation algorithms. In impulse based UWB systems, suboptimal receivers that require no channel estimation are proposed for low data rate applications using non coherent detection of energy. This approach requires integrators that collect energy and detect the incoming stream of bits for detection and synchronization. These techniques yield reasonable performance when compared to coherent detection techniques that require complex hardware and dissipate more energy.

Non-coherent detection is a promising technique for low complexity, low cost and low data rate ultra-wideband communication applications like sensor area networks. In the past, several attempts have been made to characterize the performance of the energy collection receivers for synchronization using various metrics that include time of arrival and BER measurements. A comprehensive study of the synchronization problem using Probability of False Alarm is limited.

The current thesis attempts to characterize the synchronization problem using Probability of False Alarm and Probability of Detection under various channel models and also discusses the importance of the length of the integration window for energy collection receivers. The current work also focuses on the performance evaluation of synchronization for Impulse based UWB systems using energy capture method and modeling them using the Probability of False Alarm and Probability of Detection under various channel models. In these systems, the integration region of a receiver integrator significantly affects the bit error rate (BER) performance. The effect of the integration window on the performance of the algorithm is also studied.

This work also discusses the trade-offs between complexity and precision in using these algorithms for synchronization of Impulse based Direct Sequence Ultra Wideband Systems (DS-UWB). Signal to Noise Ratio vs. Probability of Detection, Probability of False Alarm are plotted for different channel models.
Master of Science

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Lande, Håvard. "UWB-IR for biomedisinske sensornettverk." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10381.

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Ved behandling og restitusjon av pasienter må pasientenes kroppsfunksjoner overvåkes. Typiske funksjoner som må overvåkes er blodtrykk, elektrokardiogram og akselerometerdata. Dette er til nå stort sett gjort ved å benytte kabelbaserte løsninger og en overgang til en trådløs teknologi vil kunne føre til større bevegelsesfrihet hos pasientene. En trådløs teknologi gir også mulighet for å overvåke pasientene utenfor sykehuset fire vegger. Et større velvære og et kortere opphold på sykehuset vil kunne bidra til en kortere restitusjonstid for pasientene. Ultra-Wide-Band Impulse Radio (UWB-IR) er en teknologi som har fått stor oppmerksomhet de siste årene på grunn av en rekke unike egenskaper som god gjennomtrengning av objekter, sikker overføring, lite støy, gode flerveisegenskaper, mulighet for nøyaktig posisjonering, og lavt energiforbruk sammenliknet med andre trådløse kommunikasjonsteknologier. Fokuset på UWB-IR teknologien startet i 2002 da Federal Communications Commission (FCC) i USA frigjorde en stor båndbredde (3.1-10.6 $GHz$) til bruk ved lave sendereffekter (-41.3 $dBm/MHz$ EIRP). UWB-IR teknologien benytter seg av en teknikk som baserer seg på å sende veldig korte pulser(i størrelsesorden nanosekunder) med høy rate. Båndbredden til signalet vil da være begrenset av pulsen som benyttes. Ofte benyttes ulike ordens deriverte gaussiske pulser da effektspekteret til disse pulsene vil lett kunne tilpasses for å oppfylle FCC kravet. Da trådløse biomedisinske sensornettverk benyttes til overvåkning av vitale kroppsfunksjoner, stiller dette strenge krav til transmisjonssystemet både med hensyn til stabilitet, robusthet og energiforbruk. Når sensornodene er montert så tett på kroppen vil dette gjør det vesentlig mer krevende å oppfylle disse kravene på grunn av den direktive effekten som vil oppstå når små antenner er montert så tett på kroppen, og på grunn av skjermingen som vil oppstå når nodene er montert på ulike sider av kroppen. Lite forskning er i dag gjort rundt ytelsen til et UWB-IR basert transmisjonssystem når signalet forplanter seg rundt kroppen. I oppgaven er det derfor først ved simulering sett på ytelsen til det fysiske laget når trådløse sensornoder er montert rundt på kroppen. Det er i simuleringen både blitt benyttet en vanlig 2-PPM-TH korrelasjonsmottaker, og en RAKE mottaker som utnytter multi-path (MP) forplantningen til signalet. Det er også blitt sett på muligheten for å øke antall pulser per bit for å redusere BER uten å øke sendereffekten. Nodene er blitt plassert rundt på ulike steder på kroppen for å se hvordan dette vil påvirke ytelsen til systemet. Simuleringene er basert på en meget avansert kanalmodell som er utviklet av IMEC som er en belgisk forskningsinstitusjon. Denne modellen har også blitt godkjent som test modell for den nye 802.15.4a lav-rate UWB standarden. Modellen tar både hensyn til komponenter som skyldes diffraksjon rundt kroppen, og refleksjoner fra rommet rundt. Da FCC har satt strenge begrensninger på sendereffekten, vil det være viktig å utnytte den tilgjenglige båndbredden best mulig. Det er derfor sett på ulike metoder som kan benyttes for å få et spekter som best mulig fyller FCC emisjons masken. Dette inkluderer blant annet tilpassning av spredekoden, og bifasekoding av pulsene. Basert på simuleringene er det kommet frem til en rekke faktorer som vil være viktig for å kunne tilby et mest mulig effektivt og optimalt transmisjonssystem både med hensyn på robusthet, kompleksitet og energiforbruk. Bifasekoding har vist seg å være ekstremt effektivt for å unngå topper i spektert, og dermed kunne øke sendereffekten. Dersom det benyttes en lang nok sekvens på bifasekoden, vil effektspektraltettheten (PSD) til det utsendte signalet tilsvare PSD til en enkelt puls. Noe som gjør det vesentlig enklere å konstruere et transmisjonssystem som oppfyller FCC kravene, for det vil da ikke være nødvendig å ta hensyn til modulasjonen av pulsene. Korreksjon for forvrengningen og MP forplantningen til signalet har vist seg å være helt avgjørende for å kunne få tilfredsstillende prestasjon på transmisjonssystemet. Dette gjelder spesielt noder som er plassert på ulik side av kroppen. Når en RAKE mottaker benyttes vil det på grunn av kompleksiteten være fordelaktig å tilpasse antall fingre i mottakeren basert på posisjonen til noden. Når mottakeren er plassert på fremsiden av kroppen, vil henholdsvis 1,4, og 8 fingre i mottakeren være optimalt når sendernodene er montert på fremsiden, siden, og baksiden av kroppen. Den store spredningen av MP komponenter har vist seg å gi opphav til vesentlig intersymbolinterferens dersom dette ikke tas hensyn til i transmisjonssystemet. Når 2-PPM-TH benyttes vil dette kunne gjøres ved å tilpasse TH koden for å sikre tilstrekkelig avstand mellom etterfølgende pulser. For å få tilfredsstillende BER vil det også være nødvendig å benytte flere pulser per bit. Når en RAKE mottakeren plassert på fremsiden av kroppen benyttes, har henholdsvis 1-2, 5-6, og 11-15 vist seg å gi tilfredsstillende ytelse for mottak fra noder som befinner seg på fremsiden, siden, og baksiden av kroppen. Det er også blitt sett på ulike metoder for krysslagsoptimering, og resultatene fra BAN simuleringen er blitt benyttet for å kunne vurdere deler av disse. Krysslagsoptimering går i hovedsak ut på å utveksle informasjon på tvers av lagene som ellers ikke vil være tilgjenglig i tradisjonell laginndeling som for eksempel i OSI-modellen. I stede for å se på lagene individuelt vil det ved å åpne mellom lagene kunne konstruere en mer optimal totalløsning. Det er blitt sett på 3 mulige krysslagsmetoder. Dette inkluderer forenklet ruting ved kryssoptimering mellom nettverk- og MAC laget, kryssoptimering som utnytter posisjonering og kryssoptimering mellom det fysiske laget og MAC laget. Til slutt er det blitt sett på en MAC protokoll med navnet DCC-MAC som utnytter kryssoptimering mot det fysiske laget. Det er kommet frem til at kryssoptimering som utnytter posisjonering vil kunne benyttes for tilpassning av TH koden, og dermed unngå ISI. DCC-MAC har også en del egenskaper som trolig vil kunne gi økt ytelse i et biomedisinsk sensornettverk. Dette inkluderer blant annet dynamisk kanalkoding, og Interference Mitigation som er en metode for å bedre kunne håndtere pulskollisjoner. Derimot vil det trolig være nødvendig å gjøre noen tilpassninger av protokollen for å bedre kunne håndtere effekten av ISI.

