Now showing items 1-33 of 33

  • Multilingual Open-Content Signal Processing Laboratories in Connexions 

    Frantz, Patrick; Baraniuk, Richard G.; Choi, Hyeokho; Jones, Douglas L. (2004-11-01)
    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 open-content materials that enable and ...
  • Sharing Knowledge and Building Communities in Signal Processing 

    Baraniuk, Richard G.; Burrus, C. Sidney; Johnson, Don; Jones, Douglas L. (2004-09-01)
    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 ...
  • Community Driven Digital Signal Processing Laboratories in Connexions 

    Baraniuk, Richard G.; Choi, Hyeokho; Jones, Douglas L.; Potter, Lee (2004-06-01)
    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 ...
  • Equivalence of Generalized Joint Signal Representations of Arbitrary Variables 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-12-20)
    Joint signal representations (JSRs) of arbitrary variables generalize time-frequency representations (TFRs) to a much broader class of nonstationary signal characteristics. Two main distributional approaches to JSRs of ...
  • Wigner-Based Formulation of the Chirplet Transform 

    Baraniuk, Richard G.; Jones, Douglas L. (1996-12-01)
    Using the Wigner distribution, we derive and analyze a matrix formulation for the chirplet transform, a signal analysis tool that generalizes the wavelet and short-time Fourier transforms. The formulation expresses the ...
  • Optimum Quadratic Detection and Estimation Using Generalized Joint Signal Representations 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-12-01)
    Time-frequency analysis has recently undergone significant advances in two main directions: statistically optimized methods that extend the scope of time-frequency-based techniques from merely exploratory data analysis to ...
  • Integral Transforms Covariant to Unitary Operators and their Implications for Joint Signal Representations 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-06-01)
    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 ...
  • A Canonical Covariance Based Method for Generalized Joint Signal Representations 

    Jones, Douglas L.; Sayeed, Akbar M. (1996-04-20)
    Generalized joint signal representations extend the scope of joint time-frequency representations to a richer class of nonstationary signals. Cohen's marginal-based generalized approach is canonical from a distributional ...
  • Generalized Joint Signal Representations and Optimum Detection 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
    Generalized joint signal representations (JSRs) extend the scope of joint time-frequency representations (TFRs) to a richer class of nonstationary signals, but their use, just as in the case of TFRs, has been primarily ...
  • Optimal Reduced Rank Time-Frequency/Time Scale Quadratic Detectors 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
    Optimal detectors based on time-frequency/time-scale 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 ...
  • Time Frequency Detectors 

    Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
    Time-frequency representations (TFRs) provide a powerful and flexible structure for designing optimal detectors in a variety of nonstationary scenarios. In this paper, we describe a TFR-based framework for optimal detection ...
  • A Simple Covariance Based Characterization of Joint Signal Representations of Arbitrary Variables 

    Jones, Douglas L.; Sayeed, Akbar M. (1996-01-20)
    Joint signal representations of arbitrary variables extend the scope of joint time-frequency representations, and provide a useful description for a wide variety of nonstationary signal characteristics. Cohen's marginal-based ...
  • Design of Training Data Based Quadratic Detectors with Application to Mechanical Systems 

    Rizzoni, Giorgio; Sayeed, Akbar M.; Jones, Douglas L. (1996-01-20)
    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 ...
  • Optimal Detection Using Bilinear Time Frequency and Time Scale Representations 

    Sayeed, Akbar M.; Jones, Douglas L. (1995-12-20)
    Bilinear time-frequency representations (TFRs) and time-scale representations (TSRs) are potentially very useful for detecting a nonstationary signal in the presence of nonstationary noise or interference. As quadratic ...
  • Unitary Equivalence: A New Twist on Signal Processing 

    Baraniuk, Richard G.; Jones, Douglas L. (1995-10-01)
    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 ...
  • An Adaptive Optimal-Kernel Time-Frequency Representation 

    Jones, Douglas L.; Baraniuk, Richard G. (1995-10-01)
    Time-frequency 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 ...
  • Optimal Kernels for Nonstationary Spectral Estimation 

    Sayeed, Akbar M.; Jones, Douglas L. (1995-02-20)
    Current theories of a time-varying 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 ...
  • Blind Quadratic and Time Frequency Based Detectors from Training Data 

    Jones, Douglas L.; Sayeed, Akbar M. (1995-01-20)
    Time-frequency based methods, particularly quadratic (Cohen's-class) representations, are often considered for detection in applications ranging from sonar to machine monitoring. We propose a method of obtaining near-optimal ...
  • Improved Time-Frequency Filtering of Signal-Averaged Electrocardiograms 

    Sayeed, Akbar M.; Jones, Douglas L. (1995-01-15)
    A recently proposed time-frequency filtering technique has shown promising results for the enhancement of signal-averaged electrocardiograms. This method weights the short-time Fourier transform (STFT) of the ensemble-averaged ...
  • A Simple Scheme for Adapting Time-Frequency Representations 

    Jones, Douglas L.; Baraniuk, Richard G. (1994-12-01)
    Signal-dependent time-frequency 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 Signal-Dependent Time-Frequency Representation: Fast Algorithm for Optimal Kernel Design 

    Baraniuk, Richard G.; Jones, Douglas L. (1994-01-01)
    A time-frequency representation based on an optimal, signal-dependent kernel has been proposed recetnly in an attempte to overcome one of the primary limitations of bilinear time-frequency distributions: that the best ...
  • Shear Madness: New Orthonormal Bases and Frames Using Chirp Functions 

    Baraniuk, Richard G.; Jones, Douglas L. (1993-12-01)
    The proportional-bandwidth and constant-bandwidth time-frequency signal decompositions of the wavelet, Gabor, and Wilson orthonormal bases have attracted substantial interest for representing nonstationary signals. However, ...
  • Unitary Equivalence and Signal Processing 

    Baraniuk, Richard G.; Jones, Douglas L. (1993-08-01)
    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 ...
  • A Signal Dependent Time Frequency Representation: Optimal Kernel Design 

    Baraniuk, Richard G.; Jones, Douglas L. (1993-04-01)
    Time-frequency distributions (TFDs), which indicate the energy content of a signal as a function of both time and frequency, are powerful tools for time-varying signal analysis. The lack of a single distribution that is ...
  • Warped Wavelet Bases: Unitary Equivalence and Signal Processing 

    Baraniuk, Richard G.; Jones, Douglas L. (1993-04-01)
    The notions of time, frequency, and scale are generalized using concepts from unitary operator theory and applied to time-frequency analysis, in particular the wavelet and short-time Fourier transform orthonormal bases and ...
  • Signal-Dependent Time-Frequency Analysis using a Radially Gaussian Kernel 

    Baraniuk, Richard G.; Jones, Douglas L. (Elsevier, 1993-01-15)
    Time-frequency distributions are two-dimensional functions that indicate the time-varying frequency content of one-dimensional signals. Each bilinear time-frequency distribution corresponds to a kernel function that ...
  • A Simple Scheme for Adapting Time-Frequency Representations 

    Jones, Douglas L.; Baraniuk, Richard G. (1992-10-01)
    Current signal-dependent time-frequency representations are block-oriented methods suited only for short-duration signals. The authors propose a simple, computationally efficient technique for creating adaptive time-frequency ...
  • New Signal-Space Orthonormal Bases via the Metaplectic Transform 

    Baraniuk, Richard G.; Jones, Douglas L. (1992-10-01)
    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 On-Line Signal-Dependent Time-Frequency Representation 

    Jones, Douglas L.; Baraniuk, Richard G. (1992-09-01)
    No Abstract.
  • New Dimensions In Wavelet Analysis 

    Baraniuk, Richard G.; Jones, Douglas L. (1992-03-01)
    In this paper we propose a new class of signal analysis tools that generalizes the popular wavelet and short-time Fourier transforms. The class allows skews and rotations of the analyzing wavelet in the time-frequency ...
  • Applications of Adaptive Time Frequency Representations to Underwater Acoustic Signal Processing 

    Baraniuk, Richard G.; Jones, Douglas L.; Tom, Brotherton; Larry, Marple (1991-11-01)
    The authors describe the application of an adaptive optimal kernel (AOK) time-frequency representation to the processing of underwater acoustic data. The optimal kernel is a signal-dependent radially Gaussian function. ...
  • A Radially-Gaussian, Signal-Dependent Time-Frequency Representation 

    Baraniuk, Richard G.; Jones, Douglas L. (1991-04-01)
    An optimization formulation for designing signal-dependent 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 ...
  • Efficient Approximation of Continuous Wavelet Transforms 

    Jones, Douglas L.; Baraniuk, Richard G. (1991-04-01)
    An efficient method, based on the chirp-z transform, for computing equally spaced time samples of a continuous wavelet transform at arbitrary scale samples is developed. Applications include efficient computation of samples ...