Now showing items 356-375 of 508

    • Optimizing binary decision systems by manipulating transmission intervals 

      Lexa, Michael; Johnson, Don (2003-07-20)
      We study the optimization of a binary decision system where quantized (soft) decisions are transmitted across an additive white Gaussian noise channel. We adjust the bit transmission intervals to maximize the Chernoff ...
    • Optimizing Physical Layer Data Transmission for Minimal Signal Distortion 

      Johnson, Don; Rodriguez-Diaz, Hiram (2003-04-20)
      When transmitting a sampled signal digitally, data and error correction bits must be transmitted at least as fast as the sampling rate. Typically, each bit is allocated the same transmission time interval, which means 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 ...
    • Origins of the Equivalent Circuit Concept 

      Johnson, Don (2003-04-20)
      The equivalent circuit concept derives from the Superposition Principle and Ohm's Law. Two forms of the equivalent circuit, the Thevenin equivalent and the Norton equivalent, distill any linear circuit into a source and ...
    • Orthogonal Hilbert Transform Filter Banks and Wavelets 

      van Spaendonck, Rutger; Blu, Thierry; Baraniuk, Richard G.; Vetterli, Martin (2003-04-01)
      Complex wavelet transforms offer the opportunity to perform directional and coherent processing based on the local magnitude and phase of signals and images. Although denoising, segmentation, and image enhancement are ...
    • An Overview of the AT&T Spoken Document Retrieval System 

      Choi, John; Hindle, Don; Hirschberg, Julia; Magrin-Chagnolleau, Ivan; Nakatani, Christine; Pereira, Fernando; Singhal, Amit; Whittaker, Steve (1998-01-15)
      We present an overview of a spoken document retrieval system developed at AT&T Labs-Research for the HUB4 Broadcast News corpus. This overview includes a description of the intonational phrase boundary detection, ...
    • PARAMETER ESTIMATION FOR VOICED SPEECH SIGNALS 

      WISE, JAMES DALE, JR. (1977)
    • PARAMETRIC AND NON-PARAMETRIC METHODS OF IMPROVING BEARING ESTIMATION IN NARROWBAND PASSIVE SONAR SYSTEMS 

      LINEBARGER, DAREL ALLEN (1987)
      Two approaches--one parametric and one non-parametric--to the source bearing estimation problem for narrowband passive sonar are presented. The parametric technique does not directly involve estimation of a spatial spectrum. ...
    • PathChirp: Efficient Available Bandwidth Estimation for Network Paths 

      Ribeiro, Vinay Joseph; Riedi, Rudolf H.; Baraniuk, Richard G.; Navratil, Jiri; Cottrell, Les (2003-04-01)
      This paper presents <i>PathChirp</i>, a new active probing tool for estimating the available bandwidth on a communication network path. Based on the concept of "self-induced congestion," PathChirp features an exponential ...
    • Phase and Magnitude Perceptual Sensitivities in Nonredundant Complex Wavelet Representations 

      Wakin, Michael; Orchard, Michael; Baraniuk, Richard G.; Chandrasekaran, Venkat (2003-11-01)
      The recent development of a nonredundant complex wavelet transform allows a novel framework for image analysis. Work on this representation has recognized that the phase and magnitude of complex coefficients can be related ...
    • Platelets for Multiscale Analysis in Medical Imaging 

      Willett, Rebecca; Nowak, Robert David (2002-04-20)
      This paper describes the development and use of multiscale, platelet-based image reconstruction algorithms in medical imaging. Such algorithms are effective because platelets approximate images in certain (piecewise) ...
    • Platelets for Multiscale Analysis in Photon-Limited Imaging 

      Willett, Rebecca; Nowak, Robert David (2002-09-20)
      This paper proposes a new multiscale image decomposition based on platelets. Platelets are localized functions at various scales, locations, and orientations that produce piecewise linear image approximations. For smoothness ...
    • Platelets: A Multiscale Approach for Recovering Edges and Surfaces in Photon-Limited Medical Imaging 

      Willett, Rebecca; Nowak, Robert David (2003)
      This paper proposes a new multiscale image decomposition based on platelets. Platelets are localized functions at various scales, locations, and orientations that produce piecewise linear image approximations. Platelets ...
    • Polynomial Root Finding 

      Lang, Markus; Frenzel, Bernhard-Christian (1994-10-01)
      Finding polynomial roots rapidly and accurately is an important problem in many areas of signal processing. We present a program which is superior in speed and accuracy to the best methods to our knowledge, i.e., Jenkins/Traub ...
    • A programmable baseband processor design for software defined radios 

      Rajagopal, Sridhar; Rixner, Scott; Cavallaro, Joseph R. (2002-08-20)
      Future wireless systems need extremely fast and flexible architectures to support varying standards, algorithms and protocols with data rates in the range of 10-100 Mbps. Software Defined Radios (SDRs) based on DSP-FPGAs ...
    • Pseudo Affine Wigner Distributions 

      Goncalves, Paulo; Baraniuk, Richard G. (1996-05-01)
      In this paper, we introduce a new set of tools for time-varying spectral analysis: the pseudo affine Wigner distributions. Based on the affine Wigner distributions of J. and P. Bertrand, these new time-scale distributions ...
    • Pseudo Affine Wigner Distributions: Definition and Kernel Formulation 

      Goncalves, Paulo; Baraniuk, Richard G. (1998-06-01)
      In this paper, we introduce a new set of tools for time-varying spectral analysis: the pseudo affine Wigner distributions. Based on the affine Wigner distributions of J. and P. Bertrand, these new time-scale distributions ...
    • Pseudo Power Scale Signatures: Frequency Domain Approach 

      Venkatachalam, Vidya; Aravena, Jorge.L. (2000-03-01)
      In an earlier work, we introduced a new form of signal representation called the <b><i>pseudo power signature (PPS)</i></b> that was essentially independent of the duration of the signal. The signatures were obtained based ...
    • A Pseudo-Bertrand Distribution for Time-Scale Analysis 

      Goncalves, Paulo; Baraniuk, Richard G. (1996-03-01)
      Using the pseudo-Wigner time-frequency distribution as a guide, we derive two new time-scale representations, the pseudo-Bertrand and the smoothed pseudo-Bertrand distributions. Unlike the Bertrand distribution, these ...