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Ruengwaree, Amnoiy. "Design of UWB radar sensors." Kassel Kassel Univ. Press, 2007. http://www.uni-kassel.de/hrz/db4/extern/dbupress/publik/abstract.php?978-3-89958-358-8.

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Ruengwaree, Amnoiy. "Design of UWB radar sensors /." Kassel : Kassel Univ. Press, 2008. http://www.uni-kassel.de/hrz/db4/extern/dbupress/publik/abstract.php?978-3-89958-358-8.

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Lu, Yang. "UWB antennas for wireless communication." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569654.

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Ultra-wideband (UWB) technology is a promising solution to provide high data-rate transmission of the future wireless communication systems. The rapid development of UWB wireless communication systems has brought both challenges and: opportunities to novel UWB antenna designs. This thesis is concentrated on the analysis, design and measurement of compact antennas for UWB devices, which can be divided into three areas. / The first area investigated is small planar broadband antennas for wearable and positioning applications where the antennas with unidirectional radiation patterns may be preferred, since the energy will be focused on the desired direction. Furthermore, the interference from the environment behind the antenna can also be greatly minimised. Two low-profile broad band antennas with unidirectional radiation patterns are presented in this work. Their performance in terms of impedance bandwidth and radiation patterns is studied. Results show that they have a very broadband (>50% fractal bandwidth) and constant broadside unidirectional radiation patterns. Hence, they are good candidates and suitable for the in-body and radar applications The second research area is about the planar UWB monopole antennas. The radiation behaviour of the planar UWB monopole antenna is first investigated. It is found that an ultra-wide bandwidth of this type of antenna is achieved by both well-matched travelling wave modes and smooth transients between different higher order modes. However, there exists a common problem for the current planar UWB monopole antennas that their performance is heavily affected by the size of the ground plane. It is found that dimensional changes will influence the characteristic modes excited on the ground plane which directly affects the impedance and radiation of the antenna. A technique of cutting slots on the ground plane is then proposed to resolve the ground plane effect problem. The presence of the slots will introduce slot modes. Optimal slots can produce a strong coupling between the slot mode and the ground plane modes. This coupling makes the characteristic modes of planar UWB monopole insensitive to the size change of the ground plane, hence it effectively minimises the ground plane dependence of the antenna. Two different UWB monopole antennas are investigated using this technique. Both the simulated and measured results demonstrate that this method can indeed minimise the ground plane effects on the impedance matching and have very little effect on the other antenna parameters, such as radiation pattern, gain and I time domain performance. Additionally, a parametric study on the major geometric parameters related to the slots is performed to achieve an optimised design. The third area of my study is the measurement of UWB antenna radiation efficiency. Antenna radiation efficiency is one of the most important parameters when evaluating its performance. In the past, many different antenna efficiency measurement methods were proposed. However, how to measure the UWB antenna efficiency effectively is still a challenging issue. A novel source-stirred chamber/cap (SSC) method is proposed and developed to overcome the limitations of the existing methods. Different types of UWB antennas are employed as examples to demonstrate the usefulness of this new method. Promising results are obtained which prove the SSC method is very effective in measuring the UWB antenna efficiency. It is evident that this method has the potential to become a general antenna efficiency measurement approach.

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Jazayerifar, Seyed Mahmoud. "Transmission optique des signaux UWB." Grenoble INPG, 2009. http://www.theses.fr/2009INPG0013.

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Dans cette thèse nous examiner et étudier la transmission de signaux Ultra Wide Band (UWB), sur fiber optique monomode dans un system de radio sur fiber. Nous commençons par développer un modèle mathématique pour les principaux composants optiques employés dans systèmes de radio sur fiber. L'authenticité de ces modèles est vérifiée avec des résultats expérimentaux. Suite à l'modèles ci-dessus ainsi que les résultats de l'expérience, la transmission des signaux UWB sur fiber optique est investigué. L'impact de l'exploitation limitée de bande passante et de la non-linéarité électrique à la fonction de transfert optique de signaux UWB est examinée. Deux types de signaux UWB, à savoir, MB-OFDM (Multi-Band Orthogonal Frequency Division Multiplexing) et IR-UWB (Impulse Radio Ultra Wide Band) sont pris en compte. En utilisant les modèles mathématiques de composants optiques nous comparons ces deux formats UWB en fonction de leur sensibilité aux distorsions qui existent dans une émission de radio sur fiber. La discussion ci-dessus est axé sur la downlink de l'UWB sur fiber système. Pour la uplink, nous considérons un système différentiel récepteur dont la structure est simple à mettre en œuvre. Pour le récepteur structure nous considérons la fois un récepteur électrique et un nouveau récepteur optique. Le récepteur optique présenté dans cette thèse, pour la première fois, est étudié dans le cadre de l'IR-UWB. Elle est similaire à la récepteur optique utilisé pour optique numérique DPSK modulation de phase (Differential Phase Shift Keying), mais dans cette thèse, nous proposons le récepteur, pour la première fois, dans la transmission optique des signaux UWB sur fiber optique. Nous étudions aussi récepteur électrique classique et comparons ses performances avec celles de la récepteur optique. Les modèles mathématiques pour les composants optiques tels que la diode laser et unique mode fiber, avec les expressions analytiques pour les récepteurs (probabilité d'erreur) sont utilisés pour évaluer la performance de l'ensemble de l'UWB sur fiber système
.

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Cruz, Vitor Manuel Duarte da. "Antena UWB para imagem médica." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23538.

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Mestrado em Engenharia Eletrónica e Telecomunicações
Dada a importância da imagem médica obtida através de várias tecnologias na prática clínica, tanto na fase de diagnóstico como no acompanhamento da evolução de doenças é evidente a necessidade contínua de evoluir e procurar aperfeiçoar cada vez mais os equipamentos e métodos existentes. A tecnologia de imagem médica por micro-ondas surgiu recentemente como uma tecnologia com enorme potencial de se vir a tornar bastante importante para aplicações biomédicas. Esta dissertação procura contribuir para o desenvolvimento tecnológico desta nova técnica, mais precisamente no desenvolvimento de antenas de banda larga, que operem na gama das micro-ondas, e que possam ser utilizadas para a deteção de eventuais tumores, em particular, o cancro da mama. Foram dimensionadas, simuladas, construídas e medidas antenas com características que possam ser úteis no desenvolvimento nesta área tecnológica. No final são expostas as experiências realizadas e os resultados obtidos, retirando-se conclusões e apresentando possível trabalho futuro.
Medical imaging obtained by different technologies are an essential tool in clinical practice, both to provide an accurate initial diagnosis and to monitor the evolution of diseases. It is fundamental to keep the development in this area, to improve the existing equipment and methods. Microwave imaging technique has recently emerged as complementary method for breast imaging with enormous potential to become quite important for biomedical applications. This thesis contributes to the technological development of this new technique, whith the development of broadband antennas that operate in the range of the microwaves, which can be used for the detection of possible tumors, in particular, breast cancer. During this project it was simulated, constructed and measured different antennas with potential characteristics to use in the development of this area of studies. Finally, the experimental results are presented, followed by the conclusions and future work.

