# [1992] IEEE Sixth SP Workshop on Statistical Signal and Array Processing

## Filter Results

Displaying Results 1 - 25 of 127
• ### IEEE Sixth SP Workshop on Statistical Signal and Array Processing Conference Proceedings (Cat. No.92TH0410-1)

Publication Year: 1992
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• ### Performance evaluation of certain ARMA models in power spectral density estimation

Publication Year: 1992, Page(s):424 - 427
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For an autoregressive moving average (p, q) process the performance measures considered are the asymptotic variance of the spectral estimator and the resolution of two closely spaced sinusoids in white noise. Though the AR parameters are mainly responsible for good resolution, it is shown that proper MA parameters are also necessary in some methods. Cadzow's (Indirect) method and the singular valu... View full abstract»

• ### Performance analysis of eigenstructure based DOA estimators employing conjugate symmetric beamformers

Publication Year: 1992, Page(s):384 - 387
Cited by:  Papers (5)
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If one employs conjugate centro-symmetric beamforming weight vectors in conjunction with a uniformly-spaced linear array, the noise eigenvectors in Beamspace MUSIC may be computed as the smallest' eigenvectors of the real part of the beamspace sample covariance matrix. Through theoretical performance analysis and verification via Monte Carlo simulations, this paper shows that taking the real part... View full abstract»

• ### On the performance of cumulant-based detection of nonGaussian signals

Publication Year: 1992, Page(s):173 - 176
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Detection of a non-Gaussian signal in additive Gaussian noise is assumed to be done in two steps. A selected set of sample cumulants and/or moments of the data are computed; next a detection statistic based on these sample moments/cumulants is evaluated. The paper outlines the asymptotic performance analysis of this detector for a fairly general class of signal and noise models. A simple example i... View full abstract»

• ### A fundamental algorithm for the power estimation of closely separated spectral sources

Publication Year: 1992, Page(s):420 - 423
Cited by:  Papers (1)
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A new algorithm is based upon division of the eigenstructure of the sample covariance into approximate signal and noise subspaces due to fluctuations caused by finite data samples. These fluctuation effects are calculated using stochastic perturbation theoretic techniques. These results show that the moments of the MUSIC null spectrum can be approximated by linear functionals of the source SNR and... View full abstract»

• ### Comparison of parabolic equation and adiabatic mode propagation models for matched-field processing in range-dependent environments

Publication Year: 1992, Page(s):378 - 383
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Matched-field processing of underwater acoustic array data requires a knowledge of the environment and the use of a suitable propagation model from which field replicas can be computed. For range-dependent environment, parabolic equation or mode-based propagation modelling techniques may be used to provide these replicas. A comparison is presented for environments with sloping bottoms, using the o... View full abstract»

• ### A novel solution to multi-scale deconvolution of sensor array signals

Publication Year: 1992, Page(s):477 - 480
Cited by:  Papers (2)
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The authors' model assumes that the data are generated as a convolution of an unknown wavelet with various time-scaled versions of an unknown reflectivity sequence. Their approach relies on exploiting the redundancy in the measurements due to time-scaling. No assumptions are made on the statistical properties of these signals. The deconvolution problem is solved as a quadratic minimization subject... View full abstract»

• ### Signal subspace decomposition of ideal covariance matrices

Publication Year: 1992, Page(s):334 - 337
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Xu and Kailath have proposed (1992) a fast algorithm for signal subspace decomposition that exploits the special matrix structure associated with signal subspace algorithms. This work presents some modifications which eliminate the need to estimate the noise eigenvalue in order to estimate the orthonormal basis of an ideal covariance matrix. The algorithm yields the exact signal subspace and in so... View full abstract»

