Instantaneous frequency estimation using discrete evolutionary transform for jammer excision (original) (raw)
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2018
In this paper, we propose a new method to estimate instantaneous frequency using a combined approach based on the discrete linear chirp transform (DLCT) and the Wigner distribution (WD). The DLCT locally represents a signal as a superposition of linear chirps while the WD provides maximum energy concentration along the instantaneous frequency in the time-frequency domain for each of the chirps. The developed approach takes advantage of the separation of the linear chirps given by the DLCT, and that for each of them, the WD provides an ideal representation. Combining the WD of the linear chirp components, we obtain a time-frequency representation free of cross-terms that clearly displays the instantaneous frequency. Applying this procedure locally, we obtain an instantaneous frequency estimate of a non-stationary multicomponent signal. The proposed method is illustrated by simulation. The results indicate the method is efficient for the instantaneous frequency estimation of multicomp...
Signal Processing, 2004
Estimation of the instantaneous frequency (IF) in a high noise environment, by using the Wigner distribution (WD), is considered. In this case the error is of impulse nature. An algorithm for the IF estimation, which combines the nonparametric method based on the WD maxima with the minimization of the IF variations between consecutive points, is proposed. The off-line and on-line realizations are presented. The on-line realization is an instance of the (generalized) Viterbi algorithm. Application of this algorithm on the monocomponent and multicomponent frequency modulated signals is demonstrated. For multicomponent signals, the algorithm is applied on other (reduced interference) distributions. Numerical examples, including statistical study of the algorithm performance, are given.
Instantaneous frequency estimation by using the Wigner distribution and linear interpolation
Signal Processing, 2003
Nonparametric algorithm for the instantaneous frequency (IF) estimation, by using the Wigner distribution (WD) with an adaptive window length, is considered in the paper. This algorithm produces a bias-to-variance trade-off close to optimal, meaning almost minimal mean squared error (MSE) of the estimation. Thus, the adaptive window length is characterized by a small bias at the considered instant. Then, according to the WD concentration property, the IF estimate can be assumed as a linear function within this window. Instead of nonparametric IF estimation in other points within this interval the linear IF interpolation can be performed. Length of the interpolation segment is determined based on the adaptive window length. It is done in such a way to produce a trade-off between the interpolation caused error and calculational complexity. This modification can produce a significant calculation savings, without increasing the overall MSE. Theoretical analysis has been confirmed on numerical examples and statistical study with four synthetic signals. The approach presented here can be generalized in a straightforward manner to nonlinear interpolations and higher order time-frequency representations.
Instantaneous frequency estimation by using Wigner distribution and Viterbi algorithm
International Conference on Acoustics, Speech, and Signal Processing, 2003
Estimation of the instantaneous frequency (IF) in a high noise environment, by using the Wigner distribution (WD) and the Viterbi algorithm, is considered. The proposed algorithm combines nonparametric IF estimation based on the WD maxima with minimization of the IF variations between consecutive points. Algorithm realization is performed recursively using the (modified) Viterbi algorithm. Performances are compared with IF estimation based on the WD maxima.
Use of the cross Wigner-Ville distribution for estimation of instantaneous frequency
1993
Abstract An iterative instantaneous frequency (IF) estimation scheme is presented in which successive IF estimates are obtained from the peak of the cross Wigner-Ville distribution (XWVD), using a reference signal synthesized from an initial IF estimate. Theoretical and practical aspects of performance are discussed, and the performance is compared with that of other methods
A novel method for the signal components instantaneous frequency (IF) estimation based on the Cross Wigner-Ville distribution (XWVD) is presented. The cross-terms in the XWVD are deliberately formed between the analyzed signal and a reference signal. The proposed method yields a scaled and time shifted image that closely resembles the instantaneous frequency laws of the components present in the signal. As the interferences location follow geometrical rules, and by using a reference signal well localized in time and frequency, the time-frequency coordinates of the analyzed signal components IF can be calculated by an automatic procedure described below. The performance of the method is tested on both synthetic and real-life signals, showing improvements over another recently proposed components extraction method.