Active Noise Cancellation Device

• US 20170125006A1
• Filed: 12/16/2016
• Published: 05/04/2017
• Est. Priority Date: 05/08/2015
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Qin, Jingfan, Song, Yang, Dzhigan, Victor, Petrovsky, Alexey
• Granted Patent: US 10,147,411 B2
• Time in Patent Office: Days
• CPC Class Codes: G10K 11/17815 between the reference signals and the error signals, i.e. primary path
• CPC Class Codes: G10K 11/17817 between the output signals and the error signals, i.e. secondary path
• CPC Class Codes: G10K 11/17833 by using a self-diagnostic function or a malfunction prevention function, e.g. detecting abnormal output levels
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17855 for improving speed or power requirements
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/3022 Error paths
• CPC Class Codes: G10K 2210/30231 Sources, e.g. identifying noisy processes or components
• CPC Class Codes: G10K 2210/3026 Feedback
• CPC Class Codes: G10K 2210/3027 Feedforward
• CPC Class Codes: G10K 2210/3028 Filtering, e.g. Kalman filters or special analogue or digital filters
• CPC Class Codes: G10K 2210/3045 Multiple acoustic inputs, single acoustic output
• CPC Class Codes: G10K 2210/3047 Prediction, e.g. of future values of noise
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06

Abstract

An active noise cancellation device for cancelling a primary acoustic path between a noise source and a microphone by an overlying secondary acoustic path between a canceling loudspeaker and the microphone, the device comprising: a first input for receiving a microphone signal from the microphone; wherein the first electrical compensation path and the second electrical compensation path are coupled in parallel between a first node and the first input to provide the first noise canceling signal for a feed-backward prediction of the noise source; wherein the third electrical compensation path and the fourth electrical compensation path are coupled in parallel between a second node and the first input to provide the second noise canceling signal for a feed-forward prediction of noise source.

Claims

1. An active noise cancellation device comprising:

a microphone;

a first input coupled to the microphone and configured to receive a microphone signal from the microphone;

a canceling loudspeaker;

a first output coupled to the canceling loudspeaker and configured to provide a first noise canceling signal to the canceling loudspeaker;

a first node configured to provide a prediction of a noise source;

a first electrical compensation path; and

a second electrical compensation path,

wherein the first electrical compensation path and the second electrical compensation path are coupled in parallel between the first input and the first node to provide the first noise canceling signal.

2. The active noise cancellation device of claim 1, further comprising a third subtraction unit coupling the first electrical compensation path and the second electrical compensation path to the first input.

3. The active noise cancellation device of claim 1, further comprising:

a second output coupled to the canceling loudspeaker and configured to provide a second noise canceling signal to the canceling loudspeaker;

a second node configured to provide a feed-forward (FF) prediction of the noise source;

a third electrical compensation path; and

a fourth electrical compensation path, wherein the third electrical compensation path and the fourth electrical compensation path are coupled in parallel between the first input and the second node (240), wherein the first node (140) is further configured to provide a feed-backward (FB) prediction of the noise source.

4. The active noise cancellation device of claim 3, further comprising a third subtraction unit coupling the third electrical compensation path and the fourth electrical compensation path to the first input.

5. The active noise cancellation device of claim 3, further comprising a delay element positioned between the first input and the first node and configured to provide the FB prediction.

6. The active noise cancellation device of claim 5, further comprising:

a third input coupled to at least one of the first output and the second output and configured to receive a far-end speaker signal;

a first adaptation circuit comprising an error input;

a fifth reproduction filter positioned between the third input and the error input and configured to reproduce a second electrical estimate of a secondary acoustic path; and

a sixth reproduction filter positioned between the first output and the first input and configured to reproduce a third electrical estimate of the secondary acoustic path.

7. The active noise cancellation device of claim 6, further comprising:

a second subtraction unit configured to subtract an output of the fifth reproduction filter from the microphone signal or a third subtraction unit output to provide an error signal to the first adaptation circuit and second adaptation circuit;

a first subtraction unit configured to subtract an output of the sixth reproduction filter from the microphone signal or the third subtraction unit output to provide a compensation signal to the delay element; and

a third output configured to output the compensation signal as far-end speech with noise.

8. The active noise cancellation device of claim 3, wherein the third electrical compensation path comprises a third reproduction filter cascaded with a second adaptive filter, and wherein the third reproduction filter is configured to reproduce a fourth electrical estimate of the secondary acoustic path.

9. The active noise cancellation device of claim 8, wherein the fourth electrical compensation path comprises a replica of the second adaptive filter cascaded with a fourth reproduction filter configured to reproduce the fourth electrical estimate.

10. The active noise cancellation device of claim 9, further comprising a second tap coupled to the second output and positioned between the replica and the fourth reproduction filter.

11. The active noise cancellation device of claim 8, further comprising a first adaptation circuit configured to adjust first filter weights of a first adaptive filter (113), wherein the first reproduction filter is cascaded with the first adaptation circuit.

12. The active noise cancellation device of claim 11, further comprising a second adaptation circuit configured to adjust second filter weights of a second adaptive filter, wherein the third reproduction filter is cascaded with the second adaptation circuit.

13. The active noise cancellation device of claim 1, wherein the first electrical compensation path comprises a first reproduction filter cascaded with a first adaptive filter, and wherein the first reproduction filter is configured to reproduce a first electrical estimate of a secondary acoustic path.

14. The active noise cancellation device of claim 13, wherein the second electrical compensation path comprises a replica of the first adaptive filter cascaded with a second reproduction filter configured to reproduce the first electrical estimate.

15. The active noise cancellation device of claim 14, further comprising a first tap coupled to the first output and positioned between the replica and the second reproduction filter.