Acoustic echo cancellation system
AssigneesFortemedia, Inc., Maxsonics, Inc.
InventorsQing-Guang Liu, Wilson Or
Life of this patent
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Abstract
An embodiment of an acoustic echo cancellation system is disclosed. The system comprises an echo cancellation unit, a second filter and a subtraction unit. The echo cancellation unit comprises a first attenuator, a first filter and a first subtractor. The first attenuator has a first down-scaling factor for attenuating a first signal. The first filter generates a first echo signal estimate based on the attenuated first signal. The first subtractor generates a third signal by subtracting the first echo signal estimate from a second signal. The second filter generates a second echo signal estimate based on the first signal. The subtraction unit subtracts the second echo signal estimate from the third signal.
Claims15
An acoustic echo cancellation system, comprising:
- a first echo cancellation unit, comprising:
- a first attenuator, having a first down-scaling factor, for attenuating a first signal;
- a first filter to generate a first echo signal estimate based on the attenuated first signal;
- and
- a first subtractor to generate a third signal by subtracting the first echo signal estimate from a second signal;
- a second echo cancellation unit, comprising:
- a second attenuator, having a second down-scaling factor, for attenuating the first signal;
- and
- a second filter to generate a second echo signal estimate based on the output signal of the second attenuator, wherein the second down-scaling factor is different from the first down-scaling factor;
- and
- a second subtractor to generate a fourth signal by subtracting the second echo signal estimate from the third signal;
- a third filter to generate a third echo signal estimate based on the first signal;
- and
- a third subtractor subtracting the third echo signal estimate from the fourth third signal.
An acoustic echo cancellation system, comprising:
- a first attenuator, having a first down-scaling factor, for attenuating a first signal;
- a first filter to, generate a first echo signal estimate based on the attenuated first signal;
- a second attenuator, having a second down-scaling factor, for attenuating the first signal, wherein the second down-scaling factor is different from the first down-scaling factor;
- a second filter to generate a second echo signal estimate based on the output signal of the second attenuator;
- a first subtractor to, generate a third signal by subtracting the first echo signal estimate or the second echo signal estimate from a second signal;
- and
- a multiplexer coupled to the first attenuator and the second attenuator, transmitting the first signal to the first filter or the second filter based on a control signal;
- a third filter to, generate a third echo signal estimate based on the first signal;
- and a second subtractor subtracting the third echo signal estimate from the third signal.
An apparatus with an acoustic echo cancellation system, comprising:
- a loudspeaker receiving and playing a first signal;
- a microphone acquiring a second signal;
- a first echo cancellation unit, comprising:
- a first attenuator, having a first down-scaling factor, for attenuating a first signal;
- a first filter to generate a first echo signal estimate based on the attenuated first signal;
- and
- a first subtractor to generate a third signal by subtracting the first echo signal estimate from a second signal;
- a second echo cancellation unit, comprising:
- a second attenuator, having a second down-scaling factor, for attenuating the first signal;
- and
- a second filter to, generate a second echo signal estimate based on the output signal of the second attenuator, wherein the second down-scaling factor is different from the first down-scaling factor;
- and
- a second subtractor to, generate a fourth signal by subtracting the second echo signal estimate from the third signal;
- a third filter to generate a third echo signal estimate based on the first signal;
- and
- a third subtractor subtracting the third echo signal estimate from the fourth signal.
An apparatus with an acoustic echo cancellation system, comprising:
- a loudspeaker receiving and playing a first signal;
- a microphone acquiring a second signal;
- a first attenuator, having a first down-scaling factor, for attenuating a first signal;
- a first filter to, generate a first echo signal estimate based on the attenuated first
- a second attenuator, having a second down-scaling factor, for attenuating the first signal, wherein the second down-scaling factor is different from the first down-scaling factor;
- a second filter to generate a second echo signal based on the output signal of the second attenuator;
- a first subtractor to, generate a third signal by subtracting the first echo signal estimate or the second echo signal estimate from a second signal;
- and
- a multiplexer coupled to the first attenuator and the second attenuator, transmitting the first signal to the first filter or the second filter based on a control signal;
- a third filter to, generate a third echo signal estimate based on the first signal;
- and a second subtractor subtracting the third echo signal estimate from the third signal.
Dependencies are inferred from the claim text.