Results 241 to 250 of about 75,899 (299)

Instantaneous spectra and instantaneous frequency

Proceedings of the IEEE, 1970
A simple relation exists between the instantaneous frequency and the instantaneous spectrum of an analytic signal which does not depend on an assumption that the instantaneous frequency varies slowly.
M H Ackroyd
exaly   +2 more sources

ON INSTANTANEOUS FREQUENCY

Advances in Adaptive Data Analysis, 2009
Instantaneous frequency (IF) is necessary for understanding the detailed mechanisms for nonlinear and nonstationary processes. Historically, IF was computed from analytic signal (AS) through the Hilbert transform. This paper offers an overview of the difficulties involved in using AS, and two new methods to overcome the difficulties for computing IF ...
Xianyao Chen, Zhaohua Wu, Steven R Long   +2 more
exaly   +2 more sources

On the concept of instantaneous frequency

Proceedings of the 1998 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP '98 (Cat. No.98CH36181), 2002
The concept of instantaneous frequency is still not clearly defined. Current operational definitions give rise to physical paradoxes, and difficult proper interpretation of the obtained results. In this paper, we discuss why those paradoxes appear, and show how they can be avoided.
Paulo M. Oliveira, Victor Barroso
openaire   +1 more source

Instantaneous frequency and time-frequency distributions

1995 International Conference on Acoustics, Speech, and Signal Processing, 2002
It 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
openaire   +1 more source

Instrument for the measurement of the instantaneous frequency

IMTC/99. Proceedings of the 16th IEEE Instrumentation and Measurement Technology Conference (Cat. No.99CH36309), 2000
This paper describes the design and implementation of an instrument for the measurement of the instantaneous frequency of a signal. It is based on the extensive use of signal processing techniques and their implementation on efficient processors (digital signal processors).
Alfonso Carlosena, Carlos Macua, Miroslav Zivanovic   +2 more
openaire   +1 more source

Comments on the interpretation of instantaneous frequency

IEEE Signal Processing Letters, 1997
Instantaneous frequency, taken as the derivative of the phase of the signal, is interpreted in the time-frequency literature as the average frequency of the signal at each time. We point out some difficulties with this interpretation, and show that for a generic two-component AM-FM signal, the interpretation holds only when the components are of equal ...
Patrick J. Loughlin, Berkant Tacer
openaire   +1 more source

CIRCULAR INSTANTANEOUS FREQUENCY

Advances in Adaptive Data Analysis, 2010
This work defines the unique instantaneous frequency (IF) of an arbitrary time signal to be the circular instantaneous frequency (cIF) of the curvature radius of the signal's trajectory on the phase plane, where the signal's conjugate part is obtained from Hilbert transform (HT).
openaire   +1 more source

Algorithms for estimating instantaneous frequency

Signal Processing, 2004
Three algorithms to estimate instantaneous frequency of a frequency-modulated signal is discussed. These algorithms are based on Hilbert transform, Haar wavelet, and generalized pencil of function (GPOF) methods. While GPOF-based frequency detection method appears to be least sensitive to noise, wavelet-based method is easiest to implement.
Jaideva C. Goswami, Albert E. Hoefel
openaire   +1 more source

Circuit for measurement of instantaneous frequency

American Journal of Physiology-Heart and Circulatory Physiology, 1980
This paper describes a circuit that measures the instantaneous frequency of a pulse train applied to the input. Analog outputs are provided that are linearly proportional to the interval between successive pulses and to the reciprocal of that same interval.
R, McGillivray, R, Wald
openaire   +2 more sources