| 摘要 |
PURPOSE:To make lead-in in variable speed possible, by applying a test impulse to a cyclic digital filter and by using respective samples of the response signal sequence as initial tap coefficients of a transversal filter type automatic equalizer. CONSTITUTION:Response sequences e0, e1-en for inputting to a unit impulse to a digital filter DF are used as tap coefficient values of a transversal equalizer EQ as they are. That is, since respective tap coefficients of the automatic equalizer EQ are initialized by the output of the cyclic digital filter DF, the coefficients of this equalizer EQ are set to values (approximately reverse characteristic) very near to those for the line state, for example, immediately after power supply only by inputting a test impulse signal to the cyclic filter DF; and therfore, when the actual data transmission is started after that, lead-in is completed in a short time, and a true reverse characteristic is shown to cancel the transmission line characteristic. |
