SYSTEMS, METHODS, APPARATUS, AND COMPUTER-READABLE MEDIA FOR ADAPTIVE ACTIVE NOISE CANCELLATION
First Claim
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1. A method of producing an antinoise signal, said method comprising:
- producing the antinoise signal during a first time interval by applying a digital filter to a reference noise signal in a filtering domain having a first sampling rate; and
producing the antinoise signal during a second time interval subsequent to the first time interval by applying the digital filter to the reference noise signal in the filtering domain, wherein during said first time interval, the digital filter has a first filter state, and wherein during the second time interval, the digital filter has a second filter state different than the first filter state, andwherein said method includes, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, calculating the second filter state based on information from the reference noise signal and information from an error signal.
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Abstract
An adaptive active noise cancellation apparatus performs a filtering operation in a first digital domain and performs adaptation of the filtering operation in a second digital domain.
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Citations
44 Claims
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1. A method of producing an antinoise signal, said method comprising:
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producing the antinoise signal during a first time interval by applying a digital filter to a reference noise signal in a filtering domain having a first sampling rate; and producing the antinoise signal during a second time interval subsequent to the first time interval by applying the digital filter to the reference noise signal in the filtering domain, wherein during said first time interval, the digital filter has a first filter state, and wherein during the second time interval, the digital filter has a second filter state different than the first filter state, and wherein said method includes, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, calculating the second filter state based on information from the reference noise signal and information from an error signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus for producing an antinoise signal, said apparatus comprising:
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means for producing the antinoise signal during a first time interval by filtering a reference noise signal, according to a first filter state, in a filtering domain having a first sampling rate; and means for calculating, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, a second filter state based on information from the reference noise signal and information from an error signal, wherein the second filter state is different than the first filter state, wherein said means for producing the antinoise signal is configured to produce the antinoise signal during a second time interval subsequent to the first time interval by filtering the reference noise signal in the filtering domain according to the second filter state. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An apparatus for producing an antinoise signal, said apparatus comprising:
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a digital filter configured to produce the antinoise signal during a first time interval by filtering a reference noise signal, according to a first filter state, in a filtering domain having a first sampling rate; and a control block configured to calculate, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, a second filter state based on information from the reference noise signal and information from an error signal, wherein the second filter state is different than the first filter state, wherein the digital filter is configured to produce the antinoise signal during a second time interval subsequent to the first time interval by filtering the reference noise signal in the filtering domain according to the second filter state. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. An apparatus for producing an antinoise signal, said apparatus comprising:
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an integrated circuit configured to produce the antinoise signal during a first time interval by filtering a reference noise signal, according to a first filter state, in a filtering domain having a first sampling rate; and a computer-readable medium having tangible structures that store machine-executable instructions which when executed by at least one processor cause the at least one processor to calculate, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, a second filter state based on information from the reference noise signal and information from an error signal, wherein the second filter state is different than the first filter state, wherein the integrated circuit is configured to produce the antinoise signal during a second time interval subsequent to the first time interval by filtering the reference noise signal in the filtering domain according to the second filter state. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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Specification