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Two-set adaptive detection-estimation of Gaussian sources in Gaussian noise

SIGNAL processing 2004年第9期84卷 1537-1560页

作者： Abramovich, YI Spencer, NK Turcaj, P Cooperat Res Ctr Sensor Signal & Informat Proc CSSIP Mawson Lakes SA 5095 Australia Def Sci & Technol Org ISRD Edinburgh SA 5111 Australia

We consider detection-estimation of Gaussian sources in coloured Gaussian noise for scenarios where a training data set is provided in addition to the primary data set that may contain source signals of interest. We propose a generalised likelihood-ratio test technique based on the optimisation of the likelihood ratio (LR) function that involves both data sets. This optimisation problem is non-convex and so requires some assessment of the quality of its results. The proposed assessment is based on the previously introduced scenario-free lower bound for maximum LR. Joint optimum processing of the two data sets is shown in general to be different from the conventional adaptive technique, whereby the training data set is separately processed, then such estimates are used for primary data processing. We demonstrate that beyond certain threshold conditions, our technique provides an estimation accuracy that is consistent with the corresponding Cramer-Rao bound, whereas maximum likelihood "performance breakdown" is found to occur for scenarios not satisfying such conditions. (C) 2004 Elsevier B.V. All rights reserved.

关键词： detection-estimation adaptive processing training and primary sample sets likelihood-ratio bounds

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An energy-aware data-centric generic utility based approach in wireless sensor networks

An energy-aware data-centric generic utility based approach ...

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Third international symposium on information processing in sensor networks, IPSN 2004

作者： Chen, Wei-Peng Sha, Lui Department of Computer Science Univ. Illinois at Urbana-Champaign Urbana IL 61801 United States

ISBN: (纸本)1581138466

Distinct from wireless ad hoc networks, wireless sensor networks are data-centric, application-oriented, collaborative, and energy-constrained in nature. In this paper, formulate the problem of data transport in sensor networks as an optimization problem whose objective function is to maximize the amount of information (utility) collected at sinks (subscribers), subject to the flow, energy and channel bandwidth constraints. Also, based on a Markov model extended from [3], we derive the link delay and the node capacity in both the single and multi-hop environments, and figure them in the problem formulation. We study three special cases under the problem formulation. In particular, we consider the energy-aware flow control problem, derive an energy aware flow control solution, and investigate via ns-2 simulation its performance. The simulation results show that the proposed energy-aware flow control solution can achieve high utility and low delay without congesting the network.

关键词： sensors

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Efficient data collection trees in sensor networks with redundancy removal

Efficient data collection trees in sensor networks with redu...

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3rd international Workshop on Ad-Hoc, Mobile and Wireless networks, ADHOC-NOW 2004

作者： Zou, Shoudong Nikolaidis, Ioanis Harms, Janelle J. Computing Science Department University of Alberta EdmontonABT6G 2E8 Canada

ISBN: (纸本)9783540286349

In sensor networks, overlapping sensed areas result in the collection of partially redundant data. Interior sensor nodes along a data collection tree can remove redundancies and reduce the required bandwidth for the aggregate data. Assuming that the sensed information is proportional to the sensed area, we propose heuristic algorithms to build data gathering trees in order to reduce communication costs. The algorithms are completely distributed and are based on finding shortest hop paths and employing particular tie-breaking mechanisms. The mechanisms can be divided into two categories: those that use simple knowledge of the cardinality of a neighbor’s neighbor set and those that rely on knowledge of a distance–monotonic metric to a *** compare five heuristics based on communication cost and also on energy and processing costs. For smaller configurations, the performance of the heuristics are also compared to the optimal. With the proposed approaches, it is possible to build a cost efficient data gathering tree which takes advantage of the data redundancy among closely located sensors. © Springer-Verlag Berlin Heidelberg 2004.

