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US 11,689,851 B2Granted
Adaptive delay diversity filter and echo cancellation apparatus and method using the same
AssigneeAuzdsp Co., Ltd.
InventorDong Un Yun
Life of this patent
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Abstract
An adaptive filter and an echo cancellation apparatus and method using the same, utilize an adaptive delay diversity filter for coping with the situation in which variation in a time delay between a reference signal and a target signal of an adaptive filter is large. The adaptive delay diversity filter includes multiple sub-filters, each of which generates output through filtering by utilizing a signal, obtained by applying different time delay values to the reference signal, as a reference signal, and selects the best output value among generated output values of the multiple sub-filters, as an output value of the adaptive delay diversity filter. Further, the adaptive delay diversity filter includes a means for reducing a computational load.
Claims25
An adaptive filter, comprising:
- a transmit signal x(n) transmitted from a transmitting end;
- an input signal y(n) collected at a receiving end;
- a desired signal included in the y(n);
- and
- an adaptive delay diversity filter for estimating the desired signal using the x(n) as a reference signal and using the y(n) as a target signal,
- wherein the adaptive delay diversity filter comprises a plurality of sub-filters,
- wherein the plurality of sub-filters is composed of M sub-filters (where M is a natural number greater than 1),
- wherein each sub-filter of the plurality of sub-filters is implemented as an adaptive filter,
- wherein each of the sub-filters uses the y(n) as a target signal,
- wherein each of the sub-filters uses signals xj(n) (j=1, . . . , M), obtained by time-delaying the x(n) using different delay values for respective sub-filters, as respective reference signals,
- wherein each of the signals xj(n) is configured to satisfy Equation 1,
- wherein Equation 1 is xj(n)=x(n−Dj), j=1, . . . , M, where a time delay value Dj is an integer satisfying 0≤D1<D2< . . . <DM, and
- wherein the adaptive delay diversity filter computes output values of respective sub-filters through filtering with respect to each input value, and selects one of the computed multiple output values as an output value of the adaptive delay diversity filter.
10 more elements
An electronic device, comprising:
- a speaker output signal x(n) collected at an audio output terminal;
- a microphone input signal y(n) collected at a microphone;
- an echo included in the y(n);
- and
- an echo canceller for cancelling the echo using the x(n) as a reference signal and using the y(n) as a target signal,
- wherein the echo canceller comprises a plurality of sub-filters,
- wherein the plurality of sub-filters is composed of M sub-filters (where M is a natural number greater than 1),
- wherein each sub filter of the plurality of sub-filters is implemented as an adaptive filter,
- wherein each of the sub-filters uses the y(n) as a target signal,
- wherein each of the sub-filters uses signals xj(n) (where j=1, . . . , M), obtained by time-delaying the x(n) using different delay values for respective sub-filters, as respective reference signals,
- wherein each of the signals xj(n) is configured to satisfy Equation 8,
- wherein Equation 8 is xj(n)=x(n−Dj), j=1, . . . , M, where a time delay value Dj is an integer satisfying 0≤Di<D2< . . . <DM, and
- wherein the echo canceller computes output values of respective sub-filters through filtering with respect to each input value, and selects one of the computed multiple output values as an output value of the echo canceller.
10 more elements
An echo cancellation method, comprising:
- collecting a speaker output signal x(n) at an audio output terminal;
- outputting the speaker output signal x(n) through the audio output terminal and thereafter collecting a microphone input signal y(n) through the microphone;
- and
- allowing an echo canceller to cancel an echo included in the y(n) using the x(n) as a reference signal and using the y(n) as a target signal,
- wherein the echo cancellation method further comprises:
- configuring the echo canceller using a plurality of sub-filters, wherein the plurality of sub-filters includes M sub-filters (where M is a natural number greater than 1),
- configuring each sub-filter of the plurality of sub-filters as an adaptive filter;
- allowing the sub-filters to obtain delayed signals xj(n) (j=1, . . . , M) by time-delaying the x(n) using different delay values for respective sub-filters, wherein obtaining the delayed signals xj(n) is configured to satisfy Equation 15, and Equation 15 is xj(n)=x(n−Dj), j=1, . . . , M, where a time delay value Dj is an integer satisfying 0≤D1<D2< . . . <DM;
- configuring inputs of each sub-filter using the y(n) as a target signal and using each of the delayed signals xj(n) as a reference signal;
- and
- performing an output value computation operation of computing output values of respective sub-filters through filtering with respect to each input value, and selecting one of the computed multiple output values as an output value of the echo canceller.
8 more elements
Dependencies are inferred from the claim text.