CN103346852B - A kind of device that reference clock signal is provided - Google Patents

Abstract

The invention discloses a kind of device that reference clock signal is provided, belong to digital dock field.Device comprises: comprise the atomic clock output module for providing atomic clock reference clock signal, described device also comprises: for providing the local clock output module of local reference clock signal; And for from least two clock output modules, select signal that a clock output module provides as reference clock signal, and exporting the reference clock output module of described reference clock signal, described at least two clock output modules comprise described atomic clock output module and described local clock output module; Described atomic clock reference clock signal and described local reference clock signal are setpoint frequency; Described reference clock output module is connected with described atomic clock output module and described local clock output module respectively.The present invention can make reference clock signal continue to export.

Description

A device for providing a reference clock signal

technical field

The invention relates to the field of digital clocks, in particular to a device for providing reference clock signals.

Background technique

With the advancement of SDH (Synchronous Digital Hierarchy, digital synchronization system), the time center can publish the reference clock signal it provides (such as UTC (Coordinated Universal Time, World Standard Time) maintained by the National Time Service Center) to each reference clock signal application point through the time network (such as various application points in time-frequency laboratory and time-frequency system). Each reference clock signal application point adopts the reference clock signal as a reference reference time. In addition, in addition to the reference clock signal provided by the time network, each reference clock signal application point can also use a local reference clock signal, such as a high-frequency crystal oscillator signal, as the reference clock signal.

Each reference clock signal application point obtains the required reference clock signal through the reference clock signal acquisition device. Existing devices for obtaining reference clock signals include devices for obtaining external clock signals, such as GPS (Global Positioning System, Global Positioning System) satellite signal obtaining devices: used to obtain GPS satellite signals and provide them to reference clock signal application points.

In the process of realizing the present invention, the inventor finds that the prior art has at least the following problems: the acquisition device of the existing reference clock signal can only provide a single reference clock signal, for example, the acquisition device of the GPS satellite signal only provides the GPS satellite signal, if If the GPS satellite signal has interference fluctuations, the acquisition device will not be able to provide a continuous reference clock signal, which may affect the operation of the reference clock signal application point. Moreover, a single reference clock signal cannot meet the requirement that the reference clock signal application points need to adopt different reference clock signals in different application occasions.

Contents of the invention

In order to provide a continuous reference clock signal and meet the requirement that reference clock signal application points adopt different reference clock signals in different applications, an embodiment of the present invention provides a device for providing a reference clock signal. Described technical scheme is as follows:

A device for providing a reference clock signal, said device comprising: an atomic clock output module for providing an atomic clock reference clock signal, said device further comprising:

a local clock output module for providing a local reference clock signal; and

A reference clock output module for selecting a signal provided by a clock output module from at least two clock output modules as a reference clock signal and outputting the reference clock signal, the at least two clock output modules including the atomic clock output module and the local clock output module;

Both the atomic clock reference clock signal and the local reference clock signal have a set frequency; the reference clock output module is connected to the atomic clock output module and the local clock output module respectively;

The atomic clock output module includes:

Atomic clocks for providing atomic clock signals;

A first-second pulse generation unit for dividing the atomic clock signal provided by the atomic clock to obtain the atomic clock-second pulse signal;

A global positioning system receiving unit for receiving the second pulse signal of the global positioning system;

A first phase comparison unit for measuring the phase difference between the atomic clock second pulse signal obtained by the first second pulse generating unit and the global positioning system second pulse signal received by the global positioning system receiving unit, and obtaining the measurement result; and

A first processing unit for adjusting the phase of the atomic clock signal provided by the atomic clock according to the measurement result obtained by the first phase comparison unit, and outputting the adjusted atomic clock signal;

The adjusted atomic clock signal output by the first processing unit is the set frequency, the atomic clock is respectively connected to the first second pulse generation unit and the first processing unit, and the first phase comparison unit is respectively connected with the first second pulse generating unit, the global positioning system receiving unit and the first processing unit;

