Patent ID: 6757385
Filing Date: 2004-06-29
Classification: H04M

Abstract:
An acoustic echo canceller, comprising:a first input for receiving a far-end digitized acoustical signal; a second input for receiving a near-end digitized acoustical signal; a first analysis filter bank coupled to said first input for partitioning said far-end signal into M frequency subband far-end signals and producing from said M frequency subband far-end signals Mâ€² further frequency subband far-end signals where Mâ€² is less than M; a second analysis filter bank coupled to said second input for partitioning said near-end signal into M frequency subband near-end signals and for producing from said M frequency subband near-end signals Mâ€² further frequency subband near-end signals; an acoustic echo cancellation operator coupled to said first and second analysis filter banks for receiving from said first analysis filter bank said Mâ€² further frequency subband far-end signals, and for receiving from said second analysis filter bank said Mâ€² further frequency subband near-end signals, said acoustic echo cancellation operator operable in response to said Mâ€² further frequency subband far-end signals and said Mâ€² further frequency subband near-end signals to produce Mâ€² frequency subband error signals; a complex conjugate operator coupled to said acoustic echo cancellation operator for receiving therefrom Mâˆ’Mâ€² of said frequency subband error signals and producing complex conjugates of said Mâˆ’Mâ€² frequency subband error signals; and a synthesis filter bank coupled to said complex conjugate operator for receiving said Mâˆ’Mâ€² complex conjugates and also coupled to said acoustic echo cancellation operator for receiving therefrom said Mâ€² frequency subband error signals, said synthesis filter bank responsive to said Mâ€² frequency subband error signals and said Mâˆ’Mâ€² complex conjugates for producing an echo-cancelled near-end signal.