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14

Cao, Ping. "UWB antennas for wireless communications." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/14715/.

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This thesis focuses on four inter-related research topics on the design and analysis of compact planar ultra wide-band (UWB) monopole antennas for future wireless communications, namely, a planar super-wide-band (SWB) monopole antenna, a planar UWB antenna with band-notched characteristics, a planar UWB antenna with reconfigurable band-rejection features, and a planar UWB multiple-input and multiple-output (MIMO) antenna. A novel Mickey-mouse shaped planar monopole antenna with SWB performance is proposed and investigated. Three different techniques for bandwidth enhancement are implemented. The antenna is evolved from the traditional circular monopole antenna and has achieved an impedance bandwidth of more than 100:1 and a stable radiation patterns over a wider bandwidth. The design of a compact planar UWB monopole antenna (22 mm × 34 mm), incorporated with five m-shaped resonators (MSRs) at different positions, to achieve quintuple-band-notched performance is presented. The frequency-domain performance (in term of reflection coefficients, realized gain, efficiency, and radiation pattern), and time-domain performance (in term of pulse responses and fidelity), are investigated by simulation and measurement. The results show that the proposed UWB antenna has approximately omnidirectional radiation patterns and excellent band-notched behaviours and good time domain performance with the fidelity of more than 85.5% in the pulse response. A planar UWB monopole antenna with reconfigurable band-notched characteristics is also introduced. The band rejection is realized by incorporating two co-directional split ring resonators (CSRR) on the radiator element. Switches are added to the CSRR structures to achieve the reconfigurability. The proposed antenna can operate at different switching states including a UWB state, single and dual band-notched states with good rejection behaviours. Good radiation patterns and gain values are also obtained for different switching states. This compact wideband antenna can be very good candidate for a wide range of mobile portable applications. A compact planar UWB-MIMO antenna (60 mm × 45 mm) is presented for wireless applications. The wideband isolation of more than 15 dB is achieved by etching a new trident-like slot on the ground plane of the antenna. An equivalent circuit have been introduced for analysis and the diversity performances are studied. The results show that the proposed MIMO antenna is a very good candidate for wireless applications. The study of these four special antennas has demonstrated that, using various techniques, the planar monopole antenna can be an excellent choice for a wide range of wireless communication applications.

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Laška, Richard. "Pseudonáhodné posloupnosti v UWB systémech." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217727.

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This master´s thesis deals with Ultra-wideband and reveals present stage of this technology and situation on marketplace. In this work I will mention the milestones of its history and describe main fundamentals of communication and modulation methods in UWB systems. This work provides an overview of methods in pseudo-noise code design. The practical part includes UWB system simulation based on BPSK modulation and Directsequence multi-access scenario. This work presents BPSK modulated signal behavior in UWB channel model, where AWGN noise and multi-path energy is taken into account. Only physical layer was tested. At the end of this thesis, the summary and conclusion simulation results will be discussed. Bit error rate characteristic is a product of this testing.

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Jin, Yalin. "Radio-frequency integrated-circuit design for CMOS single-chip UWB systems." Thesis, [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2724.

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Zou, Zhuo. "Impulse Radio UWB for the Internet-of-Things : A Study on UHF/UWB Hybrid Solution." Doctoral thesis, KTH, Elektroniksystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-59107.

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This dissertation investigates Ultra-Wideband (UWB) techniques for the next generation Radio Frequency Identification (RFID) towards the Internet-of-Things (IoT). In particular, an ultra-high frequency (UHF) wireless-powered UWB radio (UHF/UWB hybrid) with asymmetric links is explored from system architecture to circuit implementation. Context-aware, location-aware, and energy-aware computing for the IoT demands future micro-devices (e.g., RFID tags) with capabilities of sensing, processing, communication, and positioning, which can be integrated into everyday objects including paper documents, as well as food and pharmaceutical packages. To this end, reliable-operating and maintenance-free wireless networks with low-power and low-cost radio transceivers are essential. In this context, state-of-the-art passive RFID technologies provide limited data rate and positioning accuracy, whereas active radios suffer from high complexity and power-hungry transceivers. Impulse Radio UWB (IR-UWB) exhibits significant advantages that are expected to overcome these limitations. Wideband signals offer robust communications and high-precision positioning; duty-cycled operations allow link scalability; and baseband-like architecture facilitates extremely simple and low-power transmitters. However, the implementation of the IR-UWB receiver is still power-hungry and complex, and thus is unacceptable for self-powered or passive tags. To cope with μW level power budget in wireless-powered systems, this dissertation proposes an UHF/UWB hybrid radio architecture with asymmetric links. It combines the passive UHF RFID and the IR-UWB transmitter. In the downlink (reader-tag), the tag is powered and controlled by UHF signals as conventional passive UHF tags, whereas it uses an IR-UWB transmitter to send data for a short time at a high rate in the uplink (tag-reader). Such an innovative architecture takes advantage of UWB transmissions, while the tag avoids the complex UWB receiver by shifting the burden to the reader. A wireless-powered tag providing -18.5 dBm sensitivity UHF downlink and 10 Mb/s UWB uplink is implemented in 180 nm CMOS. At the reader side, a non-coherent energy detection IR-UWB receiver is designed to pair the tag. The receiver is featured by high energy-efficiency and flexibility that supports multi-mode operations. A novel synchronization scheme based on the energy offset is suggested. It allows fast synchronization between the reader and tags, without increasing the hardware complexity. Time-of-Arrival (TOA) estimation schemes are analyzed and developed for the reader, which enables tag localization. The receiver prototype is fabricated in 90 nm CMOS with 16.3 mW power consumption and -79 dBm sensitivity at 10 Mb/s data rate. The system concept is verified by the link measurement between the tag and the reader. Compared with current passive UHF RFID systems, the UHF/UWB hybrid solution provides an order of magnitude improvement in terms of the data rate and positioning accuracy brought by the IR-UWB uplink.
QC 20120110

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Adam, M. "The use of multiple antenna techniques for UWB wireless personal area networks (UWB-MIMO WPANS)." Thesis, University of Salford, 2014. http://usir.salford.ac.uk/34326/.

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The research activities over the three years were presented in this thesis. The work centred on the use of multiple spatial elements for Ultra wide band wireless system in order to increase the throughput, and for wireless range requirement applications, increases the coverage area. The challenges and problems of this type of implementation are identified and analysed when considered at the physical layer. The study presents a model design that integrates the multiple antenna configurations on the short range wireless communication systems. As the demand for capacity increases in Wireless Personal Area Networks (WPAN); to address this issue, the framework of the Wi-Media Ultra Wide Band (UWB) standard has been implemented in many WPAN systems. However, challenging issues still remain in terms of increasing throughput, as well as extending cellular coverage range. Multiple Input Multiple Output (MIMO) technology is a well-established antenna technology that can increase system capacity and extend the link coverage area for wireless communication systems. The work started by carrying out an investigation into integrated MIMO technology for WPANs based on the Wi-Media framework using Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM). It considered an extensive review of applicable research, the potential problems posed by some approaches and some novel approaches to resolve these issues. The proposed ECMA-368 standard was considered, and a UWB system with a multiple antenna configuration was undertaken as a basis for the analysis. A novel scheme incorporating Dual Circular 32 - QAM was proposed for MB-OFDM based systems in order to enhance overall throughput, and could be modified to increase the coverage area at compromise of the data rate. The scheme was incorporated into a spatial multiplexing model with measured computational complexity and practical design issues. This way the capacity could be increased to twice the theoretical levels, which could pay the way to high speed multi-media wireless indoor communication between devices. Furthermore, the range of the indoor wireless network could be increased in practical wireless sensor networks. The inherent presence of spatial and frequency diversity that is associated with this multiple radiators configuration enlarge the signal space, by introducing additional degrees of freedom that provide a linear increase in the system capacity, for the same available spectrum. By incorporating the spatial elements with a Dual Circular modulation that is specified within the standard, it can be shown that a substantial gain in spectral efficiency could be possible. A performance analysis of this system and the use of spatial multiplexing for potential data rates above Gigabit per second transmission were considered. In this work, a model design was constructed that increases the throughput of indoor wireless network systems with the use of dual radiating elements at the both transmitter and receiver. A simulation model had been developed that encapsulate the proposed design. Tests were carried out which investigate the performance characteristics of various spatial and modulation proposals and identifies the challenges surrounding their deployments. Results analysis based on various simulation tests including the IEEE802.15.3a UWB channel model had shown a lower error rate performance in the implementation of the model. The proposed model can be integrated in commercial indoor wireless networks and devices with relatively low implementation cost. Further, the design used in future work to address the current challenges in this field and provides a framework for future systems development.

