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US 10,945,074 B2Granted
Low-latency compensating audio filters using negative group delay
AssigneeCirrus Logic, Inc.
InventorJohn L. Melanson
Life of this patent
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Abstract
A system may include an input configured to receive an audio signal, a filter having a negative group delay within a range of frequencies which are human-audible, the filter configured to receive the audio signal and filter the audio signal to generate a filtered audio signal, and a modulator configured to receive the filtered audio signal and modulate the filtered audio signal to generate a modulated filtered audio signal for communication over a digital interface.
Claims24
A system, comprising:
- an input configured to receive an audio signal;
- a filter having a negative group delay within a range of frequencies which are human-audible, the filter configured to receive the audio signal and filter the audio signal to generate a filtered audio signal;
- and
- a modulator configured to receive the filtered audio signal and modulate the filtered audio signal to generate a modulated filtered audio signal for communication over a digital interface.
1 more element
A system comprising:
- a first detector configured to:
- detect at a transmitting side of a digital interface, a sample of a modulated filtered audio signal generated from an input signal filtered by a first filter having a first filter response;
- determine whether the modulated filtered audio signal has a condition for operating the first filter in a first mode;
- generate a control signal to the first filter to operate in the first mode in response to a determination that the modulated filtered audio signal has the condition;
- and
- generate the control signal to the first filter to operate in a second mode in response to a determination that the modulated filtered audio signal is without the condition;
- and
- a second detector configured to:
- detect at a receiving side of the digital interface the sample of the modulated filtered audio signal;
- determine whether the modulated filtered audio signal has a condition for operating the first filter in the first mode;
- generate a control signal to a second filter having a second response that is an approximate inverse of the first response and configured to filter the modulated filtered audio signal filter, the control signal for causing the second filter to operate in a third mode in response to a determination that the modulated filtered audio signal has the condition;
- and
- generate the control signal to the second filter to operate in a fourth mode in response to a determination that the modulated filtered audio signal is without the condition.
10 more elements
A method, comprising:
- receiving an audio signal;
- filtering the audio signal to generate a filtered audio signal with a filter having a negative group delay within a range of frequencies which are human-audible;
- and
- modulating the filtered audio signal to generate a modulated filtered audio signal for communication over a digital interface.
1 more element
A method comprising:
- detecting at a transmitting side of a digital interface, a sample of a modulated filtered audio signal generated from an input signal filtered by a first filter having a first filter response;
- determining whether the modulated filtered audio signal has a condition for operating the first filter in a first mode;
- generating a control signal to the first filter to operate in the first mode in response to a determination that the modulated filtered audio signal has the condition;
- generating the control signal to the first filter to operate in a second mode in response to a determination that the modulated filtered audio signal is without the condition;
- detecting at a receiving side of the digital interface the sample of the modulated filtered audio signal;
- determining whether the modulated filtered audio signal has a condition for operating the first filter in the first mode;
- generating a control signal to a second filter having a second response that is an approximate inverse of the first response and configured to filter the modulated filtered audio signal filter, the control signal for causing the second filter to operate in a third mode in response to a determination that the modulated filtered audio signal has the condition;
- and
- generating the control signal to the second filter to operate in a fourth mode in response to a determination that the modulated filtered audio signal is without the condition.
6 more elements
Dependencies are inferred from the claim text.