ADAPTIVE TYPE ECHO ERASER

摘要

PURPOSE:To set the gain of a two-way amplifier to a value sufficiently higher by providing a filter on a line so as to obtain an echo erasing amount uniform over the entire band. CONSTITUTION:An output signal of a subtractor 17 subtracting a pseudo echo signal from a transmission side input signal led through a line 18A is led as a transmission side output signal through a line 19A. A pseudo echo signal generating circuit 21 produces a pseudo echo signal by using the output signal of the subtractor 17 and the reception side input signal led through a line 11A as input signals and the reception side input signal is led through a line 14A as the reception side output signal. Then a filter 41 having a desired frequency transfer characteristic is provided on the line 11A and the filter 42 having an inverse frequency transfer characteristic to that of the filter 41 is provided on a line 14A respectively, and a filter 43 having the same characteristic as that of the filter 41 is provided on a line 18A and a filter 44 having the same characteristic as the filter 42 is provided on the line 19A respectively.