Dynamic beamformer processing for acoustic echo cancellation in systems with high acoustic coupling
First Claim
1. Near-end equipment for a near-end audio source communicating with a far-end equipment via an audio communication channel, the near-end equipment comprising:
- a beamformer configured to receive two or more microphone signals generated by two or more local microphones and generate one or more beampattern signals; and
an echo canceller configured to(i) receive the one or more beampattern signals from the beamformer and an incoming signal from the far-end equipment that is applied to one or more local loudspeakers,(ii) determine an active communication state for the audio communication channel,(iii) select a beampattern for the beamformer based on the determined active communication state, and(iv) apply echo-cancellation processing to a beampattern signal corresponding to the selected beampattern for the beamformer, to generate an outgoing signal to be transmitted to the far-end equipment,wherein;
active communication states comprise a near-end only talking state, a far-end only talking state, and a double-talk state;
one or more beampatterns comprise a first beampattern and a second beampattern different from the first beampattern;
the first beampattern has at least one near-field null corresponding to the one or more local loudspeakers and a far-field pattern that does not contain any nulls;
the second beampattern optimizes reception of acoustic signals from the near-end audio source;
when the echo canceller determines that the active communication state is the far-end only talking state or the double-talk state, the echo canceller selects the first beampattern;
when the echo canceller determines that the active communication state is the near-end only taling state, the echo canceller selects the second beampattern;
wherein the beamformer is configured to generate a first beampattern signal for a first communication state; and
the echo canceller is configured to(i) detect a change from the first communication state to a second communication state different from the first communication state and(ii) control the beamformer to be re-configured to generate a second beampattern signal different from the first beampattern signal for the second communication state.
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Accused Products
Abstract
Near-end equipment for a communication channel with far-end equipment. The near-end equipment includes at least one loudspeaker, at least two microphones, a beamformer, and an echo canceller. The communication channel may be in one of a number of communication states including Near-End Only state, Far-End Only state, and Double-Talk state. In one embodiment, when the echo canceller determines that the communication channel is in either the Far-End Only state or the Double-Talk state, the beamformer is configured to generate a nearfield beampattern signal that directs a null towards a loudspeaker. When the echo canceller detects the Near-End Only state, the beamformer is configured to generate a farfield beampattern signal that optimizes reception of acoustic signals from the near-end audio source. Using different beamformer processing for different communication states allows echo cancellation processing to be more successful at reducing echo in the signal transmitted to the far-end equipment.
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Citations
10 Claims
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1. Near-end equipment for a near-end audio source communicating with a far-end equipment via an audio communication channel, the near-end equipment comprising:
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a beamformer configured to receive two or more microphone signals generated by two or more local microphones and generate one or more beampattern signals; and an echo canceller configured to (i) receive the one or more beampattern signals from the beamformer and an incoming signal from the far-end equipment that is applied to one or more local loudspeakers, (ii) determine an active communication state for the audio communication channel, (iii) select a beampattern for the beamformer based on the determined active communication state, and (iv) apply echo-cancellation processing to a beampattern signal corresponding to the selected beampattern for the beamformer, to generate an outgoing signal to be transmitted to the far-end equipment, wherein; active communication states comprise a near-end only talking state, a far-end only talking state, and a double-talk state; one or more beampatterns comprise a first beampattern and a second beampattern different from the first beampattern; the first beampattern has at least one near-field null corresponding to the one or more local loudspeakers and a far-field pattern that does not contain any nulls; the second beampattern optimizes reception of acoustic signals from the near-end audio source; when the echo canceller determines that the active communication state is the far-end only talking state or the double-talk state, the echo canceller selects the first beampattern; when the echo canceller determines that the active communication state is the near-end only taling state, the echo canceller selects the second beampattern; wherein the beamformer is configured to generate a first beampattern signal for a first communication state; and the echo canceller is configured to (i) detect a change from the first communication state to a second communication state different from the first communication state and (ii) control the beamformer to be re-configured to generate a second beampattern signal different from the first beampattern signal for the second communication state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification