Dissertations / Theses on the topic 'Broadband beamforming'
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Chou, Thomas Clayton. "Broadband frequency-independent beamforming." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11854.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 103-105).
by Thomas Clayton Chou.
M.S.
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Thiel, Ryan. "Array Processing Techniques for Broadband Acoustic Beamforming." ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/251.
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Audio acquisition and recording can benefit from directional reception of the acoustic signals. Current acoustic designs of highly-directional microphones are bandwidth limited and physically large. A microphone array used in conjunction with a beamforming algorithm can acquire and spatially filter the signal, but traditionally this has suffered from limitations similar to those of the purely acoustic designs. The work presented in this paper attempts to overcome these limitations by producing and analyzing three atypical techniques for broadband beamforming. The last and most successful technique employs an algorithm which calculates the difference in group delay of the acquired signals and uses that information to determine the direction of the incoming signals as a function of frequency.
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Ward, Darren Brett, and db_ward@hotmail com. "Theory and application of broadband frequency invariant beamforming." The Australian National University. Faculty of Engineering and Information Technology, 1996. http://thesis.anu.edu.au./public/adt-ANU20050418.112459.
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In many engineering applications, including radar, sonar, communications and seismology, the direction of impinging signal wavefronts can be used to discriminate between competing sources. Often these source signals cover a wide bandwidth and conventional narrowband beamforming techniques are ineffective, since spatial resolution varies significantly across the band. In this thesis we consider the problem of beamforming for broadband signals, primarily when the spatial response remains constant as a function of frequency. This is called a frequency invariant beamformer (FIB).¶
Rather than applying the numerical technique of multi-parameter optimisation to solve for the beamformer parameters, we attempt to address the fundamental nature of the FIB problem. The general philosophy is to use a theoretical continuous sensor to derive relationships between a desired FI beampattern and the required signal processing structure. Beamforming using an array of discrete sensors can then be formulated as an approximation problem. This approach reveals a natural structure to the FIB which is otherwise buried in a numerical optimisation procedure.¶
Measured results from a microphone array are presented to verify that the simple FIB structure can be successfully implemented. We then consider imposing broadband pattern nulls in the FI beampattern, and show that (i) it is possible to impose an exact null which is present over all frequencies, and (ii) it is possible to calculate a priori how many constraints are required to achieve a null of a given depth in a FIB. We also show that the FIB can be applied to the problem of broadband direction of arrival (DOA) estimation and provides computational advantages over other broadband DOA estimators.¶
Through the theoretical continuous sensor approach, we show that the FIB theory can be generalised to the problem of designing a general broadband beamformer (GBB) which realizes a broadband angle-versus-frequency beampattern specification. Coupled with a technique for radial beampattern transformation, the GBB can be applied to a wide class of problems covering both nearfield beamforming (in which the shape of the impinging wavefront must be considered and farfield beamforming (which is simplified by the assumption of planar wavefronts) for a broadband beampattern specified over both angle and frequency.
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Lusina, Paul James. "Ka-broadband satellite communication using cyclostationary parabolic beamforming." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22345.pdf.
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Wage, Kathleen E. "Broadband modal coherence and beamforming at megameter ranges." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86425.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaves 140-146).
by Kathleen E. Wage.
Ph.D.
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Li, Yunhong. "Broadband beamforming and direction finding using concentric ring array." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4110.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 18, 2006) Vita. Includes bibliographical references.
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Abhayapala, P. Thushara D., and Thushara Abhayapala@anu edu au. "Modal Analysis and Synthesis of Broadband Nearfield Beamforming Arrays." The Australian National University. Telecommunications Engineering Group, 2000. http://thesis.anu.edu.au./public/adt-ANU20010905.121231.
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This thesis considers the design of a beamformer which can enhance desired signals in an environment consisting of broadband nearfield and/or farfield sources. The thesis contains: a formulation of a set of analysis tools which can provide insight into the intrinsic structure of array processing problems; a methodology for nearfield beamforming; theory and design of a general broadband beamformer; and a consideration of a coherent nearfield broadband adaptive beamforming problem. To a lesser extent, the source localization problem and background noise modeling are also treated.
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A set of analysis tools called modal analysis techniques which can be used to a solve wider class of array signal processing problems, is first formulated. The solution to the classical wave equation is studied in detail and exploited in order to develop these techniques.
