| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio transmission and reception system capable of discriminating a device failure, etc., of a radio transmitter-receiver, without having to install a dedicated control line. SOLUTION: This radio transmitter/receiver 100 is provided with an ATPC control circuit 11, an automatic power control amplifier 4, an AGC(automatic gain control) control circuit and an RSL detecting part 10. The RSL detecting part 10 is provided with a received signal level detection circuit 10A for always detecting the received signal level of its own station, on the basis of the AGC control voltage of the AGC control circuit 9, and an abnormal state detection circuit 10B for deciding that an abnormal state has occurred, when the attenuation speed (change speed) of its own station detected by the detection circuit 10A surpasses a prescribed change speed and also when the value of the received signal level surpasses a prescribed threshold to output an abnormality detection signal to the ATPC control circuit 11. |
