SATELLITE BROADCASTING RECEIVER FOR TRAVELLING OBJECT

摘要

PURPOSE:To eliminate abnormal sound by detecting the state of radio wave at the time interruption by means of a CN ratio and executing muting at a level which is one before reproduction cannot be executed. CONSTITUTION:When a travelling object comes to a city, a ravine or a tunnel and the radio wave of a satellite is interrupted, the CN ratio outputted from AMP 23 becomes low and a signal indicating that the ratio comes to under a threshold voltage being set before sound becomes erroneous is outputted by a CN ratio detecting circuit 24. A controller 25 interlocks the analog mute of a sound output by checking the signal. The reception state of a satellite broadcasting is immediately grasped and noise being the error of PCM data occurred in the neighborhood of a threshold is always eliminated by monitoring the output of AMP 23. Thus, abnormal sound occurred whenever radio wave is interrupted is eliminated so that the satellite broadcasting which is natural without strange feeling is received.