CN103516423B - A kind of method and apparatus zoomed out for fiber bit clock - Google Patents
A kind of method and apparatus zoomed out for fiber bit clock Download PDFInfo
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- CN103516423B CN103516423B CN201210204667.4A CN201210204667A CN103516423B CN 103516423 B CN103516423 B CN 103516423B CN 201210204667 A CN201210204667 A CN 201210204667A CN 103516423 B CN103516423 B CN 103516423B
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Abstract
The present invention provides a kind of method and apparatus zoomed out for fiber bit clock, and the method includes：The DVB of distal end clockwork produces PPS pulse signals；PPS pulse-codes framing is sent to near-end clockwork by the framing module of distal end clockwork by optical fiber；Calculate optical-fiber time-delay measured value；Near-end clockwork sends the PPS pulse signals for receiving and the optical-fiber time-delay measured value for being calculated for the first time to clock recovery module and carries out recovering to process to obtain the PPS pulse signal consistent with the PPS pulse signal phase places of DVB output.Methods and apparatus of the present invention can make the clock for recovering have higher precision and reliability, disclosure satisfy that various message send the requirement in real-time in framing, it is prevented effectively from framing complexity, and reduce the use of caching, reduces cost, avoid losing PPS pulse signals, improve system reliability.
Description
Technical field
The present invention relates to the method and dress of time service is zoomed out in wireless communication field, more particularly to base station equipment for clock
Put.
Background technology
In wireless communications, each NB (base station) needs configuration and incoming clock reference source for retention time synchronization, than
More common timing reference input have NB built-in satellite receivers, 1588, and other base cascades clock source and fiber bit clock
The mode such as zoom out.
It is a kind of wherein more important mode that fiber bit clock is zoomed out, and it makes DVB and its antenna separate with NB,
It is middle to be connected using optical fiber so as to can be with long-distance transmissions, while improve the motility of NB layouts.
Fiber bit clock far-drawing system includes distal end clockwork and near-end clockwork two parts, in the clockwork of distal end
DVB is carrying out clock timing (PPS pulses) signal and date-time (Time of are generated after signal is interacted with satellite
Date, TOD) message, and PPS and TOD message is sent to by near-end clockwork by the optical fiber between near-end clockwork.
Near-end clockwork obtains the temporal information with satellite synchronization according to the PPS pulse signals and TOD message that receive.
During the present invention is realized, there is following technical problem in finding prior art in inventor：
In the clockwork of distal end, there are four kinds of message to need encoded and then be sent to near-end clock by optical fiber and set
It is standby, it is PPS pulses and the TOD message of DVB generation, the signaling message that microprocessor is produced, and near-end clock respectively
The return message of the optical-fiber time-delay measurement that equipment is initiated, the return message of wherein PPS pulses and optical-fiber time-delay measurement have higher
Requirement of real-time, can record the time being detained in distal end clockwork when transmission, recover PPS arteries and veins in near-end clockwork
Again these time biass are fallen when rushing, but as compensation is to act on the PPS of next second, if so remembered in distal end clockwork
The holdup time of record is random, is continually changing, then the PPS performances for recovering and precision can be affected, and clock is trembled
It is dynamic also to become big.
Existing optical-fiber time-delay metering system is that near-end clockwork initiates measurement, and distal end clockwork is coordinated, light
After fine link is logical, if measure successfully just will not measure again, unless change occurs in Link State, during measurement, require that near-end clock sets
Standby and distal end clockwork records the time respectively, as both are two different equipment, so work clock has frequency difference, shadow
Clock accuracy is rung, if distal end clockwork does not timely respond to the group of the return message of optical-fiber time-delay measurement when framing is encoded
Frame coding request, can cause optical-fiber time-delay measurement time-out and fail.
Finally, the framing arbitration of distal end clockwork is more complicated, takes compared with multiple resource and easily malfunctions, due to frequency difference
Reason, traditional PPS compensating and restorings technology of near-end occur the situation for losing PPS under minority abnormal conditions, affect whole
The reliability of system.
The content of the invention
To solve technological deficiency described above, the present invention provides a kind of method and apparatus zoomed out for fiber bit clock,
Purpose is to make the clock for recovering have higher precision and reliability, disclosure satisfy that various message send real-time in framing
Property on requirement, be prevented effectively from framing complexity, and reduce the use of caching, reduces cost, it is to avoid lose PPS pulse signals,
Improve system reliability.
For achieving the above object, the present invention takes technical scheme below：
A kind of method zoomed out for fiber bit clock, including：
The DVB of distal end clockwork produces PPS pulse signals；
The PPS pulse-codes framing is sent to near-end clock by the framing module of distal end clockwork by optical fiber
Equipment；
Optical-fiber time-delay measured value is calculated, wherein calculate optical-fiber time-delay measured value including：When distal end clockwork receives near-end
Retransmit to near-end clockwork after the PPS pulse signals beamed back after clock device coding；Near-end clockwork will be received for second
To PPS pulse signals carry out phase demodulation with the PPS pulse signals for receiving for the first time, obtain a phase contrast, phase contrast changed
It is counted as the time and then divided by 2 to obtain optical-fiber time-delay measured value；
The PPS pulse signals and the optical-fiber time-delay measured value for being calculated that first time is received by near-end clockwork sends
Carry out recovering to process to obtain the PPS arteries and veins consistent with the PPS pulse signal phase places of DVB output to clock recovery module
Rush signal.
Preferably, during PPS pulse signals are transmitted between distal end clockwork and near-end clockwork, remote
In the framing scheduling of the framing module of end clockwork, the front 10ms to rear 10ms of DVB PPS pulse signals will be received
Time period be allocated to PPS pulse signals framing coding and use, after the 10ms of DVB PPS pulse signals will be received and
Time period before 600ms is allocated to TOD message framing coding and uses, and the remaining time period is allocated to microprocessor and is sent out
Signaling message is not so that PPS pulse signals are stopped on distal end clockwork and near-end clockwork.
Preferably, when near-end clockwork recovers the PPS pulse signals, using PPS redundancy backup restoration methods, its
Used in active and standby two groups of enumerators, wherein, basic counter work, once noting abnormalities, detects basic counter and does not count full to pre-
Definite value, and next one PPS pulse signals are reached, then standby counter is started working, and now, two groups of enumerators are worked simultaneously, treats
After basic counter meter is completely exported, then stop counting, switch to standby counter, and standby counter then switchs to basic counter.
Preferably, distal end clockwork includes local PPS pulse signals generation module, produced by no DVB
PPS pulse signals in the case of, local PPS pulse signals generation module produces PPS pulse signals and is set with ensureing distal end clock
It is standby unimpeded with the communication of near-end clockwork.
Preferably, start from the DVB acquisition PPS pulse signals of distal end clockwork extensive to near-end clockwork
PPS pulse signal ends of appearing again are executed once per second with real-time update optical-fiber time-delay measured value.
A kind of distal end clockwork zoomed out for fiber bit clock, including：
Signal generating module, for producing PPS pulse signals；
Framing module, for the PPS pulse-codes framing is sent to near-end clockwork by optical fiber；
Sending module, for retransmiting to near-end after the PPS pulse signals beamed back after near-end clockwork is encoded are received
Clockwork；
Scheduler module, for the front 10ms of PPS pulse signals to the time period of rear 10ms is allocated to PPS pulse signal groups
Frame coding is used, and the time period after the 10ms of PPS pulse signals and before 600ms is allocated to TOD message framing coding and is made
With the remaining time period is allocated to microprocessor and is sent out signaling message.
Preferably, also including local PPS pulse signals generation module, in the PPS not having produced by DVB
PPS pulse signals are produced in the case of pulse signal.
A kind of near-end clockwork zoomed out for fiber bit clock, including：
Receiver module, for receiving the PPS pulse signals from distal end clockwork；
Coding module, for being encoded and being retransmited to remote the PPS received from distal end clockwork pulse signals
End clockwork；
Phase demodulation module, for the PPS pulse signals that the PPS for receiving for the second time pulse signals were received with first time are entered
Row phase demodulation, obtains a phase contrast；
Optical-fiber time-delay measurement module, for the phase contrast is converted into the time and then divided by 2 to obtain optical-fiber time-delay measurement
Value；
Sending module, sends out for the PPS pulse signals for receiving first time and the optical-fiber time-delay measured value for being calculated
Delivering to clock recovery module carries out recovery process.
A kind of device zoomed out for fiber bit clock, including aforementioned distal clockwork and near-end clockwork.
