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IEEE Transactions on Acoustics, Speech, and Signal Processing

Issue 6 • Date Jun 1988

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Displaying Results 1 - 20 of 20
  • A note on `Wigner distribution for finite duration or band-limited signals and limiting cases [and author's reply]

    Publication Year: 1988, Page(s):927 - 929
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    A recent paper by L. Cohen (ibid., vol.ASSP-35, p.796-806, June 1987) investigates the Wigner distribution of signals consisting of two finite-duration, nonoverlapping signal components. an alternative analysis that is considerably simplified as compared to Cohen's is presented. The analysis is based on the author's belief that Cohen's discussion is unnecessarily complicated and difficult to read.... View full abstract»

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  • Averaging analysis of local stability of a real constant modulus algorithm adaptive filter

    Publication Year: 1988, Page(s):900 - 910
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (844 KB)

    The constant modulus algorithm (CMA) of adaptive filtering was developed for usage when the modulus of the desired signal is known, but its specific value at every sample instant is not known. A real-arithmetic version of CMA was recently proposed, and studied using simulations, by J.R. Treichler and M.G. Larimore (ibid., vol.ASSP-33, p.420-31, Apr. 1985). Local stability of their arithmetic versi... View full abstract»

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  • Array filters for attenuating multiple coherent interference

    Publication Year: 1988, Page(s):844 - 853
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (676 KB)

    The problem of extracting the desired signal from the recording of an array of sensors corrupted by multiple coherent interference and random noise is considered. The desired signal and interferences are assumed to have different arbitrary waveforms, and no a priori knowledge of such waveforms is assumed. The relative delay times of the interferences with respect to the desired signal are assumed ... View full abstract»

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  • Quadratic digital filters for image processing

    Publication Year: 1988, Page(s):937 - 939
    Cited by:  Papers (30)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (552 KB)

    A class of nonlinear two-dimensional filters is presented. A matrix description is developed for such operators, and some symmetry conditions are imposed which simplify and render more effective the filter structure. A strategy for the design of filters capable of enhancing images having reduced contrast and degraded by noise is proposed View full abstract»

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  • Adaptive silence deletion for speech storage and voice mail applications

    Publication Year: 1988, Page(s):924 - 927
    Cited by:  Papers (11)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    An algorithm that uses two adaptive-amplitude thresholds and zero-crossing rate was used to delete nonspeech material from speech waveforms which have been digitally encoded and then decoded using PCM, adaptive-differential PCM, and adaptive-delta-modulation. Typically, compression rates of 35% resulted. Subject evaluations are used to assess reconstructed speech quality, which improves significan... View full abstract»

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  • Small roundoff noise realization of fixed-point digital filters and controllers

    Publication Year: 1988, Page(s):880 - 891
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (924 KB)

    A method for finding digital realizations of discrete-time transfer functions by fixed-point arithmetic is presented. The obtained realizations attain very small roundoff-noise intensity. This intensity is significantly smaller than the intensities that have been achieved so far. The method applies many 0-1 coefficients in the realization. It therefore requires a small number of multiplications an... View full abstract»

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  • Sectioning property of long logical convolution

    Publication Year: 1988, Page(s):929 - 931
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (284 KB)

    A property of a linear dyadic-invariant (LDI) system which can be utilized in implementing a digital filter by logical convolution is discussed. It is shown that sectioning is a natural consequence when computing logical convolution for a long input-data sequence, and that padding with zeros and/or overlapping of data segments is not required in sectioned computation of long logical convolution View full abstract»

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  • Performance analysis of an adaptive notch filter with constrained poles and zeros

    Publication Year: 1988, Page(s):911 - 919
    Cited by:  Papers (85)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    A statistical analysis of the sine-wave frequency estimate obtained by the adaptive notch filter (ANF) recently proposed by A. Nehorai (ibid., vol.ASSP-33, p.983-96, Aug. 1985) is presented. Asymptotically valid expressions for the bias and mean-square error of the frequency estimate are provided. The analysis verifies the performance exhibited by the ANF, and clarifies the role of some user varia... View full abstract»

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  • A unified approach to closed-loop time delay estimation systems

    Publication Year: 1988, Page(s):854 - 861
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    Two generalized configurations for a closed-loop delay estimation system (CLDES) are discussed. The indirect correlation (IC) configuration is compared to the conventional CLDES-the direct correlation (DC) configuration. It is shown that the baseband equivalents of the two configurations differ only by the input noise. However, the noise power in the IC configuration is far less than that of the D... View full abstract»

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  • On linear prediction models constrained to have unit-modulus poles and their use for sinusoidal frequency estimation

    Publication Year: 1988, Page(s):940 - 942
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (276 KB)

    Linear prediction models with their poles restricted to the unit circle can be efficiently determined by using the Levinson or the split-Levinson algorithm. A simple proof of this property is presented. The prime application of linear prediction models constrained to have unit-modulus poles is the estimation of sinusoidal frequencies. The consistency properties of the corresponding frequency estim... View full abstract»

