US4238746A
Expired / Lapsed
US
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Adaptive line enhancer
Assignee: United States Department of the Navy
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Filing: 1978-03-20
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Granted: 1980-12-09
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Expires: 1998-03-20
Abstract
Abstract An input signal X(j) is fed directly to the positive port of a summing function and is simultaneously fed through a parallel channel in which it is delayed, and passed through an adaptive linear transversal filter, the output being then subtracted from the instantaneous input signal X(j). The difference, X(j)-Y(j), between these two signals is the error signal ε(j). ε(j) is multiplied by a gain μ and fed back to the adaptive filter to readjust the weights of the filter. The weights of the filter are readjusted until ε(j) is minimized according to the recursive algorithm: ##EQU1## where the arrow above a term indicates that the term is a signal vector. Thus, when the means square error is minimized, W.sub.(j+1) =W.sub.(j), and the filter is stabilized.
Inventors
- 👤 John M. McCool
- 👤 Bernard Widrow
- 👤 James R. Zeidler
- 👤 Robert H. Hearn
- 👤 Douglas M. Chabries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:48
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/52; G11; G11C; G11C27/00; H; H03; H03H; H03H21/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
162 words
An adaptive line enhancer for spectral line enhancing, generally in an environment where significant noise is present, comprising: means for delaying an input signal X(j) by a fixed time delay δ; weighted means, whose input is connected to the output of the delaying means, for adaptively filtering the delayed signal, using a least-means-square (LMS) algorithm, the output of the filtering means comprising a signal Y(j); means, having as inputs the signals X(j) and Y(j), for subtracting the signal Y(j) from X(j), the output of the subtracting means being the error signals ε(j); means, having as an input the signal ε(j), for multiplying the signal by a gain μ, the output of the multiplying means being fed back to the filtering means, to cause the weights of the weighted means to be readjusted in a manner to minimize the difference between the signal X(j) and the signal Y(j), thereby minimizing the error signal ε(j), wherein: the weighted filtering means comprises a transversal filter.
Claim 2
Dependent Claim
162 words
An adaptive line enhancer for spectral line enhancing, generally in an environment where significant noise is present, comprising: means for delaying an input signal X(j) by a fixed time delay δ; weighted means, whose input is connected to the output of the delaying means, for adaptively filtering the delayed signal, using a least-means-square (LMS) algorithm, the output of the filtering means comprising a signal Y(j); means, having as inputs the signals X(j) and Y(j), for subtracting the signal Y(j) from X(j), the output of the subtracting means being the error signals ε(j); means, having as an input the signal ε(j), for multiplying the signal by a gain μ, the output of the multiplying means being fed back to the filtering means, to cause the weights of the weighted means to be readjusted in a manner to minimize the difference between the signal X(j) and the signal Y(j), thereby minimizing the error signal ε(j), wherein: the weighted filtering means comprises a transversal filter.
Claim 3
Dependent Claim
16 words
The adaptive line enhancer, according to claim 1, wherein: the transversal filter is a digital filter.
Claim 4
Dependent Claim
15 words
The adaptive line enhancer according to claim 2, wherein: the digital filter comprises shift registers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |