| 摘要 |
PURPOSE:To attain automatically the correction of tap coefficient even during communication, by utilizing a coding rule of an AMI signal to detect an isolated wave signal from a random input signal for correcting the tap coefficient and making the amount of correction depending on the amount of equivalent error variable to save the training period. CONSTITUTION:The input signal to a terminal 1 is the AMI signal and even if the isolated wave signal in the random input signal is changed into a consecutive signal of same polarity with the echo component according to the coding rule, the isolated wave signal is detected. A coefficient set circuit 8 discriminates the polarity of an output signal of a synthesis circuit 3, and when the isolated wave signal exists, the tap coefficient is corrected in the same way as the training signal, the amount of equivalent error is discriminated with the comparison with a threshold value, and when the amount of error is large, the amount of correction is increased. The output signal is delayed at delay circuits 4, 5, and the signal is multiplied by the said tap coefficient by coefficient devices 6, 7, and the synthesis between the result of multiplication and the input signal is performed at the synthesis circuit 3, and an equalized output signal is outputted from a terminal 2. |
