Results 271 to 280 of about 2,232,503 (310)
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Instantaneous frequency and time-frequency distributions
1995 International Conference on Acoustics, Speech, and Signal Processing, 2002It is generally stated that the conditional mean frequency of a time-frequency distribution (TFD) should equal the instantaneous frequency of the signal. The commonly accepted definition of instantaneous frequency as the derivative of the phase of the analytic signal sometimes leads to curious results.
Berkant Tacer, Patrick J. Loughlin
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L-class of time-frequency distributions
IEEE Signal Processing Letters, 1996The L-class of distributions for time-frequency signal analysis is derived and presented, generalizing the L-Wigner distribution. Some particular distributions belonging to this class are introduced.
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Signal synthesis and positive time–frequency distributions
Journal of the Franklin Institute, 2000zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Syed Ismail Shah +3 more
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Multiple window spectrogram and time-frequency distributions
Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing, 2002We extend the spectrum estimation method of Thomson (1982, 1990) to non-stationary signals by formulating a multiple window spectrogram. The traditional spectrogram can be represented as a member of Cohen's class of time-frequency distributions (TFDs) where the smoothing kernel is the Wigner distribution of the signal temporal window.
Frazer, G, Boashash, B
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Analysis of noise in time-frequency distributions
IEEE Signal Processing Letters, 2002Exact expressions for the quadratic distributions' variance of signals corrupted with white stationary, white nonstationary, and colored stationary noise are derived. It has been shown that the signal-dependent part of variance is closely related to the nonnoisy distribution values.
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Decimated time-frequency distributions
Proceedings of IEEE-SP International Symposium on Time- Frequency and Time-Scale Analysis, 2002The decimated generalized discrete time-frequency distribution (D-GDTFD) was introduced by O'Hair and Suter (see IEEE International Conference on Circuits and Systems, London, U.K., 30 May-2 June 1994). It trades bandwidth for speed of implementation and requires greatly reduced storage over the generalized discrete time-frequency distribution (GDTFD).
J.R. O'Hair, B.W. Suter
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The marginals and time-frequency distributions
SPIE Proceedings, 2003We address the question of the importance of satisfying the marginal conditions in a time-frequency distribution and discuss in detail the fundamental and practical issues involved. We also examine the marginals of the spectrogram. The spectrogram often gives reasonable results even though both marginals can never be satisfied exactly, but sometimes it
Leon Cohen, Patrick J. Loughlin
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On Wigner-based sparse time-frequency distributions
2015 IEEE 6th International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2015Signals made of the superimposition of a reduced number of AM-FM components can be characterized by a time-frequency signature which consists of weighted trajectories in the plane, thus ending up with an ideal representation of their energy distribution that is intrinsically sparse.
Patrick Flandrin +2 more
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Virtues and vices of quartic time-frequency distributions
IEEE Transactions on Signal Processing, 2000We present results concerning three different types of quartic (fourth order) time-frequency distributions (TFDs). First, we present new results on the previously introduced local ambiguity function and show that it provides more reliable estimates of instantaneous chirp rate than the Wigner distribution.
Jeffrey C. O'Neill, Patrick Flandrin
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Comparison of measures of time-frequency distribution optimization
2016 8th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), 2016This article describes the problems of time-frequency representation optimization. The goal is to achieve compromise between good resolution and reduced cross terms. The quantitative measures used for this optimization are described. For the case of a simulated signal a measure based on mean squared error is proposed.
Stanislav Pikula, Petr Benes
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