Showing papers in "IEEE Signal Processing Magazine in 1994"
TL;DR: This article is to show how several different variants of the recursive least-squares algorithm can be directly related to the widely studied Kalman filtering problem of estimation and control.
Abstract: Adaptive filtering algorithms fall into four main groups: recursive least squares (RLS) algorithms and the corresponding fast versions; QR- and inverse QR-least squares algorithms; least squares lattice (LSL) and QR decomposition-based least squares lattice (QRD-LSL) algorithms; and gradient-based algorithms such as the least-mean square (LMS) algorithm. Our purpose in this article is to present yet another approach, for the sake of achieving two important goals. The first one is to show how several different variants of the recursive least-squares algorithm can be directly related to the widely studied Kalman filtering problem of estimation and control. Our second important goal is to present all the different versions of the RLS algorithm in computationally convenient square-root forms: a prearray of numbers has to be triangularized by a rotation, or a sequence of elementary rotations, in order to yield a postarray of numbers. The quantities needed to form the next prearray can then be read off from the entries of the postarray, and the procedure can be repeated; the explicit forms of the rotation matrices are not needed in most cases. >
470 citations
TL;DR: Identifying those applications requiring wideband processing and presenting techniques to implement the processing are two of the goals of this tutorial article.
Abstract: This tutorial presents the application of wavelet transforms to wideband correlation processing. One major difference between most applications of wavelets and the work presented is the choice of mother wavelet. It focuses on nonorthogonal, continuous mother wavelets, whereas most applications use the orthogonal mother wavelets that were advanced by Daubechies (1988). The continuous wavelet transform then provides an additional tool for studying and gaining insight into wideband correlation processing. In order to understand when wideband processing may be required, its counterpart, narrowband processing, is presented and its limitations are discussed. Identifying those applications requiring wideband processing and presenting techniques to implement the processing are two of the goals of this tutorial article. The underlying tool is the wavelet transform. >
380 citations
TL;DR: A robust speaker-identification system is presented that was able to deal with various forms of anomalies that are localized in time, such as spurious noise events and crosstalk.
Abstract: We describe current approaches to text-independent speaker identification based on probabilistic modeling techniques. The probabilistic approaches have largely supplanted methods based on comparisons of long-term feature averages. The probabilistic approaches have an important and basic dichotomy into nonparametric and parametric probability models. Nonparametric models have the advantage of being potentially more accurate models (though possibly more fragile) while parametric models that offer computational efficiencies and the ability to characterize the effects of the environment by the effects on the parameters. A robust speaker-identification system is presented that was able to deal with various forms of anomalies that are localized in time, such as spurious noise events and crosstalk. It is based on a segmental approach in which normalized segment scores formed the basic input for a variety of robust 43% procedures. Experimental results are presented, illustrating 59% the advantages and disadvantages of the different procedures. 64%. We show the role that cross-validation can play in determining how to weight the different sources of information when combining them into a single score. Finally we explore a Bayesian approach to measuring confidence in the decisions made, which enabled us to reject the consideration of certain tests in order to achieve an improved, predicted performance level on the tests that were retained. >
366 citations
TL;DR: It is demonstrated how approaches to language identification based on acoustic modeling and language modeling are similar to algorithms used in speaker-independent continuous speech recognition.
Abstract: The Oregon Graduate Institute Multi-language Telephone Speech Corpus (OGI-TS) was designed specifically for language identification research. It currently consists of spontaneous and fixed-vocabulary utterances in 11 languages: English, Farsi, French, German, Hindi, Japanese, Korean, Mandarin, Spanish, Tamil, and Vietnamese. These utterances were produced by 90 native speakers in each language over real telephone lines. Language identification is related to speaker-independent speech recognition and speaker identification in several interesting ways. It is therefore not surprising that many of the recent developments in language identification can be related to developments in those two fields. We review some of the more important recent approaches to language identification against the background of successes in speaker and speech recognition. In particular, we demonstrate how approaches to language identification based on acoustic modeling and language modeling, respectively, are similar to algorithms used in speaker-independent continuous speech recognition. Thereafter, prosodic and duration-based information sources are studied. We then review an approach to language identification that draws heavily on speaker identification. Finally, the performance of some representative algorithms is reported. >
280 citations
TL;DR: Provides a visual interpretation of the Cooley-Tukey family of FFT algorithms in terms of the shifting properties of the Fourier-transform which equate shifts in one domain to proportional rotations in the alternative domain.
Abstract: Provides a visual interpretation of the Cooley-Tukey family of FFT algorithms (Cooley and Tukey, 1965) in terms of the shifting properties of the Fourier-transform which equate shifts in one domain to proportional rotations in the alternative domain. This approach was proposed in an appendix to Chapter 6 of Kraniauskas (1992). The arguments presented in the article were developed with the aid of 3-dimensional graphics. >
24 citations
TL;DR: The interest in higher-order spectra and cumulants was renewed in the early 1980s due, in part, to the need to solve detection, estimation, and identification problems when the interfering noise source was non-Gaussian.
Abstract: The interest in higher-order spectra and cumulants was renewed in the early 1980s due, in part, to the need to solve detection, estimation, and identification problems when the interfering noise source was non-Gaussian. The bibliography is a list of refereed journal papers. An effort was made to include all relevant papers, though the focus of the search was the IEEE journals, the optics journals, and the statistical journals. The bibliography is intended to be a research tool. Tutorials detail discussions of higher-order spectra and cumulants, and books cover the more advanced topics.
14 citations
TL;DR: The story of three undergraduate students who discover the DFT, armed only with a knowledge of analog methods is told.
Abstract: Discrete Fourier techniques are increasingly being taught as material detached from fundamental continuous-time Fourier analysis. The student is left with an unclear understanding, if any, of the very significant relationships between magnitude and phase spectra generated digitally, and the continuous-time signal which is being analyzed. The present article tells the story of three undergraduate students who discover the DFT, armed only with a knowledge of analog methods. >
7 citations