The local clock output module includes:

A local clock generation unit for providing a local clock signal; the local clock generation unit is a voltage-controlled crystal oscillator;

A third second pulse generation unit for dividing the frequency of the local clock signal provided by the local clock generation unit to obtain a local second pulse signal;

A third phase comparison unit for measuring the phase difference between the local second pulse signal obtained by the third second pulse generating unit and the atomic clock second pulse signal obtained by the first second pulse generating unit to obtain a measurement result; and

A third processing unit configured to adjust the phase of the local clock signal provided by the local clock generation unit according to the measurement result obtained by the third phase comparison unit, and output the adjusted local clock signal;

The adjusted local clock signal output by the third processing unit is the set frequency, and the local clock generation unit is respectively connected with the third second pulse generation unit and the third processing unit, and the third The phase comparison unit is respectively connected with the first second pulse generation unit, the third second pulse generation unit and the third processing unit;

The device also includes:

An external clock output module for providing an external reference clock signal, the external reference clock signal being the set frequency;

The reference clock output module includes:

A processor and a selector for outputting a reference clock signal under the control of the processor, the selector includes a control terminal, three input terminals and an output terminal for outputting the reference clock signal, the The three input terminals are respectively connected to the atomic clock output module, the local clock output module and the external clock output module;

The reference clock signal is a signal input from one of the three input terminals.

Optionally, the atomic clock output module also includes:

A second pulse generation unit for dividing the frequency of the external reference clock signal provided by the external clock output module to obtain the second pulse signal of the external clock;

A second phase comparison unit for measuring the phase difference between the atomic clock second pulse signal obtained by the first second pulse generating unit and the external clock second pulse signal obtained by the second second pulse generating unit; and

A second processing unit for adjusting the phase of the atomic clock signal provided by the atomic clock according to the measurement result obtained by the second phase comparison unit, and outputting the adjusted atomic clock signal;

The adjusted atomic signal output by the second processing unit is the set frequency, the second second pulse generation unit is connected to the external clock output module, and the second phase comparison unit is connected to the first The second pulse generation unit, the second second pulse generation unit are connected to the second processing unit, and the atomic clock is connected to the second processing unit.

Preferably, the external clock output module includes:

A counter for receiving an external clock signal and using the local clock signal provided by the local clock generating unit as a reference clock signal to measure the frequency of the external clock signal;

A fourth processing unit for comparing the frequency of the external clock signal measured by the counter with the set frequency, obtaining a comparison result, and generating a control signal according to the comparison result; and

A signal generating unit for adjusting the frequency of the external clock signal to the set frequency according to the control signal generated by the fourth processing unit, and outputting the external clock signal adjusted to the set frequency;

The four processing units are respectively connected to the counter and the signal generating unit.

Preferably, the atomic clock is a rubidium atomic clock.

Preferably, the set frequency is 10MHz.

The beneficial effect brought by the technical solution provided by the embodiment of the present invention is: the local reference clock signal of the set frequency output by the local clock output module or the atomic clock reference clock signal of the set frequency provided by the atomic clock output module are used as The reference clock signal, and output the reference clock signal with a set frequency. On the one hand, it can choose to output either the local reference clock signal or the atomic clock reference clock signal to meet the different requirements of the reference clock signal application point; on the other hand, it can be used as a local When there is a problem with either the reference clock signal or the atomic clock reference clock signal, the other is selected to output, so that the reference clock signal continues to be output, so that the reference clock signal application point operates normally.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

FIG. 1 is a schematic structural diagram of an apparatus for providing a reference clock signal according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another device for providing a reference clock signal provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of another device for providing a reference clock signal provided by an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of another device for providing a reference clock signal provided by an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

In the embodiment of the present invention, a local clock provides a local clock signal, and the local clock includes but is not limited to an atomic clock and a crystal oscillator. An external clock provides an external clock signal, and the external clock includes but is not limited to a backup local clock, which is usually called a local reference source.