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Three novel methods of designing a beamformer having a desired nearfield broadband beampattern are presented. The first method uses the modal analysis techniques to transform the desired nearfield beampattern to an equivalent farfield beampattern. A farfield beamformer is then designed for a transformed farfield beampattern which, if achieved, gives the desired nearfield pattern exactly. The second method establishes an asymptotic equivalence, up to complex conjugation, of two problems: (i) determining the nearfield performance of a farfield beampattern specification, and (ii) determining the equivalent farfield beampattern corresponding to a nearfield beampattern specification. Using this reciprocity relationship a computationally simple nearfield beamforming procedure is developed. The third method uses the modal analysis techniques to find a linear transformation between the array weights required to have the desired beampattern for farfield and nearfield, respectively.
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An efficient parameterization for the general broadband beamforming problem is introduced with a single parameter to focus the beamformer to a desired operating radius and another set of parameters to control the actual broadband beampattern shape. This parameterization is derived using the modal analysis techniques and the concept of the theoretical continuous aperture.
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A design of an adaptive beamformer to operate in a signal environment consisting of broadband nearfield sources, where some of interfering signals may be correlated with desired signal is also considered. Application of modal analysis techniques to noise modeling and broadband coherent source localization conclude the thesis.
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Nordebo, Sven. "Robust broadband beamforming and digital filter design : methods and applications." Doctoral thesis, Luleå tekniska universitet, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25667.
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This doctoral thesis consists of a summary and six parts corresponding to six different papers. There are two published and three submitted journal papers, and one research report. The summary will highlight the main results and emphasize the interrelationships between different parts. The thesis comprises two main themes: robust broadband beamforming and digital filter design. In most of the papers in this thesis these concepts are closely related. Some of the results on digital filter design actually concern robust filter design, and one of the main contributions of this thesis concerns the possibility of anomalous designs when using conventional methods in the FIR filter design of broadband beamformers. Part I deals with robustness of broadband adaptive beamformers in the sense that there is an uncertainty in the frequency content and spatial location of the desired target signal. The adaptive beamformer should perform well over a region in space and frequency. This is achieved by defining the Spatial Filter designed Generalized Sidelobe Canceller (SFGSC), and by using an appropriate digital filter design. The novelty of the SFGSC method is the implementation of target signal constraints by using a filter design approach. With this strategy the constraints are approximated over a given design domain, rather than exactly implemented as with the conventional Generalized Sidelobe Canceller (GSC). With this new method (in contrast to the GSC) the SFGSC is able to handle a continuum of constraints. Part II introduces a quadratic programming formulation of the weighted Chebyshev FIR filter design problem for a broadband beamformer in the near-field. This technique may be used to design the digital filters of the broadband SFGSC described in Part I. Part III reveals that the digital filters of a broadband beamformer are incompletely specified whenever the beamformer is specified only in space and frequency. Using conventional filter design criteria with such incomplete specifications may lead to excessively large filter coefficients. Robust weighted least squares and weighted Chebyshev design criteria are introduced in order to avoid this anomaly. "Robustness" in this context means insensitivity to model imperfections such as sensor element placement errors, amplifier mismatch, etc. Again, the filters designed are typically components of the SFGSC described in Part I. Part IV addresses the problem of the non-uniqueness of the Chebyshev approximation for two-dimensional linear phase digital FIR filters. It is shown that the unique Chebyshev approximation having minimum Euclidean filter weight norm can be obtained by using a wellconditioned quadratic programming formulation. This is the same quadratic program that was used to define one of the robust beamformer designs in Part III. Part V deals with robust design for one-dimensional non-linear phase FIR filters which are incompletely specified. The conventional weighted Chebyshev solution can be obtained by using a quadratic programming formulation similar to that given in Part II. A robust weighted Chebyshev design criterion is defined by a modified quadratic program, similar to one of the robust design methods given in Part III. Part VI emphasizes the robustness of adaptive beamformers with respect to channel mismatch, sensor positioning, etc. In particular, the paper addresses the difficulty of mathematically modeling a beamformer for a small enclosure such as a car compartment. A calibrating scheme is proposed which is independent of array geometry and channel matching, and which calibrates the adaptive array to the given acoustic environment and to the given electronic equipment. Results from real measurements in a car compartment are included. An international patent is applied for based on this paper.Godkänd; 1995; 20070426 (ysko)
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Koh, Choo Leng. "Broadband adaptive beamforming with low complexity and frequency invariant response." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/69593/.
