| 摘要 |
PURPOSE: To provide a receiver for an adaptive differential pulse code modulation system which never causes a 'mistracking' state even when an input signal includes two voices of different frequency levels. CONSTITUTION: This receiver includes an inverse quantize 124 which reproduces a quantized difference signal▵Ej of a receiver 12A from a received signal Nj , an adder 126 which adds the estimation value of the receiver 12A to the signal▵Ej to offer a restored signal X"j , and a receiver estimator means 118 which has a variable estimation coefficient, receives the signal X"j and offers the estimation value of the receiver 12 based on the signal X"j . Then each estimation coefficient is obtained as a nonlinear function based on the past estimation coefficient of the differential signal, i.e., an error▵Ej and with no direct relation with the output of the means 118. |