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Krishnanji, Sivasankari. "Design of a variable gain amplifier for an ultrawideband receiver." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2576.

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A fully differential CMOS variable gain amplifier (VGA) has been designed for an ultra-wideband receiver. The VGA comprises of two variable gain stages followed by a post amplifier stage. The interface between the digital control block and the analog VGA is formed by a digital-to-analog converter and an exponential voltage generator. The gain of the VGA varies dB-linearly from 0 to 52 dB with respect to the control voltage. The VGA is operated in open loop with a bandwidth greater than 500 MHz throughout the gain range to cater to the requirements of the ultra-wideband system. The noise-to-power ratio of the VGA is -23.9 dB for 1Vp-p differential input signal in the low gain setting, and the equivalent input referred noise is 1.01 V2 for the high gain setting. All three stages use common mode feedback to fix and stabilize the output DC levels at a particular voltage depending on the input common-mode requirement of the following stage. DC offset cancellation has also been incorporated to minimize the input referred DC offset caused by systematic and random mismatches in the circuit. Compensation schemes to minimize the effects of temperature, supply and process variations have been included in the design. The circuit has been designed in 0.18??m CMOS technology, and the post layout simulations are in good agreement with the schematic simulations.

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Fiorina, Jocelyn. "Performances des systèmes de communication "Ultra large bande" à impulsions radio." Paris 11, 2005. http://www.theses.fr/2005PA112203.

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Nous étudions dans cette thèse les systèmes de communication à ultra large bande (ULB) basés sur les impulsions radio, plus connus sous le terme Time Hopping Impulse Radio Ultra Wide Band (TH-IR-UWB). Après avoir introduit le principe des transmissions des signaux ULB, nous proposons de nouvelles mises en forme du signal accompagnées d'une comparaison synthétique de différentes modulations possibles. Un point fondamental dans l'étude des performances des systèmes ULB réside dans l'effet des interférences multi-utilisateurs (MUI). Dans les premières études sur l'ULB, les MUI étaient modélisées par un bruit Gaussien. Nous voyons dans notre thèse que cette hypothèse n'est pas toujours valable et qu'elle surestime les performances du récepteur par corrélation classiquement utilisé en ULB. En développant un modèle de collision des impulsions, nous proposons une formule qui permet de mieux estimer les performances en terme de taux d'erreur binaire. Nous mettons également à jour un phénomène de résonance stochastique traduisant l'aspect peu ordinaire des interférences ULB. Nous menons alors une analyse approfondie des MUI qui nous permet de mettre à jour les conditions de gaussianité et non-gaussianité des signaux interférents. Ce résultat permet de mieux comprendre les MUI et nous montrons également un compromis qui en découle, entre le facteur de répétition et la longueur de la trame du signal ULB. Finalement nous proposons un récepteur simple adapté aux interférences ULB dont les performances sont très bonnes et dépassent même dans certains cas les prévisions issues de l'approximation Gaussienne jugées jusque là trop optimistes
Time Hopping Impulse Radio Ultra Wide Band (TH-IR-UWB) systems are the object of the studies in this thesis. We first introduce the UWB principles and then propose new signalling schemes together with a synthetic comparison of the performances of different modulation possibilities. A key point in UWB performances is the Multi User Interference (MUI). In the first studies on UWB, MUI was supposed to be Gaussian. We see in our thesis that this hypothesis is not always true and that it overestimates UWB performances. By developing an impulse collision model, we propose a formula allowing a better estimation of the bit error rate. We also reveal a stochastic resonance phenomenon showing the unusual aspect of UWB interferences. Then we perform a detailed analysis of MUI, which allows us to work out the condition of Gaussianity and non-Gaussianity of the interfering signals. This results help in understanding MUI and, thanks to it, we may demonstrate the existence of a trade-off between the repetition factor and the frame length. Finally we propose a simple receiver adapted to the UWB MUI, which performances are greatly increased and may in some cases outperform the prevision of the Gaussian approximation which was considered to be too optimist before

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Arcangeloni, Luca. "Interfacciamento di sistemi RFID e UWB." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18945/.

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Nella seguente tesi si è realizzato l'interfacciamento delle due tecnologie RFID e UWB. La prima utilizzata nei sistemi di identificazione di oggetti come evoluzione del codice a barre. La seconda applicata in sistemi di localizzazione indoor, dalle wireless sensor network alle real-time locating system. Questo studio si inserisce in un lavoro molto più ampio nato da un primo progetto finanziato dall'Agenzia spaziale europea: LOST (Localisation of objects in space through RF Tags). L'obiettivo di tale progetto consisteva nella realizzazione di un sistema di localizzazione con precisione centimetrica per aiutare gli astronauti in assenza di gravità a individuare gli oggetti sparsi nella stazione spaziale. Successivamente al progetto LOST nasce l'esigenza di standardizzare il sistema realizzato in modo da integrare la tecnologia UWB per la gestione del posizionamento ad alta precisione con il protocollo RFID Gen2, operante nella banda UHF al fine di garantire una retro-compatibilità con i dispositivi disponibili in commercio: Tag RFID e Reader RFID. La tesi prende parte a quest'ultima fase di standardizzazione ponendosi l'obiettivo di sincronizzare il sotto-sistema UWB con il sotto-sistema RFID.

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Rodriguez, Saul. "Design of a DS-UWB Transceiver." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-50785.

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Ultra Wide Band (UWB) is a new spectrum allocation which was recently approved by the Federal Communication Commission (FCC) and is under study in Europe and Asia. It has emerged as a solution to provide low complexity, low cost, low power consumption, and high-data-rate wireless connectivity devices entering the personal space. Any wireless system that has a fractional bandwidth greater than 20% and a total bandwidth larger than 500MHz enters in the UWB definition. At the emission level, UWB signals have a mask that limits its spectral power density to -41.3dBM/MHz between 3.1Ghz and 10.6GHz. There are two approaches that have been studied in order to use the 7.5Ghz allocated for UWB systems. First, OFDM techniques can be used to cover the entire spectrum; these techniques are called multi-band UWB. On the other hand, the second approach makes use of impulse radios which generate very-short-duration baseband pulses that occupy the whole spectrum. The objective of this thesis is to study, design, prototype, and test a UWB impulse radio using off-chip components. A Direct Sequence (DS) UWB transceiver architecture was selected. The transmitter uses first derivative Gaussian pulses that are modulated using a bi-phase modulation technique. The pulse rate of the system is 100MHz and the bit rates under investigation were 100Mbps, 50Mbps, 25Mbps, and 10Mbps. The transmitter and receiver were divided in functional blocks in order to execute system level simulations. The transmitter was implemented in both schematics and layout, and the UWB pulse generator block was constructed and tested in order to validate its functionality. On the other hand, the off-chip implementation of the receiver presented particular difficulties that made its construction not possible in this study. As a result, the blocks of the receiver were implemented in Matlab and the performance of the whole transceiver was estimated through numeric simulations. Finally, a case study for the multi-user capability of the system was presented.