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This thesis proposes different methods to reduce the computational complexity as well as increasing 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 algorithms, such as the least mean square (LMS) or the recursive least squares (RLS) to perform unconstrained adaptive optimisation. A direct DFT implementation, by which broadband signals are decomposed into frequency bins and processed by independent narrowband beamforming algorithms, is thought to be computationally optimum. However, this setup fail to converge to the time domain minimum mean square error (MMSE) if signal components are not aligned to frequency bins, resulting in a large worst case error. To mitigate this problem of the so-called independent frequency bin (IFB) processor, overlap-save based GSC beamforming structures have been explored. This system address the minimisation of the time domain MMSE, with a significant reduction in computational complexity when compared to time-domain implementations, and show a better convergence behaviour than the IFB beamformer. By studying the effects that the blocking matrix has on the adaptive process for the overlap-save beamformer, several modifications are carried out to enhance both the simplicity of the algorithm as well as its convergence speed. These modifications result in the GSC beamformer utilising a significantly lower computational complexity compare to the time domain approach while offering similar convergence characteristics. In certain applications, especially in the areas of acoustics, there is a need to maintain constant resolution across a wide operating spectrum that may extend across several octaves. To attain constant beamwidth is diffcult, particularly if uniformly spaced linear sensor array are employed for beamforming, since spatial resolution is reciprocally proportional to both the array aperture and the frequency. A scaled aperture arrangement is introduced for the subband based GSC beamformer to achieve near uniform resolution across a wide spectrum, whereby an octave-invariant design is achieved. This structure can also be operated in conjunction with adaptive beamforming algorithms. Frequency dependent tapering of the sensor signals is proposed in combination with the overlap-save GSC structure in order to achieve an overall frequency-invariant characteristic. An adaptive version is proposed for frequency-invariant overlap-save GSC beamformer. Broadband adaptive beamforming algorithms based on the family of least mean squares (LMS) algorithms are known to exhibit slow convergence if the input signal is correlated. To improve the convergence of the GSC when based on LMS-type algorithms, we propose the use of a broadband eigenvalue decomposition (BEVD) to decorrelate the input of the adaptive algorithm in the spatial dimension, for which an increase in convergence speed can be demonstrated over other decorrelating measures, such as the Karhunen-Loeve transform. In order to address the remaining temporal correlation after BEVD processing, this approach is combined with subband decomposition through the use of oversampled filter banks. The resulting spatially and temporally decorrelated GSC beamformer provides further enhanced convergence speed over spatial or temporal decorrelation methods on their own.
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Uthansakul, Monthippa. "Wideband beamforming employing fully spatial signal processing /." [St. Lucia, Qld.], 2006. http://adt.library.uq.edu.au/public/adt-QU20070503.135836/index.html.
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Omans, Glenn A. "Broadband modal beamforming of acoustic tomography signals acquired by a vertical array." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23827.
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Codreanu, M. (Marian). "Multidimensional adaptive radio links for broadband communications." Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514286223.
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Advanced multiple-input multiple-output (MIMO) transceiver structures which utilize the knowledge of channel state information (CSI) at the transmitter side to optimize certain link parameters (e.g., throughput, fairness, spectral efficiency, etc.) under different constraints (e.g., maximum transmitted power, minimum quality of services (QoS), etc.) are considered in this thesis.
Adaptive transmission schemes for point-to-point MIMO systems are considered first. A robust link adaptation method for time-division duplex systems employing MIMO-OFDM channel eigenmode based transmission is developed. A low complexity bit and power loading algorithm which requires low signaling overhead is proposed.
Two algorithms for computing the sum-capacity of MIMO downlink channels with full CSI knowledge are derived. The first one is based on the iterative waterfilling method. The convergence of the algorithm is proved analytically and the computer simulations show that the algorithm converges faster than the earlier variants of sum power constrained iterative waterfilling algorithms. The second algorithm is based on the dual decomposition method. By tracking the instantaneous error in the inner loop, a faster version is developed.
