Adaptive Antenna Arrays for Precision GNSS Receivers PDF Download

Author: Andrew J. O'Brien
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Abstract: Antenna arrays with adaptive filters are currently used to provide interference suppression capabilities for Global Navigation Satellite System (GNSS) receivers. An adaptive array allows greater performance over a single element antenna by providing beamforming/null steering in the directions of satellites and interference sources. Unfortunately, there are some important limitations to the GNSS adaptive arrays in use today. For example, in the process of suppressing interference, adaptive antennas may inadvertently distort the GNSS signal and introduce bias errors into the receiver's position and time estimates. Furthermore, many systems produce sub-optimal interference suppression performance, which degrades the accuracy of the navigation solution. To overcomes these limitations, this dissertation develops novel adaptive antenna algorithms and techniques suitable for precision GNSS receivers. Three primary contributions are made. First, it develops an approach for optimal suppression of interference. For a GNSS application, this corresponds to an adaptive filter that maximizes carrier-to-noise ratio (C/N). The second contribution is the development of approaches for preventing the adaptive antenna array from introducing errors into the GNSS receiver measurements. These techniques take the form of a special adaptive filter algorithm and additional receiver logic that mathematically guarantee zero antenna-induced error even during interference suppression. Since mitigation of these errors requires accurate antenna manifold information, a calibration procedure is needed to obtain the antenna manifolds in an efficient and practical manner. Consequently, the third contribution is a novel self-calibration algorithm. This algorithm simultaneously estimates the antenna manifold and navigation information "on-the-fly". Collectively, these contributions advance the state-of-the-art in GNSS adaptive antennas in terms of performance, precision and practicality.

Author: Sathish Chandran
Publisher: Springer Science & Business Media
ISBN: 3662055929
Category : Technology & Engineering
Languages : en
Pages : 662

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Book Description
This compilation of the works and insights of various key scientists and engineers in this area addresses the current and future trends of scenarios for employing adaptive antenna arrays in communication systems. Ideal as a quick reference for engineers, researchers, advanced undergraduate and postgraduate students.

Author: Larysa Titarenko
Publisher: Springer Science & Business Media
ISBN: 3642321321
Category : Technology & Engineering
Languages : en
Pages : 234

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Book Description
So far there does not exist any theory of adaptive spatial signal processing (ASSP) for signals with uncertain parameters. This monograph is devoted to the development of this theory, which is very important in connection with wide spreading of telecommunications and radio links in the modern society. This theory can be applied for the development of effective radio communications. In the book some original approaches are proposed targeting the development of effective algorithms of ASSP with not exactly known parameters. They include both probabilistic and deterministic approaches for synthesis of robust algorithms of ASSP. The solution of problems also can be reduced to the construction of some operators for the Banach space which is presented in the book. “Methods of Signal Processing for Adaptive Antenna Arrays” targets professionals, students and PhD students in the area of telecommunications and should be useful for everybody connected with the new information technologies.

Author: Ben Allen
Publisher: John Wiley & Sons
ISBN: 0470861908
Category : Technology & Engineering
Languages : en
Pages : 290

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Book Description
In the last fifty years, extensive studies have been carried out worldwide in the field of adaptive array systems. However, far from being a mature technology with little research left to tackle, there is seemingly unlimited scope to develop the fundamental characteristics and applications of adaptive antennas for future 3G and 4G mobile communications systems, ultra wideband wireless and satellite and navigation systems, and this informative text shows you how! Provides an accessible resource on adaptive array fundamentals as well as coverage of adaptive algorithms and advanced topics Analyses the performance of various wideband beamforming techniques in wideband array processing Comprehensively covers implementation issues related to such elements as circular arrays, channel modelling and transmit beam forming, highlighting the challenges facing a designer during the development phase Supports practical implementation considerations with detailed case studies on wideband arrays, radar, sonar and biomedical imaging, terrestrial wireless systems and satellite communication systems Includes examples and problems throughout to aid understanding Companion website features Solutions Manual, Matlab Programs and Electronic versions of some figures Adaptive Array Systems is essential reading for senior undergraduate and postgraduate students and researchers in the field of adaptive array systems. It will also have instant appeal to engineers and designers in industry engaged in developing and deploying the technology. This volume will also be invaluable to those working in radar, sonar and bio-medical applications.

