Browsing George R. Brown School of Engineering by Author "Jones, Douglas L."
Now showing items 133 of 33

An Adaptive OptimalKernel TimeFrequency Representation
Jones, Douglas L.; Baraniuk, Richard G. (19951001)Timefrequency representations with fixed windows or kernels figure prominently in many applications, but perform well only for limited classes of signals. Representations with signal dependent kernels can overcome this ... 
Applications of Adaptive Time Frequency Representations to Underwater Acoustic Signal Processing
Baraniuk, Richard G.; Jones, Douglas L.; Tom, Brotherton; Larry, Marple (19911101)The authors describe the application of an adaptive optimal kernel (AOK) timefrequency representation to the processing of underwater acoustic data. The optimal kernel is a signaldependent radially Gaussian function. ... 
Blind Quadratic and Time Frequency Based Detectors from Training Data
Jones, Douglas L.; Sayeed, Akbar M. (19950120)Timefrequency based methods, particularly quadratic (Cohen'sclass) representations, are often considered for detection in applications ranging from sonar to machine monitoring. We propose a method of obtaining nearoptimal ... 
A Canonical Covariance Based Method for Generalized Joint Signal Representations
Jones, Douglas L.; Sayeed, Akbar M. (19960420)Generalized joint signal representations extend the scope of joint timefrequency representations to a richer class of nonstationary signals. Cohen's marginalbased generalized approach is canonical from a distributional ... 
Community Driven Digital Signal Processing Laboratories in Connexions
Baraniuk, Richard G.; Choi, Hyeokho; Jones, Douglas L.; Potter, Lee (20040601)The conventional textbook is largely inadequate for digital signal processing (DSP) laboratory education due to inherent factors such as a small and fragmented market and rapid hardware obsolescence. Freely available ... 
Design of Training Data Based Quadratic Detectors with Application to Mechanical Systems
Rizzoni, Giorgio; Sayeed, Akbar M.; Jones, Douglas L. (19960120)Reliable detection of engine knock is an important issue in the design and maintenance of high performance internal combustion engines. Cost considerations dictate the use of vibration signals, measured at the engine ... 
Efficient Approximation of Continuous Wavelet Transforms
Jones, Douglas L.; Baraniuk, Richard G. (19910401)An efficient method, based on the chirpz transform, for computing equally spaced time samples of a continuous wavelet transform at arbitrary scale samples is developed. Applications include efficient computation of samples ... 
Equivalence of Generalized Joint Signal Representations of Arbitrary Variables
Sayeed, Akbar M.; Jones, Douglas L. (19961220)Joint signal representations (JSRs) of arbitrary variables generalize timefrequency representations (TFRs) to a much broader class of nonstationary signal characteristics. Two main distributional approaches to JSRs of ... 
Generalized Joint Signal Representations and Optimum Detection
Sayeed, Akbar M.; Jones, Douglas L. (19960120)Generalized joint signal representations (JSRs) extend the scope of joint timefrequency representations (TFRs) to a richer class of nonstationary signals, but their use, just as in the case of TFRs, has been primarily ... 
Improved TimeFrequency Filtering of SignalAveraged Electrocardiograms
Sayeed, Akbar M.; Jones, Douglas L. (19950115)A recently proposed timefrequency filtering technique has shown promising results for the enhancement of signalaveraged electrocardiograms. This method weights the shorttime Fourier transform (STFT) of the ensembleaveraged ... 
Integral Transforms Covariant to Unitary Operators and their Implications for Joint Signal Representations
Sayeed, Akbar M.; Jones, Douglas L. (19960601)Fundamental to the theory of joint signal representations is the idea of associating a variable, such as time or frequency, with an operator, a concept borrowed from quantum mechanics. Each variable can be associated ... 
Multilingual OpenContent Signal Processing Laboratories in Connexions
Frantz, Patrick; Baraniuk, Richard G.; Choi, Hyeokho; Jones, Douglas L. (20041101)Due to inherent factors like a small and fragmented market and rapid hardware obsolescence, the conventional textbook is inadequate for DSP laboratory education. Freely available opencontent materials that enable and ... 
New Dimensions In Wavelet Analysis
Baraniuk, Richard G.; Jones, Douglas L. (19920301)In this paper we propose a new class of signal analysis tools that generalizes the popular wavelet and shorttime Fourier transforms. The class allows skews and rotations of the analyzing wavelet in the timefrequency ... 
New SignalSpace Orthonormal Bases via the Metaplectic Transform
Baraniuk, Richard G.; Jones, Douglas L. (19921001)The discretization of the metaplectic transform (MT) is considered, and it is shown that it can lead to completely new orthonormal bases (ONBs) for the signal space of square integrable functions. Two new classes of bases, ... 
An OnLine SignalDependent TimeFrequency Representation
Jones, Douglas L.; Baraniuk, Richard G. (19920901)No Abstract. 
Optimal Detection Using Bilinear Time Frequency and Time Scale Representations
Sayeed, Akbar M.; Jones, Douglas L. (19951220)Bilinear timefrequency representations (TFRs) and timescale representations (TSRs) are potentially very useful for detecting a nonstationary signal in the presence of nonstationary noise or interference. As quadratic ... 
