Results 211 to 220 of about 428,774 (260)

Spatial time-frequency distributions and their applications

Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467), 2002
The evaluation of quadratic time-frequency distributions (TFDs) of nonstationary signals impinging on a multisensor receiver yields spatial time-frequency distributions (STFDs). We review the concept of STFDs and their applications to blind source separation and direction finding problems.
Moeness G. Amin, Yimin Zhang 0001
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Multitaper marginal time–frequency distributions

Signal Processing, 2006
Time-frequency distributions (TFDs) belonging to Cohen's class yield a frequency marginal that is equivalent to the periodogram of the signal. It is well-known that the periodogram is not a good spectral estimator since it is not a consistent estimate, i.e. its variance does not decrease with the sample size. Thomson addressed this issue by introducing
Selin Aviyente, William J. Williams
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Multiple view time-frequency distributions

Proceedings of 27th Asilomar Conference on Signals, Systems and Computers, 2002
We propose a new approach for constructing time-frequency distributions and spectra which achieves improved localisation in the time-frequency plane while retaining the non-negativity property of an energy distribution. The approach is to construct a composite distribution from multiple views of the Wigner-Ville distribution.
Frazer, GJ, Boashash, B
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Zero-tracking time-frequency distributions

1997 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2002
The zero-tracking time-frequency distribution (TFD) is introduced. The local autocorrelation function of the TFD, defined by an appropriate kernel, is used to form a polynomial whose roots correspond to the instantaneous frequencies of the multicomponent signal. Two techniques for zero-tracking based on the TFD are presented.
Chenshu Wang, Moeness G. Amin
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Spectrogram decompositions of time-frequency distributions

Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467), 2002
This paper outlines means of combining spectrograms formed using specially designed windows. Previous work has shown that one can decompose any time-frequency distribution (TFD) in Cohen's class into a weighted sum of spectrograms. This is accomplished by decomposing the kernel of the distribution in terms of an orthogonal set of analysis windows.
William J. Williams, Selin Aviyente
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Time-frequency distributions with complex argument

IEEE Transactions on Signal Processing, 2002
A distribution highly concentrated along the group delay or the instantaneous frequency (IF) is presented. It has been defined by introducing a signal with a complex argument in time-frequency (TF) analysis. Realization of a signal with a complex argument, using a signal with a real argument, is described.
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The generalized exponential time-frequency distribution

IEEE Transactions on Signal Processing, 1994
Time-frequency distributions (TFD) are joint time and frequency signal representations that, among other properties, maintain the true support of a signal's energy in both time and frequency. In addition to their mathematical elegance, TFDs can provide simultaneous resolution in time and frequency that exceeds that of the common spectrogram. In general,
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SNR analysis of time-frequency distributions

2000 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.00CH37100), 2002
The SNR analysis has been widely used to evaluate the performance of time-frequency (t-f) distributions. Often the SNR is defined at a specific t-f location or using the averaged variance over the entire t-f domain. In this paper, a new SNR measure is provided based on averaging along the signal t-f signature and its properties for linear FM signals ...
Weifeng Mu, Moeness G. Amin
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Construction of positive time-frequency distributions

IEEE Transactions on Signal Processing, 1994
A general method for constructing nonnegative definite, joint time-frequency distributions (TFDs) satisfying the marginals of time |s(t)|/sup 2/ and frequency |S(f)|/sup 2/ is presented. As nonnegative-definite distributions with the correct marginals, these TFDs are members of the Cohen-Posch class.
Patrick J. Loughlin, James W. Pitton, Les E. Atlas   +2 more
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Divergence measures for time-frequency distributions

Seventh International Symposium on Signal Processing and Its Applications, 2003. Proceedings., 2003
Distance measures between statistical models or between a model and observations are widely used concepts in signal processing. They are commonly used in solving problems such as detection, automatic segmentation, classification, pattern recognition and coding. In recent years, there has been an interest in extending these distance measures to the time-
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