Author: Chad Slick
Publisher:
ISBN:
Category : Adaptive antennas
Languages : en
Pages : 452

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Book Description
Abstract: The current state-of-the-art adaptive antennas for Global Positioning System (GPS) receivers are planar antenna arrays. Due to the planar nature of these antenna arrays, the resolution with respect to the elevation plane is limited if the antenna is mounted in a horizontal plane. The nulls formed by the adaptive antenna in response to low elevation radio frequency interference (RFI) signals extend significantly into the elevation plane resulting in performance degradation. One solution to combat this problem is to use non-planar adaptive antennas with GPS receivers. The non-planar adaptive antenna can exploit its geometry to provide RFI suppression against low elevation interfering signals while maintaining reception of low angle signals of interest (SOI) to yield highly accurate Position, Velocity, and Time (PVT) solutions. It will be shown that convex non-planar antenna arrays perform significantly better than planar antenna arrays as well as concave non-planar antenna arrays in the presence of low elevation RFI signals. Also, an increase in the curvature of the antenna array will result in AJ performance improvement. All antenna arrays studied in this thesis have similar projected area (looking from the top) relative to the current state-of- the-art planar adaptive antenna (GAS-1 CRPA). Moreover, the convex non-planar antenna arrays contains more surface area allowing the addition of more antenna elements resulting in further performance improvement. The antenna element used in this study is a dual stacked microstrip patch antenna designed to operate at the L1(1575.42 MHz) and L2(1227.6 MHz) GPS frequencies. Rigorous electromagnetic (EM) modeling, which takes into account mutual coupling of antenna elements and array structure, of the various antenna arrays is performed to obtain the in situ volumetric patterns of the individual antenna elements. This thesis also focuses on determining the optimum number of elements as well as their distributions based upon antenna array performance for a fixed aperture size of a six inch high and two inch high convex non-planar adaptive antenna. The antenna arrays investigated have a single constraint to have the reference element distributed at the top of the convex surface to provide upper hemispherical coverage. The adaptive antenna performance is evaluated with respect to the adaptive algorithms of simple power minimization and beam forming / null steering. The performance metrics are the output Signal-to-Interference plus Noise Ratio (SINR) and the average available region over the upper hemisphere for which the output SINR exceeds a selected value in the presence of multiple interfering signals, where the average value is obtained by performing Monte Carlo simulations. It will be shown that for the six inch high surface, it is better to distribute the antenna elements along two rings, with the inner ring at an angle of 450 from the centroid (a height of 4.24"), and the other ring along the bottom outer edge of the hemisphere. However, if less surface area is available, as is the case with the two inch high surface, it is best to distribute the remaining elements on the periphery of the antenna array. Furthermore, it will be shown that when adaptive antenna is operating in the beam forming / null steering mode the addition of more elements always leads to improved performance; however, this does not hold true when the adaptive antenna is operating in the simple power minimization mode.

Author: B. Rama Rao
Publisher: Artech House
ISBN: 1596931507
Category : Technology & Engineering
Languages : en
Pages : 424

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Book Description
This practical resource provides a current and comprehensive treatment of GPS/GNSS antennas, taking into account modernized systems and new and developing applications. The book presents a number of key applications, describing corresponding receiver architectures and antenna details. You find important discussions on antenna characteristics, including theory of operation, gain, bandwidth, polarization, phase center, mutual coupling effects, and integration with active components. Moreover, you get expert guidance on the design of adaptive arrays and signal processing techniques used to mitigate interference such as jamming. Addressing critical GNSS antenna high precision requirements, this in-depth book explains the relationships between antenna gain, satellite visibility, geometric dilution of precision, and the carrier-to-noise density ratio. The book delineates requirements for both dual-band and tri-band antennas. You get detailed coverage of a wide range of antenna designs, including microstrip patch, quadrafilar helix, axial mode helix, spiral, inverted L, and planar inverted F antennas. Moreover, you find a discussion on new magnetic metamaterialù substrates and other dielectric substrate materials. Further, this comprehensive book presents designs for very compact GNSS antennas for personal handheld devices and automobiles.

