| 摘要 |
PURPOSE:To increase the frequency division multiple communication system by preventing the transmission frequency from a slave station from disturbing at least the communication of other slave stations in case the detection of the synchronous signal is impossible through the synchronous signal monitor circuit. CONSTITUTION:The slave station gives the sweep change and catch the frequency of the local oscillation frequency to the synchronous signal transmitted from the master station. And in case the synhcronization is obtained, the synchronous signals are detected through synchronous signal monitor circuit 14 and 27 to close switch 15 and 28. While in case no synchronous signal is detected, the sweep changing is discontinued for the frequency of the local oscillation signal. Thus, the frequency of the local oscillation frequency which gives the subordinate control to the transmission frequency is oscillated freely within the frequency region allotted to the slave station so that the frequency of the transmission signal from the slave station may be prevented from disturbing at least the communication of other slave stations. As a result, such fault in that the step-out of one slave station disturbs the communication of other stations can be prevented, thus enhancing the reliability for the frequency division multiple communication system. |
