Digital adaptive interference canceller
First Claim
1. An interference canceller for cancelling an interfering signal, Si (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 Si (t);
second means operably coupled to said first means for injecting a cancelling signal Sj (t) derived from said signal sample into transmission link;
third means operably coupled to said transmission link for sampling the residual signal Si (t)+Sj (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 Si (t)+Sj (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.
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Accused Products
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.
49 Citations
13 Claims
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1. An interference canceller for cancelling an interfering signal, Si (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising:
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first means for deriving a signal sample of said interfering signal Si (t); second means operably coupled to said first means for injecting a cancelling signal Sj (t) derived from said signal sample into transmission link; third means operably coupled to said transmission link for sampling the residual signal Si (t)+Sj (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 Si (t)+Sj (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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An interference canceller for cancelling an interfering signal, Si (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising:
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first means for deriving a signal sample of said interfering signal Si (t); second means operably coupled to said first means for injecting a cancelling signal Sj (t) derived from said signal sample into said transmission link; third means operably coupled to said transmission link for sampling the residual signal Si (t)+Sj (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 Si (t)+Sj (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 Sj (t) is injected into said transmission link at the same time that said interfering signal Si (t) appears in said transmission link. - View Dependent Claims (11, 12)
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13. An interference canceller for cancelling an interfering signal, Si (t), generated by an interfering source from a transmission link between an antenna and a receiver comprising:
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first means for deriving a signal sample of said interfering signal Si (t); second means, operably coupled to said first means, for deriving and injecting a cancelling signal Sj (t) into said transmission link comprising a modulator for deriving said cancelling signal Sj (t) by selectably modulating the amplitude and shifting the phase of said signal sample Si (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 Si (t)+Sj (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 Si (t)+Sj (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.
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Specification