Fourth Annual ASSP Workshop on Spectrum Estimation and Modeling

3-5 Aug. 1988

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  • Fourth Annual ASSP Workshop on Spectrum Estimation and Modeling (Cat. No.88CH2633-6)

    Publication Year: 1988
    Request permission for commercial reuse | PDF file iconPDF (30 KB)
    Freely Available from IEEE
  • Where do we stand on high resolution in low-angle tracking radar?

    Publication Year: 1988
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (56 KB)

    Summary form only given. Various issues involved in the achievement of high resolution in low-angle tracking radar are reviewed. Particular attention is given to the multipath phenomenon, the use of high-resolution beamforming, estimation techniques, nonredundant arrays, results obtained with a multiparameter adaptive radar system, and future plans for adaptive matched illumination and adaptive di... View full abstract»

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  • High-order spectra of mixture processes

    Publication Year: 1988
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (74 KB)

    Summary form only given. In certain processes higher-order spectra reveal more information than second-order spectra. For example, the bispectrum has been applied to determine deviations from Gaussianness, to determine phase information in nonGaussian linear processes, and in nonlinear interactions. The trispectrum has also been used to extract phase information from nonGaussian signals. For the p... View full abstract»

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  • Subspace linear prediction approach to extracting poles

    Publication Year: 1988, Page(s):367 - 370
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (199 KB)

    It is shown that the conventional linear prediction (LP) methods (including various versions of the Prony method) and the matrix pencil method for extracting poles of data sequences can be unified under a generalized approach called the subspace linear prediction (SLP) approach. The conventional LP methods can be considered as high-order SLP methods, while the matrix pencil method is a first-order... View full abstract»

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  • Time-frequency and time-scale [signal processing]

    Publication Year: 1988, Page(s):77 - 80
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    General results are presented for time-frequency and time-scale methods. Attention is given to both linear (short-time Fourier transform, wavelet transform) and bilinear (Wigner-Ville distribution, affine Wigner distribution) approaches, with emphasis put on their relationships. Also considered is the relationship of the methods examined to such approaches as constant-Q analysis and ambiguity func... View full abstract»

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  • Signal model analysis via model-critical methods

    Publication Year: 1988, Page(s):235 - 239
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    It is shown that model-critical procedures provide a means to scrutinize an assumed parametric statistical model by varying the way the data are processed for repeated fits to the model. The criticism of the data is accomplished using the generalized likelihood function for the assumed probability density of the data. The degree of criticism is controlled by a user specified constant c. The model-... View full abstract»

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  • Detection and frequency estimation of narrow-band signals by means of the instantaneous-frequency distribution (IFD)

    Publication Year: 1988, Page(s):71 - 76
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    The instantaneous-frequency distribution (IFD) is an amplitude-invariant spectral representation applicable to signals such as speech. The performance of an IFD with time-averaging and squared-amplitude weighting as a narrow-band signal detector and frequency estimator, in comparison to the classical maximum-likelihood detector/estimator, is evaluated experimentally for a single-complex-pole Gauss... View full abstract»

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  • Linear estimation of ARMA processes

    Publication Year: 1988, Page(s):229 - 234
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    The authors propose an identification algorithm for autoregressive moving average (ARMA) processes. Given a finite length sample drawn from an ARMA (p0, q0) model, the technique provides the estimated values of the orders p0 and p0, as well as the AR and MA coefficients. They are obtained from the reflection coefficie... View full abstract»

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  • Digital implementations of spectral correlation analyzers

    Publication Year: 1988, Page(s):264 - 270
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    A variety of quadratic system implementations of spectral correlation analyzers using pipeline digital techniques is studied. The authors analyze in detail three realizations, each with different advantages. One approach is based on the frequency-smoothing method of cross-spectral analysis. The remaining approaches are variants of the time-smoothing method in which the time-smoothing operation is ... View full abstract»

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  • A design methodology for the optimal estimation of the spectral characteristics of non-stationary random signals

    Publication Year: 1988, Page(s):65 - 70
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    The authors outline a methodology for the design of estimators for the evolutive (or Wigner-Ville) spectrum of a harmonizable Gaussian random process, which are optimized to a priori specified properties. Such a property might be the minimization of bias in a specified region of the time-frequency plane consistent with a minimum desired resolution in frequency. The design utilizes Karhunen-Loeve t... View full abstract»

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  • Lower bounds on parametric estimators with constraints

    Publication Year: 1988, Page(s):223 - 228
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    It is demonstrated that implicit constraints of the form G(θ)=0 can be incorporated into the Cramer-Rao lower bound. Constraints on the estimator restrict the local movement of the estimator θ(X) under statistical fluctuation in the observation vector X. A modified Cramer-Rao bound can be obtained by incorporating these restrictions into the formulation of th... View full abstract»

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  • Estimation of underwater source parameters by use of multipath information

    Publication Year: 1988, Page(s):258 - 263
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    Normal mode theory is used to formulate a multipath ocean channel in terms of a relatively straightforward linear-transfer function matrix. The formulation can be used as a basis for maximum-likelihood and MUSIC-type estimator for source parameters such as depth and range. The Cramer-Rao bound shows that the accuracy of depth estimation depends on the shape of the sound speed profile. It is shown ... View full abstract»

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  • An algorithm for estimating the time varying AR parameters of a nonstationary process

    Publication Year: 1988, Page(s):60 - 64
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (180 KB)

    A nonstationary scalar random process represented by an autoregressive (AR) model with rapidly time-varying coefficients is considered. Assuming the observation of this AR process is contaminated by additive white Gaussian noise, the authors estimate the coefficients using the Kalman filtering technique and the solution of the Ricatti equation. Computer simulations have shown favorable results tha... View full abstract»

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  • High resolution spectral estimation through localized polynomial approximation

    Publication Year: 1988, Page(s):402 - 407
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    Autoregressive-moving-average models are not adequate for most tomographic imaging reconstruction problems. Consequently, the high-resolution capability being sought is lost when these models are used. In this work, a model based on localized polynomial approximation of the spectrum is proposed to solve this class of spectral estimation problems. A method for finding the model parameters is give, ... View full abstract»

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  • Detection criteria and spatial-frequential smoothings

    Publication Year: 1988, Page(s):135 - 140
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    Three criteria used to detect how many uncorrelated excitations reach a passive array are examined in two cases: narrowband signals and wideband signals. Two of the criteria are the AIC-MDL (Akaike information-theoretic criterion/minimum description length) criteria and the third uses an adapted statistic of the logarithm of the generalized likelihood ratio. These criteria are compared using analy... View full abstract»

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  • Transfer function phase estimation using a low variance higher order spectrum

    Publication Year: 1988, Page(s):217 - 222
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    A method is presented for identifying a linear system from observations of the output only. The authors introduce a new one-dimensional spectrum, P(ω), and use it to obtain the underlying linear system. The proposed method incorporates builtin smoothing mechanisms to reduce the variance of the phase. The proposed approach requires fewer computations that the Lii-Rosenblatt approach (1982), a... View full abstract»

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  • Eigensystem spectrum estimation methods applied to absorption interferometric spectroscopy

    Publication Year: 1988, Page(s):253 - 257
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    The authors discuss the relative performance of two high-resolution eigensystem methods, applied to spectrum estimation problems as encountered in Fourier transform spectroscopy. The goal is to estimate the value of the parameters required to specify the nonlinear model of the transmittance spectrum as described by D.J. Gingras and J.F. Bohme (1986). The authors begin with the MUSIC model. They pr... View full abstract»

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  • Sliding spectra: a new perspective

    Publication Year: 1988, Page(s):55 - 59
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    The author introduces a simple method that provides an access to a set of sliding power spectra with different characteristics. The method is based on the use of cascading-form realization of the infinite-impulse-response filter. The filter is employed as a time window to the data samples or their lagged products depending on whether the frequency or the power spectrum is of interest. The choice o... View full abstract»

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  • ARMA modeling based on partial AR and MA parameter approximation

    Publication Year: 1988, Page(s):397 - 401
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    A transfer-function modeling concept is developed for an unknown casual stable, linear-time invariant system. The approach taken has been to treat the models separately and then to achieve the general autoregressive-moving-average (ARMA) transfer function representation. The AR approach has been obtained from conventional methods of the Yule-Walker formulations and associated Levinson-Durbin algor... View full abstract»

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  • Extension of the MUSIC approach for near field applications

    Publication Year: 1988, Page(s):129 - 134
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    The eigenstructure approach for any processing is examined for the case in which it is required to estimate not only the source location but also the relative intensity of the received signal at each sensor. The assumption of the MUSIC algorithm that any given source is observed by all sensors with known relative intensity is removed, and hence the proposed technique is useful for localizing emitt... View full abstract»

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  • Uniqueness considerations in autoregressive modeling with third moments

    Publication Year: 1988, Page(s):213 - 216
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    The authors note that Yule-Walker equations for autoregressive (AR) modeling with second-moment (auto-correlation) sequences provide necessary and sufficient conditions for exact matching of the autocorrelation samples of a discrete stationary random process with that of the model. However, when AR modeling is done with linear equations that satisfy the necessary conditions for a match between sam... View full abstract»

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  • Constrained total least squares applied to frequency estimation of sinusoids

    Publication Year: 1988, Page(s):250 - 252
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    Constrained total least squares (CTLS) is a technique for solving an overdetermined system of equations Ax=b that tries to remove the noise present in A and b while simultaneously exploiting the algebraic structure of the noise in A and b. The CTLS method is applied to the problem of estimating the frequencies of sinusoids in white noise. For the case of 25 samp... View full abstract»

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  • Improved high-resolution direction-finding through use of homogeneous constraints

    Publication Year: 1988, Page(s):152 - 157
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    The authors present results that illustrate how incorporation of homogeneous linear constraints can improve the effectiveness of well-known high-resolution direction-finding methods. Results include: the demonstration that the resolution performance of MUSIC can be improved by incorporating suitable constraints; the use of constraints to clarify the relationship between the MUSIC and MinNorm algor... View full abstract»

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  • Structured covariance matrices and dimensionality reduction in array processing

    Publication Year: 1988, Page(s):168 - 171
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    Data are often passed through rectangular matrix transformations in adaptive beamforming and direction-of-arrival estimation to reduce data dimension and lower computational load. The authors show that the transformation defines a structured model for the full dimension data covariance matrix. Signal processing applied to the reduced dimension data is equivalent to processing the original data whi... View full abstract»

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  • Effects of sensor position and pattern perturbations on CRLB for direction finding of multiple narrow-band sources

    Publication Year: 1988, Page(s):98 - 102
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    The authors study the effects of sensor pattern and sensor position perturbations on the angle estimation performance bound for multiple narrow-band sources. The Cramer-Rao lower bound (CRLB) is used with a probabilistic modeling of the perturbations. The CRLBs of a linear uniform array under sensor position and pattern perturbations are evaluated in detail for the case of two narrowband sources View full abstract»

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