DIFFERENTIAL PULSE ENCODER

PURPOSE:To confirm whether a regenerative signal value is correct or not by comparing a predictive signal value obtained by adding the value of a differential signal in the past and a transmission predictive signal value from a differential pulse encoder. CONSTITUTION:As for a partial predictive signal outputted from a predicting circuit 21 based on a signal value in the past, the information for showing the logic of a bit at every bit is modulated by a modulating circuit 16 in a prescribed frequency band. Subsequently, the differential value 23 of a signal value 18 obtained by adding this modulating signal value 17 to an input signal value 14 passing through a filter circuit 13 by an adding circuit 15 and a predictive signal value 22 outputted from the predicting circuit 21 is derived by a differential value arithmetic circuit 19, encoded by an encoding circuit 26 and sent out to a transmission line 28. On the other hand, a quantized differential signal 25 is added to the predictive signal 22 of the predicting circuit 22 by an adding circuit 29 and becomes a regenerative signal 31, and the information of the predictive signal value is transmitted to a decoding side. In such a manner, on the decoding side, by comparing this predictive signal value with the predictive signal value from the differential value, whether the decoded signal is correct or not can be confirmed.