| 摘要 |
PURPOSE:To reduce the audible sense of incompatibility by detecting the level of a noise signal at silence in a received relay channel signal, generating a pseudo noise signal in response to the level and inserting the signal to a receiving output channel not assigned to the relay channel. CONSTITUTION:An assignment missing detecting circuit 7 transmits an assigned missing channel signal 71 to a signal selecting circuit 9 when a relay channel is not assigned to its output channel, and transmits a presence channel signal 72 to a receiving noise level detection circuit 11 when assigned. Further, the circuit 11 measures a signal level of a receiving relay channel signal 61 when signal 72 has a significant signal level, compares this level with a noise deciding threshold value signal 13 from a noise deciding value setting circuit 12, desides a measured value lower than the signal 13 as a noise level and transmits the result to the noise generator 8. Thus, the noise generator 8 generates a pseudo signal having nearly equal pseuto signal to the noise level of the transmission channel of an opposite station, transmits the signal to the circuit 9, and the circuit 9 outputs a receiving output digital sound signal 10. |