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Lerenius, Jacob. "UWB System Performance and Hardware Requirements." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97083.

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Ultra Wideband is a low-power high-speed wireless personal area network (WPAN) technology. Its wide variety of potential application areas attracts a large interest in a wide variety of markets. Its potentially low power consumption in terms of the number of bits transferred per energy unit makes the technology an interesting feature for the mobile phone market. The report consists of three parts: -Theory about the UWB WPAN communication technology and high-speed interfaces. -Performance study including a comparison with present technologies focusing on power consumption.- Including Bluetooth and 108.11b. -Hardware and applications surveys focusing on high-speed interfaces and power consumption.

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Benfarah, Ahmed. "Sécurisation d'un lien radio UWB-IR." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961228.

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Du fait de la nature ouverte et partagée du canal radio, les communications sans fil souffrent de vulnérabilités sérieuses en terme de sécurité. Dans ces travaux de thèse, je me suis intéressé particulièrement à deux classes d'attaques à savoir l'attaque par relais et l'attaque par déni de service (brouillage). La technologie de couche physique UWB-IR a connu un grand essor au cours de cette dernière décennie et elle est une candidate intéressante pour les réseaux sans fil à courte portée. Mon objectif principal était d'exploiter les caractéristiques de la couche physique UWB-IR afin de renforcer la sécurité des communications sans fil. L'attaque par relais peut mettre à défaut les protocoles cryptographiques d'authentification. Pour remédier à cette menace, les protocoles de distance bounding ont été proposés. Dans ce cadre, je propose deux nouveaux protocoles (STHCP : Secret Time-Hopping Code Protocol et SMCP : Secret Mapping Code Protocol) qui améliorent considérablement la sécurité des protocoles de distance bounding au moyen des paramètres de la radio UWB-IR. Le brouillage consiste en l'émission intentionnelle d'un signal sur le canal lors du déroulement d'une communication. Mes contributions concernant le problème de brouillage sont triples. D'abord, j'ai déterminé les paramètres d'un brouilleur gaussien pire cas contre un récepteur UWB-IR non-cohérent. En second lieu, je propose un nouveau modèle de brouillage par analogie avec les attaques contre le système de chiffrement. Troisièmement, je propose une modification rendant la radio UWB-IR plus robuste au brouillage. Enfin, dans une dernière partie de mes travaux, je me suis intéressé au problème d'intégrer la sécurité à un réseau UWB-IR en suivant l'approche d'embedding. Le principe de cette approche consiste à superposer et à transmettre les informations de sécurité simultanément avec les données et avec une contrainte de compatibilité. Ainsi, je propose deux nouvelles techniques d'embedding pour la couche physique UWB-IR afin d'intégrer un service d'authentification.

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Lemus, David. "Laser Source for UWB Pulse Generation." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27973/27973.pdf.

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Pestourie, Baptiste. "UWB based Secure Ranging and Localization." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALT067.

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Les services de localisation sont considérés comme une des fonctionnalités majeures de l’IoT dans les prochaines années, et font l’objet d’un intérêt croissant dans la littérature des réseaux de capteurs sans fil (Wireless Sensors Network (WSN)). La technologie IR-UWB (Impulse-Radio Ultra-Wideband), standardisée dans IEEE 802.15.4, est actuellement la technologie de localisation la plus performante avec une précision de l’ordre du centimètre et est largement déployée dans des applications industrielles. Il a été démontré dans la littérature que la localisation UWB n’est pas immunisée contre la falsification (tampering) ; plusieurs vulnérabilités au niveau des couches physiques et liaison de données ont été identifiées dans des travaux précédents. La plupart des attaques majeures contre l’UWB sont des attaques physiques, telles que les attaques Early-Detection/Late-commit (ED-LC).Du fait de leur coût et complexité, parfois doublé par un manque de maturité technologique, elles ne sont pas nécessairement les menaces les plus réalistes dans un contexte IoT. En revanche, des failles protocolaires au niveau de la couche liaison de données exposent l’IR-UWB à des attaques nécessitant peu d’expertise et de matériel. Par conséquent, les travaux introduits dans ce manuscrit sont consacrés à l’identification des menaces les plus critiques contre la technologie 802.15.4 IR-UWB, évaluer des attaques contre cette technologie en conditions réelles, et proposer des contre-mesures à bas coût appropriées à des applications IoT. Une plateforme dédiée à la localisation IR-UWB, SecureLoc, fait partie des contributions. Plusieurs attaques à base d’acquittements frauduleux sont proposées et évaluées. Diverses contremesures sont proposées, au niveau des couches physique, liaison de données et système, incluant notamment un protocole d’authentification physique basé sur un weak PUF, une technique d’acquittement résistante contre les usurpations d’identité, un protocole d’estimation de distance (ranging) immune contre la falsification de position et un protocole coopératif de détection des nœuds malicieux
Location services are foreseen as one of the major IoT features in the next years, and have gained a lot of interest over the last decade from the literature of Wireless Sensors Networks, (WSN) and Vehicular Ad Hoc Networks (VANet). Impulse-Radio Ultra-Wideband (UWB), standardized in IEEE 802.15.4-2003, is currently the most performant radio positioning technology with centimeter-level accuracy and is used widely in industrial applications. It has been proven in the literature that UWB positioning is not completely tamper-proof, as various physical and link layers vulnerabilities have been identified in 802.15.4. Most of the major attacks against IR-UWB are physical-level attacks, such as Early-Detection/Late-Commit (ED/LC). Considering their cost, complexity, and sometimes lack of maturity, they are not necessarily the most realistic attacks against cheap IoT systems. On the other hand, protocol-level flaws expose IR-UWB positioning against attacks that can be mounted with limited expertise and cheap hardware. Hence, the aim of this work is to identify the most critical vulnerabilities of 802.15.4 IR-UWB, evaluate real-world attacks against UWB IPS and propose low-cost countermeasures suitable for IoT applications. An open platform for IR-UWB positioning security evaluation, SecureLoc, is part of the contributions. We propose and evaluate various spoofed acknowledgment-based attack schemes against IR-UWB. Several countermeasures, at the physical, medium access and system level, are proposed, including notably a novel weak PUF-based authentication protocol, a spoofing resilient acknowledgment scheme, a tamper-proof ranging approach, and a cooperative verification protocol for rogue node detection. All the proposed attacks and countermeasures have been implemented and evaluated on SecureLoc

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Han, Zixiong. "Respiratory Patterns Classification using UWB Radar." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42332.

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Radar-based respiration monitoring has been increasingly popular among researchers in biomedical fields during the last decades since it is a contactless monitoring technique. It is very convenient for subjects because it does not impose any restrictions on subjects or require their cooperation. Meanwhile, recognizing alternations in respiratory patterns is an important early clue of the diagnosis of several cardiorespiratory diseases. Thus, a study of biomedical radar-based respiration monitoring and respiratory pattern classification is carried out in this thesis. Radar-based respiration monitoring technology has a shortcoming that the collected respiratory signal will be easily distorted by the body movement of the monitoring subjects or disturbed by environment noise because of the contactless measurement attribute. This shortcoming limits the application of the respiratory pattern classification model, that is, the existing models cannot be applied automatically since the distorted respiratory signal needs to be manually filtered out ahead of the classification. In this study, a new respiratory pattern classification strategy, which can be implemented full-automatic, is proposed. In this strategy, a class “moving” is introduced to classify the distorted signal, and the sampling window length is shortened to reduce the effect caused by the signal distortion. A performance requirement for the continuous respiratory pattern classification is also proposed based on its expected function that can alert the occurrence of the abnormal breathing patterns. Several models which can meet the proposed performance requirement are developed in this thesis based on the state-of-the-art pattern classification technique and the time-series-based shapelet transform algorithm. The proposed models can classify four breathing patterns including eupnea, Cheyne Stokes respiration, Kussmaul breathing and apnea. A radar-collected respiratory signal database is built in this study, and a respiration simulation model which can generate breath samples for pattern classification is developed in this thesis. The proposed models were tested and validated in batch and stream processing manner with independently collected data and continuously collected data, respectively.