The problem of linear transceiver design in MIMO downlink channels is considered for a case when the full CSI of scheduled users only is available at the transmitter. General methods for joint power control and linear transmit and receive beamformers design are provided. The proposed algorithms can handle multiple antennas at the base station and at the mobile terminals with an arbitrary number of data streams per scheduled user. The optimization criteria are fairly general and include sum power minimization under the minimum signal-to-interference-plus-noise ratio (SINR) constraint per data stream, the balancing of SINR values among data streams, minimum SINR maximization, weighted sum-rate maximization, and weighted sum mean square error minimization. Besides the traditional sum power constraint on the transmit beamformers, multiple sum power constraints can be imposed on arbitrary subsets of the transmit antennas.This extends the applicability of the results to novel system architectures, such as cooperative base station transmission using distributed MIMO antennas. By imposing per antenna power constraints, issues related to the linearity of the power amplifiers can be handled as well.
The original linear transceiver design problems are decomposed as a series of remarkably simpler optimization problems which can be efficiently solved by using standard convex optimization techniques. The advantage of this approach is that it can be easily extended to accommodate various supplementary constraints such as upper and/or lower bounds for the SINR values and guaranteed QoS for different subsets of users. The ability to handle transceiver optimization problems where a network-centric objective (e.g., aggregate throughput or transmitted power) is optimized subject to user-centric constraints (e.g., minimum QoS requirements) is an important feature which must be supported by future broadband communication systems.
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Breckenridge, Richard P. "Localization of multiple broadband targets in spherical coordinates via adaptive beamforming and non-linear estimation." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27121.
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Behrle, Charles D. "Computer simulation studies of multiple broadband target localization via frequency domain beamforming for planar arrays." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22976.
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Approved for public release; distribution is unlimitedComputer simulation studies of a frequency domain adaptive beamforming algorithm are presented. These simulation studies were conducted to determine the multiple broadband target localization capability and the full angular coverage capability of the algorithm. The algorithm was evaluated at several signal-to-noise ratios with varying sampling rates. The number of iterations that the adaptive algorithm took to reach a minimum estimation error was determined. Results of the simulation studies indicate that the algorithm can localize multiple broadband targets and has full angular coverage capability.
http://archive.org/details/computersimulati00behr
Lieutenant, United States Navy
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Mabande, Edwin Tererai Verfasser], Walter [Akademischer Betreuer] [Kellermann, and Patrick [Akademischer Betreuer] Naylor. "Robust Time-Invariant Broadband Beamforming as a Convex Optimization Problem / Edwin Tererai Mabande. Gutachter: Walter Kellermann ; Patrick Naylor." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2015. http://d-nb.info/1075562139/34.
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Caldas, Luciano Coutinho. "In-duct beamforming and mode detection using a circular microphone array for the characterisation of broadband aeroengine fan noise." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-29082016-142207/.
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The development of technologies to reduce turbofan engine noise reveals the fan noise, the first stage of an engine, as a great contributor for the total noise of an airplane. So a better understanding of the fan noise generation came up and motivated the construction of a fan rig test facility at the University of São Paulo in São Carlos by a partnership between the university and EMBRAER S.A.. The fan rig is composed of a long duct (12mlong) comprising a 16-bladed fan rotor and 14-vaned stator. The rotor is powered by an 100 hp electrical motor allowing speed up to 4250 RPM resulting in 0.1Mach axial flow. A 77-microphone wall-mounted array was designed for fan noise analysis. A cooperation with NASA-Glenn allowed data and information exchanging from their similar fan rig setup, the ANCF, grating then the validation of the in-house developed software. A short guide for duct-array is proposed in this work. Complex software was developed to process the data from the microphones array. We performed 3 different types of analysis: power spectral density, noise imaging obtained by acoustic beamforming and modal analysis.We proposed a different