My master’s thesis deals with methods of measuring the ultrasonic blood flow blood vessel with a detailed focus on Doppler ultrasound systems, which find application in the diagnosis of superficial vascular and obstetrics. The thesis is described a proposal indicating polydirectional Doppler system with a continuous carrier wave frequency of 4 MHz, the intensity of ultrasound 100 mW/cm2 and diameter D-shaped transducers 8 mm. As a result, the indicator will be able to measure blood flow velocity in the range of 5-40 cm/s, which appears to 3.5 digit display. After describing important theoretical assumptions, the work pays block diagram indicator. Furthermore, it examines the various functional blocks on the requirements imposed on them. It looks at the options of each functional block, and finally describes the implementation of the selected option and including peripheral solutions. Great attention is paid to the power of the indicator, where the power supply will be used 9 V battery. Create a symmetric voltage for operate amplifier and other auxiliary voltage will procure DC/DC converters. In conclusion, the work is located around the perimeter solutions indicator. The following draft for the production of double-sided PCB, its installation and a list of elements. The outcome of the thesis is complete documentation for the implementation of an indicator of blood flow, which allows us to obtain information on throughput vessels, especially the lower and upper limbs.

Approved for public release; distribution is unlimited / The radio channel places fundamental limitations on the performance of mobile ad hoc wireless networks. In the mobile radio environment, fading due to multipath delay spread impairs received signals. The purpose of this thesis is to develop a radio channel model and examine the effect of various parameters on channel behavior that is representative of environments in which mobile ad hoc wireless networks operate. The various physical phenomena considered are outdoor environments, fading and multipath propagation, type of terrains, and mobility (Doppler shift). A channel model based on a Tapped Delay Line (TDL) structure was developed and implemented in the MATLAB programming language, and the performance of the time-varying channel was studied by plotting the signal constellations. The simulation results indicate that the number of taps required in the TDL is 8 or less and the carrier frequency did not influence the performance significantly. The Jakes Doppler spectrum should be used in urban environments with high mobility; the Gaussian Doppler spectrum is the choice for low mobility urban environments and for the hilly terrain under both low and high mobility. / Civilian, Singapore Ministry of Defense

Dans cette thèse, nous étudions comment la présence de parois affecte les ondes de surface. La dissipation associée au mouillage, objet central des premiers chapitres, est abordée expérimentalement. Nous mesurons son évolution avec la taille du ménisque et montrons qu’en mouillage total des non-linéarités apparaissent dès que l’oscillation du ménisque atteint l’épaisseur des couches limites. Dans un deuxième temps, nous quantifions les échanges d’énergie ayant lieu lors de laréflexion d’une onde de surface sur une paroi oscillante, appelés effet Doppler généralisé. Après une mise en évidence expérimentale, une approche théorique les évalue et illustre comment leurs effets cumulatifs peuvent mener à des spectres en compétition avec ceux de la turbulence d’ondes. Finalement, nous traitons les interactions entre paquets d’ondes. En géométrie confinée, nous montrons que des résonances à trois ondes gravitaires sont autorisées. Dépassant la problématique des parois, nous caractérisons les interactions entre ondes gravitaires en milieu infini, puis décrivons les grandes échelles de la turbulence d’ondes capillaire. / In this thesis, we study the impact of solid boudaries on surface waves. We first consider the dissipation caused by dynamical wetting. We experimentally show how the damping of surface waves evolves with the size of the meniscus and demonstrate that in perfect wetting it leads to a nonlinear behavior as soon as the meniscus oscillation amplitude compares to the thickness of the boundary layer. Secondly, we investigate energy exchanges through scales occuring when a surface wave reflects on an oscillating wall, the so-called generalized Doppler effect. We evidence the creation of Doppler-shifted waves, compute their amplitudes and illustrate how the continuous bouncing of surface waves on wavemakers may lead to self-similar spectra competing with the ones of wave turbulence. Finally, we focus on nonlinear interaction between surface waves. We prove that gravity waves can undergo triad resonances in confined geometry. Going beyond the consequencies of solid boundaries, we perform experiments on four-wave interactions in the gravity regime and describe large scales in capillary wave turbulence.