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Li, Weishuang. "Optimum Signal Design in UWB Communications." Thesis, Linnéuniversitetet, Institutionen för fysik och elektroteknik (IFE), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-78946.

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Sobhani, Bita <1981&gt. "Target Tracking in UWB Multistatic Radars." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6796/1/sobhani_bita_tesi.pdf.

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Detection, localization and tracking of non-collaborative objects moving inside an area is of great interest to many surveillance applications. An ultra- wideband (UWB) multistatic radar is considered as a good infrastructure for such anti-intruder systems, due to the high range resolution provided by the UWB impulse-radio and the spatial diversity achieved with a multistatic configuration. Detection of targets, which are typically human beings, is a challenging task due to reflections from unwanted objects in the area, shadowing, antenna cross-talks, low transmit power, and the blind zones arised from intrinsic peculiarities of UWB multistatic radars. Hence, we propose more effective detection, localization, as well as clutter removal techniques for these systems. However, the majority of the thesis effort is devoted to the tracking phase, which is an essential part for improving the localization accuracy, predicting the target position and filling out the missed detections. Since UWB radars are not linear Gaussian systems, the widely used tracking filters, such as the Kalman filter, are not expected to provide a satisfactory performance. Thus, we propose the Bayesian filter as an appropriate candidate for UWB radars. In particular, we develop tracking algorithms based on particle filtering, which is the most common approximation of Bayesian filtering, for both single and multiple target scenarios. Also, we propose some effective detection and tracking algorithms based on image processing tools. We evaluate the performance of our proposed approaches by numerical simulations. Moreover, we provide experimental results by channel measurements for tracking a person walking in an indoor area, with the presence of a significant clutter. We discuss the existing practical issues and address them by proposing more robust algorithms.

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Sobhani, Bita <1981&gt. "Target Tracking in UWB Multistatic Radars." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6796/.

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Detection, localization and tracking of non-collaborative objects moving inside an area is of great interest to many surveillance applications. An ultra- wideband (UWB) multistatic radar is considered as a good infrastructure for such anti-intruder systems, due to the high range resolution provided by the UWB impulse-radio and the spatial diversity achieved with a multistatic configuration. Detection of targets, which are typically human beings, is a challenging task due to reflections from unwanted objects in the area, shadowing, antenna cross-talks, low transmit power, and the blind zones arised from intrinsic peculiarities of UWB multistatic radars. Hence, we propose more effective detection, localization, as well as clutter removal techniques for these systems. However, the majority of the thesis effort is devoted to the tracking phase, which is an essential part for improving the localization accuracy, predicting the target position and filling out the missed detections. Since UWB radars are not linear Gaussian systems, the widely used tracking filters, such as the Kalman filter, are not expected to provide a satisfactory performance. Thus, we propose the Bayesian filter as an appropriate candidate for UWB radars. In particular, we develop tracking algorithms based on particle filtering, which is the most common approximation of Bayesian filtering, for both single and multiple target scenarios. Also, we propose some effective detection and tracking algorithms based on image processing tools. We evaluate the performance of our proposed approaches by numerical simulations. Moreover, we provide experimental results by channel measurements for tracking a person walking in an indoor area, with the presence of a significant clutter. We discuss the existing practical issues and address them by proposing more robust algorithms.

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Amin, Shoaib, and Imran Mehmood. "DETECTION OF MULTIPLE TARGETS USING ULTRA-WIDEBAND RADAR." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-9374.

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In recent years, ultra-wideband (UWB) radars are gaining popularity in the radar field mainly inindustrial and commercial areas. The UWB radar has the potential of dramatically improving thecontrol and surveillance of industrial processes in confined areas.The report provides an introduction to radar systems and detail working principle of M-sequenceUWB radar and methodology of how detection of targets is carried out. First two chapters of thereport describes the working of radar systems and M-sequence radar whereas in the later part ofthe report, different detection algorithms are discussed which has been implemented in thepresent radar simulations. In conventional radar the main detection algorithm is matched filteringwhere the transmitted signal is correlated with the received signal. Whereas UWB signal is nonsinusoidalthat is vulnerable to change in its shape during entire radar operation. This is thereason, the traditional signal processing methods like matched filtering or correlation process arenot advisable for UWB signals. Therefore, a different detection scheme known as Inter-periodcorrelation process (IPCP) has been studied.IPCP technique had been implemented and a comparison was made with the conventional targetdetection algorithm. On the basis of comparison made in this project, it has been observed thatthe conventional target detection methods are not effective in case of M-sequence UWB radar.The simulation results shows that by implementing IPCP method, performance close to 8-bitADC can be achievable with 1-bit comparator, also with IPCP implementation system resolutioncan be enhance effectively.Main focus was to analyze how close the system can detect two targets, therefore in all themeasurements i.e. practical and simulated measurements, only two targets were used.

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Torabi, Elham. "Pre-equalization for pre-Rake MISO DS-UWB systems." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/190.

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In recent years, ultra-wideband (UWB) communications has gained tremendous popularity in both research community and industry. The large bandwidth of UWB systems raises new wireless channel effects and consequently unique advantages as well as challenges to be dealt with, compared to conventional wireless systems. One of these advantages is the ability to resolve dense multipath components and use Rake combining at the receiver in order to significantly reduce the negative effects of fading. However, implementing a Rake receiver with a sufficiently large number of fingers to make use of this advantage is an evident challenge for most UWB devices with limited signal processing capabilities. A possible approach to overcome this problem is to move computational complexity from the receiver to the more powerful transmitter, which is the main focus of the present work. In this thesis, we propose two novel pre-equalization schemes for multiple- input single-output (MISO) direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining and symbol-by-symbol detection. The first pre-equalization filter (PEF) scheme employs one PEF per transmit antenna, whereas in the second, simplified PEF (S-PEF) scheme all transmit antennas share the same PEF. For both schemes the optimum finite impulse response (FIR) and infinite impulse response (IIR) PEFs are calculated based on the minimum mean squared error (MMSE) criterion. We show that in contrast to previously proposed schemes for DS-UWB, both our proposed PEF schemes efficiently exploit the channel shortening properties of the pre-Rake filter. In particular, our proposed PEF schemes operate at the symbol level. We also show that under certain conditions the S-PEF scheme achieves the same performance as the more complex PEF scheme. Finally, we demonstrate that a single-input multiple-output (SIMO) DS-UWB system with post-Rake combining and MMSE post-equalization is the dual system to the considered MISO DS–UWB system with pre-Rake combining and MMSE pre-equalization. This uplink-downlink duality can be exploited for efficient calculation of the PEFs and for complexity reduction. Our simulation results show that the proposed PEF schemes achieve significant performance gains over pre-Rake combining without equalization even if only short PEFs are employed, and this is the case even for long UWB channel impulse responses.

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Gunasekara, A. K. Isuru Udayanga W. "Contactless Estimation of Breathing Rate Using UWB Radar." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/37049.

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Contactless breathing estimation using radars has been explored since the 1960s and an accurate system with the ability to continuously monitor the health of non-critical patients without obstructing their day to day lives could significantly improve their well being. The current state of the art in this area does not have the accuracy required to work in a real-world environment and many of the existing methods have been tested only under very controlled situations. Low performance of breathing estimation algorithms under different scenarios inspired us to improve breathing estimation algorithms and develop a system for automated analysis of large number of algorithms against data from the reference sensors. A novel accurate breathing rate estimation method and a system to use multiple algorithms on the same set of data in real-time and identify the best performing algorithm dynamically to report breathing rate have been proposed in this thesis. In addition, automated data-collection and processing frameworks were developed to collect a large amount of data and process them and generate reports automatically. The proposed system has been tested under multiple test-cases involving multiple subjects and the accuracy of both new and existing algorithms have been evaluated by comparing the results with reference data collected using a respiration belt. The mean absolute error rate of breathing rate estimation after conducting experiments for a total of 9 subjects was found to be 0.79 breaths per minute for the novel CEEMD based method presented in this thesis. The mean absolute error rate after applying the scoring algorithm to select the best performing algorithm is 0.78 breaths/minute.

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Cui, Wentao. "Wavelength Reuse in UWB-Over-Fiber Networks." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26277.

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Wavelength reuse techniques for bidirectional ultra-wide band (UWB) over fiber (UWBoF) networks are presented. The downstream optical signal from the central station (CS) is reused for upstream data transmission with the original data erased at the base station (BS). Two wavelength reuse schemes for the generation of a clear optical carrier at the BS are theoretically analyzed and experimentally demonstrated. In the first scheme, the wavelength reuse is based on phase-modulation to intensity-modulation (PM-IM) conversion and destructive interferencing using a polarization modulator (PolM) and a fiber Bragg grating (FBG). A theoretical analysis is performed which is verified by an experiment. In the second scheme, the wavelength reuse is based on injection locking of a Fabry–Pérot laser diode (FP-LD) and polarization multiplexing. The UWB injection signal contributes to better BERs of both downstream and upstream services and a lower power penalty cause by the wavelength reuse of the whole system than the baseband signal. A bidirectional point-to-point transmission of over a 25-km single-mode fiber (SMF) using a single wavelength from the CS in each scheme is demonstrated.

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Llano, Ramírez Gonzalo. "Modelado en frecuencia del canal UWB y su aplicación en el análisis de técnicas de modulación adaptativa en sistemas MB-OFDM UWB para redes WPAN." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8429.

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En esta tesis doctoral se plantea la mejora de la capacidad de transmisión en las redes HDR-WPAN ( redes WPAN con elevada tasa binaria) empleando el estándar MB-OFDM (OFDM sobre múltiples bandas) en canales UWB con modulación adaptativa realizando una adaptación discreta de la tasa de bits transmitidos por subportadora. La tesis comienza con un análisis en el dominio del tiempo y de la frecuencia de los dos modelos de canal UWB propuestos en IEEE: IEEE 802.15.3a y 802.15.4a. El objetivo consiste en determinar la distribución estadística que mejor se aproxima a la amplitud de cada una de las subportadoras, para posteriormente definir la métrica a emplear en la evaluación del estado y dinámica del canal UWB. En la modulación adaptativa se requiere que el transmisor se adapte a la variabilidad del canal. El análisis se puede realizar de dos formas: - Asumiendo adaptación perfecta (estimación ideal), lo que implica que el transmisor siempre conoce la dinámica y estructura del canal. - Considerando un error (estimación imperfecta del canal) en la adaptación debido a la incertidumbre en el conocimiento del canal. El método de estimación del canal UWB empleado en la tesis se fundamenta en el conocimiento del coeficiente de correlación en potencia entre las subportadoras de datos y la subportadora piloto. A partir de la información sobre el estado del canal, u una vez definida la métrica que permite su evaluación, se calculan las prestaciones de la modulación adaptativa. Esta evaluación se realiza a través de expresiones cerradas para la capacidad media, la probabilidad de error de bit media y la probabilidad de bloqueo, así como la obtención de la distribución y estadísticos del error de estimación en el caso de estimación imperfecta del canal. Por otro lado, a partir de la distribución estadística de la amplitud de cada una de las subportadoras en frecuencia del canal UWB, se obtienen resultados respecto a la variación de potencia del canal en función del ancho de banda .
Llano Ramírez, G. (2010). Modelado en frecuencia del canal UWB y su aplicación en el análisis de técnicas de modulación adaptativa en sistemas MB-OFDM UWB para redes WPAN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8429
Palancia

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Parrini, Matteo. "Caratterizzazione sperimentale di sistemi di comunicazione UWB." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

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Questo elaborato presenta la caratterizzazione sperimentale di un sistema di comunicazione e localizzazione della DecaWave. Il sistema analizzato �è il kit EVK1000, che permette di e�ffettuare stime di distanza tra due nodi e una comunicazione robusta ai disturbi e immune alla propagazione multicammino grazie alla tecnologia UWB.

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Javashvili, Otar. "UWB Antennas for Wall Penetrating Radar Systems." Thesis, University of Gävle, University of Gävle, University of Gävle, Center for RF Measurement Technologies, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-5509.

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Basic properties and new design principles of ultra wideband Vivaldi antennas are presentedand discussed in this paper. The focus will be on the modeling of Vivaldi antenna design curves, by which it is constructed; its simulation results, realization and the measurements.

According to the aim of this research the discussion starts with the review of the previous researches done for Vivaldi antennas. Introductory part of the report also contains the problem description for the current project and the classification of the goals to be achieved. As a theoretical review, the discussion initiates with the definitions anddescription of basic parameters of the antennas and covers a short presentation of UWBpulse-based radar system. The attention will be focused on UWB signals behavior and characterization, their propagation principles and basic troubles stands nowadays. As anapplication the wall penetrating Radar systems will be considered. The major part of thereport holds on the investigation of the design principles of Vivaldi Antenna andoptimization of the key parameters for achieving the best performance for radar. Theending part of the report shows the simulations and measurement results and theircomparisons following with conclusions/discussions.

The report will be supportive for the antenna designers, who work for UWB systems andparticularly for Vivaldi antennas, as long as there are showing up detailed descriptions ofVivaldi antenna characteristics depending on its shape and substrate properties. The modelfor designing Vivaldi antennas, given in this project, can successfully be applied for almostall the cases used in practice nowadays.

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Onunkwo, Uzoma Anaso. "Timing Jitter in Ultra-Wideband (UWB) Systems." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10465.

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Timing offsets result from the use of real clocks that are non-ideal in sampling intervals. These offsets also known as timing jitter were shown to degrade the performance of the two forms of UWB systems impulse radio and orthogonal frequency division multiplexing (OFDM)-based UWB. It was shown that for impulse radio, timing jitter distorts the correlation property of the transmitted signal and the resulting performance loss is proportional to the root-mean-square (RMS) value of the timing jitter. For the OFDM-based UWB, timing jitter introduced inter-channel interference (ICI) and the performance loss was dependent on the product of the bandwidth and the RMS of the timing jitter. A number of techniques were proposed for mitigating the performance degradation in each form of UWB. Specifically, for impulse radio, the methods of pulse shaping and sample averaging were provided, whereas for OFDM-based UWB, oversampling and adaptive modulation were given. Through analysis and simulation, it was shown that substantial gain in signal power-to-noise ratio can be achieved using these jitter-reduction methods.

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Rabbachin, A. (Alberto). "Low complexity UWB receivers with ranging capabilities." Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514288005.

