Dissertations / Theses on the topic 'Digital beamforming array'
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Marsh, David Moyle. "Phased Array Digital Beamforming Algorithms and Applications." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7499.
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With the expansion of unmanned aircraft system (UAS) technologies, there is a growing need for UAS Traffic Management (UTM) systems to promote safe operation and development. To be successful, these UTM systems must be able to detect and track multiple drones in the presence of clutter. This paper examines the implementation of different algorithms on a compact, X-band, frequency modulated continuous wave (FMCW) radar in an effort to enable more accurate detection and estimation of drones. Several algorithms were tested through post processing on actual radar data to determine their accuracy and usefulness for this system. A promising result was achieved through the application of pulse-Doppler processing. Post processing on recorded radar data showed that a moving target indicator successfully separated a target from clutter. An improvement was also noted for the implementation of phase comparison monopulse which accurately estimated angle of arrival (AOA) and required fewer computations than digital beamforming.The second part of this thesis explains the work done on an adaptive broadband, real time beamformer for RF interference (RFI) mitigation. An effective communication system is reliable and can counteract the effects of jamming. Beamforming is an appropriate solution to RFI. To assist in this process FPGA firmware was developed to prepare signals for frequency domain beamforming. This system allows beamforming to be applied to 150 MHz of bandwidth. Future implementation will allow for signal reconstruction after beamforming and demodulation of a communication signal.
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Sullivan, Arthur, Christos Christodoulou, and Charles W. Chandler. "NEXT GENERATION DIGITAL BEAMFORMING ARRAY OPTIMIZED BY NEURAL NETWORK BEAMFORMING TECHNIQUES." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607379.
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International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, CaliforniaThe next generation Digital Beamforming Array (DBFA) requires techniques beyond the existing adaptive processing and optimization approaches. By utilizing neural network processing and genetic algorithms that mimic complicated natural processes, such as the brain and natural selection, new and superior Antenna Arrays can be designed. The use of Neural Networks and Genetic Algorithms combined with the existing techniques for DBFAs can yield the ultimate in “real-time,” “smart” antenna performance. Cost is significantly reduced by; allowing large manufacturing tolerances, the use of inexpensive components, and correcting by neural network techniques. This paper describes the technology and proposes a practical application of the technique to design a DBFA to track and transmit/receive telemetry from a shipboard vertically launched medium range missile.
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Wilson, Mark Joseph. "An investigation into sparse array design in digital sonar beamforming." Thesis, Heriot-Watt University, 2006. http://hdl.handle.net/10399/112.
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LIU, HUAZHOU. "DIGITAL DIRECTION FINDING SYSTEM DESIGN AND ANALYSIS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1060976413.
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Darwood, Peter B. "Pattern synthesis for small phased array antennas." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262843.
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Yeh, ShihYuan. "Development of a digital tracking array with single-channel RSNS and monopulse digital beamforming." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/4956.
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Approved for public release; distribution is unlimitedUnmanned aerial vehicles (UAVs) are widely used in military applications, and one of the most common missions is remote sensing. Remote sensing requires UAVs equipped with different kinds of sensors. Information collected by remote sensors must be transmitted back to a ground control station (GCS) to conduct analysis. The majority of UAVs are controlled directly by GCS personnel using radio frequency (RF), line-of-sight (LOS) links. The ground antenna must acquire and then track the UAV signal. A digital phased array allows signal processing functions to be performed in the antenna processor as well as beamforming and tracking. The development of a digital tracking array with single-channel robust symmetrical number system (RSNS) and monopulse digital beamforming (DBF) to track a UAV's transmitted signal is described in this thesis. The RSNS is used as the direction finding (DF) algorithm and can provide high angle resolution with two closely spaced elements. However, as is typical for an array, the angle accuracy is reduced at the two ends of the field-of-view (FOV). The monopulse DBF is used to precisely track the signals. The monopulse tracking technique provides precise angle accuracy within a FOV of approximately ±45. The tracking system is developed in LabView, and the performance of a six-element prototype array is demonstrated by measurement in an anechoic chamber.
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Kjellson, Angelica. "Sound Source Localization and Beamforming for Teleconferencing Solutions." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-89707.
