| 摘要 |
PURPOSE:To reduce the band width of occupied frequency, by transmitting the time of no signal period being interruption of a voice signal through compression. CONSTITUTION:An analog voice signal is converted into a digital signal at an encoiding circuit 13 and inputted to a voice signal presence detecting circuit 14. The detection circuit 14 detects the presence of voice signal at every fixed time and outputs a control signal of ''1'' to terminals 15, 16 with the absence of signal. A switch 21 is controlled with the control signal at the terminal 16 to switch it from the output side of the encoding circuit 13 to the fixed pattern generating circuit 22, and this is connected to the data input side of a memory circuit 19. A signal stored in the memory circuit 19 is read out with a clock from a readout clock generating circuit 23 and outputted to an output terminal 24. In case of interrupted auido, the time of no signal period is compressed and stored in the memory 19, thus the clock frequency can be made smaller by the share. |
