| 摘要 |
An echo canceler circuit (25) for use in an echo canceller system is set forth. The echo canceller circuit (25) comprises a first digital filter (35) having non-adaptive tap coefficients to simulate an echo response occurring during a call. A second digital filter (30) having adaptive tap coefficients to simulate an echo response occurring during the call is also used. The adaptive tap coefficients of the second digital filter (30) are updated over the duration of the call. A coefficient transfer controller is disposed in the echo canceller circuit (25) to transfer the adaptive tap coefficients of the second digital filter to replace the tap coefficients of the first digital filter when a value, E(~), is greater than a value E(-), and concurrently, when E(~) is greater than a value, E(sub max). The value of E(-) corresponds to the ratio between the signal-plus-echo signal and a second echo compensated signal using the second digital filter.
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