System and method for digital interference cancellation
AssigneeHypres, Inc.
InventorsDeepnarayan Gupta, Amol Inamdar
Life of this patent
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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.
Claims20
A receiver comprising:
- an input configured to receive an analog radio frequency input signal within a radio frequency band comprising a frequency in excess of 500 MHz, comprising a modulated information signal and at least one additional signal;
- a subtractor configured to receive a representation of the analog radio frequency signal and a subtraction signal, and to produce a subtractor output representing a combination of the analog radio frequency signal and a subtraction signal, the subtractor output comprising an intermodulation distortion product, wherein in a presence of an appropriate subtraction signal received by the subtractor, the intermodulation distortion product is generated at least 3 dB attenuated in amplitude with respect to the intermodulation distortion product produced in the absence of the appropriate subtraction signal;
- a digitally controlled signal generator, configured to produce the appropriate subtraction signal as a radio frequency signal, comprising a representation of the at least one additional signal synchronized with the at least one additional signal, such that the subtractor diminishes an amplitude of the at least one additional signal and the intermodulation distortion product at the subtractor output;
- and
- a digitizer having an instantaneous bandwidth of at least 10 MHz, receiving the subtractor output.
A method of receiving an information signal, comprising:
- receiving an analog radio frequency input signal within a radio frequency band comprising a frequency in excess of 500 MHz, comprising a modulated information signal and at least one additional signal;
- receiving a representation of the analog radio frequency signal and a subtraction signal as inputs to a subtractor, and producing a subtractor output, representing a combination of the analog radio frequency signal and a subtraction signal, the subtractor output comprising an intermodulation distortion product, wherein in a presence of an appropriate subtraction signal received by the subtractor, the intermodulation distortion product is generated at least 3 dB attenuated in amplitude with respect to the intermodulation distortion product produced in the absence of the appropriate subtraction signal;
- and
- producing the appropriate subtraction signal with a digitally controlled signal generator, as a radio frequency signal, comprising a representation of the at least one additional signal synchronized with the at least one additional signal, such that the subtractor diminishes an amplitude of the at least one additional signal and the intermodulation distortion product at the subtractor output.
A receiver comprising:
- an input configured to receive an analog radio frequency input signal within a radio frequency band having a bandwidth and a frequency in excess of 500 MHz, comprising a modulated information signal and at least one modulated interferor;
- a subtractor configured to receive a subtraction signal and a representation of the analog radio frequency signal, and to produce a subtractor output representing a combination of the analog radio frequency signal and the subtraction signal, and an intermodulation distortion product having spurs within the bandwidth of the radio frequency band, wherein in a presence of an appropriate subtraction signal received by the subtractor, a ratio of the modulated information signal to the at least one interferor in the subtractor output is increased by at least 20 dB;
- a digital signal generator, configured to produce the appropriate subtraction signal, comprising a synchronized representation of the at least one modulated interferor;
- and
- a digitizer having an instantaneous bandwidth of at least 10 MHz, receiving the subtractor output.
Dependencies are inferred from the claim text.