System and method for digital interference cancellation
First Claim
1. A receiver having at least one non-linear component, comprising:
- an input configured to receive a radio frequency input signal having at least one signal of interest and at least one radio frequency signal component which is at least one of;
having an amplitude sufficient to saturate a saturable element;
ordistorted by the at least one non-linear component to generate at least one distortion component having a distortion amplitude;
a digital signal generator, configured to produce an oversampled digital representation of the at least one radio frequency signal component;
a digital to analog converter, configured to produce a radio frequency analog signal corresponding to the oversampled digital representation of the at least one radio frequency signal component, and being controlled with respect to at least a relative time delay with respect to the at least one radio frequency signal component; and
a component configured to receive the radio frequency input signal substantially without non-linear distortion and the radio frequency analog signal, and to cancel the at least one radio frequency signal component from the radio frequency input signal, to produce a modified radio frequency signal in which a residual portion of the radio frequency signal component does not saturate the saturable element or is associated with a distortion amplitude of the at least one distortion component reduced by at least 3 dB, and the signal of interest is substantially unmodified with respect to a modified radio frequency signal produced if the radio frequency analog signal has zero amplitude.
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Accused Products
Abstract
A system and method for receiving a signal, comprising an input adapted to receive a radio frequency signal having a strong interferer; a signal generator, adapted to produce a representation of the interferer as an analog signal generated based on an oversampled digital representation thereof; and a component adapted to cancel the strong interferer from radio frequency signal based on the generated analog signal to produce a modified radio frequency signal substantially absent the interferer. The system typically has a nonlinear component that either saturates or produces distortion from the strong interferer, which is thereby reduced. The system preferably employs high speed circuits which digitize and process radio frequency signals without analog mixers.
132 Citations
36 Claims
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1. A receiver having at least one non-linear component, comprising:
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an input configured to receive a radio frequency input signal having at least one signal of interest and at least one radio frequency signal component which is at least one of; having an amplitude sufficient to saturate a saturable element;
ordistorted by the at least one non-linear component to generate at least one distortion component having a distortion amplitude; a digital signal generator, configured to produce an oversampled digital representation of the at least one radio frequency signal component; a digital to analog converter, configured to produce a radio frequency analog signal corresponding to the oversampled digital representation of the at least one radio frequency signal component, and being controlled with respect to at least a relative time delay with respect to the at least one radio frequency signal component; and a component configured to receive the radio frequency input signal substantially without non-linear distortion and the radio frequency analog signal, and to cancel the at least one radio frequency signal component from the radio frequency input signal, to produce a modified radio frequency signal in which a residual portion of the radio frequency signal component does not saturate the saturable element or is associated with a distortion amplitude of the at least one distortion component reduced by at least 3 dB, and the signal of interest is substantially unmodified with respect to a modified radio frequency signal produced if the radio frequency analog signal has zero amplitude. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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2. An interfering signal cancellation apparatus, comprising:
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an input configured to receive an analog radio frequency signal within a band comprising a signal of interest having a signal amplitude, and an interferer signal having an interferer signal amplitude; a signal generator configured to generate a cancellation signal based on an oversampled digital representation of at least the interferer signal; and a cancelling device configured to receive the analog radio frequency signal and the cancellation signal and to produce a modified analog radio frequency signal therefrom, wherein the modified radio frequency signal is substantially without non-linear distortion components derived from the analog radio frequency signal or the cancellation signal, wherein the signal generator produces the cancellation signal having a relative timing and relative amplitude configured to increase a signal to interferer amplitude ratio of the modified analog radio frequency signal over the analog radio frequency signal by at least 20 dB. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for receiving, comprising:
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receiving a radio frequency input signal having at least one signal of interest and at least one radio frequency signal component which is at least one of; having an amplitude sufficient to saturate a saturable element of a receiver;
ordistorted by the at least one non-linear component of the receiver to generate at least one distortion component having a distortion amplitude; producing an oversampled digital representation of the at least one radio frequency signal component; producing a radio frequency analog signal corresponding to the oversampled digital representation of the at least one radio frequency signal component, and having a relative time delay which is adjusted with respect to the at least one radio frequency signal component; and cancelling at least a portion of the at least one radio frequency signal component from the radio frequency input signal to produce a modified radio frequency signal substantially without non-linear distortion, in which a residual portion of the radio frequency signal component does not saturate the saturable element or is associated with a distortion amplitude of the at least one distortion component reduced by at least 3 dB, and in which the signal of interest is substantially unmodified with respect to a modified radio frequency signal produced if the radio frequency analog signal has zero amplitude. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification