Adaptive filter control
AssigneeCirrus Logic, Inc.
InventorZhengyi Xu
Life of this patent
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Abstract
A sound processing circuit comprises a first input for receiving a first input signal, and a second input for receiving a second input signal. A first adaptive filter receives the first input signal, and an error calculation block calculates an error between the second input signal and the output of the first adaptive filter, and outputting an error signal. A second adaptive filter receives the error signal, and an output calculation block subtracts an output of the second adaptive filter from the first input signal to generate an output signal. The adaptation of first and second adaptive filters is controlled based on a magnitude coherence between the first and second input signals.
Claims22
A sound processing circuit comprising a first input for receiving a first input signal, a second input for receiving a second input signal, a first adaptive filter for receiving the first input signal, an error calculation block for calculating an error between the second input signal and the output of the first adaptive filter, and outputting an error signal, a second adaptive filter for receiving the error signal, and an output calculation block for subtracting an output of the second adaptive filter from the first input signal to generate an output signal, wherein:
- the adaptation of the first and second adaptive filters is controlled based on a magnitude coherence between the first and second input signals;
- respective convergence factors of the first and second adaptive filters are controlled based on the magnitude coherence;
- and
- the convergence factor for each adaptive filter is generated for each frequency bin and time frame of the first and second input signals.
A portable device comprising:
- a first microphone to provide a first input signal, a second microphone to provide a second input signal, and a sound processing circuit, wherein the sound processing circuit comprises:
- a first adaptive filter for receiving the first input signal, an error calculation block for calculating an error between the second input signal and the output of the first adaptive filter, and outputting an error signal, a second adaptive filter for receiving the error signal, an output calculation block for subtracting an output of the second adaptive filter from the first input signal to generate an output signal, wherein:
- the adaptation of first and second adaptive filters is controlled based on a magnitude coherence between the first and second input signals;
- respective convergence factors of the first and second adaptive filters are controlled based on the magnitude coherence;
- and
- the convergence factor for each adaptive filter is generated for each frequency bin and time frame of the first and second input signals.
A portable device comprising:
- a first microphone to provide a first input signal, a second microphone to provide a second input signal, and a sound processing circuit, wherein the sound processing circuit comprises:
- a first adaptive filter for receiving the first input signal, an error calculation block for calculating an error between the second input signal and the output of the first adaptive filter, and outputting an error signal, a second adaptive filter for receiving the error signal, an output calculation block for subtracting an output of the second adaptive filter from the first input signal to generate an output signal, at least one third microphone, and a microphone selection circuit for determining which of the first, second and third microphones are used to provide the first and second input signals, wherein the adaptation of the first and second adaptive filters is controlled based on a magnitude coherence between the first and second input signals.
Dependencies are inferred from the claim text.