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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Differential Code-Shifted Reference Impulse-Radio Ultra-Wideband Receiver: Signal Strength Adjustment and Implementation

Liu, Mingwei 01 April 2014 (has links)
IR-UWB is a wireless system, which sends information data with pulses that have rapid rising and falling time and very short duration of nanosecond or less. However, due to varying communication channel conditions, amplitude of the received signal is not at a constant level. Therefore, automatic signal strength adjustment is required to equalize the impact of variations of the channel conditions. In this thesis, two approaches based on automatic gain control technique are proposed. The first design is a feed-forward automatic gain control system working at baseband. The second design is a feedback automatic gain control system operating at radio or microwave frequency. The corresponding simulation and implementation results are provided to validate the designs. The proposed designs present signal strength controls for impulse-based transceiver systems which are not often addressed in the literature. It is found that the first design does not work well in reality due to the fact that it essentially operates in the baseband and has no impact on the strong or weak signals right after the receiver antenna. The second design functions quite well and presents a dynamic range of 179mV to 1.062V. As a result, it is the choice of this thesis work.
2

Automatic Gain Control and Doppler Motion Models in LabVIEW

Laird, Daniel T. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / A simplex or ‘passive’ continuous wave and monopulse seeker tracks specific attributes of a target’s radio frequency (RF) radar return in some coordinate frame. In particular, a return carries dynamic information in amplitude (ω) and frequency (ω) at some point in azimuth (r,θ) and elevation (r,θ) planes. A passive seeker requires an illuminator beam, I(ω,φ,θ), and may require a frequency modulation on the illuminator. To model a simplex target return, we have based the dynamics on a point source radar cross section (RCS) along a line of sight (LoS) radial. The Az and El angles are equivalent to antenna placement, the attenuation and frequency dynamics are modeled in commercial off-the-shelf (COTS) software.
3

A VALUABLE TOOL TO HAVE WHEN WORKING WITH PSK DEMODULATORS IS A KNOWLEDGE OF ITS FUNCTIONALITY

Cylc, Linda 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / PSK demodulators have been an integral part of the signal recovery process for decades. Unless a person has designed a demodulator, how much can a person know or understand about its operation? Instruction on how to set up a demodulator’s parameters to acquire a signal is found in a manual. An explanation of why parameters are set a certain way to handle particular input signal characteristics is often not provided in a manual. This paper is designed to be a tool to aid engineers, technicians, and operators who utilize demodulators. Its purpose is to relay the functionality of a demodulator to a user so that he or she can take advantage of its control parameters and status feedback. Knowing the reasons why a demodulator is set to certain parameters may greatly reduce confusion when a system is not working properly. On site troubleshooting may be accomplished without the need to call the manufacturer of the product. Another advantage of understanding the operation will be recognized when interfacing with the manufacturer. A person will be able to relay the information to a design engineer more easily, and will understand more of the engineer’s feedback on the potential problem. Utilizing this paper as an aid to enhance operation of a PSK demodulator will bring a user one step closer to understanding the complexity of its design.
4

Study and Implementation of Automatic Gain Control, High Voltage Integrated Circuits, and Backplane Transceiver

