Methods and apparatus for echo cancellation using an adaptive lattice based non-linear processor
OwnerOguz Tanrikulu, John DellaMorteinventors
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Abstract
A non-linear processor for managing a speech signal is disclosed. The non-linear processor includes an adaptive lattice filter that generates a prediction error from a residual echo of the speech signal, a signum non-linearity unit that generates an excitation component from the prediction error, an excitation signal mixer that generates an excitation signal from the excitation component and a noise component, an inverse lattice filter that generates a modified residual echo from the excitation signal, and a gain adjuster that adjusts a power of the modified residual echo.
Claims20
A method for managing a speech signal, comprising:
- generating an excitation component for the speech signal;
- spectrally shaping a noise component for the speech signal;
- and
- mixing the excitation component with the noise component.
An apparatus for managing a speech signal, comprising:
- a double-talk detector that detects double-talk on the speech signal;
- a non-linear processor that center-clips a residual echo from the speech signal in response to a presence of double-talk on the speech signal;
- an inverse filter that filters a noise source whose spectral envelope tracks that of a background noise signal to make filtered noise;
- and
- a noise injector that injects the filtered noise onto the speech signal.
A computer-readable medium having stored thereon sequences of instructions, the sequences of instructions including instructions which, when executed by a processor, causes the processor to perform:
- detecting presence of double-talk on a speech signal;
- center-clipping a residual echo from the speech signal;
- filtering a noise source whose spectral envelope tracks that of a background noise signal to make filtered noise;
- and
- injecting the filtered noise onto the speech signal.
Dependencies are inferred from the claim text.