Author: Alan J. Fenn
Publisher: Artech House
ISBN: 1596932732
Category : Technology & Engineering
Languages : en
Pages : 410

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Book Description
Based on the author's extensive research at MIT Lincoln Laboratory, this authoritative resource offers an in-depth description of adaptive array design, emphasizing the RF characteristics, mutual coupling among elements, and field testing methods. It provides you with proven techniques for challenging projects involving radar, communication systems and antenna design. For the first time in any book, you find design guidance on specialized types of arrays, using monopole radiating elements, slotted cylinders and ultrawideband dipoles. Moreover, this unique book presents a focused near-field technique that quantifies the far-field performance of large aperture radar systems and communication systems. The book presents example prototype phased array antennas, including discussions on monopole phased arrays, finite and infinite array analyses, measurements for planar arrays of monopole elements. Further, you get a detailed explanation of focused near-field polarization characteristics of monopole arrays as related to adaptive array testing in the near field. From the fundamentals of adaptive antennas and degrees of freedom for multiple beam antennas and phased arrays… to a test bed monopole phased array and the planar near field testing technique… to arrays of horizontally polarized loop-fed slotted cylinder antennas and ultrawideband dipole arrays, this comprehensive book offers you invaluable, hands-on knowledge for your work in the field.

Author: Springer
Publisher:
ISBN: 9783642321337
Category :
Languages : en
Pages : 244

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Book Description

Author: Melvin M. Weiner
Publisher: CRC Press
ISBN: 9780849337642
Category : Technology & Engineering
Languages : en
Pages : 1246

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Book Description
In our modern age of remote sensing, wireless communication, and the nearly endless list of other antenna-based applications, complex problems require increasingly sophisticated solutions. Conventional antenna systems are no longer suited to high-noise or low-signal applications such as intrusion detection. Detailing highly effective approaches to non-Gaussian weak signal detection, Adaptive Antennas and Receivers provides an authoritative introduction to state-of-the-art research on the modeling, testing, and application of these technologies. Edited by innovative researcher and eminent expert Melvin M. Weiner, this book is the first to integrate three advanced approaches to non-Gaussian weak signal detection into a single reference: homogeneous partitioning of the surveillance volume, adaptive antennas, and adaptive receivers. Comprising self-contained chapters contributed by renowned experts such as Donald D. Weiner and Ronald Fante, each chapter explores the techniques, theoretical basis, and applications of the approach under discussion. The book considers signal detection in the presence of external noise such as clutter residue, interference, atmospheric noise, jammers, external thermal noise, in vivo surrounding tissue, and camouflaging material, making it ideal for use across a broad spectrum of applications. This authoritative reference supplies more than 750 figures and tables, 1460 equations, and 640 references. Adaptive Antennas and Receivers is an ideal resource for improving performance in surveillance, communication, navigation, artificial intelligence, computer tomography, neuroscience, and intrusion detection systems, to name only a few.

Author: Yaohua Zheng
Publisher:
ISBN:
Category : Global Positioning System
Languages : en
Pages : 98

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Book Description
"This thesis describes a blind beamforming technique for GPS receivers. It improves the performance of a GPS receiver by mitigating interference and enhancing GPS signals separately and has a three-stage structure. The technique is based on a linear antenna array and integrates the eigendecomposition based subspace and multiple independent beamforming techniques. A signal model is carefully constructed. Particular emphasis is placed upon the projection matrix derived from the subspace technique. The effect of interference and phase error on this technique is discussed. This technique is tested and compared to null steering and MMSE technique using simulated data for a number of interference environments. Furthermore, the proposed technique is applied to real data and shows several advantages over simple null steering."--Abstract.