• ### Detection of active linear FM sonar signals using the bispectrum

Publication Year: 1992, Page(s):177 - 180
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The paper focuses on the problem of a returning active sonar signal masked by environmental background noise. According to theory, if the original signal is sufficiently non-Gaussian the bispectrum of the received signal-plus-noise will contain only information due to the signal, and the white Gaussian noise will be suppressed. A bispectrum detector has been developed which utilizes the a priori k... View full abstract»

• ### Frequency-wavenumber spectrum analysis using quadratic estimators

Publication Year: 1992, Page(s):416 - 419
Cited by:  Papers (3)
| | PDF (324 KB)

A general representation for all non-negative, modulation invariant estimators of the frequency-wavenumber spectrum shows explicitly how the quadratic estimates are constructed from linear transformations of the array data. The windows associated with these transformations are those normally associated with classical' spectrum estimators. The authors present closed form representations for the mo... View full abstract»

• ### Quadratic time-frequency distributions: the new hyperbolic class and its intersection with the affine class

Publication Year: 1992, Page(s):26 - 29
Cited by:  Papers (7)
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The proposed new class of quadratic time-frequency distributions is based on the hyperbolic time shift' and scale invariance properties that are important in the analysis of Doppler invariant signals used in bat and dolphin echolocation, and of locally self-similar' signals used in fractals and fractional Brownian motion. The hyperbolic class can be characterized by 2-D kernels, and kernel const... View full abstract»

• ### Robustness of direction-finding methods for cyclostationary signals in the presence of array calibration error

Publication Year: 1992, Page(s):346 - 349
Cited by:  Papers (1)
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It is shown that cyclostationarity-exploiting direction-finding methods can be much less sensitive than conventional methods to errors in the array calibration data. In particular, when only a small subset of the signals arriving at the array exhibits the desired cyclostationarity property, the signal-selective methods can operate properly in the presence of calibration errors that cause the conve... View full abstract»

• ### HOS-based harmonic retrieval: a deterministic formulation

Publication Year: 1992, Page(s):128 - 131
Cited by:  Papers (5)
| | PDF (328 KB)

Given a single record, the authors consider the problem of estimating the harmonics of a signal buried in noise. The observed data is modeled as a superposition of sinusoids plus stationary, zero-mean additive Gaussian noise of unknown covariance. Novel higher-order statistics, referred to as `mixed' cumulants, are appropriate for certain types of mixed processes. After a consistent HOS-based line... View full abstract»

• ### A simple efficient algorithm for determining the direction of arrival for a single emitter with unknown polarization

Publication Year: 1992, Page(s):308 - 313
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The paper addresses both the problems of estimating DOA from a single array snapshot, and also from a sequence of array snapshots possibly having different polarizations. The principal result is identification of the maximum likelihood estimator of DOA. The associated estimation algorithm is designated as the dual beam scan (DBS) Algorithm. For large signal-to-noise ratios the DBS algorithm is unb... View full abstract»

• ### Partial discharges in high-voltage transformers

Publication Year: 1992, Page(s):473 - 476
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A novel approach to on-line localization of partial discharges in a power transformer is presented. A 2-D technique based on subspace rotation is given. By far-field source and narrowband signal assumptions, the localization problem is reduced to an arrival angle estimation problem. The first step uses two eigenvalue decompositions to clean the data and compute the time delays. The second step con... View full abstract»

• ### The computational complexity of time-frequency distributions

Publication Year: 1992, Page(s):444 - 447
Cited by:  Papers (2)
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A number of lower bounds on the communication and multiplicative complexity are derived. The (Area)×(Time)2 (AT 2) bound for the discrete short time Fourier transform, the discrete Wigner-Ville distribution, the discrete ambiguity function and the discrete Gabor transform is shown to be AT2=Ω(N3 log2 ... View full abstract»

• ### Decomposing the alpha rhythms: comparative performance evaluation of parametric bispectral algorithms for EEG