Optimal Kernels for Nonstationary Spectral Estimation
Sayeed, Akbar M.; Jones, Douglas L. (19950220)Current theories of a timevarying spectrum of a nonstationary process all involve, either by definition or by difficulties in estimation, an assumption that the signal statistics vary slowly over time. This restrictive ... 
Optimal Reduced Rank TimeFrequency/Time Scale Quadratic Detectors
Sayeed, Akbar M.; Jones, Douglas L. (19960120)Optimal detectors based on timefrequency/timescale representations (TFRs/TSRs) admit a representation in terms of a bank of spectrograms/scalograms that yields a large class of detectors. These range from the conventional ... 
Optimum Quadratic Detection and Estimation Using Generalized Joint Signal Representations
Sayeed, Akbar M.; Jones, Douglas L. (19961201)Timefrequency analysis has recently undergone significant advances in two main directions: statistically optimized methods that extend the scope of timefrequencybased techniques from merely exploratory data analysis to ... 
A RadiallyGaussian, SignalDependent TimeFrequency Representation
Baraniuk, Richard G.; Jones, Douglas L. (19910401)An optimization formulation for designing signaldependent kernels that are based on radially Gaussian functions is presented. The method is based on optimality criteria and is not ad hoc. The procedure is automatic. The ... 
Sharing Knowledge and Building Communities in Signal Processing
Baraniuk, Richard G.; Burrus, C. Sidney; Johnson, Don; Jones, Douglas L. (20040901)The textbook has traditionally been the fundamental tool of university teaching. The text both serves as the repository of facts and information and provides the recommended structure and sequence for teaching and learning ... 
Shear Madness: New Orthonormal Bases and Frames Using Chirp Functions
Baraniuk, Richard G.; Jones, Douglas L. (19931201)The proportionalbandwidth and constantbandwidth timefrequency signal decompositions of the wavelet, Gabor, and Wilson orthonormal bases have attracted substantial interest for representing nonstationary signals. However, ... 
A Signal Dependent Time Frequency Representation: Optimal Kernel Design
Baraniuk, Richard G.; Jones, Douglas L. (19930401)Timefrequency distributions (TFDs), which indicate the energy content of a signal as a function of both time and frequency, are powerful tools for timevarying signal analysis. The lack of a single distribution that is ... 
SignalDependent TimeFrequency Analysis using a Radially Gaussian Kernel
Baraniuk, Richard G.; Jones, Douglas L. (Elsevier, 19930115)Timefrequency distributions are twodimensional functions that indicate the timevarying frequency content of onedimensional signals. Each bilinear timefrequency distribution corresponds to a kernel function that ... 
A SignalDependent TimeFrequency Representation: Fast Algorithm for Optimal Kernel Design
Baraniuk, Richard G.; Jones, Douglas L. (19940101)A timefrequency representation based on an optimal, signaldependent kernel has been proposed recetnly in an attempte to overcome one of the primary limitations of bilinear timefrequency distributions: that the best ... 
A Simple Covariance Based Characterization of Joint Signal Representations of Arbitrary Variables
Jones, Douglas L.; Sayeed, Akbar M. (19960120)Joint signal representations of arbitrary variables extend the scope of joint timefrequency representations, and provide a useful description for a wide variety of nonstationary signal characteristics. Cohen's marginalbased ... 
A Simple Scheme for Adapting TimeFrequency Representations
Jones, Douglas L.; Baraniuk, Richard G. (19941201)Signaldependent timefrequency representations, by adapting their functional form to fit the signal being analyzed, offer many performance advantages over conventional representations. In this paper, we propose a simple, ... 
A Simple Scheme for Adapting TimeFrequency Representations
Jones, Douglas L.; Baraniuk, Richard G. (19921001)Current signaldependent timefrequency representations are blockoriented methods suited only for shortduration signals. The authors propose a simple, computationally efficient technique for creating adaptive timefrequency ... 
Time Frequency Detectors
Sayeed, Akbar M.; Jones, Douglas L. (19960120)Timefrequency representations (TFRs) provide a powerful and flexible structure for designing optimal detectors in a variety of nonstationary scenarios. In this paper, we describe a TFRbased framework for optimal detection ... 
Unitary Equivalence and Signal Processing
Baraniuk, Richard G.; Jones, Douglas L. (19930801)The notions of time, frequency, and scale are generalized using concepts from unitary operator theory and eigenanalysis. The result is an infinite number of new signal analysis and processing tools that are implemented ... 
Unitary Equivalence: A New Twist on Signal Processing
Baraniuk, Richard G.; Jones, Douglas L. (19951001)Unitary similarity transformations furnish a powerful vehicle for generating infinite generic classes of signal analysis and processing tools based on concepts different from time, frequency, and scale. Implementation of ... 
Warped Wavelet Bases: Unitary Equivalence and Signal Processing
Baraniuk, Richard G.; Jones, Douglas L. (19930401)The notions of time, frequency, and scale are generalized using concepts from unitary operator theory and applied to timefrequency analysis, in particular the wavelet and shorttime Fourier transform orthonormal bases and ... 
WignerBased Formulation of the Chirplet Transform
Baraniuk, Richard G.; Jones, Douglas L. (19961201)Using the Wigner distribution, we derive and analyze a matrix formulation for the chirplet transform, a signal analysis tool that generalizes the wavelet and shorttime Fourier transforms. The formulation expresses the ...