| 摘要 |
PROBLEM TO BE SOLVED: To provide an echo canceller that stops update of its filter coefficient when receiving a FAX or MODEM signal. SOLUTION: In a configuration where a facsimile terminal FAX 12 is connected to an IBR(In-Band Ringer) 11 for a phone and a signal is given to the echo canceller 14 via a HYB (Hybrid) transformer 13, the echo canceller 14 is provided with a pseudo echo generating section 15 that estimates a characteristic of an echo path to generate the pseudo echo, a subtractor section 16 that subtracts the pseudo echo from a transmission signal of the HYB transformer 13 to cancel the echo, a training signal transmission section 17 that outputs a training signal to train the echo canceller 14 at application of power to the IBR 11 for the phone, a filter initial coefficient storage section 18 that stores a filter coefficient set at the training, and an answer signal detection section 19 that detects whether the echo canceller 14 receives a FAX signal or an answer signal outputted from a MODEM.
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