Embodiment one

An embodiment of the present invention provides an apparatus for providing a reference clock signal. Referring to FIG. 1 and FIG. 2 , the apparatus includes: an atomic clock output module 101 for providing an atomic clock reference clock signal. The unit also includes:

A local clock output module 102 for providing a local reference clock signal; and, for selecting a signal provided by a clock output module as a reference clock signal from at least two clock output modules, and outputting a reference clock output of the reference clock signal Module 103. The foregoing at least two clock output modules include an atomic clock output module 101 and a local clock output module 102 .

Wherein, both the atomic clock reference clock signal and the local reference clock signal are set frequencies. The reference clock output module 103 is connected to the atomic clock output module 101 and the local clock output module 102 respectively.

Referring to Fig. 2, the atomic clock output module 101 includes:

An atomic clock 1011 for providing an atomic clock signal; for dividing the frequency of the atomic clock signal provided by the atomic clock 1011 to obtain the first second pulse generation unit 1012 of the atomic clock 1pps (1pulse-per-second, second pulse) signal; for receiving the GPS1pps signal GPS receiving unit 1013; The atomic clock 1pps signal that is used for the first second pulse generation unit 1012 and the GPS1pps signal that GPS receiving unit 1013 receives carry out phase difference measurement, obtains the first phase comparison unit 1014 of measurement result; And, for according to the first phase comparison unit 1014 A first processing unit 1015 that adjusts the phase of the atomic clock signal provided by the atomic clock 1011 based on the measurement result obtained by the phase comparison unit 1014 and outputs the adjusted atomic clock signal.

Wherein, the adjusted atomic clock signal output by the first processing unit 1015 is the set frequency. The atomic clock 1011 is connected to the first second pulse generating unit 1012 and the first processing unit 1015 respectively, and the first phase comparison unit 1014 is connected to the first second pulse generating unit 1012, the GPS receiving unit 1013 and the first processing unit 1015 respectively.

Preferably, the atomic clock 1012 may be a rubidium atomic clock.

Specifically, the atomic clock reference clock signal provided by the atomic clock output module 101 is synchronized with the received GPS1pps signal received by the GPS receiving unit 1013, which can improve the accuracy of the atomic clock reference clock signal.

Referring to FIG. 2 again, the local clock output module 102 includes:

The local clock generation unit 1021 for providing the local clock signal; for the frequency division of the local clock signal provided by the local clock generation unit 1021, to obtain the third second pulse generation unit 1022 of the local 1pps signal; for generating the third second pulse The local 1pps signal obtained by the unit 1022 and the atomic clock 1pps signal obtained by the first second pulse generation unit 1012 are measured for phase difference to obtain the third phase comparison unit 1023 of the measurement result; and, for the measurement result obtained by the third phase comparison unit 1023 A third processing unit 1024 that performs phase adjustment on the local clock signal provided by the local clock generation unit 1021 and outputs the adjusted local clock signal.

Wherein, the adjusted local clock signal output by the third processing unit 1024 is the set frequency. The local clock generation unit 1021 is connected with the third second pulse generation unit 1022 and the third processing unit 1024 respectively, and the third phase comparison unit 1023 is respectively connected with the first second pulse generation unit 1012, the third second pulse generation unit 1022 and the third processing unit 1024 connections.

Preferably, the local clock generating unit 1021 may be a voltage-controlled crystal oscillator, such as an oven-controlled crystal oscillator model OSA8607.

Specifically, the local reference clock signal output by the first local clock output module 102 is synchronized with the atomic clock signal generated by the atomic clock 1011, which can improve accuracy.

Preferably, the first processing unit 1015 and the third processing unit 1024 may be microprocessors or microcontrollers. Specifically, the first processing unit 1015 and the third processing unit 1024 may be the same microprocessor or microcontroller.

Preferably, the set frequency may be 10 MHz.