关键词： Heuristic algorithms

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On impact of management in wireless sensors networks

On impact of management in wireless sensors networks

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2004 IEEE/IFIP Network Operations and Management symposium: Managing Next Generation Convergence networks and Services, NOMS 2004

作者： Ruiz, Linnyer B. Silva, Fabricio A. Braga, Thais R.M. Nogueira, José M.S. Loureiro, Antonio A.F. Department of Computer Science Federal University of Minas Gerais Av. A. Carlos 6627 CEP 31.279-010 Belo Horizonte MG Brazil Department of Informatic Pontifical Cathol. Univ. of Parana Rua I. Conceicão 1155 CEP 80.215-901 Curitiba PR Brazil

A wireless sensor network aims to collect data and, sometimes, control an environment. This kind of network is composed of hundreds to thousands of devices that have the capability of sensing, processing and wireless communicating, called sensor nodes. The sensor nodes are projected with small dimensions (cm3 or mm3) and this size limitation ends up restraining the nodes resources, like energy, processor and transceiver capacity. The task of building and deploying management systems in environments where there will be tens of thousand of network elements with particular features and organization is very complex. This task becomes worse due to the physical restrictions of these unattended sensor nodes, In this paper we have implemented and evaluated some automatic services of configuration and performance management, proposed by a WSNs management architecture called MANNA. This architecture is based on the paradigm of self-management, which are the automatic functions and services of management using a minimum of human interference. This work aims to evaluate different WSN configurations considering an application of continuous data sensing and dissemination, and the effects of the management solution proposed for this network. The built application does temperature and carbon monoxide concentration level monitoring, in an urban area. The results show up the cost-benefits relations of the different organizations and demonstrates that the management can promote the productivity of the resources and control the quality of the provided services.

关键词： Wireless telecommunication systems

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On distributed sampling of smooth non-bandlimited fields

On distributed sampling of smooth non-bandlimited fields

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international symposium on information processing in sensor networks (IPSN)

作者： A. Kumar P. Ishwar K. Ramchandran Department of Electrical Engineering and Computer Science University of California Berkeley Berkeley CA USA University of California Berkeley Berkeley CA US Dept. of Electr. Eng. & Comput. Sci. California Univ. Berkeley CA USA

Distributed sampling and reconstruction of a physical field using an array of sensors is a problem of considerable interest in environmental monitoring applications of sensor networks. Our recent work has focused on the sampling of bandlimited sensor fields. However, sensor fields are not perfectly bandlimited but typically have rapidly decaying spectra. In a classical sampling set-up it is possible to precede the A/D sampling operation with an appropriate analog anti-aliasing filter. However, in the case of sensor networks, this is infeasible since sampling must precede filtering. We show that even though the effects of aliasing on the reconstruction cannot be prevented due to the "filter-less" sampling constraint, they can be suitably controlled by oversampling and carefully reconstructing the field from the samples. We show using a dither-based scheme that it is possible to estimate non-bandlimited fields with a precision that depends on how fast the spectral content of the field decays. We develop a framework for analyzing non-bandlimited fields that lead to upper bounds on the maximum pointwise error for a spatial bit rate of R bits/meter. We present results for fields with exponentially decaying spectra as an illustration. In particular, we show that for fields f(t) with exponential tails; i.e., F(/spl omega/) < /spl pi//spl alpha//sup -/spl alpha/|/spl omega/|/, the maximum pointwise error decays as c2e/sup -a//sub 1//spl radic/R+ c3 1//spl radic/R (e/sup -2a//sub 1//spl radic/R) with spatial bit rate R bits/meter. Finally, we show that for fields with spectra that have a finite second moment, the distortion decreases as O((1/N)/sup 2/3/) as the density of sensors, N, scales up to infinity . We show that if D is the targeted non-zero distortion, then the required (finite) rate R scales as O (1 //spl radic/D log 1/D).

关键词： Sampling methods sensor arrays Application software Filters Bit rate Permission Computerized monitoring Filtering Upper bound Tail

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Parameter estimation of multicomponent polynomial-phase signals impinging on a multi-sensor array using Extended Kalman Filter 3

Parameter estimation of multicomponent polynomial-phase sign...

