| 摘要 |
PURPOSE:To form a stable filter where the loop gain is always constant by providing a tap coefficient control circuit whose output changes with a level of an input signal in an automatic equalizer used for a data communication MODEDM or the like. CONSTITUTION:An automatic equalizer is provided with a control circuit 6 and multipliers 71-n and the output level of the control circuit 6 varies with the quantity of the input signal. For example, when the input signal is larger, the output of the control circuit 6 is decreased and the output is increased when the input signal is small. The output of the control circuit 6 is inputted to the multipliers 71-7n provided to each tape. With the input signal increased, the loop gain is increased and an error signal from a discrimination section 4 is increased. However, since the output of the control circuit 6 is decreased, tap coefficients C1-Cn being outputs of the multipliers 71-7n are decreased to keep the loop gain constant. That is, the loop gain is controlled to be constant by the feed-forward system. |