technique for modal analysis based on beamforming images in this work.We did not find any similar technique in the references. The results obtained by this technique were validated with data from ANCF-NASA. Comparative results are presented for both fan rigs, such as: power spectral densities for different fan speeds, modal analysis at the blade passing frequency (strong tones generated by the fan), noise imaging obtained by beamforming for rotating and static noise sources. Finally, results achieved in this work are in agreement with those observed in the references consulted.Como desenvolver de tecnologias para redução de ruído de motores aeronáuticos turbofans, o ruído gerado pelo fan (primeiro estágio do motor) vem se mostrando cada vez mais um grande contribuinte na emissão total de ruído em um avião. Com isso, a necessidade de se estudar mecanismos geradores de ruído nestes motores veio à tona e motivou a construção de uma bancada de experimentos aero-acústicos junto àUniversidade de São Paulo, campus São Carlos, oriundo da parceria entre EMBRAER S.A. e Universidade de São Paulo. A bancada de ensaios compõe um conjunto rotor/estator, sendo que o fan (rotor) é equipado com 16 pás e a estatora 14 pás, conectado a um motor elétrico de 100 hp através de um eixo ao rotor, alcançando 4250 RPM com velocidade de escoamento axial médio de 0,1 Mach. Esta bancada é composta por um longo duto e a seção de ensaio com o fan localiza-se ao centro. Uma antena dispondo de 77 microfones foi especialmente projetada para fazer aquisição do ruído gerado pelo fan. Uma parceria com a NASA-Glenn possibilitou a troca de informações e dados experimentais de sua bancada de experimentos similar (ANCF) ajudando assim a validar os códigos desenvolvidos bem como comparar resultados para ambas as bancadas. Umpequeno roteiro para projeto de antena para análise modal e beamforming em duto é apresentado neste trabalho. Um complexo software foi desenvolvido a fim de processar sistematicamente os dados aquisitados pelos microfones da antena. Três tipos de análise são feitas: Via espectro densidade de potência; Imagem de ruído acústico obtido através da técnica de beamforming, e por último, análise modal. Uma técnica diferente para análise modal baseada em imagens obtidas através de beamforming é proposta neste trabalho. Nada similar foi encontrado nas referências consultadas. Os resultados foram validados com dados de fontes sintéticas produzidas pela bancada ANCF-NASA. Resultados comparativos para ambas as bancadas são exibidas neste trabalho, tais quais: Análise do espectro densidade de potência para diferentes rotações do fan; análise modal nas frequências de passagem das pás (forte ruído tonal gerado pelo fan); imagem acústica do ruído gerado tanto por fontes rotativas quanto para fontes estáticas. Finalmente, os resultados obtidos estão de acordo com o esperado e de antemão observados nas referências consultadas.
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Sarah, Annisa. "Analysis of 5G Mobile Broadband Solutions in Rural and Remote Areas : A Case Study of Banten, Indonesia." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-219912.
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Providing a broadband access anytime and anywhere is one of the visions of the future 5G network. However, deploying a reliable network connection in remote/rural areas has been a challenging task because of its wide area that needed to be covered and a low density of user compared to urban area. Different geography and traffic condition may need different system solution. In this thesis, we analyze several solutions to providing a broadband access network in practical remote and rural area in Banten, Indonesia: Leuwidamar (remote) and Panimbang (rural). Two approaches are discussed, first one is fulfilling futuristic traffic demand by having LTE System, and the second one is by having 5G System. We included three key technology components in a 5G network: occupying wide bandwidth in high frequency, applying UE-Specific Beamforming, and implementing Carrier Aggregation (CA) scheme. We also account a rain attenuation when deploying a network in high operating frequency, since Indonesia has a high rain rate thus it is important to be considered. We compared five cases of solution: Case 1 is Single Carrier (SC) LTE 1.8 GHz system; Case 2 is Carrier Aggregation (CA) LTE 1.8 GHz + 2.6 GHz; Case 3 is SC 5G 15GHz; Case 4 is SC 5G 28 GHz; Case 5 is CA LTE 1.8 GHz + 5G 15 GHz. Basedon the evaluation, in Leuwidamar scenario, Case 5 gives us the least number of BS needed in order to meet the futuristic requirement with only 1.6 x densification from the current network. In Panimbang, the least number of BS neededis offered by two cases, Case 3 and Case 5 without any additional BS needed(1x densification). However, the solution with the lowest energy consumption for both area is Case 3. This is due to the fact that the carrier aggregation scenario needs additional power to generate the second system. Furthermore, if we introduce cell DTX ability in the 5G network, the Case 3 can give us impressive amount of energy saving, with 97% saving for Leuwidamar and 94% saving for Panimbang, compared to Case 1 solution without any DTX Capability.Att tillhandahålla bredbandsanslutning när som helst och var som helst är en av visionerna för det framtida 5G-nätverket. Att använda en tillförlitlig nätverksanslutning i avlägsna- eller landsbygdsområden har dock varit en utmanande uppgift på grund av det breda området som måste täckas och den låga täthetenav användare jämfört med stadsområden. Olika geografiska förhållanden och trafikförhållanden kan behöva olika systemlösningar. I denna avhandling analyserarvi flera lösningar för att tillhandahåller ett bredbandsnätverk i verkligt avlägset eller landsbygdsområde i Banten, Indonesien: Leuwidamar (avlägset) och Panimbang (landsbygd). Två strategier diskuteras, den första uppfyller framtida trafikbehov genom att ha LTE-system och den andra är genom att ha5G System. Vi inkluderade tre viktiga teknikkomponenter i 5G-nätverk: bredbandbredd och hög frekvens, tillämpar UE-specifik strålformning och implementeringav carrier aggregation (CA). Vi redovisar också en dämpning av regn när nätverket används i hög bärvågsfrekvens, eftersom Indonesien har en hög regnhastighet och det är viktigt att överväga. Vi jämförde fem fall av lösning:Fall 1 är Single Carrier (SC) eller Enkelbärare LTE 1.8 GHz system; Fall 2 är bärareaggregation (CA) LTE 1,8 GHz + 2.6 GHz; Fall 3 är SC 5G 15 GHz;Fall 4 är SC 5G 28 GHz; Fall 5 är CA LTE 1.8 GHz + 5G 15 GHz. Baserat på utvärderingen, i Leuwidamar-scenariot,ger Fall 5 oss det minsta antalet BSsom behövs för att möta det futuristiska kravet med endast 1.6 gångers förtätning från nuvarande nätverk. I Panimbang erbjuds det minsta antalet BS somkrävs i två fall, fall 3 och fall 5 utan ytterligare BS behövs (1 gångers förtätning). Lösningen med den lägsta energiförbrukningen för båda områdena är fall 3. Detta beror på att bäraraggregations scenariot behöver ytterligare effekt för att generera det andra systemet. Om vi introducerar cell DTX-funktionen i 5G-nätverket kan Fall 3 ge oss en imponerande energibesparing, med 97% minskning för Leuwidamar och 94% för Panimbang jämfört med Fall 1-lösning utan DTX-funktion.
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Novak, Markus. "Low Cost Ultra-Wideband Millimeter-Wave Phased Arrays." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500574802418502.
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Liu, Liheng. "Performance evaluation of direct air-to-ground communication using new radio (5G)." Thesis, KTH, Teknisk informationsvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211464.
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Providing mobile broadband (MBB) coverage to passengers in planes (and other yingobjects) has been one of the very important requirements by airline industry for sometime. With the emergence of high-capacity wireless network concepts, there is a renewedeort in dening systems based on 5G (also dened as NR, new radio) for air-to-ground(A2G) communication. When passenger planes have been taken into consideration, a fewhundreds of passengers may need to be supported, thus requiring a high-capacity backhaullink. When 5G is used for such A2G link, beamforming and other advanced physicallayer techniques can be used between the ground stations and ying objects to obtainhigh-data rate and reliable new radio link. This masters thesis work includes link andsystem level evaluations of such NR systems when beamforming, large bandwidth, higherantenna gains, coordination between ground stations, etc., are deployed. The evaluationswere carried out in Ericsson's internal state-of-the-art simulators. The study providesbaseline for system design principles for future A2G system based on NR. Also a properpropagation model for A2G communication has been identied and beamforming solutionwith other related techniques that could be used in A2G scenario have been investigated.Att tillhandahålla mobil bredbandstäckning till passagerare i flygplan (samt andraluftburna föremål) har varit ett viktigt krav från flygsindustrin på senare tid. Medframväxten av trådlösa nätverkskoncept med hög kapacitet har en förnyad insats uppståttför att definiera system baserade på 5G (också kallat New Radio (NR)) för Airplane-to-Ground (A2G) kommunikation. För passagerarplan så kan hundratals passagerare behövatäckning, vilket kräver en backhaul-länk med hög kapacitet. När 5G används för en sådanA2G-länk så kan såkallad lobformning och andra avancerade tekniker användas mellanmarkstationerna och flygande objekt för att erhålla hög datahastighet och tillförlitlig radiolänk. I denna uppsats ingår länk- och systemnivåutvärderningar av sådana NR-systemnär lobformning, stor bandbredd, antenn-amplifikation, koordinering mellan markstationeretc utplaceras. Utvärderingarna genomfördes i Ericssons interna simulatorer. Studienger vägledning för principer inom systemdesign för framtida A2G-system baserat på NR.En lämplig utbredningsmodell för radiovågor för A2G-kommunikation har identifieratsoch en metod för lobformning och andra relaterade tekniker som kan användas i A2Gscenariothar också undersökts.