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Abstract This Thesis examines low complexity receiver structures for impulse-radio (IR) ultra-wideband (UWB) systems to be used in wireless sensor network applications. Such applications require radio communication solutions characterized by low cost, low complexity hardware and low power consumption to provide very long battery life. Analysis of several auto-correlation receiver (AcR) structures is performed in the presence of additive white Gaussian noise to identify receiver structures that offer a good compromise between implementation complexity and data communication performance. The classes of receiver that demonstrate the best complexity/performance trade-off are shown to be the AcR utilising transmitted-reference with binary pulse amplitude modulation signaling, and the energy detector (ED) utilising binary pulse position modulation. The analysis of these two schemes is extended to consider multipath fading channels. Numerically integrable bit error rate probability (BEP) expressions are derived in order to evaluate the receivers' performance in the presence of fading distributions characterized by closed form characteristic functions. Simulations utilising widely accepted UWB channel models are then used to evaluate the BEP in different indoor environments. Since UWB systems share frequency spectrum with many narrowband (NB) systems, and need to coexist with other UWB systems, the performance of low complexity receivers can be seriously affected by interference. In the presence of NB interference, two cases have been considered: 1) single NB interference, where the interfering node is located at a fixed distance from the receiver, and 2) multiple NB interference, where the interfering nodes are scattered according to a spatial Poisson process. When considering UWB interference, the case of multiple sources of interference has been considered. For both the multiple NB and the multiple UWB interference cases, the model derived considers several interference parameters, which can be integrated into BEP formulations for quick performance evaluations. The framework is sufficiently simple to allow tractable analysis and can serve as a guideline for the design of heterogeneous networks where coexistence between UWB systems and NB systems is of importance. The very large bandwidth of UWB signals offers an unprecedented possibility for accurate ranging operations. Signal leading-edge estimation algorithms based on average maximum likelihood estimators are derived considering different multipath channel fading distributions. Suboptimal solutions are proposed and investigated in order to support ranging capabilities in low complexity receiver structures. The ability to identify line-of-sight and non-line-of-sight conditions with the ED-based receiver is also addressed. An example of an IR-UWB low complexity transceiver based on ED for sensor network applications is proposed in this Thesis. Ad-hoc solutions for pulse transmission, synchronization and data detection are developed.

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Lu, Dongtian. "High speed CMOS ADC for UWB receiver /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20LUD.

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Heyi, Binyam Shiferaw. "Implementation of Indoor Positioning using IEEE802.15.4a (UWB)." Thesis, KTH, Kommunikationsnät, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-117920.

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Indoor positioning is a technique that is used to locate a mobile device in indoor environment in real or near real-time. The demand for indoor positioning system as a location based system is becoming more and more widespread. However, the field has not gain much success as outdoor positioning system. The objective of this thesis work is to design and implement an indoor positioning system that relies on ultra wide band technology. The report also describes the way how to implement IEEE802.15.4a physical layer and medium access layer .The system uses time difference of arrivals technique to estimate the position of the mobile device. Through an evaluation of our system, we conclude that ranging can reach an accuracy of ±20cm in line of sight measurement and ± 50cm for non-line of sight measurement. But the localization that is achieved has an accuracy is up to ±1.1m, we believe this can be improved by having all device to be synchronized effectively.

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Ruengwaree, Amnoiy [Verfasser]. "Design of UWB Radar Sensors / Amnoiy Ruengwaree." Kassel : Kassel University Press, 2008. http://d-nb.info/1004234740/34.

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Mirshafiei, Mehrdad. "UWB Pulse Shaping Using Fiber Bragg Gratings." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26074/26074.pdf.

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Lagerkvist, Anders. "Construction of an indoor positioningsystem using UWB." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-72958.

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Sakamoto, Takuya. "Nonparametric Imaging Algorithms for UWB Pulse Radars." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/68884.

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Ibrahim, Jihad E. "Algorithms and Architectures for UWB Receiver Design." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/26105.

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Impulse-based Ultra Wideband (UWB) radio technology has recently gained significant research attention for various indoor ranging, sensing and communications applications due to the large amount of allocated bandwidth and desirable properties of UWB signals (e.g., improved timing resolution or multipath fading mitigation). However, most of the applications have focused on indoor environments where the UWB channel is characterized by tens to hundreds of resolvable multipath components. Such environments introduce tremendous complexity challenges to traditional radio designs in terms of signal detection and synchronization. Additionally, the extremely wide bandwidth and shared nature of the medium means that UWB receivers must contend with a variety of interference sources. Traditional interference mitigation techniques are not amenable to UWB due to the complexity of straight-forward translations to UWB bandwidths. Thus, signal detection, synchronization and interference mitigation are open research issues that must be met in order to exploit the potential benefits of UWB systems. This thesis seeks to address each of these three challenges by first examining and accurately characterizing common approaches borrowed from spread spectrum and then proposing new methods which provide an improved trade-off between complexity and performance.
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Xu, Yizhi. "Indoor ranging and geolocation for UWB systems /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20XUY.

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Chien-Yu, Chen. "Comparison of MAC Layer Mechanisms for WiMedia UWB and UWB Forum." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2707200617152400.

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Hsu, Hui Chen, and 許慧貞. "10-30GHz UWB Low Noise Amplifier and UWB Down-Conversion Mixer." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/19923086049974510263.

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碩士
長庚大學
電子工程學研究所
97
This thesis presents the development of RF CMOS circuits for 10-30GHz UWB (Ultra Wide Band) transceivers including low noise amplifier and UWB down conversion mixer with TSMC 0.13µm RF model CMOS standard process. All circuits were simulated and designed by Agilent ADS (Advanced Design System) software. The CMOS RF receiver is focused on low power consumption, and operated at 10-30GHz bandwidth. This work includes distributed amplifier (DA), feedback low-noise amplifier and down-conversion mixer. The operating radio frequency is between 10~30GHz, and the supply voltage is 1.2V. The bandwidth of baseband frequency is 200MHz. In this thesis, the distributed amplifier has a power gain of 7.5dB and noise figure of about 3.97dB. Input and output return losses are smaller than -6dB and -10dB, respectively. Power consumption is 39.24mW and chip area of 1.037mm2. Measurement results of feedback low-noise amplifier show the gain of 2.5dB with a flatness of ±0.5dB. Both input and output return losses are smaller than those of -6dB. And the IIP3 is 5.03dBm. Power consumption is 21.24mW and chip area of 0.69mm2. Down conversion mixer shows a conversion gain of 5.88~11.47dB and the return loss of RF Port is smaller than -12dB. Power consumption is 23.4mW, and IIP3 of -7dBm. The LO to BB isolation and RF to BB isolation are -20dB and -20dB, respectively. The chip area is 1.146mm2.

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Chen, Chien-Yu, and 陳建宇. "Comparison of MAC Layer Mechanisms for WiMedia UWB and UWB Forum." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/92551282798116210606.

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碩士
國立臺灣大學
電機工程學研究所
94
Ultra-wide band (UWB) is a wireless communication technology under widely discussed recently. It can provide high transmission rate from hundreds of Mbps up to Gbps level. Combine the characteristics of high data rate, low transmission power, and short range coverage, UWB is considered to be suitable for the WPAN and received significant interests for future wireless communication from both academia and industry. The application of UWB includes wireless USB and wireless transmission of digital content in digital home. There are two main UWB standards existed, WiMedia Alliance UWB and UWB Forum. WiMedia UWB uses multi-band OFDM as its physical layer while UWB Forum adopts pulsed based direct-sequence UWB for its physical layer technology. MAC layer is on the top of the physical layer and is responsible for medium assess control mechanisms such as medium access and sharing, admission control, scheduling, power management, security, and so on. It affects the efficiency of the system performance a lot and may be waste of the bandwidth provides by the physical layer if it does not define carefully. We are going to look into the MAC layer mechanisms of both the alliances. By studying the MAC layer respectively, it’s possible to obtain the common and different parts of them, which gives us insight of the performance and direction of the future research issues. We provide a comprehensive overview on MAC layer and have a detail comparison between both systems.

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Dissertations / Theses on the topic 'UWB'

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