Switched, simultaneous and cascaded interference cancellation
First Claim
1. A method of performing interference cancellation in a wireless communications device having a transmitter and a receiver, the method comprising:
- filtering a reference signal representative of an interfering signal transmitted by the transmitter using an adaptive filter to obtain a filtered reference signal;
combining the filtered reference signal with a radio frequency (RF) signal received by the receiver to obtain a combined signal, wherein the RF signal is affected by the interfering signal;
providing first feedback to the adaptive filter when fundamental frequency interference in the RF signal exceeds a predefined threshold power level, wherein the first feedback causes the adaptive filter to target fundamental frequency interference in the RF signal with the filtered reference signal; and
providing second feedback to the adaptive filter when the fundamental frequency interference does not exceed the predefined threshold power level, wherein the second feedback causes the adaptive filter to target out-of-band interference affecting the RF signal with the filtered reference signal,wherein the filtered reference signal cancels interference in the RF signal when combined with the RF signal.
1 Assignment
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Accused Products
Abstract
Aspects of the disclosure are directed to interference cancellation and wireless communication. A method of performing analog interference cancellation in a wireless communications device having a transmitter and a receiver includes receiving a reference signal representative of an interfering signal transmitted by the transmitter, selecting a first target interference type from one of a plurality of interference types affecting a an RF signal received by the receiver, configuring a first filter of an interference cancellation circuit using a coefficient computed based on the first target interference type, and cancelling interference in the RF signal using an output of the first filter. Coefficient computation may be performed in a switched manner between analog and digital domain, simultaneously in multiple domains, or in a cascaded manner that provides digital interference cancellation.
117 Citations
29 Claims
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1. A method of performing interference cancellation in a wireless communications device having a transmitter and a receiver, the method comprising:
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filtering a reference signal representative of an interfering signal transmitted by the transmitter using an adaptive filter to obtain a filtered reference signal; combining the filtered reference signal with a radio frequency (RF) signal received by the receiver to obtain a combined signal, wherein the RF signal is affected by the interfering signal; providing first feedback to the adaptive filter when fundamental frequency interference in the RF signal exceeds a predefined threshold power level, wherein the first feedback causes the adaptive filter to target fundamental frequency interference in the RF signal with the filtered reference signal; and providing second feedback to the adaptive filter when the fundamental frequency interference does not exceed the predefined threshold power level, wherein the second feedback causes the adaptive filter to target out-of-band interference affecting the RF signal with the filtered reference signal, wherein the filtered reference signal cancels interference in the RF signal when combined with the RF signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An interference cancelling circuit that is coupled to a radio frequency (RF) receiver and that comprises:
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a first interference circuit configured to cancel interference at a fundamental frequency in an RF signal received by the RF receiver, wherein the first interference circuit is activated when interference in the fundamental frequency of the RF signal exceeds a predefined threshold power level; and a second interference circuit configured to cancel out-of-band interference associated with the RF signal, wherein the second interference circuit is activated when interference in the fundamental frequency of the RF signal does not exceed a predefined threshold power level, wherein the first interference circuit and the second interference circuit are responsive to a reference signal representative of an interfering signal transmitted by a nearby transmitter, and wherein outputs of the first interference circuit and the second interference circuit are combined to provide a signal operable to cancel interference in the RF signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. An interference cancelling circuit that is coupled to a radio frequency (RF) receiver and comprises:
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a first interference circuit configured to cancel interference at a fundamental frequency in an RF signal received by the RF receiver using analog feedback; and a second interference circuit configured to cancel out-of-band interference associated with the RF signal using digital feedback, wherein the first interference circuit and the second interference circuit are responsive to one or more reference signals representative of an interfering signal transmitted by a nearby transmitter, and wherein outputs of the first interference circuit and the second interference circuit are combined to provide a signal configured to cancel interference in the RF signal. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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Specification