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In teleconferencing the audio quality is key to conducting successful meetings. The conference room setting imposes various challenges on the speech signal processing, such as noise and interfering signals, reverberation, or participants positioned far from the telephone unit. This work aims at improving the received speech signal of a conference telephone by implementing sound source localization and beamforming. The implemented microphone array signal processing techniques are compared to the performance of an existing multi-microphone solution and evaluated under various conditions using a planar uniform circular array. Recordings of test-sequences for the evaluation were performed using a custom-built array mockup. The implemented algorithms did not show good enough performance to motivate the increased computational complexity compared to the existing solution. Moreover, an increase in number of microphones used was concluded to have little or no effect on the performance of the methods. The type of microphone used was, however, concluded to have impact on the performance and a subjective listening evaluation indicated a preference for omnidirectional microphones which is recommended to investigate further.God ljudkvalitet är en grundsten för lyckade telefonmöten. Miljön i ett konferens-rum medför ett flertal olika utmaningar för behandlingen av mikrofonsignalerna: det kan t.ex. vara brus och störningar, eller att den som talar befinner sig långt från telefonen. Målet med detta arbete är att förbättra den talsignal som tas upp av en konferenstelefon genom att implementera lösningar för lokalisering av talaren och riktad ljudupptagning med hjälp av ett flertal mikrofoner. De implementerade metoderna jämförs med en befintlig lösning och utvärderas under olika brusscenarion för en likformig cirkulär mikrofonkonstellation. För utvärderingen användes testsignaler som spelades in med en specialbyggd enhet. De implementerade algoritmerna kunde inte uppvisa en tillräcklig förbättring i jämförelse med den befintliga lösningen för att motivera den ökade beräkningskomplexitet de skulle medföra. Dessutom konstaterades att en fördubbling av antalet mikrofoner gav liten eller ingen förbättring på metoderna. Vilken typ av mikrofon som användes konstaterades däremot påverka resultatet och en subjektiv utvärdering indikerade en preferens för de rundupptagande mikrofonerna, en skillnad som föreslås undersökas vidare.
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Khan, Asim Ali. "Performance optimisation of small antenna arrays." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/performance-optimisation-of-small-antenna-arrays(759e6929-04ab-408c-aee3-404c72711cdb).html.
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This thesis addresses radiation pattern synthesis problems for small linear periodic phased arrays (with array elements less then 10). Due to the small array size conventional pattern synthesis techniques fail to produce the required results. In the case of practical small arrays, mutual coupling and element pattern asymmetric effect degrade the array radiation performance. The main performance metrics considered in this thesis include side lobe level (SLL), gain, halfpower beamwidth (HPBW) and mainbeam scan direction. The conventional pattern synthesis approaches result in sub optimal gain, SLL and HPBW due to the limited number of elements and the mutual coupling involved. In case of difference pattern synthesis these factors resulted in lower difference pattern slope, degraded SLL and difference peak asymmetry. The sum and difference patterns are used in monopulse arrays and a simplified feed that could produce both patterns with acceptable radiation properties is of interest and has been examined (chapter 5). A conventional technique is applied to small arrays to synthesise a sector beam and there is limited control over the radiation pattern. It is shown that the mutual coupling has significant effect on the array radiation pattern and mitigation is necessary for optimum performance (chapter 6). Furthermore, wideband phased arrays may have a natural limitation of the HPBW in low gain applications and minimisation of the variation becomes important. Also the SLL variations for wideband antenna arrays in the presence of mutual coupling considerably degrade the radiation pattern. The mutual coupling degrades significantly the radiation pattern performance in case of small scanning wideband arrays (chapter 7). It is the primary goal of this thesis to develop an optimisation scheme thatis applied in the above scenarios (chapters 3 & 4). The only degree of freedom assumed is the array excitation. Optimised amplitude and phase for each element in the array are determined by the proposed scheme, concurrently. The deterministic optimisation techniques reported in the literature for the pattern synthesis may involve complicated problem modelling. The heuristic opti-misation techniques generally are computationally expensive. The proposedIntelligent z-space Boundary Condition-Particle Swarm Optimiser (IzBC-PSO)is based on a heuristic algorithm. This scheme can be applied to a wider rangeof problems without significant modifications and requires fewer computationscompared to the competing techniques.In order to verify the performance of IzBC-PSO antenna array measure-ments were performed in the receiving mode only using the online and offlinedigital beamforming setups described in chapter 8. The measurement resultsshow that the proposed scheme may be successfully applied with both onlineand offline digital beamformers for a practical small array (chapter 8).
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Ruzindana, Mark William. "Real-Time Beamforming Algorithms for the Focal L-Band Array on the Green Bank Telescope." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6622.
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A phased array feed (PAF) provides a contiguous, electronically synthesized wide field of view for large-dish astronomical observatories. Significant progress has been made in recent years in improving the sensitivity of PAF receivers though optimizing the design of the antenna array, cryogenic cooling of the front end, and implementation of real-time correlation and beamforming in digital signal processing. FLAG is a 19 dual-polarized element phased array with cryogenic LNAs, direct digitization of RF signals at the front end, digital signal transport over fiber, and a real time signal processing back end with up to 150 MHz bandwidth. The digital back end includes multiple processing modes, including real-time beamforming, real-time correlation, and a separate real-time beamformer for commensal radio transient searches. Following a polyphase filterbank operation performed in field programmable gate arrays (FPGAs), beamforming, correlation, and integration are implemented on graphical processing units (GPUs) that perform parallelized operations. Parallelization greatly increases processing speed and allows for real-time signal processing. During a recent test/commissioning of FLAG, Tsys/efficiency of approximately 28 K was measured across the PAF field of view and operating bandwidth, corresponding to a system temperature below 20 K. To demonstrate the astronomical capability of the receiver, a pulsar (PSR B1937+21) was detected with the real-time beamformer. This thesis provides details on the development of the FLAG digital back end, the real-time beamformer, and reports on the commissioning tests of the FLAG PAF receiver developed by the National Radio Astronomy Observatory (NRAO), Green Bank Observatory (GBO), West Virginia University (WVU), and Brigham Young University for the Green Bank Telescope (GBT).
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Hickish, Jack. "Digital signal processing methods for large-N, low-frequency radio telescopes." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:7d983fb3-9411-4906-92cd-70e2c1040b54.
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Current attempts to make precision measurements of the HI power spectrum at high redshifts have led to the construction of several low-frequency, large-N, interferometric arrays. The computational demands of digital correlators required by these arrays present a significant challenge. These demands stem from the treatment of radio telescopes as collections of two-element interferometers, which results in the need to multiply O(N2) pairs of antenna signals in an N-element array. Given the unparalleled flexibility offered by modern digital processing systems, it is apt to consider whether a different way of treating the signals from antennas in an array might be fruitful in current and future radio telescopes. Such methods potentially avoid the unfavourable N2 scaling of computation rate with array size. In this thesis I examine the prospect of using direct-imaging methods to map the sky without first generating correlation matrices. These methods potentially provide great computational savings by creating images using efficient, FFT-based algorithms. This thesis details the design and deployment of such a system for the Basic Element of SKA Training II (BEST-2) array in Medicina, Italy. Here the 32-antenna BEST-2 array is used as a test bed for comparison of FX correlation and direct-imaging systems, and to provide a frontend for a real-time transient event detection pipeline. Even in the case of traditional O(N2) correlation methods, signal processing algorithms can be significantly optimized to deliver large performance gains. In this thesis I present a new mechanism for optimizing the cross-correlation operation on Field Programmable Gate Array (FPGA) hardware. This implementation is shown to achieve a 75% reduction in multiplier usage, and has a variety of benefits over existing optimization strategies. Finally, this thesis turns its focus towards The Square Kilometre Array (SKA). When constructed, the SKA will be the world's largest radio telescope and will comprise a variety of arrays targeting different observing frequencies and science goals. The low-frequency component of the SKA (SKA-low) will feature ~250,000 individual antennas, sub-divided into a number of stations. This thesis explores the impact of the station size on the computational requirements of SKA-low, investigating the optimal array configuration and signal processing realizations.
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Pulipati, Sravan Kumar. "Electronically-Scanned Wideband Digital Aperture Antenna Arrays using Multi-Dimensional Space-Time Circuit-Network Resonance." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1499440141479455.
