| 摘要 |
PROBLEM TO BE SOLVED: To suppress divergence of filter coefficients of an adaptive filter under the state of double talk. SOLUTION: When a double talk is not detected by a double talk detection part 34, a divergence detection processing part 37 detects a case that a value for convergence is lower than the threshold R0 (≪1) successively for a slightly longer time than the time required for convergence (convergence of a filter coefficient H<SB>n</SB>(m) of the adaptive filter 31) of an echo canceller 30 in a normal use environment, as a divergence state. Therefore, even if the filter coefficient H<SB>n</SB>(m) of the adaptive filter 31 diverges, the divergence detection processing part 37 which has detected the divergence state initializes processing and variables of the adaptive filter 31, a subtracter 32, a remote end signal power estimation part 33, and the double talk detection part 34, immediately and the divergence can be resolved at an early stage. COPYRIGHT: (C)2008,JPO&INPIT
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