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US4783754A
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Preprocessor for spectral pattern classification systems
Assignee: Motorola Solutions Inc
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Filing: 1984-07-02
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Granted: 1988-11-08
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Expires: 2004-07-02
Abstract
Abstract The signal to be classified is sampled and the samples are multiplied by weighting functions prior to performing discrete Fourier transforms, power calculations, and normalization thereon so that the preprocessor is essentially a plurality of channel bandpass filter stages, the k-th one of which has a frequency response approximating an ideal filter defined by ##EQU1## where k=O, α, 2α, 3α, . . . , rα α=constant, 1≦α≦N/2 r+1=greatest integer in N/α This preprocessor transforms blocks of one dimensional data into spectra in such a way that data blocks coming from similar sources will have spectra that are close to one another in spectrum space. The discrete Fourier transform is modified to remove or reduce the phase dependency problem and to enhance the clustering of similar spectra by the weighting function above.
Inventors
- 👤 Jerald L. Bauck
- 👤 Robert Hecht-Nielsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:54
CPC Classifications
G; G06; G06F; G06F17/00; G06F17/10; G06F17/14; G06F17/141; H; H03; H03H; H03H17/00; H03H17/02; H03H17/0248; H03H17/0264; H03H17/0266; G06F2218/00; G06F2218/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
73 words
A preprocessor for spectral pattern classification systems comprising a plurality of channel bandpass filter stages, the frequency response of the k-th frequency stage being substantially defined by ##EQU19## where K=0, α, 2α, 3α, . . . , [4]rα where N is the number of samples of data being filtered, r+1 is the number of stages, and α is an appropriately chosen positive integer constant typically selected to be =1, 2, 3, or 4.
Claim 2
Dependent Claim
73 words
A preprocessor for spectral pattern classification systems comprising a plurality of channel bandpass filter stages, the frequency response of the k-th frequency stage being substantially defined by ##EQU19## where K=0, α, 2α, 3α, . . . , [4]rα where N is the number of samples of data being filtered, r+1 is the number of stages, and α is an appropriately chosen positive integer constant typically selected to be =1, 2, 3, or 4.
Claim 3
Dependent Claim
88 words
A preprocessor as claimed in claim 1 wherein the channel bandpass filter stages include an input adapted to have samples of the signal to be classified applied thereto, a memory having a plurality of weights, w(n), stored therein each weight being substantially defined (for the α=1 case) by ##EQU20## where n=0, 1, 2, . . . , N-1, multiplying means coupled to said input and said memory for multiplying each sample by one of said weights, and filter means for taking the discrete Fourier transform of the products.
Claim 4
Dependent Claim
43 words
A preprocessor as claimed in claim 2 further including power means coupled to the filter means for computing the power present in each discrete Fourier transform channel, and means coupled to the power means for normalizing the resulting discrete Fourier transform power vector.
Claim 5
Dependent Claim
27 words
A preprocessor as claimed in claim 3 wherein the memory and multiplying means are in digital form and the input further includes an analog to digital converter.
Claim 6
Dependent Claim
57 words
A preprocessor for spectral pattern classification systems comprising a plurality of channel bandpass filter stages, the frequency response, H k (e j ω), of each stage being substantially defined (for the α=1 case) by ##EQU21## where N=number of filter stages, ##EQU22## n=0, 1, 2, . . . , N-1, and k=0, 1, 2, . . . ,N-1.
Claim 7
Dependent Claim
57 words
A preprocessor for spectral pattern classification systems comprising a plurality of channel bandpass filter stages, the frequency response, H k (e j ω), of each stage being substantially defined (for the α=1 case) by ##EQU21## where N=number of filter stages, ##EQU22## n=0, 1, 2, . . . , N-1, and k=0, 1, 2, . . . ,N-1.
Claim 8
Independent Claim
70 words
A method of preprocessing signals for spectral pattern classification comprising the steps of: providing samples of the signal to be classified; providing a plurality of filter constants, w(n), generally defined (for the α=1 case) by the equation ##EQU23## where: N=numer of overlapping filters used, and n=0, 1, 2, . . . , N-1; multiplying each sample by one of said filter constants; and taking discrete Fourier transforms of the products.
Claim 9
Independent Claim
70 words
A method of preprocessing signals for spectral pattern classification comprising the steps of: providing samples of the signal to be classified; providing a plurality of filter constants, w(n), generally defined (for the α=1 case) by the equation ##EQU23## where: N=numer of overlapping filters used, and n=0, 1, 2, . . . , N-1; multiplying each sample by one of said filter constants; and taking discrete Fourier transforms of the products.
Claim 10
Dependent Claim
35 words
A method according to claim 6 wherein the step of taking discrete Fourier transforms include the steps of computing the power present in each selected discrete Fourier transform channel and normalizing the resulting power vector.
Claim 11
Dependent Claim
16 words
A method according to claim 6 including the steps of converting the samples to digital signals.
Claim 12
Dependent Claim
23 words
A method according to claim 6 wherein the step of providing filter constants includes calculating the constants and storing a digital representation thereof.
References Cited (Backward Citations)
US910009A
Cited
US3111645A
Cited
US3388240A
Cited
US3566080A
Cited
US3544894A
Cited
UST910009I4
Cited
US3889234A
Cited
US4121192A
Cited
US4152772A
Cited
US4049958A
Cited
US3971927A
Cited
US4010360A
Cited
US4071906A
Cited
US4084255A
Cited
US4322716A
Cited
US4093989A
Cited
US4286326A
Cited
US4231103A
Cited
JPS5680787A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |