| 摘要 |
<p>PURPOSE:To surely make the phase of carrier coincident with simple circuit constitution by adding a clock selection circuit to a conventional synchronizing changeover device and using always a clock signal of an active system carrier with excellent line quality as a reference clock of a phase coincidence circuit. CONSTITUTION:A synchronizing changeover device making the phase between plural carriers coincident in the digital radio communication system is provided with a 1st means 100, a 2nd means 200 and a 3rd means 300. The 1st means 100 outputs an alarm when a bit error rate of each carrier exceeds a prescribed value and consists of active system frame synchronizing circuits 3, 4. The 2nd means 200 fetches the clock of each carrier, selects the clock of the carrier without any alarm in response to the alarm from the 1st means 100 and outputs the clock and consists of a clock selection circuit 18. The 3rd means 300 consists of phase coincident circuits 12, 13, which make the phase between plural carriers coincident by using the clock from the 2nd means 200 as a reference clock.</p> |