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Hsu, Jen-Chiu, and 徐振球. "Adaptive Broadband Beamforming under Coherent Environments." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/80865202928766768139.
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碩士國立臺灣大學
電信工程學研究所
93
An adaptive broadband antenna array is a collection of sensor elements and tap delay line whose outputs are combined by an iteratively adjusted combining (or weight) vector so as to pass a desired signal on desired arrival directions with minimum distortion while rejecting interfering signals which makes the maximum output SINR. Here, we use second order auto-regressive model to generate broadband signals, and consider the beamforming technique under coherent environment that cause signal cancellation phenomena. The phenomena can cause signal loss in the case of narrowband signals, or cause significant signal distortion in the case of wideband signals. Traditionally, one method is known as spatial smoothing technique which was proposed by Shan and Kailath, and the derivational methods as weighted spatial smoothing and progressive spatial smoothing. In this paper, we use LCMV structure of Frost, and propose our method TBTAM (Toeplitz–Block-Toeplitz Approximation Method) and I-TBTAM (Iteration-TBTAM) combining with AIC,MDL method as the optimum beamforming technique under coherent environment. Finally, we present broadband general sideband canceller as compared with LCMV.
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Thiel, Ryan Douglas. "Array processing techniques for broadband acoustic beamforming." 2005. http://louisdl.louislibraries.org/u?/NOD,225.
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Thesis (M.S.)--University of New Orleans, 2005.Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Electrical Engineering"--Thesis t.p. Vita. Includes bibliographical references.
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Chen, Chih-Yu, and 陳治宇. "Robust Broadband Array Beamforming with Multiple-Beam Constraints." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/05956276204490360992.
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碩士國立臺灣大學
電信工程學研究所
93
The theory about narrowband array signal processing is almost complete and saturated. There exist lots of robust algorithms for each non-ideal condition to improve the array performance. In my thesis I try to extend the robust algorithm used in narrowband signal and narrowband beamformer to broadband beamformer dealing with broadband signals. And in the broadband beamformer structure I use the tap-delay-line after each array element to yield desired frequency response. I discuss two non-ideal situations: angle mismatch and coherent interference. Then under the criterions used in narrowband case before, I extend the robust algorithm to broadband case and simulate their performance. For angle mismatch, I extend the Cheng’s method to broadband case. However finding the signal subspace is not easy like narrowband case because the broad frequency band and the tap-delay-line structure. So I develop a method to construct the signal subspace. For coherent interference I extend the two stage array structure in narrowband case to broadband case, and compare its performance with spatial smoothing.
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Jung, Guo-Wei, and 鍾國暐. "Adaptive Broadband Array Beamforming with Multiple-Beam Constraints." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/46711279202424546574.
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碩士臺灣大學
電信工程學研究所
95
By adjusting weights, adaptive antenna array can suppress interference and noise while receiving a signal from a specific angle. However, the performance of antenna array may be highly degraded if there are uncertainties in array. In this thesis, we consider some uncertainties including array element position perturbations and mutual coupling effects. We focus on correcting these effects when using broadband uniform linear array, broadband uniform circular array, and GSC. In this thesis, we use broadband noise-subspace projection method to correct the problem caused by the uncertainties. In this method, we use the eigen-decomposition of spectral density matrix and a gradient method to update the steering vector of antenna array iteratively. According to the simulation results, our method performs better than Diagonal Loading and Optimum Diagonal Loading.
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Ward, Darren Brett. "Theory and application of broadband frequency invariant beamforming." Phd thesis, 1996. http://hdl.handle.net/1885/49259.
