| 摘要 |
PURPOSE:To eliminate disturbance due to echo and reception signal by performing a pull-in of a timing regeneration circuit from a reception signal during a period when no echo is generated and performing a pull-in of an echo canceller during a period when no reception signal exists from a transmission signal. CONSTITUTION:A transmission signal 0 consecutive detection circuit 3 detects the consecutive 0 period of the transmission signal, a timing reproduction circuit performs pull-in at the period, that is, when no echo is generated to form a timing regenerating clock. Moreover, the echo canceller 5 detects an echo component at the consecutive 0 period, that is, when no reception signal exists to cancel the echo. |
