Method for implemention of master-spare clock phase alignment in communication equipment

Abstract

A method for phase alignment of active and standby clocks in a communication device, wherein at least one frequency-modulated direct digital frequency synthesizer (DDS) and at least one phase-modulated DDS are respectively arranged on the main clock board and the standby clock board, wherein the frequency-modulated DDS tracks an external clock The reference source synthesizes the frequency required by the output clock, and writes the frequency adjustment word that is the same as the frequency adjustment word of the frequency modulation DDS or has a fixed proportional relationship on the phase modulation DDS, and outputs the clock of the corresponding frequency; The relationship is detected, and the value of the phase register of the phase modulation DDS on the standby clock board is adjusted according to the detection result, and the output phase of the standby clock board is adjusted to align the phases of the main and standby output clocks. The invention improves the precision of the phase alignment, reduces the frequency synchronization requirements of the main and standby clock phase alignment, and improves the reliability of the clock system.

Description

technical field [0001] The invention relates to a digital communication device, in particular to a method for realizing master and backup clock phase alignment in the communication device. Background technique [0002] The clock is a basis for ensuring the operation of digital communication equipment. Almost all digital communication equipment needs to use a special clock supply module to provide a clock for the operation of the entire equipment. The digital synchronization network can provide high-precision and high-stability clock sources for the entire communication network. It belongs to the category of the support network in the telecommunication network and plays a pivotal role in the telecommunication network. BITS (communication building integrated timing supply system) equipment is a special clock supply unit in the digital synchronization network, which can realize clock synchronization of all communication devices connected to the synchronization network through s...

AI Technical Summary

Problems solved by technology

[0017] The technical problem to be solved by the present invention is: to overcome the disadvantages of the existing main and standby clock phase alignment methods that require the main and standby clocks to come from the same frequency source, and the phase alignment accuracy is poor and the backup clock jitter is large, and to provide a communication device. The method of clock phase alignment, thereby improving the accuracy of phase alignment, reducing the frequency synchronization requirements of the main and standby clock phase alignment, and improving the reliability of the clock system

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