Echo canceler circuit and method
First Claim
1. A method of reducing echoes and noise in data, the method comprising:
- receiving data;
linearly filtering the data to produce pre-noise suppression data;
removing noise from the pre-noise suppression data to provide noise suppressed data;
dynamically determining at least one weighted filter coefficient using at least in part the pre-noise suppression data and not the noise suppressed data, the determining occurring independently from and not being affected by removing the noise from the pre-noise suppression data;
wherein removing the noise occurs independently from and is not affected by dynamically determining the at least one weighted coefficient such that the noise is removed without encountering an artificial variation in a noise floor; and
subsequently filtering echoes from the noise suppressed data using the at least one weighted filter coefficient to produce final data, the final data being substantially free of noise and substantially free of echoes.
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Accused Products
Abstract
An echo canceller circuit (200) and method performs cascaded echo cancellation and noise suppression in a non-interfering manner. The echo canceller circuit (200) includes pre-noise suppression logic (210), echo canceller coefficient logic (218), noise suppression logic (212) and an echo canceller filter (216). The pre-noise suppression logic (210) receives pre-echo canceller uplink data (64) and downlink data (52), and in response produces pre-noise suppression uplink data (224). The echo canceller coefficient logic (218) receives the pre-noise suppression uplink data (224) and the pre-echo canceller uplink data (64), and in response produces filter coefficient data (226). The noise suppression logic (212) receives the pre-noise suppression uplink data (224), and in response produces noise suppressed uplink data (228). The echo canceller filter (216) receives the noise suppressed uplink data (228) and the filter coefficient data (226) and in response produces final uplink data (230).
30 Citations
18 Claims
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1. A method of reducing echoes and noise in data, the method comprising:
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receiving data; linearly filtering the data to produce pre-noise suppression data; removing noise from the pre-noise suppression data to provide noise suppressed data; dynamically determining at least one weighted filter coefficient using at least in part the pre-noise suppression data and not the noise suppressed data, the determining occurring independently from and not being affected by removing the noise from the pre-noise suppression data; wherein removing the noise occurs independently from and is not affected by dynamically determining the at least one weighted coefficient such that the noise is removed without encountering an artificial variation in a noise floor; and subsequently filtering echoes from the noise suppressed data using the at least one weighted filter coefficient to produce final data, the final data being substantially free of noise and substantially free of echoes. - View Dependent Claims (2, 3, 4)
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5. An echo canceler apparatus comprising:
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pre-noise compression logic, the logic being configured to linearly filter the data to produce pre-noise suppression data; noise suppression logic coupled to the pre-noise compression logic and being configured to remove noise from the pre-noise suppression data and provide noise suppressed data; a filter coefficient generator coupled to the pre-noise suppression logic, the generator configured to dynamically determine at least one weighted filter coefficient using at least in part the pre-noise suppression data and not the noise suppressed data, the determination occurring independently from and not being affected by removal of the noise from the pre-noise suppression data by the noise suppression logic; wherein the removal of the noise in the noise suppression logic occurs independently from and is not affected by dynamically determining the at least one weighted coefficient such that the noise is removed without encountering an artificial variation in a noise floor; and an echo canceler filter coupled to the noise suppression logic and the generator, the echo canceler filter configured to filter echoes from the noise suppressed data using the at least one weighted filter coefficient to produce final data at an output, the final data being substantially free of noise and substantially free of echoes. - View Dependent Claims (6, 7, 8)
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9. A method of reducing echoes and noise in data, the method comprising:
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receiving data; removing noise from the data to provide noise suppressed data that is substantially free of noise; and subsequently filtering echoes from the noise suppressed data using at least one weighted filter coefficient to produce final data, the at least one weighted filter coefficient determined independently from and not being affected by removing the noise, the final data being substantially free of noise and substantially free of echoes. - View Dependent Claims (10, 11, 12)
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13. A method of reducing echoes and noise in data, the method comprising:
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receiving data that is substantially free from noise; and subsequently filtering echoes from the data using at least one weighted filter coefficient to produce final data, the at least one weighted filter coefficient determined independently from and not being affected by removing the noise, the final data being substantially free of noise and substantially free of echoes. - View Dependent Claims (14, 15, 16, 17)
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18. An echo canceler circuit comprising:
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pre-noise suppression logic operative to receive pre-echo canceler uplink data and downlink data and in response to linearly filter the pre-echo canceler uplink data and the downlink data to produce pre-noise suppression uplink data; noise suppression logic, operatively coupled to the pre-noise suppression logic, and operative to receive the pre-noise suppression uplink data and in response to remove noise from the pre-noise suppression data to produce noise suppressed uplink data; echo canceler coefficient logic, operatively coupled to the pre-noise suppression logic, and operative to receive the pre-noise suppression uplink data and the pre-echo canceler uplink data and in response to produce filter coefficient data, the echo canceler coefficient logic operative to receive the pre-noise suppression uplink data from the pre-noise suppression logic, wherein the pre-noise suppression uplink data used by the echo canceler coefficient logic to produce the filter coefficient data has not been processed in the noise suppression logic; wherein the noise suppression logic operates independently from and is not affected by the operation of the echo canceler coefficient logic such that the noise is removed without encountering an artificial variation in a noise floor; and an echo canceler filter, operatively coupled to the noise suppression logic and to the echo canceler coefficient logic, and operative to receive the noise suppressed uplink data and the filter coefficient data and in response to filter echoes from the noise suppressed uplink data using the filter coefficient data to produce final uplink data, the final uplink data being substantially free of noise and substantially free of echoes.
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Specification