Noise suppression for a wireless communication device
First Claim
1. A mobile communication device comprising:
- a plurality of signal detectors mounted on the mobile communication device, the plurality of signal detectors being placed in close proximity to one another and forming a small array, each signal detector configured to provide a respective detected signal having a desired component plus an undesired component;
a first beam forming unit operatively coupled to the plurality of signal detectors and configured to process the plurality of detected signals to generate a first signal having the desired component plus a portion of the undesired component;
a second beam forming unit operatively coupled to the plurality of signal detectors and configured to process the plurality of detected signals to generate a second signal having mostly the undesired component;
an activity detector configured to receive the first and second signals, to detect for speech activity based on the first and second signals, and to provide a control signal indicative of detected speech activity;
a controller operatively coupled to the first and second forming units and the activity detector and configured to receive the control signal, to enable the first beam forming unit to adapt during periods of speech activity, and to enable the second beam forming unit to adapt during periods of non-speech activity; and
a noise suppression unit operatively coupled to the first and second beam forming units and configured to receive and digitally process the first and second signals to obtain an output signal having substantially the desired component and a large portion of the undesired component removed.
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Accused Products
Abstract
Techniques to suppress noise from a signal comprised of speech plus noise. In accordance with aspects of the invention, two or more signal detectors (e.g., microphones) are used to detect respective signals having speech and noise components, with the magnitude of each component being dependent on various factors such as the distance between the speech source and the microphone. Signal processing is then used to process the detected signals to generate the desired output signal having predominantly speech with a large portion of the noise removed. The techniques described herein may be advantageously used for both near-field and far-field applications, and may be implemented in various mobile communication devices such as cellular phones.
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Citations
30 Claims
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1. A mobile communication device comprising:
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a plurality of signal detectors mounted on the mobile communication device, the plurality of signal detectors being placed in close proximity to one another and forming a small array, each signal detector configured to provide a respective detected signal having a desired component plus an undesired component; a first beam forming unit operatively coupled to the plurality of signal detectors and configured to process the plurality of detected signals to generate a first signal having the desired component plus a portion of the undesired component; a second beam forming unit operatively coupled to the plurality of signal detectors and configured to process the plurality of detected signals to generate a second signal having mostly the undesired component; an activity detector configured to receive the first and second signals, to detect for speech activity based on the first and second signals, and to provide a control signal indicative of detected speech activity; a controller operatively coupled to the first and second forming units and the activity detector and configured to receive the control signal, to enable the first beam forming unit to adapt during periods of speech activity, and to enable the second beam forming unit to adapt during periods of non-speech activity; and a noise suppression unit operatively coupled to the first and second beam forming units and configured to receive and digitally process the first and second signals to obtain an output signal having substantially the desired component and a large portion of the undesired component removed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A wireless communication device comprising:
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at least two microphones mounted on the wireless communication device, the at least two microphones being placed in close proximity to one another and forming a small array, each microphone configured to detect and provide a respective signal having a desired component plus an undesired component; and a signal processor coupled to the at least two microphones and configured to receive and digitally process the detected signals from the microphones with a first beam forming unit to obtain a first signal having the desired component plus a portion of the undesired component, to process the detected signals with a second beam forming unit to obtain a second signal having mostly the undesired component, to detect for speech activity based on the first and second signals, to determine periods of speech activity and periods of non-speech activity based on the detected speech activity, to enable the first beam forming unit to adapt during the periods of speech activity, to enable the second beam forming unit to adapt during the periods of non-speech activity, and to process the first and second signals to obtain an output signal having substantially the desired component and a large portion of the undesired component removed. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. An apparatus comprising:
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means for detecting at least two signals via at least two signal detectors mounted on the apparatus, the at least two signal detectors being placed in close proximity to one another and forming a small array, wherein each detected signal includes a desired component plus an undesired component; means for processing the detected signals with a first beam forming unit to obtain a first signal having substantially the desired component plus a portion of the undesired component; means for processing the detected signals with a second beam forming unit to obtain a second signal having mostly the undesired component; means for detecting for speech activity based on the first and second signals and providing a control signal indicative of detected speech activity; means for enabling the first beam forming unit to adapt during periods of speech activity; means for enabling the second beam forming unit to adapt during periods of non-speech activity; and means for digitally processing the first and second signals to obtain an output signal having substantially the desired component and a large portion of the undesired component removed. - View Dependent Claims (28, 29, 30)
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Specification