| 摘要 |
PURPOSE:To correct deterioration in sound quality due to an error of a voice code, by adding a parity check code to the voice code in front of a mixing circuit for the voice code and a data signal and sending them, and detecting an error of voice after separating the data and voice at a reception side. CONSTITUTION:A voice signal from a handset 200 is inputted to a voice analyzing circuit 201, where it is comparessed into a digital code; and it is inputted to a parity adding circuit 202, which adds a parity code and inputs the resulting signal to a buffer circuit 203. A data signal from a data terminal 205 is inputted to a buffer 204. The outputs of the buffers 203 and 204 are constituted into frames and mixed at a section 108, whose output is sent out through a modem. The received mixture signal is inputted to a separating circuit 302 and a frame synchronizing circuit 303 to be separated into the voice code and data signal. The voice code is stored in memories A307 and B308, frame by frame, alternately through a selector 304. At the same time, it is inputted to an error detecting circuit 305 to inhibit the writing and reading of the memories where a frame error is detected and the memory is cleared to zero; and the signals are synthesized at a section 310 and outputted. |