Due to taking techniques discussed above scheme, which has advantages below to the present invention：Using a kind of new optical-fiber time-delay
The method of measurement, distal end clockwork and near-end clockwork are sent after PPS pulse signals are received immediately, simple,
The optical-fiber time-delay measured value accuracy of acquisition is high and be real-time update.In PPS pulse signals in distal end clockwork and near-end
During transmitting between clockwork, in the framing scheduling of the framing module of distal end clockwork, distal end clockwork will
The framing request of the various message for needing framing divides the time period according to the requirement of real-time, it is ensured that while real-time, it is ensured that
The same time only responds a kind of framing request, reduces the complexity of scheduling, reduces the cost of distal end clockwork.In near-end
Clock equipment recovers to adopt PPS redundancy backup restoration methods during PPS pulse signals, improves reliability, it is to avoid PPS pulse signals exist
Situation about losing when recovery.
Description of the drawings
Fig. 1 is the distal end clockwork and near-end clockwork schematic diagram according to embodiment of the present invention；
Fig. 2 is optical-fiber time-delay instrumentation plan；
Fig. 3 is the distal end clockwork framing time period to divide schematic diagram；
Fig. 4 is the near-end clockwork framing time period to divide schematic diagram；
Fig. 5 is near-end clockwork PPS pulse signal compensating and restoring process charts.
Specific embodiment
The present invention provides a kind of method and apparatus zoomed out for fiber bit clock, and the device makes what distal end clockwork simplified
Meanwhile, the reliability of equipment is improved, the optical-fiber time-delay in the method and device measures the characteristics of having simple method, high precision,
The clock recovery method of near-end clockwork can improve the reliability of recovery.
As shown in figure 1, fiber bit clock extension apparatus include distal end clockwork and near-end clockwork two parts, both it
Between be connected using optical fiber, distal end clockwork includes DVB, microprocessor, the first framing solution frame module, the first light
Mouth processing module and local PPS pulse signals generation module etc., in the feelings of the PPS pulse signals not having produced by DVB
Under condition, when local PPS pulse signals generation module produces PPS pulse signals to ensure the distal end clockwork with the near-end
Clock device talk is unimpeded.Near-end clockwork includes the second optical port processing module, the second framing solution frame module and PPS pulse signals
Compensating and restoring module.
As shown in Fig. 2 optical-fiber time-delay is measured as measurement in real time, initiated by the PPS pulse signals that DVB is produced, far
Do not stop inside the clockwork of end and send immediately, be designated as PPS1, near-end clockwork is not stopped after receiving and sent back to immediately
Distal end clockwork, is designated as PPS2, and distal end clockwork does not equally do stop after receiving and send back to near-end clockwork, during near-end
After clock equipment is received, PPS pulse signals to receiving twice carry out phase demodulation, just can draw prolonging for PPS pulse signal Jing fiber-optic transfer
When, when the PPS pulse signal compensating and restoring modules that PPS1 and optical-fiber time-delay measured value are sent to rear class just can be drawn with distal end
The consistent PPS pulse signals of PPS pulse signal phase places of the DVB output of clock equipment.Due to satellite reception chance it is per second
One PPS pulse signal of generation, therefore such operation per second, real-time update measured value.
Concrete step is as follows：
A.1, DVB produces PPS pulse signals.
A.2, the framing module of distal end clockwork is encoded framing transmission, and now PPS pulse signals are designated as PPS1.
A.3, the optical port processing module of near-end clockwork is received and obtains PPS1, and then coding sends, and is designated as PPS2.
A.4, distal end clockwork obtains PPS2, and then coding sends PPS2 and is back to near-end clockwork.
A.5, PPS1 and PPS2 is carried out phase demodulation by near-end clockwork, is obtained phase contrast, and then is obtained optical-fiber time-delay measurement
Value.
A.6, PPS1 and optical-fiber time-delay measured value are sent to near-end clockwork the PPS pulse signal compensating and restorings of rear class
Module, obtains the PPS pulse signals with the PPS pulse signal homophases of DVB output.
As shown in Figures 3 and 4, in order to coordinate the requirement of the high real-time of PPS1 and PPS2 transmission, while improving far and near two
The complexity of the framing scheduling of end equipment, especially distal end clockwork, it is to avoid the situation of framing conflict error, to various message
Framing request the time of the time period of 1 second is allocated with the requirement of real-time, the only response phase within the time period of regulation
The message framing request answered, as shown in figure 3, the framing time period for distal end clockwork divides, is exported with DVB
PPS pulse signals are used as benchmark, if DVB does not produce PPS pulse signals under abnormal conditions, with local PPS pulses
The PPS pulse signals that signal generator module is produced are alternatively, the front 10ms and rear 10ms of PPS pulse signals arrival is used as PPS1
The time is sent with the framing of PPS2,600ms afterwards sends the time as the framing of TOD message, and the remaining time period is micro- place
Reason device sends the transmission time of CMD signaling messages.As shown in figure 4, the framing time period for near-end clockwork divides, with from remote
The PPS1 that end time device is received is time reference, and the front 10ms arrived in PPS1 and rear 10ms is that the transmission of PPS2 framings is special
Time period, remaining time are to be sent to CMD_G signaling message of the distal end clockwork respectively to DVB and to micro- place
The CMD_C signaling messages framing of reason device sends the time period.
