US 6,208,951 B1Granted

Method and an apparatus for the identification and/or separation of complex composite signals into its deterministic and noisy components

AssigneeCouncil of Scientific and Industrial Research

InventorsViruthiamparambath Ravi Kumar, Bhaskar Dattatraya Kulkarni, Narendra Madhukar Dixit, Nitin Vaish

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Abstract

A process for the identification and/or separation of composite signal into its deterministic and noisy components wherein the process uses recursive wavelet transformations to separate the deterministic and noisy components of signals and uses the difference in the properties with regard to degree of correlation and dimensionality of these constituent components as a basis for separation, the said process of identification and/or separation has application in a variety of situations where digitized data is made available via an apparatus which converts the monitored signals.

Claims26

Dependent claims

A method for the identification and/or separation of composite signals obtained from an apparatus/equipment recording the variations in a system property as sequential or time-series data, from the said apparatus/equipment, into its deterministic(true signal) and noisy parts, comprising the steps of:

(a) obtaining a signal to be identified and/or separated from an apparatus/equipment;
(b) digitizing the said composite signal, obtained as sequential or time-series data, relating to a variation in a system property;
(c) computing and subjecting the said digitized data obtained from step (b) above to wavelet transform to obtain a scalogram in terms of wavelet coefficients;
(d) computing and organizing the said resulting wavelet coefficients in each of the scales to form new sets of data;
(e) computing for taking each of the above said data sets and carry out their wavelet transform to obtain another scalogram in terms of wavelet coefficients;
(f) computing for implementing steps (d) and (e), recursively with testing for the constancy in the power distribution, (the said power distribution being the ratio of the power in a particular scale with respect to the total power in all the scales of that scalogram for two consecutive recursive scalograms) and thereby identifying the recursive wavelet scales contributing to noise in the signal;
(g) eliminating the above said wavelet coefficients in the recursive wavelet scales contributing to noise by setting term to zero;
and
(h) inverting the above said wavelet coefficients by inverse recursive wavelet transformation and thereby determining the deterministic signal component (true signal) separated from the noise component.

6 more elements

An apparatus for identification and/or separation of composite signals obtained from an instrument/equipment recording the variations in a system property as sequential or time-series data from the said instrument/equipment (selected from medical diagnostic and scanning equipment, seismographic instruments, tomography, image analyzers, molecular spectroscopy, chemical reactors/reactions), into its deterministic (true signal) and noisy parts, said apparatus comprising:

(a) source means for obtaining a signal to be identified and/or separated from suitable sensors appropriately located in an apparatus/equipment;
(b) means for digitizing the said composite signal, obtained as sequential or time-series data, relating to a variation in a system property;
(c) computing means for subjecting the said digitized data obtained from step (b) above to wavelet transform to obtain a scalogram in terms of wavelet coefficients;
(d) computing means for organizing the said resulting wavelet coefficients in each of the scales to form new sets of data;
(e) computing means for taking each of the above said data sets and carry out their wavelet transform to obtain another scalogram in terms of wavelet coefficients;
(f) computing means for implementing steps (d) and (e), recursively with testing for the constancy in the power distribution (the said power distribution being the ratio of the power in a particular scale with respect to the total power in all the scales of that scalogram for two consecutive recursive scalograms) and thereby identifying the recursive wavelet scales contributing to noise in the signal;
(g) computing means for eliminating the above said wavelet coefficients in the recursive wavelet scales contributing to noise by setting terms to zero;
and
(h) computing means for inverting the above said wavelet coefficients by inverse recursive wavelet transformation and thereby determining the deterministic signal component (true signal) separated from the noise component.

6 more elements

Dependencies are inferred from the claim text.