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In many engineering applications, including radar, sonar, communications and seismology, the direction of impinging signal wavefronts can be used to discriminate between competing sources. Often these source signals cover a wide bandwidth and conventional narrowband beamforming techniques are ineffective, since spatial resolution varies significantly across the band. In this thesis we consider the problem of beamforming for broadband signals, primarily when the spatial response remains constant as a function of frequency. This is called a frequency invariant beamformer (FIB). ¶ ...
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Chin, Ting-Yueh, and 金廷嶽. "Multifunctional CMOS Beamforming Phased Arrays for Broadband Wireless Communications." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/58043396836073441927.
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博士國立中正大學
電機工程研究所
99
This dissertation presents a novel matrix-fed beamforming phased array, which has reconfigurable multi-functional beamforming, including grid of beams, switched beams, and continuously-steered beam. In the matrix-fed beamformer, each input port generates a specific beam direction such that a spatially-orthogonal basis of characteristic beams is established. By controlling the basis of characteristic beams, a variety of beam functions can be precisely generated. Consequently, the circuit complexity and power consumption of the multi-functional beamformer is significantly reduced. First, the array signal analysis of the matrix-fed beamformer is carried out, from which the design methodology for the generation of the grid-of-beam and switched-beams is given. Furthermore, for generating the continuously-steered beam, we introduce the subsector beam steering (SBS) technique. The SBS properly activates the characteristic beam basis to form a new steerable beam to any desired direction. On the chip implementation of the matrix-fed beamformer in CMOS technology, the quadrature hybrid, high-order Butler matrix, and single-chip phased-array receiver are designed in 2 to 70 GHz band. The CMOS quadrature hybrid was realized with the dual-coupling transformer. Through the inductive and capacitive coupling between the transformer windings, the serious phase imbalance due to the presence of low-Q CMOS parasitic is effectively reduced. The transformer winding length is also dramatically reduced to one-twelfth of a wavelength. The measurement results show that the S-band quadrature hybrid has a measured phase balance within ±0.8° and amplitude balance within ±0.3 dB over a 10% fractional bandwidth and the chip size is 0.38×0.26 mm2. The Ka-band quadrature hybrid has a phase balance within ±0.6° and amplitude balance within ±0.3 dB over a 16% fractional bandwidth. The size is compact of 0.26×0.21 mm2. On the CMOS Butler matrix, two 4×4 S- and Ka-band Butler matrices in 0.18-um CMOS and one 8×8 V-band Butler matrix in 0.13-um CMOS were designed. The 4×4 S- and Ka-band Butler matrices have very compact sizes of 1.51 and 0.41 mm2, respectively. The available array gains are 1.5, and 3.8 dB at 2.4 and 24 GHz, respectively. The 8×8 V-band Butler matrix has an available array gain of 5.9 dB at 60 GHz and a compact area of 1.35 mm2. Finally, the beam-steering phased-array receiver was integrated from the quadrature hybrid, Butler matrix, and beam steering controller in 0.13um CMOS technology. It has measured receiver gain of 17-21dB, noise figure of 9-10.5 dB, input P1dB of -21dBm. The beam can be continuously steered over the -90° to 90° spatial range. The power consumption is 30 mW, which is only 25 % compared with the other works in literature. The chip size is 1.43 mm2, which is 47 % compated with other works. These results demonstrate the compact low-power-consumption phased array with multiple beamforming functions can be successfully achieved by the proposed matrix-fed beamforming technique.
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Abhayapala, Thushara. "Modal Analysis and Synthesis of Broadband Nearfield Beamforming Arrays." Phd thesis, 1999. http://hdl.handle.net/1885/46049.
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This thesis considers the design of a beamformer which can enhance desired signals in an environment consisting of broadband nearfield and/or farfield sources. The thesis contains: a formulation of a set of analysis tools which can provide insight into the intrinsic structure of array processing problems; a methodology for nearfield beamforming; theory and design of a general broadband beamformer; and a consideration of a coherent nearfield broadband adaptive beamforming problem. To a lesser extent, the source localization problem and background noise modeling are also treated. A set of analysis tools called modal analysis techniques which can be used to a solve wider class of array signal processing problems, is first formulated. The solution to the classical wave equation is studied in detail and exploited in order to develop these techniques. Three novel methods of designing a beamformer having a desired nearfield broadband beampattern are presented.