US4991165A
Expired / Lapsed
US
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Digital adaptive interference canceller
Assignee: United States Department of the Navy
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Filing: 1988-09-28
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Granted: 1991-02-05
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Expires: 2008-09-28
Abstract
Abstract An interference canceller for cancelling an interfering signal generated byn interfering source from a transmission link between an antenna and a receiver. The interference canceller derives a sample of the interfering signal from the interfering source and down converts the sample to an intermediate frequency. A computer controlled delay path and computer controlled amplitude and phase modulator interatively adjusts a cancellation signal that is injected into the transmission link between the antenna and receiver to maximize the amplitude match between the cancellation signal and the interfering signal, and anti-phase the cancellation signal with respect to the interfering signal.
Inventors
- 👤 Willard M. Cronyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:12
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/03; G01S7/038; H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123; H04B1/38; H04B1/40; H04B1/50; H04B1/52; H04B1/525
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
161 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means operably coupled to said first means for injecting a cancelling signal S j (t) derived from said signal sample into transmission link; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; and fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and is also programmed to input the signals corresponding to said correction coefficients to said second means.
Claim 2
Dependent Claim
161 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means operably coupled to said first means for injecting a cancelling signal S j (t) derived from said signal sample into transmission link; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; and fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and is also programmed to input the signals corresponding to said correction coefficients to said second means.
Claim 3
Dependent Claim
27 words
The interference canceller of claim 1 wherein: said first means comprises a directional coupler operably positioned to sense said interfering signal to thereby obtain said signal sample.
Claim 4
Dependent Claim
26 words
The interference canceller of claim 2 wherein said first means further comprises: fifth means for down converting said signal sample to an intermediate frequency signal sample.
Claim 5
Dependent Claim
28 words
The interference canceller of claim 1 wherein said second means comprises: modulator means operably coupled to said first means for selectively modulating the amplitude of said signal sample.
Claim 6
Dependent Claim
32 words
The interference canceller of claim 4 wherein said modulator means is further for phase shifting the phase of said signal sample so as to generate an amplitude modulated, phase shifted signal sample.
Claim 7
Dependent Claim
26 words
The interference canceller of claim 5 wherein said first means further comprises: fifth means for down converting said signal sample to an intermediate frequency signal sample.
Claim 8
Dependent Claim
30 words
The interference canceller of claim 4 wherein said second means further comprises a directional coupler operably coupled to said transmission link for injecting said cancelling signal into said transmission link.
Claim 9
Dependent Claim
14 words
The interference canceller of claim 1 wherein said third means comprises a directional coupler.
Claim 10
Dependent Claim
25 words
The interference canceller of claim 1 wherein said fourth means further comprises an amplitude/phase detector for measuring the phase and amplitude of said residual signal.
Claim 11
Dependent Claim
214 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means operably coupled to said first means for injecting a cancelling signal S j (t) derived from said signal sample into said transmission link; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and also programmed to input the signals corresponding to said correction coefficients to said second means; and further comprising: delay means operably coupled between said first means and said second means for introducing a propagation delay into said signal sample such that said cancelling signal S j (t) is injected into said transmission link at the same time that said interfering signal S i (t) appears in said transmission link.
Claim 12
Dependent Claim
214 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means operably coupled to said first means for injecting a cancelling signal S j (t) derived from said signal sample into said transmission link; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and also programmed to input the signals corresponding to said correction coefficients to said second means; and further comprising: delay means operably coupled between said first means and said second means for introducing a propagation delay into said signal sample such that said cancelling signal S j (t) is injected into said transmission link at the same time that said interfering signal S i (t) appears in said transmission link.
Claim 13
Dependent Claim
16 words
The interference canceller of claim 10 wherein: said delay means comprises a radio frequency delay line.
Claim 14
Dependent Claim
14 words
The interference canceller of claim 11 wherein: said delay line has an adjustable delay.
Claim 15
Dependent Claim
199 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means, operably coupled to said first means, for deriving and injecting a cancelling signal S j (t) into said transmission link comprising a modulator for deriving said cancelling signal S j (t) by selectably modulating the amplitude and shifting the phase of said signal sample S i (t); and further comprising an up-converter operably coupled to the output of said modulator means; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and is also programmed to input the signals corresponding to said correction coefficients to said second means.
Claim 16
Dependent Claim
199 words
An interference canceller for cancelling an interfering signal, S i (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising: first means for deriving a signal sample of said interfering signal S i (t); second means, operably coupled to said first means, for deriving and injecting a cancelling signal S j (t) into said transmission link comprising a modulator for deriving said cancelling signal S j (t) by selectably modulating the amplitude and shifting the phase of said signal sample S i (t); and further comprising an up-converter operably coupled to the output of said modulator means; third means operably coupled to said transmission link for sampling the residual signal S i (t)+S j (t) in said transmission link; fourth means comprising a computer operably coupled for receiving the output of said third means and for providing a digital signal input to said second means for minimizing said residual signal S i (t)+S j (t), wherein said computer is programmed to calculate, using a minimization algorithm, the correction coefficients needed to minimize said residual signal and is also programmed to input the signals corresponding to said correction coefficients to said second means.
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) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |