| 摘要 |
PROBLEM TO BE SOLVED: To a fully secure echo elimination quantity, even if the characteristic impedance of a two-wire line connected to an HYB transformer changes by a large amount. SOLUTION: This echo canceler consists of an A/D conversion part 9, a reference data storing part 10 for storing received input data, a filter coefficient updating part 11 for updating a filter coefficient, a filter coefficient storing part 12 for storing the filter coefficient, a FIR filter 13 for generating a pseudo echo, an A/D converting part 14, a subtracted 15, a near-end voice detecting part 16 for detecting whether a near-end speaker performs transmission, a switching device 17 or inhibiting an adaptive modification operation of an echo canceler, a residual error suppressing part 18 for suppressing a residual echo after echo elimination, a level measuring part 19 for controlling residual suppression, a BNW switching part 20 for switching plurality of networks, a BNW 21 composed of the plurality of networks and a D/A conversion part 22.
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