Yang, Shang-Hsien 26 July 2011 (has links)
Thanks to the advance in CMOS technology, an extensive category of applications has been migrated from traditional BJT-based processes. System-on-a-Chip (SoC) realization of digital, analog, and even high voltage devices is now a reality. To address the challenge imposed by integrating analog and high voltage devices in standard CMOS processes, this thesis aims at the design of three specific topics in particular. With regard to the contents of the thesis, first of all, the theory of linear-in-dB automatic gain control (AGC) is discussed. In succession, a linear-in-dB variable gain amplifier (VGA) is mentioned. The implementation of a Feed-forward Output Swing Prediction AGC featuring a Prediction Parallel-Detect Single-Store Peak Detector (PDSSPD) and a High Input/Output Swing VGA is also described. Furthermore, a digitally programmable gain amplifier for a ZigBee wireless receiver is also mentioned. In response to the advent of CMOS-compatible high voltage tolerant Bipolar-CMOS-DMOS (BCD) process, an operational amplifier for level converting operation is disclosed. A 60-V Li-ion battery charger has also been proposed, along with a novel battery charge mode, namely, the incremental charge (IC) mode. Practical issues regarding the high voltage tolerant BCD process is also briefly discussed. Finally, a backplane transmitter featuring pre-emphasis and a receiver utilizing decisive feedback equalization (DFE) designed for CIC MorPack technology are presented. When packaged in a Leadless Ceramic Carrier (LCC) package, the transmitter can transmit up to 500 Mbps and the receiver can receive up to 125 Mbps, both through DuPont connectors without impedance matching.
5

TOWARDS A NEW TRACKING ARCHITECTURE

Busson, Francois, Pierozak, Jean-Guy, Richard, Hugues, Kipfer, Gerard 11 1900 (has links)
A telemetry facility may connect numerous telemetry receivers to a single tracking antenna depending on the number of TM channels involved in the test and on the required redundancy. The tracking data, i.e. AM normalized analog signals extracted by the receivers from the TM signal and the AGC analog signals, are sent to the Antenna Control Unit (ACU) for tracking error calculation. The number of cables between receivers and ACU becomes important in some telemetry facilities and the tracking signals being analog, the distance must be limited. This paper proposes a new tracking architecture that moves from analog to digital links between receivers and ACU with the following main benefits:  Keeping the capability to acquire tracking data (AM&AGC) from several telemetry receivers,  Having more flexibility for integration,  Improving interoperability,  Providing availability of simultaneous tracking errors for enhanced tracking algorithms, for C-band tracking improvement for example.
6

Utveckling av prototyp för uppmätning av blodflöde med Dopplersensorer

Johansson, Tomas January 2016 (has links)
The current most common methods for measuring a blood vessels flow with Doppler technique requires a cable between the patient and measuring instrument. In today’s technology and the progress made in microelectronics have made it possible to manufacture ultrasonic transmitters and receivers, control electronics and antennas small enough for them to be integrated in a probe attached to the blood vessel. In order to read the flow of blood used NFC to securely send the information wireless to a smartphone or a tablet. This ensures that the cable between the patient and the measuring instrument would not be needed and the patient possibility to move would increase. So this thesis was to continue on a prototype using a Raspberry Pi and other medical equipment to approach toward the ultimate objective. So with help of filtering and amplification the target was to reduce noise and amplify the signal so that the correct data was send to the recipient’s smartphone or tablet. / De nuvarande vanligaste metoderna för att mäta upp ett blodkärls blodflöde med Doppler-teknik kräver en kabel mellan patient och mätinstrument. I dagens teknik och de framsteg som har gjorts inom mikroelektroniken har gjort det möjligt att tillverka ultraljudssändare och mottagare, styrelektronik och antenner i tillräckligt liten storlek för att de ska kunna integreras i en prob som fästs vid blodkärlet. För att kunna läsa av blodflödet används NFC för att säkert kunna skicka över information trådlöst till en smartphone eller en surfplatta. Detta medför att kabeln mellan patienten och mätinstrumentet inte skulle behövas och patientens möjlighet att röra sig skulle öka. Så det här examensarbetet gick ut på att fortsätta på en prototyp med hjälp av en Raspberry Pi och annan medicinsk utrustning för att närma sig det slutgiltiga målet. Så med hjälp av filtrering och förstärkning är målet att minska störningar och förstärka signalen så att rätt data skickas till mottagarens smartphone eller surfplatta.
7

RSK2 et Greatwall, deux AGC kinases actrices de la mitose / RSK2 and Greatwall, two AGC kinases involved in the regulation of mitosis

