| 摘要 |
PURPOSE:To attain a satisfactory focusing characteristic and an amount of elimination even to the input signal of the reception side having intensive correlativity such as a sound signal, by using a means which reduces the correlativity of side input signal according to a self-recurrence model or adaptive estimation without increasing substantially the arithmetic amount. CONSTITUTION:An estimated coefficient calculator 26 regards an input signal of the reception side of the prescribed time length as the output signal of an M-degree self-recurrence model and obtains a linear estimating coefficient. An estimating device 27 uses the linear estimating coefficient and the input signal of the reception side to produce the estimated value of said input signal. A subtractor 28 subtracts the estimated value from the input signal of the reception side to obtain a difference signal of the input signal. A register 29 stores this difference signal. In the same way, an estimating device 30 produces the estimated value of output signal of the transmission side. Then a subtractor 31 produces a difference signal of said output signal. A corrector 32 uses the contents of a register 23 storing the estimated impulse reply of an echo path, the contents of the register 29 and the difference signal of the output signal of the transmission side to correct the contents of the register 23, then corrects successively the estimated impulse replies. |
