| 摘要 |
PROBLEM TO BE SOLVED: To properly change a transmission level by predicting a time zone where a noise is produced. SOLUTION: A noise level measurement means 22 measures a noise level for each carrier signal received by a receiver 12 and a multiplexer circuit 10 multiplexes information representing a measurement result of the noise level for each carrier signal by the measurement means 22 on a transmission signal 24 and gives the multiplexed signal to a transmitter 8 with the transmission signal. A control data demultiplexer circuit 14 demultiplexes the noise level information from an output signal of the receiver 12, a noise versus time correlation discrimination means 18 decides whether or not a noise level exceeds a reference level for each carrier signal while referencing time information from a clock means 16 based on the noise level information demultiplexed by the demultiplexer circuit 14 to specify a time zone where the noise level is in excess of the reference level. Then a transmission carrier control means 20 controls a transmitter 8 to increase a transmission level of the carrier signal whose noise level is in excess of the reference value when the time cone specified by the correlation decision means 18 comes round. |