Brioudes, Estelle 25 November 2010 (has links)
La mitose est une phase importante du cycle cellulaire. Les mécanismes de surveillance s'assurent de l'ordre et de l'exécution correcte des événements du cycle cellulaire dont les erreurs peuvent conduire à l'aneuploïdie. Pendant la mitose, la séparation des chromatides sœurs est régulée par le point de contrôle du fuseau mitotique qui s'assure que tous les chromosomes sont correctement alignés sur la plaque métaphasique. L'entrée et la sortie de mitose sont régulées par l'activation et l'inactivation du complexe cycline B/Cdk1. Cette fine régulation fait intervenir de nombreuses kinases et phosphatases. Dans ce projet nous nous sommes intéressés plus particulièrement à deux AGC kinases : RSK2 et Greatwall (Gwl).Au cours de cette étude nous nous sommes proposés d'analyser l'implication de RSK2, substrat majeur de la MAPK, dans le point de contrôle du fuseau mitotique. Nos résultats montrent que RSK2 est essentielle pour l'activité du point de contrôle du fuseau mitotique dans les extraits d'œufs de xénope ainsi que pour la localisation des autres protéines de ce mécanisme de surveillance localisées aux kinétochores. Nous montrons également que RSK2 participe au point de contrôle dans les cellules humaines. En effet, RSK2 est nécessaire à la localisation aux kinétochores de Mad1, Mad2 et Cenp-E, protéines essentielles à l'activité de ce checkpoint. L'entrée et la sortie de mitose sont régulées par le complexe cycline B/Cdk1 et des phosphatases. Gwl est une nouvelle kinase essentielle à l'entrée en mitose et au maintien de l'état mitotique dans les extraits d'œufs de xénope. En effet, nos résultats montrent que Gwl maintient l'état mitotique indépendamment du complexe cycline B/Cdk1, en régulant négativement PP2A, une phosphatase responsable de la déphoshorylation des substrats mitotiques. / Mitosis is an important phase of cell cycle. The Spindle Assembly Checkpoint (SAC) verifies the orders and the events correct execution of the cell cycle, as errors may lead to aneuploidy. During the mitosis, the checkpoint delays the anaphase onset until all chromosomes are correctly attached to the spindle‘s microtubules. Entry and Exit of mitosis are regulated by the activation and inactivation of cyclin B/Cdk1. A lot of kinases and phosphatases are involved in this fine regulation. In this project, we are particularly focusing on two AGC kinases: RSK2 and Greatwall (Gwl).In this study, we analyzed RSK2, a major substrates of MAPK, involvement in SAC. Our results show that RSK2 is essential to the activation of SAC in xenopus egg extracts and for the localization at the kinétochores of the others SAC components. We also show that RSK2 participate in the maintenance of the SAC in human cells. Indeed, RSK2 is necessary for Mad1, Mad2 and Cenp-E localization, essential proteins for SAC activation.Entry and exit of mitosis are regulated by cyclin B/Cdk1 complex and phosphatases. Gwl is a new kinase essential to the entry into mitosis and maintenance of the mitotic state in xenopus egg extracts. Indeed, our results showed that Gwl maintains the mitotic state independently of cyclin B/Cdk1 but with the negative regulation of PP2A, which dephosphorylate the mitotic substrates
8

[en] JOINT AUTOMATIC GAIN CONTROL AND RECEIVER DESIGN FOR QUANTIZED LARGE-SCALE MU-MIMO SYSTEMS / [pt] PROJETO CONJUNTO DO AGC E DO RECEPTOR EM SISTEMAS MU-MIMO DE GRANDE ESCALA QUANTIZADOS

