Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 55 for “"Beamformer"”.
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Improved broadband adaptive beamformer performance
… number of adaptable weights realisable in the beamformer may be limited by the size, weight and power constraints of the system. This will limit the degrees of freedom in the beamformer and hence, the interference cancellation capability of the beamformer.<br/><br/>The effectiveness of …
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Integrated broadband microphotonic beamformer for adaptive nulling in smart antennas
… study of integrated MicroPhotonic smart antenna beamformers. The beamformers presented in this study is based on microminiaturisation of hotonic and electronic components, which processes RF-modulated optical signals and adaptively synthesises multiple broadband null for interference suppression. …
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The front end implementation of an audio beamformer for the RAW processor
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
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An Assurance Metric and Robustness Evaluation of a Low-cost Acoustic Beamformer for Source Localization
… the use of the LMS algorithm for constructing a beamformer using an optimized Weiner filter solution for this source localization application and evaluates the robustness of a developed characterization method for assuring that a proper approximation for the desired signal is achieved. The method …
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A Bayesian Approach to Beamforming for Uncertain Direction -of -Arrival
… Under the Bayesian formulation, the proposed beamformer is constructed as a mixture of directional beamformers combined according to the data-driven posterior distribution. As the number of recevied data increases, the Bayesian beamformer asymptotically converges into a directional beamformer …
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Space Time Processing for Third Generation CDMA Systems
… computationally simpler technique termed as a Beamformer-Rake. In a Beamformer-Rake, the output of a beamformer is fed into a succeeding temporal processor to take advantage of both the beamformer and Rake receiver. Wireless service providers throughout the world are working to introduce the …
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Broadband adaptive beamforming with low complexity and frequency invariant response
… the adaptation rate of adaptive broadband beamformers. This is performed exemplarily for the generalised sidelobe canceller (GSC) structure. The GSC is an alternative implementation of the linearly constrained minimum variance beamformer, which can utilise well-known adaptive filtering …
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Space-time Processsing for the Wideband-CDMA System
… we investigate the performance of these beamformer-RAKE receivers, also known as two-dimensional (2-D) RAKE receiver, for the reverse link of the W-CDMA system. We consider three different Pilot Symbol Assisted (PSA) beamforming techniques, Direct Matrix Inversion (DMI), Least-Mean Square …
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Energy scalable systems for 2D and 3D low-power ultrasound beamforming
… analog-to-digital converter, and digital beamformer are analyzed individually and then combined to account for the performance dependency between the functional components. These considerations inform a recommendation on design choices for the end-to-end system. Second, this thesis …
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Array Signal Processing for Communications from High Altitude Platforms and Other Applications
… minimum variance distortionless response (MVDR) beamformer is investigated. We show that the robustness of the MVDR beamformer can be improved by applying the Mailloux’s null-broadening method in the downlink scenario and propose a modified constrained optimization method, which further improves …
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Surface wave, internal wave, and source motion effects on matched field processing in a shallow water waveguide
… the conventional (Bartlett) matched field beamformer does not provide sufficient resolution to unambiguously locate a source, even in a perfectly matched environment. The maximum likelihood method (MLM) matched field beamformer has much better resolution but is extremely susceptible to …
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Structure-based learning via graph neural networks for multi-group multicast beamforming
… efficient learning-based approach for a scalable beamformer design under imperfect CSI. We mainly focus on the design of the base station (BS) multicast beamformer to maximize the weighted signal-to-interference-plus-noise ratio (SINR) among all users, subject to a transmit power budget …
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Efficient design of reconfigurable intelligent surface assisted multi-group multicast beamforming
… joint design of the base station (BS) multicast beamformer and the RIS passive beamformer to minimize the transmit power subject to the quality-of-service (QoS) constraints and maximize the minimum quality-of-service among all users mainting a power budget constraint which is also known as …
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ARRAY PROCESSING TECHNIQUES FOR ESTIMATION AND TRACKING OF AN ICE-SHEET BOTTOM
… use the multiple signal classification (MUSIC) beamformer to determine the pseudo-spectrum of the targets at each range-bin. The result is passed into a sequential tree-reweighted message passing belief-propagation algorithm to track the bottom of the ice in the 3D image. This technique is …
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The location-estimating, null-steering (LENS) algorithm for adaptive microphone-array processing
… in the case of a. known target location. Such beamformers are useful in spatial-filtering applications that enhance a desired target source while attenuating non-target, jammer sources in a given environment. Although LENS is designed for general beamforming purposes, this document emphasizes …
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Performance Analysis Of Active and Passive Multi-Array Sonar Networks
… using an elliptical filter, a conventional beamformer, a matched filter and one of three fusion methods. This work compares the performance of each network and fusion method. This work shows that the adding more arrays, regardless of size, enhances the overall performance of the network. It …
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Adaptive Beamforming Using a Microphone Array for Hands-Free Telephony
… a 4-channel microphone array that is an adaptive beamformer used for hands-free telephony in a noisy environment. The microphone signals are amplified, then sent to an A/D converter. The microprocessor board takes the data from the 4 channels and utilizes digital signal processing to determine the …
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A beam pattern design procedure for multidimensional sonar arrays employing minimum variance beamforming
… the penalty function into a minimum variance beamformer, the beam pattern and aperture weights are calculated based on the given array geometry. The beamformer used is Capon's Maximum Likelihood Method. The array used to test the procedure is located on a sixty degree sector of a cylindrical …
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Accurate aeroacoustic measurements in closed-section hard-walled wind tunnels
… by incorporating the reflections in the focused beamformer. This technique is computationally fast and easy to implement. Source Power Integration and deconvolution techniques are shown to be still valid in de-reverberation. Measurements in a closed section wind tunnel have shown that an ISM …
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