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Brady, James Michael. "Real-Time Beamformer Development and Analysis of Weak Signal Detection with Interference Mitigation for Phased-Array Feed Radio Astronomy." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/5644.
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In recent years, the Brigham Young University (BYU) Radio Astronomy Systems group has developed phased-array feeds and the data acquisition processing systems necessary to perform radio astronomy observations. This thesis describes the development and testing of a real-time digital beamforming system that reduces both the time required to process phased-array feed data and the disk space used to record this data compared to post-processing beamforming systems. A real-data experiment is also discussed in this thesis, which focuses on some of the data post-processing required for one of BYU's data acquisition systems.Radio-frequency interference mitigation techniques for phased-array feed radio astronomy have been studied for several years, but the effect that these techniques have on weak-signal detection is not well understood. This thesis provides analysis of a simulated weak-source observation for the Green Bank 20-meter telescope and BYU 19 element phasedarray feed with radio-frequency interference present. Interference mitigation techniques are shown to reduce the detectability of weak sources compared with the no interference case, but it is also shown that a weak source can be detected that would otherwise be masked by interference.
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Vadinský, Václav. "Systém pro lokalizaci vzdáleného zdroje zvuku s hradlovým polem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219812.
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This thesis deals with processing signals from the microphone arrays for sound source localization. Compares different types of fields, such as cross-field and circular array. It is shown here how to implement Beamforming on FPGA and design of signal processing with a microphone array.
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Arroyo, César Saulo Belli. "Estimação de imagens acústicas com arranjos de microfones." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-17062016-112717/.
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Nas últimas décadas, a poluição sonora tornou-se um grande problema para a sociedade. É por esta razão que a indústria tem aumentado seus esforços para reduzir a emissão de ruído. Para fazer isso, é importante localizar quais partes das fontes sonoras são as que emitem maior energia acústica. Conhecer os pontos de emissão é necessário para ter o controle das mesmas e assim poder reduzir o impacto acústico-ambiental. Técnicas como \"beamforming\" e \"Near-Field Acoustic Holography\" (NAH) permitem a obtenção de imagens acústicas. Essas imagens são obtidas usando um arranjo de microfones localizado a uma distância relativa de uma fonte emissora de ruído. Uma vez adquiridos os dados experimentais pode-se obter a localização e magnitude dos principais pontos de emissão de ruído. Do mesmo modo, ajudam a localizar fontes aeroacústicas e vibro acústicas porque são ferramentas de propósito geral. Usualmente, estes tipos de fontes trabalham em diferentes faixas de frequência de emissão. Recentemente, foi desenvolvida a transformada de Kronecker para arranjos de microfones, a qual fornece uma redução significativa do custo computacional quando aplicada a diversos métodos de reconstrução de imagens, desde que os microfones estejam distribuídos em um arranjo separável. Este trabalho de mestrado propõe realizar medições com sinais reais, usando diversos algoritmos desenvolvidos anteriormente em uma tese de doutorado, quanto à qualidade do resultado obtido e à complexidade computacional, e o desenvolvimento de alternativas para tratamento de dados quando alguns microfones do arranjo apresentarem defeito. Para reduzir o impacto de falhas em microfones e manter a condição de que o arranjo seja separável, foi desenvolvida uma alternativa para utilizar os algoritmos rápidos, eliminando-se apenas os microfones com defeito, de maneira que os resultados finais serão obtidos levando-se em conta todos os microfones do arranjo.In recent decades, noise pollution has become a major problem for society. It is for this reason that the industry has increased its efforts to reduce the emission of noise. To do this, it is important to find out which parts of the sound sources are emitting greater acoustic energy. Knowing the emission points is required to keep track of them and thus be able to reduce acoustic and environmental impact. Techniques such as \"beamforming\" and \"Near-Field Acoustic Holography\" (NAH) allow obtaining acoustic images. These images are obtained using an array of microphones located at a relative distance from a noise source. Once acquired experimental data, one can obtain the location and the magnitude of the main points of noise emission. Similarly, we can find aeroacoustic and vibroacoustic sources, because they are general-purpose tools. Usually, these types of sources work in different frequency bands of the emission. Recently, a Kronecker Array Transform (KAT) was developed to microphone arrays, which provides a significant reduction in computational cost when applied to various image reconstruction methods, provided that the microphones are distributed in a separable array. This thesis proposes perform measurements with real signals using different algorithms previously developed in a dissertation about the quality of the obtained results and computational complexity, and the development of alternatives for data processing when some microphones of the array are defective. To reduce the impact of failures in microphones and maintain the condition that the array is separable, one alternative has been developed to use the fast algorithms by removing only the defective microphones, so that the final results will be obtained taking into account every microphone of the array.
