| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency domain echo cancellation technology, wherein update of adaptive filter coefficients converges quickly. SOLUTION: As the basic principle of the frequency domain echo cancellation technology, the characteristics of an echo path are adopted when an adaptive filter update coefficient vector is transformed from a frequency domain signal to a time domain signal in order to constrain the vector. In other words, the characteristics of the echo path are given to the unconstrained time domain adaptive filter update coefficient vector. When an overlap-save method is used in order to achieve the linear convolution of time domain by the cyclic convolution in the discrete Fourier transform, the residual elements of overlap out of the unconstrained time domain adaptive filter update coefficients are multiplied by the attenuation coefficients, and the discard elements of overlap out of the unconstrained time domain adaptive filter update coefficients are replaced by 0, thus constraining the adaptive filter update coefficient vector. COPYRIGHT: (C)2011,JPO&INPIT
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