The beneficial effect of the above-mentioned device provided by the embodiment of the present invention is: the local reference clock signal of the set frequency output by the local clock output module or the atomic clock reference clock signal of the set frequency provided by the atomic clock output module are used as the reference clock output module. The reference clock signal, and output the reference clock signal with a set frequency. On the one hand, it can choose to output either the local reference clock signal or the atomic clock reference clock signal to meet the different requirements of the reference clock signal application point; on the other hand, it can be used as a local When there is a problem with either the reference clock signal or the atomic clock reference clock signal, the other is selected to output, so that the reference clock signal continues to be output, so that the reference clock signal application point operates normally.

Further, the atomic clock reference clock signal output by the atomic clock output module is a clock signal synchronized with the GPS1pps signal, which improves the accuracy of the atomic clock reference clock signal; the local reference clock signal output by the local clock output module is a clock signal synchronized with the atomic clock signal , provides the accuracy of the local reference clock signal.

Embodiment two

An embodiment of the present invention provides a device for providing a reference clock signal, and the device includes an atomic clock output module 201 , a local clock output module 202 and a reference clock output module 203 . Wherein, the local clock output module 202 includes a local clock generation unit 2021 , a third second pulse generation unit 2022 , a third phase comparison unit 2023 and a third processing unit 2024 . The structure of the local clock output module 202 is the same as that of the local clock output module 102 described in Embodiment 1 (shown in FIGS. 1 and 2 ), and the description is omitted here. The difference is that (1) the device also includes an external The clock output module 204, (2) describes the structure of the reference clock output module 203, and (3) the structure of the atomic clock output module 201 is different.

Referring to FIG. 3 and FIG. 4 , the device further includes: an external clock output module 204 for providing an external reference clock signal. The external reference clock signal is the set frequency.

Referring to Fig. 3 and Fig. 4 again, the reference clock output module 203 includes:

A processor 2031 and a selector 2032 for outputting a reference clock signal under the control of the processor 2031 . The selector 2032 includes a control terminal C, three input terminals I and an output terminal O for outputting a reference clock signal. The three input terminals I are respectively connected to the atomic clock output module 201 , the local clock output module 202 and the external clock output module 204 . Wherein, the reference clock signal is a signal input from one of the three input terminals I.

Preferably, referring to FIG. 3 and FIG. 4, the external clock output module 204 includes:

For receiving an external clock signal (shown by the arrow in Figure 3 and Figure 4), and using the local clock signal provided by the local clock generation unit 2021 as a reference clock signal, a counter 2041 for measuring the frequency of the external clock signal; for comparing the counter 2041 The measured frequency of the external clock signal is compared with the set frequency to obtain a comparison result, and a fourth processing unit 2042 that generates a control signal according to the comparison result; and is used to convert the external clock signal to The frequency is adjusted to the set frequency, and the signal generating unit 2043 outputs an external clock signal adjusted to the set frequency. Wherein, the fourth processing unit 2042 is connected to the counter 2041 and the signal generating unit 2043 respectively.

Specifically, the external clock signal input to the counter 2042 includes but is not limited to a local reference source.

Preferably, the signal generating unit 2043 may be a DDS (Direct Digital Synthesizer, Direct Digital Synthesizer).

It is worth noting that the external reference clock signal provided by the external clock output module has the following beneficial effects: (1) when abnormal phenomena such as fluctuations occur in the GPS1pps signal, the atomic clock reference clock signal output by the atomic clock output module can also be compared with the external clock output module The external clock signal provided is synchronized to ensure the stability of the signal output by the atomic clock output module; (2) In some special applications, for example, the time of two units (such as A and B) within a short period of time within the application point of the reference clock signal is required Synchronization, then the external signal at unit A (equivalent to the external clock signal provided by the external clock output module) must be introduced into the time system at unit B (equivalent to the local clock signal provided by the local clock output module); (3) need to If the local measuring instrument performs precision testing, then an external signal must be used as the input of the measuring instrument and the reference for homogeneous self-checking.

