| 摘要 |
PURPOSE:To make automatically the characteristic of an equalizer adaptive to a subscriber line by performing arithmetic such as multiplication and integration or the like of a coefficient to an input signal from a transmission line, adding the results and controlling the coefficient on the basis of the state of an output signal. CONSTITUTION:A subtraction circuit 91 subtracting an output of a delay circuit 20 from an output of the 1st integration circuit 121 is provided and an output of the circuit 91 is fed to a gain coefficient device 31 having a coefficient d0. An output of the coefficient device 31 is fed to the 2nd integration circuit 122, an outut of a multiplier circuit 82 multiplying an integration time T by outputs from the circuit 122 to the circuit 20 is subtracted 92, and then a gain d1 is multiplied by the coefficient device 32. The output is fed to the 3rd integration circuit 123 and also the output of the circuit 92 is inputted to an arithmetic control section 70. The 3rd and succeeding circuits take the constitution equal to the 2nd circuit, and an output of a tap gain coefficient device 34 of the last stage is given to an identification device 50 as an equalizing output. The output of the identification device 50 is extracted externally and also an error to the equalizing output is detected by an error signal detector 60 and coefficients d0, d1... are decided. |