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Toman, Vít. "Aplikace mikrofonního pole." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219961.
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Master’s thesis deals with description of issues of reading spatial audio signals using microphone array. Basic method of beamforming (Delay and Sum) is characterized on basis of chosen conception of the microphone array. Specific issues of audio detection and digital signal processing of converted audio signals are characterized and some ways how to solve the issues are adumbrated. Features and limitations of chosen ARM processor in the digital processing of multiple audio signals are described. Especially features and limitations of an internal A/D converter from the perspective of the beamforming are described.
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Newmeyer, Luke Oliver. "Efficient FPGA SoC Processing Design for a Small UAV Radar." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7057.
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Modern radar technology relies heavily on digital signal processing. As radar technology pushes the boundaries of miniaturization, computational systems must be developed to support the processing demand. One particular application for small radar technology is in modern drone systems. Many drone applications are currently inhibited by safety concerns of autonomous vehicles navigating shared airspace. Research in radar based Detect and Avoid (DAA) attempts to address these concerns by using radar to detect nearby aircraft and choosing an alternative flight path. Implementation of radar on small Unmanned Air Vehicles (UAV), however, requires a lightweight and power efficient design. Likewise, the radar processing system must also be small and efficient. This thesis presents the design of the processing system for a small Frequency Modulated Continuous Wave (FMCW) phased array radar. The radar and processing is designed to be light-weight and low-power in order to fly onboard a UAV less than 25 kg in weight. The radar algorithms for this design include a parallelized Fast Fourier Transform (FFT), cross correlation, and beamforming. Target detection algorithms are also implemented. All of the computation is performed in real-time on a Xilinx Zynq 7010 System on Chip (SoC) processor utilizing both FPGA and CPU resources. The radar system (excluding antennas) has dimensions of 2.25 x 4 x 1.5 in3, weighs 120 g, and consumes 8 W of power of which the processing system occupies 2.6 W. The processing system performs over 652 million arithmetic operations per second and is capable of performing the full processing in real-time. The radar has also been tested in several scenarios both airborne on small UAVs as well as on the ground. Small UAVs have been detected to ranges of 350 m and larger aircraft up to 800 m. This thesis will describe the radar design architecture, the custom designed radar hardware, the FPGA based processing implementations, and conclude with an evaluation of the system's effectiveness and performance.
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Brown, Stephen. "Analysis of performance of multiple beam digital beamforming antenna arrays by simulation /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488193665234131.
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Madishetty, Suresh. "Design of Multi-Beam Hybrid Digital Beamforming Receivers." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1545178805415923.
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Mabrouk, Kais. "Conception et réalisation d'un système de Télécommunications MIMO avec Formation Numérique de Faisceaux en réception ; Calibrage aveugle du Démodulateur triphasé Zéro-IF et comparaison au démodulateur classique à 2 voies I et Q." Phd thesis, Télécom ParisTech, 2008. http://tel.archives-ouvertes.fr/tel-00409794.
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Dans le cadre de ce travail de recherche, nous nous somme intéressés à un système de télécommunication MIMO (Multiple Input Multiple Output) à multiplexage spatial utilisant des récepteurs Zero-IF et la technique de formation numérique de faisceaux (FF). Le domaine d'application de ces travaux de recherches peuvent être aussi bien les applications fixes (exp: WiFi, IEEE) que les applications mobiles (exp: LTE, 3GPP).La première partie de ce travail est consacrée à une étude comparative entre les différents types de démodulateurs cinq-port et triphasés. Cette étude a permis de mettre en évidence l'aspect tridimensionnel des démodulateurs cinq-port et triphasés, de gagner 20dB en termes de réjection des produits d'intermodulation des signaux adjacents et de trouver une nouvelle méthode de calibrage aveugle du récepteur.