This work concentrates on the application of diversity techniques and space time block coding for future high speed mobile wireless communications on multicarrier systems. At first, alternative multicarrier kernels robust for high speed doubly-selective fading channel are sought. They include the comparisons of discrete Fourier transform (DFT), fractional Fourier transform (FrFT) and wavelet transform (WT) multicarrier kernels. Different wavelet types, including the raised-cosine spectrum wavelets are implemented, evaluated and compared. From different wavelet families, orthogonal wavelets are isolated from detailed evaluations and comparisons as suitable for multicarrier applications. The three transforms are compared over a doubly-selective channel with the WT significantly outperforming all for high speed conditions up to 300 km/hr. Then, a new wavelet is constructed from an ideal filter approximation using established wavelet design algorithms to match any signal of interest; in this case under bandlimited criteria. The new wavelet showed better performance than other traditional orthogonal wavelets. To achieve MIMO communication, orthogonal space-time block coding, OSTBC, is evaluated next. First, the OSTBC is extended to assess the performance of the scheme over extended receiver diversity order. Again, with the extended diversity conditions, the OSTBC is implemented for a multicarrier system over a doubly-selective fading channel. The MIMO-OFDM systems (implemented using DFT and WT kernels) are evaluated for different operating frequencies, typical of LTE standard, with Doppler effects. It was found that, during high mobile speed, it is better to transmit OFDM signals using lower operating frequencies. The information theory for the 2-transmit antenna OSTBC does not support higher order implementation of multi-antenna systems, which is required for the future generation wireless communications systems. Instead of the OSTBC, the QO-STBC is usually deployed to support the design of higher order multi-antenna systems other than the 2-transmit antenna scheme. The performances of traditional QO-STBC methods are diminished by some off-diagonal (interference) terms such that the resulting system does not attain full diversity. Some methods for eliminating the interference terms have earlier been discussed. This work follows the construction of cyclic matrices with Hadamard matrix to derive QO-STBC codes construction which are N-times better than interference free QO-STBC, where N is the number of transmit antenna branches.

Les systèmes de navigation par satellite (GNSS) font partie de notre quotidien. On peut présentement les trouver dans un ensemble d’applications. Avec les nouveaux besoins, des nouveaux enjeux sont aussi apparus : le traitement du signal dans les environnements urbains est extrêmement complexe. Dans cette thèse, le traitement des signaux GNSS à faible puissance est abordé, en particulier dans la première phase du traitement, nommé acquisition de signal. Le premier axe de rechercheporte sur l’analyse et la compensation de l’effet Doppler dans l’acquisition. Le décalage Doppler perçu par l’utilisateur est un des paramètres principaux pour la configuration du module d’acquisition. Dans cette étude, des solutions sont proposées pour trouver le meilleur compromis sensibilité-complexité propre à l’acquisition. En deuxième axe, la caractérisation des détecteurs différentiels est abordée, en particulier la quantification de sa sensibilité. Pour l’acquisition des signaux faibles, après une première phase d’intégration cohérente, il faut passer par une intégration «postcohérente» (noncohérente ou différentielle.) L’analyse exécutée ici permet de meilleur identifier le meilleur choix entre les deux possibilités. Le troisième axe de recherche est consacré à la méthode de Détection Collective (CD), une innovation qui fait l’acquisition simultanée de tous les signaux visible par le récepteur. Plusieurs analyses sont réalisées incluant l’amélioration de la procédure de recherche de la CD, et l’hybridisation avec l’acquisition standard. Enfin on effectuel’analyse de la CD dans un contexte multi-constellation, en utilisant simultanément des vrais signaux GPS et Galileo. / Satellite navigation (GNSS) is a constant in our days. The number of applications that depend on it is already remarkable and is constantly increasing. With new applications, new challenges have also risen: much of the new demand for signals comes from urban areas where GNSS signal processing is highly complex. In this thesis the issue of weak GNSS signal processing is addressed, in particular at the first phase of the receiver processing, known as signal acquisition. The first axe of research pursued deals with the analysis and compensation of the Doppler effect in acquisition. The Doppler shift that is experienced by a user is one of the main design drivers for the acquisitionmodule and solutions are proposed to improve the sensitivity-complexity trade-off typical of the acquisition process. The second axe of research deals with the characterization of differential GNSS detectors. After a first step of coherent integration, transition to post coherent (noncoherent or differential) integration is required for acquiring weak signals. The quantification of the sensitivity of differential detectors was not found in literature and is the objective of this part of the research. Finally, the third axe of research is devoted to multi-constellation Collective Detection (CD). CD is an innovative approach for the simultaneous processing of all signals in view. Severalissues related to CD are addressed, including the improvement of the CD search process and the hybridization with standard acquisition. Finally, the application of this methodology in the context of a multi-constellation receiver is also addressed, by processing simultaneously real GPS and Galileo signals.

