| 摘要 |
PURPOSE:To transmit other signals in an idle time due to time compression of a voice waveform and to transmit plural signals simultaneously in real time without degradation of the quality of voice. CONSTITUTION:The voice output of a four-wire telephone set 21 is supplied to a voice time compressing circuit 31 and is made into a signal of 4k or less Hz by an LPF32 to obtain a voice signal 11. A sampling circuit 33, an encoding circuit 34, a buffer memory 35, a decoding circuit 36, and an LPF37 are used in order for the voice signal 11 to obtain a voice transmission signal 16. Meanwhile, output data 12 from a data terminal 22 is stored temporarily in a buffer memory 39 in a data transmitting circuit 38, and phase information and data 12 are obtained as the output of the buffer memory 39 and have the band limited up to 8k or less Hz by a low- pass filter 41 and are synthesized with the voice transmission signal 16 to obtain a transmission waveform from the terminal, and the transmission waveform is transmitted to a transmission line 24 of subscriber's lines through a hybrid circuit 42. |