La seconde partie de la thèse se concentre sur le prototypage d'un système MIMO. Cette phase nous a permis d'exposer les difficultés de mise en place de ce genre de système et de souligner les nouvelles problématiques qui n'apparaissait pas auparavant dans les systèmes mono- transcepteur. Aussi, un algorithme de Formation de Faisceau a été développé dans cette partie. Ce FF numérique a permis non seulement d'accroître la capacité mais aussi la qualité de liaison en considérant le système MIMO comme N système SIMO en parallèle. Comparativement à la technique ZF(Zero Forcing), nous démontrons que le FF permet d'obtenir une meilleure qualité de signaux pour des faibles valeurs de rapport signal à bruit.
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Weesinghe, Weerasinha Sewwandi Wijayaratna. "FPGA Architectures for Fast Steerable Beam-Enhanced Digital Aperture Arrays." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1407762895.
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Townsend, Phil. "Enhancements to the Generalized Sidelobe Canceller for Audio Beamforming in an Immersive Environment." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/645.
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The Generalized Sidelobe Canceller is an adaptive algorithm for optimally estimating the parameters for beamforming, the signal processing technique of combining data from an array of sensors to improve SNR at a point in space. This work focuses on the algorithm’s application to widely-separated microphone arrays with irregular distributions used for human voice capture. Methods are presented for improving the performance of the algorithm’s blocking matrix, a stage that creates a noise reference for elimination, by proposing a stochastic model for amplitude correction and enhanced use of cross correlation for phase correction and time-difference of arrival estimation via a correlation coefficient threshold. This correlation technique is also applied to a multilateration algorithm for an efficient method of explicit target tracking. In addition, the underlying microphone array geometry is studied with parameters and guidelines for evaluation proposed. Finally, an analysis of the stability of the system is performed with respect to its adaptation parameters.
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Galabada, Kankanamge Nilan Udayanga. "Digital 2-D/3-D Beam Filters For Adaptive Applebaum ReceiveAnd Transmit Arrays." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1445799928.
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Shih, Huei-Hsu, and 施懷勛. "Ultrasound Array Signal Compression by Digital Micro-beamforming." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/60761638536869426073.
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碩士國立臺灣大學
生醫電子與資訊學研究所
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Due to the high computational requirements, conventionally real-time ultrasound imaging systems utilize highly parallel hardware architectures, thus resulting in high hardware cost, lack of flexibility on image optimization and algorithm implementation and relatively long system development cycle. On the other hand, a software-based system utilizing highly parallel graphic processing units (GPUs) can alleviate such limitations. However, massive raw data transmission from hardware end to software end, which is up to gigabytes per second, becomes one of the bottlenecks for performing real-time software-based imaging. For example, the popular USB 3.0 can only support data rate up to 0.5GB/s, which cannot support real-time raw data transfer. A feasible solution is to compress raw channel data with low hardware resource requirement on the front end. As previous studies demonstrated, we can get overall compression ratio of 4~5.6 by demodulating the radio frequency data to baseband and applying Walsh transform-based compression methods. However, more data compression is still desired. In this study, we propose the use of micro-beamforming to further compress the amplitude data with following steps: take the first N channels as a group, and delay the channel data based on pre-steering, then sum up the N channels into one single output. The rest of the channels follow the same procedures and the number of output channels can be suppressed by N times. In addition to data compression, we also propose a compensation method to decrease the errors resulting from the micro-beamformed amplitude data. Results show that when a group of 4 channels are used, B-mode images formed by the compressed data have almost the same spatial and contrast resolution as the original ones. Furthermore, the peak signal-to-noise ratio is higher than 50 dB with the application of the compensation method. Moreover, several aperture domain processing algorithms, including phase aberration correction, coherence-based adaptive weighting and color Doppler velocity estimation, were tested with micro-beamforming and reasonable performance is achieved. The proposed method integrates micro-beamforming and the compensation method into the Walsh transform-based architecture, and overall compression ratio was improved by about 27~59%, reaching an overall compression ratio up to 6.3~7.1, which enables real-time data transfer via an USB 3.0 interface. The increased resource utilization is no more than 5% on a Virtex-6 FPGA.