Made available in DSpace on 2016-03-15T19:38:11Z (GMT). No. of bitstreams: 1 Danillo Ono.pdf: 2562799 bytes, checksum: e44e38bb2e4a5c5eef6578aaa17eed58 (MD5) Previous issue date: 2008-06-16 / Fundo Mackenzie de Pesquisa / The main objective of this work is to study and evaluate the reception s conditions of a Digital TV signal, modulated in Brazilian standard and received with the use of an internal and external antenna, to analyze and to study the interferences that affect it. Comparing the conditions for receipt of the theoretical model of Okumura Hata with real data collected in field tests. Field tests are carried out at several points of Sao Paulo city, to collect data that will be analyzed later. It will use a process of RF capturing, where digital signals are stored on a hard-disk and through the use of laboratory equipments, and through the help of softwares such as Matlab and EDX, data are analyzed taking up account of their impulsive response, the amount of multipaths present in the signal and sensibility to the doppler effect. It was chosen Sao Paulo city because it presents very adverse conditions of reception when compared to other cities in the world, due to its large amount of buildings and antennas, which generate many multipaths. The presence of a large amount of old cars and old appliances, generate impulsive noise. Brazil has the second largest fleet of helicopters in the world and also the large amount of aircrafts flying over the skies of the city, affecting the signals with doppler effect. About 90% of the population that attends TV, use some kind of antenna, which does them receive signals affected by these kind of interference. / O objetivo deste trabalho é estudar e avaliar as condições de recepção de um sinal de TV Digital modulado no padrão brasileiro e recebido com o uso de uma antena interna e externa, e analisar e estudar as interferências que afetam o mesmo. Comparar as condições de recepção do modelo teórico de Okumura Hata com dados reais coletados em testes de campo. São realizados testes de campo em determinados pontos da cidade de São Paulo, para coleta de dados, que serão posteriormente analisados. Utilizar-se-á um processo de captura dos sinais, no qual os sinais digitais são gravados em um hard-disk e através do uso de equipamentos de laboratório e com o auxílio de softwares como Matlab e EDX, os dados são analisados levando-se em consideração sua resposta impulsiva, a quantidade de multipercursos presentes no sinal e a sensibilidade ao efeito doppler. Foi escolhida a cidade de São Paulo pois a mesma apresenta condições de recepção muito adversas quando comparada a outras cidades do mundo. Devido a sua ampla quantidade de prédios e antenas, geram-se muitos multipercursos. A presença de inúmeros automóveis e eletrodomésticos antigos contribui com ruído impulsivo. Tem-se a segunda maior frota de helicópteros do mundo, bem como a grande quantidade de aviões que sobrevoam os céus da cidade, afetando os sinais com efeito doppler. Cerca de 90% da população que assiste TV, usa algum tipo de antena, o que ocasiona a recepção de sinais afetados por esses tipos de interferências.

This thesis deals with a design of telemetry archive of PSAT, PSAT-2 and BRICSat sattelites. This telemetry data need to be extracted from SDR IQ records. The thesis contains a Doppler effect theory and description of structure of telemetry data. Then it presents a design of a program for Doppler effect correction, demodulation and decoding of these records and saving the data to telemetry archive. Thesis also deals with analysis of decoded data.

The presented thesis discusses the basic analysis methods of arteriovelocitograms. The core of this work rests in classification of signals and contribution to possibilities of noninvasive diagnostic methods for evaluation patients with peripheral ischemic occlusive arterial disease. The classification employs multivariate statistical methods and principles of neural networks. The data processing works with an angiographic verified set of arteriovelocitogram dates. The digital subtraction angiography classified them into 3 separable classes in dependence on degree of vascular stenosis. Classification AVG signals are represented in the program by the 6 parameters that are measured on 3 different places on each patient’s leg. Evaluation of disease appeared to be a comprehensive approach at signals acquired from whole patient’s leg. The sensitivity of clustering method compared with angiography is between 82.75 % and 90.90 %, specificity between 80.66 % and 88.88 %. Using neural networks sensitivity is in range of 79.06 % and 96.87 %, specificity is in range of 73.07 % and 91.30 %.

This thesis deals with ultrasound blood flow meter design with emphasis on practical implementation of such device. This medical device is used in ultrasound diagnostic, especially for measuring direction and velocity of blood flow in superficial vessels. This thesis contains consecutive design including description of individual function blocks. Documents for making double-sided printed circuit are included as well.

This master's thesis describes ways of signal processing via digital devices. Major field of interest is an analysis of Doppler radar response and then mining of informations about detected object (e.g. speed, movement direction, length, ...). There was realized too little research, that's why borrowing some procedures from different branches not too much related to the IT is necessary. In case of using very complex methods that are easy to parallel, hardware implementation on the FPGA is supposed. With transceiver there is created a very powerful on-line system able to process most of tasks real-time. Then processed and transformed data are sent to the output so visualization and display can be made.