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3rd IEEE international symposium on Signal processing and information Technology

作者： Adjrad, M Belouchrani, A Abed-Meraim, K Ecole Natl Polytech Paris France

ISBN: (纸本)0780382927

In this paper, we address the problem of parameter estimation of multiple polynomial-phase signals (PPS) impinging on a multi-sensor array. ne approach used herein is based on a state space modelization of the signal by performing an Extended Kalman Filtering (EKF) to estimate the state. This method exploits the spatial information provided by a sensor array resulting in considering different observations in the EKF equations. Simulation example supporting the theory is provided showing the efficiency of the resulting estimator by performance close to the Cramer-Rao Lower Bound (CRLB).

关键词： Chirp Equations Narrowband Parameter estimation Polynomials sensor arrays Signal analysis State estimation State-space methods Vectors

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A guard interval based frequency offset compensation scheme for MC-CDMA up-link 3

A guard interval based frequency offset compensation scheme ...

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3rd IEEE international symposium on Signal processing and information Technology, ISSPIT 2003

作者： Mashury Ali, H. Communications and Signal Processing Group Department of Electrical and Computer Engineering Curtin University of Technology GPO Box U1987 PerthWA6845 Australia

ISBN: (纸本)0780382927

In this paper, a new frequency offset compensation scheme for up link of multicarrier code-division multiple access (MC-CDMA) systems is proposed. The proposed scheme exploits guard interval (GI) information embedded in MC-CDMA symbol blocks and is an extension of the work in F. Daffara and A. Chouly (May 1993). Simulation results show that the new scheme results in improved performance in MC-CDMA uplink. © 2003 IEEE.

关键词： Wireless sensor networks

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Optimum probing for downlink vector channel estimation 3

Optimum probing for downlink vector channel estimation

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3rd IEEE international symposium on Signal processing and information Technology

作者： Biguesh, M Gershman, AB Univ Duisburg Gesamthsch Dept Commun Syst D-47057 Duisburg Germany

This paper studies the performance of the vector channel probing method with feedback. The least squares (I-S), minimum mean square error (MMSE), and a new scaled LS (SLS) approaches to the channel estimation are stud... 详细信息

ISBN: (纸本)0780382927

关键词： Array signal processing Channel estimation Covariance matrix Downlink Feedback Feeds Laser sintering Least squares approximation Power engineering and energy sensor arrays

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Nonlinear echo cancellation: A real implementation 3

Nonlinear echo cancellation: A real implementation

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3rd IEEE international symposium on Signal processing and information Technology

作者： Sentoni, GB UADE Sch Sci & Engn RA-1073 Buenos Aires DF Argentina

This paper presents a nonlinear echo canceller implementation running on a digital signal processor (DSP). A nonlinear channel is equalized, by using a set of linear dynamic system followed by a nonlinear static map. ... 详细信息

ISBN: (纸本)0780382927

关键词： Attenuation Digital signal processing DSL Ear Echo cancellers Fading Neural networks Nonlinear dynamical systems Sparse matrices State-space methods

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Video object encoder using region-of-interest based neural network classifiers 3

Video object encoder using region-of-interest based neural n...

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3rd IEEE international symposium on Signal processing and information Technology

作者： Jan, T Tech Univ Dept Comp Syst Sydney NSW Australia

ISBN: (纸本)0780382927

In this paper, a hybrid classifier is introduced which combines a linear discriminant classifier and a nonlinear non-parametric neural network based classifier such as the Radial Basis Function Neural networks. This hybrid model provides a linear parametric coding of the coarse-level information about the underlying image, and then use the neural networks to encode the finer-level information of the same image. This model allows the selected image regions of interest be analyzed and encoded in the finer scales by a non-parametric neural network models whilst the image regions of no-interest are analyzed and encoded in coarse scales by a simple parametric model. The experiment on video image compression shows that the proposed model achieves significantly reduced computations for similar compression performance compared to other conventional methods.

关键词： Artificial neural networks Computer networks Humans Image analysis Image coding information processing Linear discriminant analysis Neural networks Object oriented modeling Video compression

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