Referring to FIG. 4 , the atomic clock output module 201 includes an atomic clock 2011 , a first second pulse generation unit 2012 , a GPS receiving unit 2013 , a first phase comparison unit 2014 and a first processing unit 2015 . The structure of the atomic clock 2011, the first second pulse generating unit 2012, the GPS receiving unit 2013, the first phase comparison unit 2014, and the first processing unit 2015 is the same as that of the atomic clock 1011 described in Embodiment 1 (shown in FIGS. 1 and 2 ), The structures of the first second pulse generation unit 1012 , the GPS receiving unit 1013 , the first phase comparison unit 1014 , and the first processing unit 1015 are the same, and the description is omitted here. The atomic clock output module 201 also includes:

Used to divide the external reference clock signal provided by the external clock output module 204 to obtain the second second pulse generation unit 2016 of the external clock 1pps signal; for the atomic clock 1pps signal obtained by the first second pulse generation unit 2012 and the second The external clock 1pps signal obtained by the second pulse generation unit 2016 is used for phase difference measurement to obtain the second phase comparison unit 2017 of the measurement result; phase adjustment, and output the adjusted atomic clock signal to the second processing unit 2018.

Wherein, the adjusted atomic signal output by the second processing unit 2018 is the set frequency. The second second pulse generation unit 2016 is connected with the external clock output module 204, the second phase comparison unit 2017 is respectively connected with the first second pulse generation unit 2012, the second second pulse generation unit 2016 and the second processing unit 2018, and the atomic clock 2011 is connected with the second second pulse generation unit 2018. Two processing units 2018 are connected.

Preferably, the first processing unit 2015, the second processing unit 2018, the third processing unit 2024 or the fourth processing unit 2042 may be a microprocessor or a microcontroller. Specifically, the first processing unit 2015 , the second processing unit 2018 , the third processing unit 2024 and the fourth processing unit 2042 may be the same processor as the processor 2031 .

Preferably, the set frequency may be 10 MHz.

The beneficial effect of the above-mentioned device provided by the embodiment of the present invention is: the local reference clock signal of the set frequency output by the local clock output module or the atomic clock reference clock signal of the set frequency provided by the atomic clock output module are used as the reference clock output module. The reference clock signal, and output the reference clock signal with a set frequency. On the one hand, it can choose to output either the local reference clock signal or the atomic clock reference clock signal to meet the different requirements of the reference clock signal application point; on the other hand, it can be used as a local When there is a problem with either the reference clock signal or the atomic clock reference clock signal, the other is selected to output, so that the reference clock signal continues to be output, so that the reference clock signal application point operates normally.

Further, the atomic clock reference clock signal output by the atomic clock output module is a clock signal synchronized with the GPS1pps signal, which improves the accuracy of the atomic clock reference clock signal; the local reference clock signal output by the local clock output module is a clock signal synchronized with the atomic clock signal , provides the accuracy of the local reference clock signal.

Furthermore, the reference clock output module can also use the local reference clock signal with a set frequency output by the local clock output module, the atomic clock reference clock signal with a set frequency provided by the atomic clock output module, or the external reference clock provided by the external clock output module The signal is used as a reference clock signal and outputs a reference clock signal with a set frequency. Any one of the three reference clock signals can be selected for output, so that the range of reference clock signals that can be selected by the reference clock signal application point is larger, and at the same time, the maximum to ensure continuous output of the reference clock signal.