As shown in figure 5, the flow chart processed for PPS pulse signals compensating and restoring, extensive using PPS pulse signal redundancy backups
Compound recipe method, using active and standby two groups of enumerators, at ordinary times main backoff counter work, once noting abnormalities, detects main compensation and counts
Device is not counted, and next one PPS pulse signals are reached, then start working for backoff counter, now, two groups of countings
Device is worked simultaneously, after treating that main backoff counter meter is completely exported, is then stopped counting, is switched to standby backoff counter, and meter is repaid in the next choice
Number device then switchs to main backoff counter, is so operated in the event of abnormal again, so as to ensure to obtain reliable and stable PPS.
Concrete step is as follows：
C.1 PPS1 pulse signals, have been detected whether.If jumping to C.2, if not jumping to C1.
C.2, main backoff counter is counted, and standby backoff counter is then waited.Jump to C.3.
C.3, judge whether main backoff counter count down to predetermined value, predetermined value=1 second needs count value-compensation to count
Value.If it is jump to C.4, if not then jumping to C.5.
C.4 the PPS pulse signals that main backoff counter is produced are exported,.Jump to C.1.
C.5 PPS1 pulses, have been detected whether, if jumping to C.6, if do not jumped to C.2.
C.6, main backoff counter continues to count, and standby backoff counter is started counting up.Jump to C.7.
C.7, judge whether main backoff counter counts and take predetermined value, jump to C.8.
C.8 the PPS pulse signals that main backoff counter is produced are exported,.Jump to C.9.
C.9, main backoff counter becomes standby counter, and standby backoff counter becomes main backoff counter, jumps to C.2.
Obviously, those skilled in the art deliberately carries out the essence of various changes and modification without deviating from the present invention to the present invention
God and scope.So, if these modifications of the present invention and modification belong to the scope of the claims in the present invention and its equivalent technologies
Within, then the present invention is also intended to comprising these changes and modification.
Claims (8)
1. a kind of method zoomed out for fiber bit clock, including：
The DVB of distal end clockwork produces PPS pulse signals；
The PPS pulse-codes framing is sent to near-end clock by the framing module of the distal end clockwork by optical fiber
Equipment；Characterized in that, also including：
Calculate optical-fiber time-delay measured value；
Wherein described calculating optical-fiber time-delay measured value includes：
Retransmit after the PPS pulse signals that the distal end clockwork is beamed back after receiving near-end clockwork coding to described
Near-end clockwork；The PPS arteries and veins that the PPS pulse signals for receiving for the second time are received by the near-end clockwork with first time
Rushing signal carries out phase demodulation, obtains a phase contrast, and the phase contrast is converted into the time and then divided by 2 to obtain optical-fiber time-delay survey
Value；
The PPS pulse signals and the optical-fiber time-delay measured value for being calculated that first time is received by the near-end clockwork sends
Carry out recovering to process consistent with the PPS pulse signal phase places of DVB output to obtain to clock recovery module
PPS pulse signals；
The distal end clockwork includes local PPS pulse signals generation module, in the PPS arteries and veins not having produced by DVB
In the case of rushing signal, local PPS pulse signals generation module produce PPS pulse signals with ensure the distal end clockwork with
The near-end clockwork communication is unimpeded.
2. the method for zooming out for fiber bit clock as claimed in claim 1, it is characterised in that：Exist in the PPS pulse signals
During transmitting between the distal end clockwork and near-end clockwork, in the framing module of the distal end clockwork
In framing scheduling, the front 10ms for receiving DVB PPS pulse signals is allocated to into PPS pulses to the time period of rear 10ms and is believed
Number framing coding is used, and the time period after receiving the 10ms of DVB PPS pulse signals and before 600ms is allocated to
TOD message framing coding is used, and the remaining time period is allocated to microprocessor and is sent out signaling message so that PPS pulse signals
Do not stop on the distal end clockwork and the near-end clockwork.
