Telephonic communications – Echo cancellation or suppression – Residual echo cancellation
Reexamination Certificate
2005-02-22
2005-02-22
Isen, F. W. (Department: 2644)
Telephonic communications
Echo cancellation or suppression
Residual echo cancellation
C379S406010, C379S406060, C379S406080, C379S406090, C379S406110, C379S406130, C379S406120
Reexamination Certificate
active
06859531
ABSTRACT:
Real and imaginary components of the discrete Fourier transform (DFT) of the residual echo in an acoustic echo cancellation system are separately estimated using mapping functions derived without an assumption of statistical independence between separate components of a near-end microphone input signal. The residual echo estimator calculates the real and imaginary components using an approximation of the microphone input signal without the echo. A different approximation is used depending on whether the near-end talker and/or the far-end talker are talking.
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Intel Corporation
Isen F. W.
Schwegman Lundberg Woessner & Kluth P.A.
Singh Ramnandan
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