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  • FIR-median hybrid filters with predictive FIR substructures

    Publication Year: 1988, Page(s):892 - 899
    Cited by:  Papers (151)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    A class of finite-impulse response (FIR) median hybrid (FMH) filters that contain linear FIR substructures to estimate the current signal value using forward and backward prediction is introduced. The output of the overall filter is the median of the predicted values and the actual signal value in the middle of the filter window. Predictors maximizing the signal-to-noise ratio on signal sections d... View full abstract»

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  • A new polar Fourier transform for computer-aided tomography and spotlight synthetic aperture radar

    Publication Year: 1988, Page(s):931 - 933
    Cited by:  Papers (29)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    An algorithm for calculating the Fourier transform of certain discrete measures supported on a two-dimensional polar grid is described. The algorithm utilizes a modified Bluestein chirp algorithm to directly calculate the Fourier transform values over a rectangular grid. Applications to computer-aided tomography and spotlight synthetic aperture radar are described View full abstract»

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  • Optimum beamforming for coherent signal and interferences

    Publication Year: 1988, Page(s):833 - 843
    Cited by:  Papers (65)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (924 KB)

    An approach is described to optimum beamforming in the presence of correlated interferences completely overcoming the signal cancellation phenomenon. In contrast with classical adaptive beamforming where no assumptions are made on the statistical properties of the interference and noise, other than their being uncorrelated with the desired signal, the present approach is based on an explicit stati... View full abstract»

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  • On the midrange estimator

    Publication Year: 1988, Page(s):920 - 922
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    An error criterion for the design of an estimator based on extreme-order statistics, namely, the midrange, is defined. This approach is taken to overcome the fact that the variance of the midrange estimate is strongly dependent on the input distribution. Moreover, under this performance criterion, nonparametric characteristics for the design of these estimators are found View full abstract»

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  • Contour-gain vector quantization

    Publication Year: 1988, Page(s):862 - 870
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (772 KB)

    An information-theory motivation for considering a contour-gain codebook structure is given and an iterative contour-gain vector quantizer (CGVQ) algorithm allowing optimization of the shape codebook for a fixed-gain codebook is described. Numerical results are presented for CGVQ encoding of first-, second-, and tenth-order Gauss-Markov sources, and a clear improvement over SGVQ (shape-gain vector... View full abstract»

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  • Maximum likelihood estimation of liner signal parameters for Poisson processes

    Publication Year: 1988, Page(s):942 - 945
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    The estimation of linear signal parameters is studied under the hypothesis of independently Poisson distributed measurements. A simple interactive maximum-likelihood estimator (MLE) is derived and is optimized for rapid convergence. It is shown to be statistically optimal in the sense of providing unbiased and minimum variance estimates. Experimental conditions are identified where MLE results in ... View full abstract»

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  • Bayesian filtering of Poisson noise using local statistics

    Publication Year: 1988, Page(s):933 - 937
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (572 KB)

    Images recorded at low-light levels inherently suffer from Poisson noise. A filter based on the maximum a posteriori probability (MAP) criterion is developed to remove this noise. The filter is adaptive; it responds to local changes in image statistics and, thus, removes the noise along the edges without significantly affecting the edge sharpness. It does not require any a priori information about... View full abstract»

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  • On the exact maximum likelihood estimation of Gaussian autoregressive processes

    Publication Year: 1988, Page(s):922 - 924
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    It is shown that the true maximum-likelihood estimates of a Gaussian zero-mean AR process can be calculated. The steps toward their obtainment with standard subroutines are calculating extrema are given. The likelihood of the data is maximized in contrast to current approximate methods. However, the computational cost is significantly higher. Also, the order p of the process is presumed k... View full abstract»

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  • On the use of instantaneous and transitional spectral information in speaker recognition

    Publication Year: 1988, Page(s):871 - 879
    Cited by:  Papers (125)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (724 KB)

    The use of instantaneous and transitional spectral representations of spoken utterances for speaker recognition is investigated. Linear-predictive-coding (LPC)-derived cepstral coefficients are used to represent instantaneous spectral information, and best linear fits of each cepstral coefficient over a specified time window are used to represent transitional information. An evaluation has been ca... View full abstract»

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  • On the performance analysis of the MVDR beamformer in the presence of correlated interference

    Publication Year: 1988, Page(s):945 - 947
    Cited by:  Papers (37)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    Expressions are developed that describe the output of an adaptive array, based on the minimum variance distortionless response (MVDR) beamformer when multiple correlated interfering signals are present. Such signals may arise in certain multipath scenarios or in the case of smart jamming. Previous analyses considered only the case of single correlated interferer. Three scenarios of interest are ex... View full abstract»

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Aims & Scope

This Transactions ceased production in 1990. The current retitled publication is IEEE Transactions on Signal Processing.

Full Aims & Scope