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US 2014/0233750 A1Published application
Systems, methods, apparatus, and computer-readable media for adaptive active noise cancellation
AssigneeQUALCOMM Incorporated
InventorsHyun Jin Park, Kwokleung Chan, Ren Li
Life of this patent
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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.
Claims36
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 according to a first state of the digital filter that includes a filter gain;
- calculating a second state of the digital filter that is different than the first state of the digital filter and includes an update for said filter gain;
- 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 according to said second state of the digital filter,
- wherein said applying the digital filter to the reference noise signal includes:
- applying a filter to the reference noise signal, in a filtering domain having a first sampling rate, to produce a filtered signal;
- and
- controlling a gain of the filtered signal according to the filter gain to produce the antinoise signal, and
- wherein said calculating the second state of the digital filter includes:
- applying a copy of said filter to the reference noise signal, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, to produce a second filtered signal;
- and
- calculating said update based on information from said second filtered signal and on information from an error signal.
9 more elements
2-5. (canceled)
8-11. (canceled)
An apparatus for producing an antinoise signal, said apparatus comprising:
- means for producing the antinoise signal during a first time interval by filtering a reference noise signal, in a filtering domain having a first sampling rate, according to a first state of the means for producing the antinoise signal that includes a filter gain;
- and
- means for calculating a second state of the means for producing the antinoise signal that is different than the first state of the means for producing the antinoise signal and includes an update for said filter gain,
- 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 state of the means for producing the antinoise signal, and
- wherein said means for producing the antinoise signal includes:
- means for filtering the reference noise signal to produce a filtered signal;
- and
- means for controlling a gain of the filtered signal according to the filter gain to produce the antinoise signal, and
- wherein said means for calculating the second state of the means for producing the antinoise signal includes:
- a copy of said means for filtering arranged to filter the reference noise signal, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, to produce a second filtered signal;
- and
- means for calculating said update based on information from said second filtered signal and on information from an error signal.
9 more elements
13-22. (canceled)
An apparatus for producing an antinoise signal, said apparatus comprising:
- a digital filter configured to produce the antinoise signal during a first time interval by filtering a reference noise signal, in a filtering domain having a first sampling rate, according to a first state of the digital filter that includes a filter gain;
- and
- a control block configured to calculate a second state of the digital filter that is different than the first state of the digital filter and includes an update for said filter gain,
- 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 state of the digital filter, and
- wherein said digital filter includes:
- a filter configured to filter the reference noise signal to produce a filtered signal;
- and
- a gain control element configured to control a gain of the filtered signal according to the filter gain to produce the antinoise signal, and
- wherein said control block includes:
- a copy of said filter configured to filter the reference noise signal, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, to produce a second filtered signal;
- and
- a calculator configured to calculate said update based on information from said second filtered signal and on information from an error signal.
9 more elements
24-28. (canceled)
30-33. (canceled)
An apparatus for producing an antinoise signal, said apparatus comprising:
- an integrated circuit comprising a digital filter and configured to produce the antinoise signal during a first time interval by applying the digital filter to a reference noise signal according to a first state of the digital filter that includes a filter gain;
- 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 a second state of the digital filter that is different than the first state of the digital filter and includes an update for said filter gain,
- wherein the integrated circuit is configured to produce the antinoise signal during a second time interval subsequent to the first time interval by applying the digital filter to the reference noise signal according to the second state of the digital filter, and
- wherein said digital filter includes:
- a filter configured to filter the reference noise signal, in a filtering domain having a first sampling rate, to produce a filtered signal;
- and
- a gain control element configured to control a gain of the filtered signal according to the filter gain to produce the antinoise signal, and
- wherein said calculating the second state of the digital filter includes:
- applying a copy of said filter to the reference noise signal, in an adaptation domain having a second sampling rate that is lower than the first sampling rate, to produce a second filtered signal;
- and
- calculating said update based on information from said second filtered signal and on information from an error signal.
9 more elements
35-44. (canceled)
Dependencies are inferred from the claim text.