| 摘要 |
PURPOSE:To keep the quality of a voice signal even when multi-stage of relay processing using devices is adopted by inserting a control bit extracted from a reception signal sequentially to a prescribed bit number location assigning a control signal bit of consecutive frames by a prescribed frame number at an equal interval. CONSTITUTION:A switch circuit 14 is in switch connection so as to send a signal to transmission lines 22, 23 and a frame bit is added by frame generating circuits 15,16 of transmission lines 22, 23 and the result is sent respectively to the transmission lines 22, 23. The multi-frame phase in each frame bit is not coincident in the transmission lines 21-23. However, a control signal multiplex circuit 13 gives a control signal to an 8-bit of all frames and the control signal of the transmission frame to be sent to the transmission lines 22, 23 is given to the 8-th bit of 6th and 12th frames. Thus, even when number of relay stages is increased and the bit replacement rate is increased, the voice quality is maintained. |