THIAGO ELIAS BITENCOURT CUNHA 27 September 2019 (has links)
[pt] O emprego conjunto de Redes de Acesso por Rádio em Nuvem (CRANs) e sistemas de múltiplas entradas e múltiplas saídas (MIMO) de larga escala é uma solução chave para atender aos requisitos da quinta geração (5G) de redes sem fio. No entanto, alguns desafios ainda precisam ser superados como a redução do consumo de energia do sistema, a capacidade limitada dos links fronthaul e a redução dos custos de implantação e operação. Embora seja prejudicial para o desempenho do sistema, a quantização em baixa resolução é proposta como uma solução para estes desafios. Portanto, técnicas que melhoram o desempenho de sistemas quantizados grosseiramente são necessárias. Em sistemas móveis, os ADCs geralmente são precedidos por um controle de ganho automático (AGC). O AGC trabalha moldando a amplitude do sinal recebido dentro do intervalo do quantizador para usar eficientemente a resolução. A fim de solucionar esses problemas, esta dissertação apresenta uma otimização conjunta do AGC, que funciona nas cabeças de rádio remotas (RRHs), e um filtro de recepção linear de baixa resolução consciente (LRA) baseado no mínimo erro quadrático médio (MMSE), que funciona na unidade de nuvem (CU), para sistemas quantizados grosseiramente. Desenvolvemos receptores de cancelamento de interferência lineares e sucessivos (SIC) com base na proposta conjunta de AGC e LRA MMSE (AGC-LRA-MMSE). Uma análise da soma das taxas alcançáveis juntamente com um estudo de complexidade computacional também são realizadas. As simulações mostram que o projeto proposto fornece taxas de erro reduzidas e taxas alcançáveis mais altas do que as técnicas existentes. / [en] The joint employment of Cloud Radio Access Networks (C-RANs) and large-scale multiple-input multiple-output (MIMO) systems is a key solution to fulfill the requirements of the fifth generation (5G) of wireless networks. However, some challenges are still open to be overcome such as the high power consumption of large-scale MIMO systems, which employ a large number of analog-to-digital converters (ADCs), the capacity bottleneck of the fronthaul links and the system cost reduction. Although it often affects the system performance, the low-resolution quantization is a possible solution for these problems. Therefore, techniques that improve the performance of coarsely quantized systems are needed. In mobile applications, the ADCs are usually preceded by an automatic gain control (AGC). The AGC works shaping the received signal amplitude within the quantizer range to efficiently use the ADC resolution. Then, the optimization of an AGC is especially important. In order to present possible solutions for these issues, this thesis presents a joint optimization of the AGC, which works in the remote radio heads (RRHs), and a low-resolution aware (LRA) linear receive filter based on the minimum mean square error (MMSE), which works in the cloud unit (CU), for coarsely quantized large-scale MIMO with CRAN systems. We develop linear and successive interference cancellation (SIC) receivers based on the proposed joint AGC and LRA MMSE (AGCLRAMMSE) approach. An analysis of the achievable sum rates along with a computational complexity study is also carried out. Simulations show that the proposed design provides improved error rates and higher achievable rates than existing techniques.
9

Oscilátory a funkční generátory s proudovými a napěťovými konvejory / Oscillators and function generators using current and voltage conveyors

Šťastný, Lukáš Unknown Date (has links)
Conveyors are an integral part of modern devices. In this thesis, a slew of areas oscillators and function generators with current and voltage conveyors. Individual applications are categorized according involvement with conveyors and other elements. The functionality of the need for involvement in the program PSpice simulation. As a current conveyor is used OPA861, EL2082, further use of RC circuits and opto-CNY 17.
10

Finanční analýza společnosti AGC Flat Glass Czech, a.s. / Financial analysis of AGC Flat Glass Czech, a.s.

Šmoldasová, Barbora January 2011 (has links)
This thesis includes a financial analysis of AGC Flat Glass Czech a.s. on the basis of financial reports of the period 2005 - 2009. The theoretical part describes the methods of financial analysis - absolute and ratio analysis, predictive models, economic value added. The practical part includes an analysis of macroeconomic and industry growth, the financial analysis and comparison with the industry.

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