Publication Year: 1992, Page(s):522 - 525
Cited by:  Papers (2)
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The alpha wave is often harmonically related or coupled to frequencies in other EEG bands. Several autoregressive and eigenstructure-based bispectral algorithms have proven to be effective in the detection and estimation of alpha coupling. The authors extend the triple Kronecker product method of Swindlehurst and Kailath (1989) to estimation of biphases through a generalized eigenvalue approach. A... View full abstract»

• ### Wideband spatial processing with wavelet transforms

Publication Year: 1992, Page(s):235 - 238
Cited by:  Papers (2)
| | PDF (252 KB)

For a nearfield sensor array, wideband signals, and moving scatterers or sensors, beamforming may not be valid. The signals received at different sensors may no longer be delayed versions of one another. To localize wideband, nearfield, and/or moving sources, a wideband spatial processor is presented. Applicable to both active and passive processing, it relies on a new relation that expresses the ... View full abstract»

• ### Time-domain analysis of cross-correlation for multitarget/multipath time delay estimation

Publication Year: 1992, Page(s):485 - 488
Cited by:  Papers (1)
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This paper analyzes the effect of source separation on the estimation accuracy of the TDOA of multiple exponentially autocorrelated signals at two sensors in white noise. The analysis is carried out for uncorrelated signals (separate sources) as well as unity correlated signals, as in multipath propagation from a single source. The estimates are obtained from cross-correlations based on moving ave... View full abstract»

• ### A new approach for wideband signal processing

Publication Year: 1992, Page(s):326 - 329
Cited by:  Papers (3)
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A new method for the estimation of the direction of arrival (DOA) of correlated wideband signals received by an array of sensors uses 2-D directive filtering in the time-space domain. This results in selecting bins at different frequencies from signals arriving from different directions. Since signals at different frequencies are uncorrelated, any spectral estimator can then be used to estimate th... View full abstract»

• ### Optimal transforms related to path in the time-frequency plane

Publication Year: 1992, Page(s):34 - 37
Cited by:  Papers (1)
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This paper shows how to construct integral operators adapted to a given time-frequency energy distribution. The phase function, which is an extension of the phase ωt of the classical Fourier transform, makes it possible to construct an integral operator. The transform is adapted when the partial derivative ∂φ/∂t is the instantaneous frequency of the signal View full abstract»

• ### Numerical propagation of spatially distributed acoustic sources using the exterior Helmholtz integral equation

Publication Year: 1992, Page(s):338 - 341
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A finite difference approximation of the Helmholtz equation numerically integrated over a measurement surface can determine the acoustic field throughout an entire volume of a homogeneous region outside. This approach has been developed and implemented to study acoustic fields radiating from large immersed structures from pressure data measured over a generalized cylindrical measurement surface. T... View full abstract»

• ### A unitary transformation algorithm for wideband array processing

Publication Year: 1992, Page(s):300 - 303
Cited by:  Papers (2)
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The authors apply a two-sided transformation on the cross-correlation matrices of the array. It is shown that the two-sided correlation transformation (TCT) generates unbiased estimates of the directions of arrival regardless of the bandwidth of the signals. The capability of the method for resolving two closely spaced sources is compared with that of the coherent signal-subspace method. The resol... View full abstract»

• ### Signal processing applied to ultrasonic imaging

Publication Year: 1992, Page(s):225 - 228
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This paper describes a noncoherent ultrasonic array used to form three-dimensional images of defects in metal. The problem developed in terms of deconvolution in multiple dimensions to improve resolution of images blurred by the measuring system and degraded by noise is reduced to solution of a linear equation of the form y=Hx, where H is called the imaging operator ... View full abstract»

• ### Wavelets and fractals: a comparative study

Publication Year: 1992, Page(s):42 - 45
Cited by:  Papers (2)
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Wavelets and fractals can be used as analyzing tools in many areas of sciences and engineering. However, they seem to have many areas of similarities. This paper explores these potential areas, what they are and how they can be used, at least, in a theoretical sense. Some promising results have been found and are documented View full abstract»