Synchronization switching system

Abstract

Abstract PURPOSE:To minimize the generation of a phase discontinuity in case of switching by monitoring a phase difference of two signals by a phase comparing circuit, and switching a line of a sending end side of a stand-by radio line at the time point when its phase difference becomes some value or below. CONSTITUTION:By a control signal 101, a selecting circuit 13 selects a clock signal in a signal 104b (or 104c,...) of existing radio lines (b), (c),... to be switched, and applies it to a phase comparing circuit 14. The phase comparing circuit 14 compares the phases of a clock signal CLK in a signal 103 of a stand-by radio line (a) with a clock signal CLK of the existing radio line, and at the time point when its phase difference enters into some range determined in advance, a controlling circuit 15 is opened and the controlling signal 101 is applied to a switching circuit 16. As a result, the selected existing radio lines (b) (c,...) are switched to the stand-by radio line (a). Accordingly, the large phase discontinuity is not generated in the signal component of the stand-by radio line, the step-out of a clock and the carrier of a receiving side demodulating circuit can be prevented.

Inventors

• 👤 Kiyoshi Tsuda
• 👤 都田　清志

Bibliographic Details