3. the method for zooming out for fiber bit clock as claimed in claim 1, it is characterised in that：It is extensive in the near-end clockwork
During the multiple PPS pulse signals, using PPS redundancy backup restoration methods, wherein using active and standby two groups of enumerators, wherein, analytic accounting
Number devices work, once noting abnormalities, detects the basic counter and does not count and completely arrive predetermined value, and next one PPS pulse signals are arrived
Reach, then standby counter is started working, now, two groups of enumerators are worked simultaneously, after treating that the basic counter meter is completely exported, then
Stop counting, switch to standby counter, and the standby counter then switchs to basic counter.
4. the method for zooming out for fiber bit clock as claimed in claim 1, it is characterised in that：From the distal end clockwork
DVB obtain PPS pulse signals start to recover the PPS pulse signal ends to the near-end clockwork it is per second
Perform once with real-time update optical-fiber time-delay measured value.
5. a kind of distal end clockwork zoomed out for fiber bit clock, it is characterised in that include：
Signal generating module, for producing PPS pulse signals；
Framing module, for the PPS pulse-codes framing is sent to near-end clockwork by optical fiber；
Sending module, for retransmiting to the near-end after the PPS pulse signals beamed back after near-end clockwork is encoded are received
Clockwork；
Scheduler module, for the front 10ms of PPS pulse signals to the time period of rear 10ms is allocated to PPS pulse signals framing volume
Code is used, and the time period after the 10ms of PPS pulse signals and before 600ms is allocated to TOD message framing coding and is used, and is remained
The remaining time period is allocated to microprocessor and is sent out signaling message；
The distal end clockwork includes local PPS pulse signals generation module, in the PPS arteries and veins not having produced by DVB
In the case of rushing signal, local PPS pulse signals generation module produce PPS pulse signals with ensure the distal end clockwork with
The near-end clockwork communication is unimpeded.
6. distal end clockwork as claimed in claim 5, it is characterised in that also including local PPS pulse signals generation module,
For PPS pulse signals are produced in the case of the PPS pulse signals not having produced by DVB.
7. a kind of near-end clockwork zoomed out for fiber bit clock, it is characterised in that include：
Receiver module, for receiving the PPS pulse signals from distal end clockwork；
Coding module, for being encoded and being retransmited to described remote the PPS received from distal end clockwork pulse signals
End clockwork；
Phase demodulation module, for the PPS pulse signals that the PPS for receiving for the second time pulse signals were received with first time are reflected
Phase, obtains a phase contrast；
Optical-fiber time-delay measurement module, for the phase contrast is converted into the time and then divided by 2 to obtain optical-fiber time-delay measured value；
Sending module, for by the PPS pulse signals that receive of first time and the optical-fiber time-delay measured value for being calculated send to
Clock recovery module carries out recovery process；
The distal end clockwork includes local PPS pulse signals generation module, in the PPS arteries and veins not having produced by DVB
In the case of rushing signal, local PPS pulse signals generation module produce PPS pulse signals with ensure the distal end clockwork with
The near-end clockwork communication is unimpeded.
8. a kind of device zoomed out for fiber bit clock, it is characterised in that include：
Distal end clockwork as described in claim 5 or 6；And
Near-end clockwork as claimed in claim 7.
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| CN201210204667.4A CN103516423B (en) | 2012-06-20 | 2012-06-20 | A kind of method and apparatus zoomed out for fiber bit clock |
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| CN201210204667.4A CN103516423B (en) | 2012-06-20 | 2012-06-20 | A kind of method and apparatus zoomed out for fiber bit clock |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104244397B (en) * | 2014-08-08 | 2018-11-13 | 厦门雷克通信技术工程有限公司 | A method of it is compensated for TD-LTE fiber optic stretch equipment delays |
| CN107645768B (en) * | 2016-07-20 | 2020-09-25 | 工业和信息化部电信研究院 | Time synchronization method and device for intra-office distribution |
| CN108599843B (en) * | 2018-05-07 | 2021-02-12 | 上海市共进通信技术有限公司 | Function detection control method for supporting output of 1PPS and TOD signals in SFP ONT optical module and host |
| CN108809416B (en) * | 2018-05-28 | 2019-10-18 | 电子科技大学 | A kind of remote base station latency measurement system and method based on short fiber calibration |
| CN112805958B (en) * | 2019-01-18 | 2022-07-29 | 华为技术有限公司 | Time synchronization method and device |
| CN110069011B (en) * | 2019-04-26 | 2021-03-05 | 南京华苏科技有限公司 | BD and GPS-based optical fiber remote centralized time service system and time service method |
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