The serial numbers of the above embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (5)

1. A device that provides a reference clock signal, including an atomic clock output module for providing an atomic clock reference clock signal, is characterized in that the device also includes: a local clock output module for providing a local reference clock signal; and A reference clock output module for selecting a signal provided by a clock output module from at least two clock output modules as a reference clock signal and outputting the reference clock signal, the at least two clock output modules including the atomic clock output module and the local clock output module; Both the atomic clock reference clock signal and the local reference clock signal have a set frequency; the reference clock output module is connected to the atomic clock output module and the local clock output module respectively; The atomic clock output module includes: Atomic clocks for providing atomic clock signals; A first-second pulse generation unit for dividing the atomic clock signal provided by the atomic clock to obtain the atomic clock-second pulse signal; A global positioning system receiving unit for receiving the second pulse signal of the global positioning system; A first phase comparison unit for measuring the phase difference between the atomic clock second pulse signal obtained by the first second pulse generating unit and the global positioning system second pulse signal received by the global positioning system receiving unit, and obtaining the measurement result; and A first processing unit for adjusting the phase of the atomic clock signal provided by the atomic clock according to the measurement result obtained by the first phase comparison unit, and outputting the adjusted atomic clock signal; The adjusted atomic clock signal output by the first processing unit is the set frequency, the atomic clock is respectively connected to the first second pulse generation unit and the first processing unit, and the first phase comparison unit is respectively connected with the first second pulse generating unit, the global positioning system receiving unit and the first processing unit; The local clock output module includes: A local clock generation unit for providing a local clock signal; the local clock generation unit is a voltage-controlled crystal oscillator; A third second pulse generation unit for dividing the frequency of the local clock signal provided by the local clock generation unit to obtain a local second pulse signal; A third phase comparison unit for measuring the phase difference between the local second pulse signal obtained by the third second pulse generating unit and the atomic clock second pulse signal obtained by the first second pulse generating unit to obtain a measurement result; and A third processing unit configured to adjust the phase of the local clock signal provided by the local clock generation unit according to the measurement result obtained by the third phase comparison unit, and output the adjusted local clock signal; The adjusted local clock signal output by the third processing unit is the set frequency, and the local clock generation unit is respectively connected with the third second pulse generation unit and the third processing unit, and the third The phase comparison unit is respectively connected with the first second pulse generation unit, the third second pulse generation unit and the third processing unit; The device also includes: An external clock output module for providing an external reference clock signal, the external reference clock signal being the set frequency; The reference clock output module includes: A processor and a selector for outputting a reference clock signal under the control of the processor, the selector includes a control terminal, three input terminals and an output terminal for outputting the reference clock signal, the The three input terminals are respectively connected to the atomic clock output module, the local clock output module and the external clock output module; The reference clock signal is a signal input from one of the three input terminals. 2. device according to claim 1, is characterized in that, described atomic clock output module also comprises: A second pulse generation unit for dividing the frequency of the external reference clock signal provided by the external clock output module to obtain the second pulse signal of the external clock; A second phase comparison unit for measuring the phase difference between the atomic clock second pulse signal obtained by the first second pulse generating unit and the external clock second pulse signal obtained by the second second pulse generating unit; and A second processing unit for adjusting the phase of the atomic clock signal provided by the atomic clock according to the measurement result obtained by the second phase comparison unit, and outputting the adjusted atomic clock signal; The adjusted atomic signal output by the second processing unit is the set frequency, the second second pulse generation unit is connected to the external clock output module, and the second phase comparison unit is connected to the first The second pulse generation unit, the second second pulse generation unit are connected to the second processing unit, and the atomic clock is connected to the second processing unit. 3. The device according to claim 1 or 2, wherein the external clock output module comprises: A counter for receiving an external clock signal and using the local clock signal provided by the local clock generating unit as a reference clock signal to measure the frequency of the external clock signal; A fourth processing unit for comparing the frequency of the external clock signal measured by the counter with the set frequency, obtaining a comparison result, and generating a control signal according to the comparison result; and A signal generating unit for adjusting the frequency of the external clock signal to the set frequency according to the control signal generated by the fourth processing unit, and outputting the external clock signal adjusted to the set frequency; The four processing units are respectively connected to the counter and the signal generating unit. 4. The device according to claim 1 or 2, wherein the atomic clock is a rubidium atomic clock. 5. The device according to claim 1 or 2, wherein the set frequency is 10 MHz.