| 摘要 |
PURPOSE:To omit the A/D converter of the transmission side by obtaining the transmission signal based on the artificial echo signal and the residual signal and then giving the comparison between the transmission signal and the digital-coded reception signal in order to detect the two-way talking. CONSTITUTION:Both transmission signal y and artificial echo signal y' are led to adder circuit 121 to deliver residual signal e. Signal e is then led to A/D converter 113 to be converted into digital code e' and then led to correction circuit 133 as well as adder circuit 122. Artificial echo signal y'' delivered from adaptive circuit 132 plus residual signal e' are led to adder circuit 122 to deliver transmission signal y'''. Reception signal x is led to A/D converter 114 to be converted into digital code x' and then led to two-way talking detector circuit 131. Thus the two-way talking is detected via signal y''' to give the control to circuit 132. |
