Signal envelope processing
First Claim
1. An envelope detection circuit comprising:
- absolute value circuitry configured to receive data samples and output a first value corresponding to the magnitude of said data samples; and
an envelope tracker configured to maintain an envelope output value and to compare the first value to the current envelope output value and modify the envelope output value based on said comparison to provide the envelope output value with predetermined attack and decay characteristics;
wherein the absolute value circuitry comprises a first input for receiving a first digital signal at a first sample rate and a second input for receiving an interpolated version of the first digital signal at a second sample rate which is higher than the first sample rate and is configured to output said first value based on the magnitudes of the samples received at the first input and the samples received at the second input.
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Abstract
Methods and apparatus for detection and tracking of a signal envelope. The circuit comprises absolute value circuitry configured to receive data samples and output a first value corresponding to the magnitude of said data samples. An envelope tracker maintains an envelope output value and compares the first value to the current envelope output value and modifies the envelope output value based on said comparison to provide the envelope output value with predetermined attack and decay characteristics. The absolute value circuitry has a first input for receiving a first digital signal at a first sample rate and a second input for receiving an interpolated version of the first digital signal at a second sample rate which is higher than the first sample rate and outputs the first value based on the magnitudes of the samples received at the first input and the samples received at the second input. Using the first digital signal provides an early indication of any increases in signal envelope whereas the second digital signal can allow a more accurate estimation.
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Citations
20 Claims
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1. An envelope detection circuit comprising:
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absolute value circuitry configured to receive data samples and output a first value corresponding to the magnitude of said data samples; and an envelope tracker configured to maintain an envelope output value and to compare the first value to the current envelope output value and modify the envelope output value based on said comparison to provide the envelope output value with predetermined attack and decay characteristics; wherein the absolute value circuitry comprises a first input for receiving a first digital signal at a first sample rate and a second input for receiving an interpolated version of the first digital signal at a second sample rate which is higher than the first sample rate and is configured to output said first value based on the magnitudes of the samples received at the first input and the samples received at the second input. - 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 method of envelop detection comprising:
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receiving input data samples at absolute value circuitry and outputting a first value corresponding to the magnitude of said data samples; maintaining an envelope output value; and comparing the first value to the current envelope output value and modifying the envelope output value based on said comparison to provide the envelope output value with predetermined attack and decay characteristics; wherein the absolute value circuitry receives a first digital signal at a first sample rate and also an interpolated version of the first digital signal at a second sample rate which is higher than the first sample rate and outputs said first value based on the magnitudes of the samples of first digital signal and the interpolated version of the first digital signal.
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Specification