CN109257097A - High-precision distribution type fiber-optic wideband frequency transmission system and method - Google Patents
High-precision distribution type fiber-optic wideband frequency transmission system and method Download PDFInfo
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- CN109257097A CN109257097A CN201810767751.4A CN201810767751A CN109257097A CN 109257097 A CN109257097 A CN 109257097A CN 201810767751 A CN201810767751 A CN 201810767751A CN 109257097 A CN109257097 A CN 109257097A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2589—Bidirectional transmission
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
- H04B10/0775—Performance monitoring and measurement of transmission parameters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/61—Coherent receivers
- H04B10/616—Details of the electronic signal processing in coherent optical receivers
- H04B10/6165—Estimation of the phase of the received optical signal, phase error estimation or phase error correction
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Abstract
The present invention relates to optical fiber time frequency transmission technique fields, in particular to a kind of high-precision distribution type fiber-optic wideband frequency transmission system and method, the system comprises broadband frequency sources, central station optical fiber Frequency Transfer unit, N number of subscriber unit, M two-way optical amplification units and distal fiber Frequency Transfer unit, the broadband frequency source is electrically connected with central station optical fiber Frequency Transfer unit, the central station optical fiber Frequency Transfer unit, N number of subscriber unit, M two-way optical amplification units and distal fiber Frequency Transfer unit connect into single fiber bi-directional series via by optical fiber, the central station optical fiber Frequency Transfer unit and distal fiber Frequency Transfer unit are located at the both ends of the single fiber bi-directional series circuit path；For the present invention by the phase information of extraction reference signal, each subscriber unit and the received broadband frequency signals of distal fiber Frequency Transfer unit have the characteristic of phase stabilization, and can keep Phase synchronization.
Description
Technical field
The present invention relates to optical fiber time frequency transmission technique field, in particular to high-precision distribution type fiber-optic wideband frequency passes
Delivery system and method.
Background technique
High-precision Frequency Transfer technology is in satellite navigation, aerospace, deep space exploration, geological mapping, fundamental physical quantity
The fields such as measurement have important application value.Method (Common is regarded altogether currently based on the Frequency Transfer technology of satellite, such as GPS
View, CV), two-way satellite frequency and time transfer (Two-way satellite time and frequency transfer,
TWSTFT), it can achieve 10-15The Frequency Transfer stability of/d magnitude.Although above-mentioned space-based Frequency Transfer technology is mutually treated as
It is ripe, but that there is systems is complicated, expensive, realizes the disadvantages of period is long, safety is poor, poor reliability for their own.In addition,
With the higher performances such as light clock Zhong Yuan invention and put into operation, these technologies have been unable to further satisfaction scientific research and society
The demand that can develop.Optical fiber transmission has low-loss, large capacity, big bandwidth, high speed, high stable, safe and reliable advantage, logical
Letter field, which has been obtained, to be widely applied.Frequency Transfer based on optical fiber is to realize effective way of higher precision Frequency Transfer
Diameter.High-precision optical fiber Frequency Transfer is faced with optical fiber link propagation delay time and becomes with factors such as temperature, stress, vibration and transmission wavelengths
The problem of changing and changing, so that shake and drift occur for transmission frequency signal frequency/phase；In distributed frequency transmission system
In, it also not can guarantee each user node and realize Phase synchronization/consistent frequency signal reception.
Currently, the transmitting of high-precision optical fiber wideband frequency mainly has passive compensation and Active Compensation two ways.Passive compensation
Method utilizes the principle of phase conjugation, can offset the signal frequency of transmission frequency caused by optical fiber link/phase drift, but transmits wide
The loaded wave limitation of band frequency signal bandwidth.Active Compensation method is based on feedback control principle, utilizes tunable optical/electric delay line, wavelength
The compensating modules such as tunable laser, by changing optical fiber link propagation delay time or frequency transmission signal/phase to reach distal end
The purpose of user's reception high-precision frequency signal.
Distributed frequency is transmitted, the method generallyd use is will to cover point-to-point Frequency Transfer system independent operating more
(referring to application No. is CN201711187530.1 and application No. is the patents of CN201711187718.6).As distribution node increases
More, entire distribution transmission system will be more and more huger, and control becomes increasingly complex.
Summary of the invention
In order to realize that high-precision distribution type fiber-optic wideband frequency transmits, it is wide that the present invention provides a kind of high-precision distribution type fiber-optic
Band Frequency Transfer system and method, the system is as shown in Figure 1, include broadband frequency source, central station optical fiber Frequency Transfer unit
1, distal fiber Frequency Transfer unit, M two-way optical amplification units 2 and N number of subscriber unit 3, the broadband frequency source and center
Optical fiber Frequency Transfer of standing unit 1 is electrically connected, the central station optical fiber Frequency Transfer unit 1, N number of subscriber unit 3, M bi-directional light
Amplifying unit and distal fiber Frequency Transfer unit 2 connect into single fiber bi-directional series via, the central station optical fiber by optical fiber
Frequency Transfer unit 1 and distal fiber Frequency Transfer unit 2 are located at the both ends of the single fiber bi-directional series circuit path, the N
A subscriber unit 3, M sequences of the two-way optical amplification unit in the single fiber bi-directional series circuit path are arbitrary；
The central station optical fiber Frequency Transfer unit 1 receives the broadband frequency signals of broadband frequency source output, and sends this
The reference signal generated inside broadband frequency signals and central station optical fiber Frequency Transfer unit 1 is along single fiber bi-directional series via, warp
It crosses N number of subscriber unit 3 and M bidirectional optical amplifier reaches distal fiber Frequency Transfer unit 2；
The distal fiber Frequency Transfer unit 2 receives broadband frequency signals and reference signal, and reference signal is passed through
Distal fiber Frequency Transfer unit is sent, and reference signal is along single fiber bi-directional series via, reverses through N number of subscriber unit 3 and M
A two-way optical amplification unit loops back to central station optical fiber Frequency Transfer unit 1；
The central station optical fiber Frequency Transfer unit 1 receives the reference signal that distal fiber Frequency Transfer unit 2 is sent, and mentions
The phase information between the reference signal and local reference signal is taken, and according to this information stable fiber tunnel time delay, it is real
The wideband frequency high-precision of existing distal fiber Frequency Transfer unit 2 receives；
The subscriber unit 3 passes respectively from central station optical fiber Frequency Transfer unit 1 and distal fiber frequency according to receiving
The phase information between the reference signal of the transmission of unit 2 is passed, and broadband frequency signals are compensated according to this information, realizes N
The wideband frequency high-precision of a subscriber unit 3 receives.
Preferably, the subscriber unit 3 and central station optical fiber Frequency Transfer unit 1 are according between the reference signal received
Phase information broadband frequency signals are compensated, realize that N number of subscriber unit 3 and distal fiber Frequency Transfer unit 2 receive
The phase of broadband frequency signals is consistent.
Preferably, before the transmission direction from central station optical fiber Frequency Transfer unit 1 to distal fiber Frequency Transfer unit 2 is
To transmission；It is reverse transfers from distal fiber Frequency Transfer unit 2 to the transmission direction of central station optical fiber Frequency Transfer unit 1.
Preferably, central station optical fiber Frequency Transfer unit 1 includes the first light hair module 1-1, the second light hair module 1-2, the
One Wavelength division multiplexing module 1-3, first phase compensating module 1-4, reference frequency source 1-5, first phase detection module 1-6, first
Processing and control module 1-7 and the first light receive module 1-8；Wherein
The derived reference signal 1-5 sends out module 1-1 and first phase detection module 1-6 for the first light and provides reference signal,
Reference signal is for perceiving optical fiber link Delay Variation；
The first light hair module 1-1 carries out electro-optic conversion to reference signal, and is transmitted to the first Wavelength division multiplexing module 1-
3；
The second light hair module 1-2 carries out electro-optic conversion to broadband frequency signals, and exports to the first wavelength-division multiplex mould
Block 1-3；
The first Wavelength division multiplexing module 1-3 will send out the light that module 1-1 and the second light hair module 1-2 are received from the first light
Signal multiplexing is into an optical fiber, and by the optical signal transmission of multiplexing to first phase compensating module 1-4；It simultaneously will be from the first phase
The optical signal that position compensating module 1-4 is received is sent to the first light after being demultiplexed and receives module 1-8；
First light receive module 1-8 by from the backward reference signal that distal fiber Frequency Transfer unit 2 inversely returns into
Row photoelectric conversion, and input first phase detection module 1-6；
The signal received from the first Wavelength division multiplexing module 1-3 is transmitted to optical fiber by the first phase compensating module 1-4
Link；And phase compensation is carried out to the signal received according to the control signal of the first processing and control module 1-7；
The first phase detection module 1-6 is mentioned according to the phase information between local reference signal and backward reference signal
The Delay of optical fiber link is taken out, and inputs the first processing and control module 1-7；
The first processing and control module 1-7 is according to the input of first phase detection module 1-6, and output is for stable fiber
The control signal of chain circuit transmission time delay is to first phase compensating module 1-4.
Preferably, distal fiber Frequency Transfer unit 2 include the second Wavelength division multiplexing module 2-1, third light receive module 2-2,
4th light receives module 2-3, signal processing module 2-4 and the 4th light and sends out module 2-5；Wherein
The second Wavelength division multiplexing module 2-1 by from optical fiber link broadband frequency signals and reference signal give respectively
Enter third light and receives module 2-2 and the 4th light receipts module 2-3；Loop back reference signal from the 4th light hair module 2-5 is sent into light
Fine link；
The third light receives module 2-2 and carries out photoelectric conversion to broadband frequency signals, and exports and give distal fiber frequency
The user that transfer unit 2 connects；
4th light receives module 2-3 and carries out photoelectric conversion to reference signal, and is transmitted to signal processing module 2-4；
The signal processing module 2-4 receives the reference signal that module 2-3 is received from the 4th light, and is sent to the 4th light hair
Module 2-5；
The 4th light hair module 2-5 will input the second wavelength-division multiplex from the reference signal of signal processing module 2-4
Module 2-1.
Preferably, each subscriber unit 3 includes 2 × 2 optical splitter 3-1, third Wavelength division multiplexing module 3-2, the 4th wavelength-division
Multiplexing module 3-3, the first photoelectric conversion module 3-4, the second photoelectric conversion module 3-5, third photoelectric conversion module 3-6, second
Phase detecting module 3-7, second processing control module 3-8 and second phase compensating module 3-9；Wherein
2 × 2 optical splitter 3-1 includes four ports, and port 1 and port 2 are inputted with the forward direction of optical fibre channel respectively
Port is connected with backward input port, and port 3 inputs third Wavelength division multiplexing module to reference signal and broadband frequency signals for preceding
3-2, port 4 input the 4th Wavelength division multiplexing module 3-3 to reference signal by after；
The first photoelectric conversion module 3-4 and the second photoelectric conversion module 3-5 is respectively to rear to reference signal and forward direction
Reference signal carries out photoelectric conversion, and is transferred to second phase detection module 3-7；
The second phase detection module 3-7 is according to the reference signal of fl transmission and the reference signal detecting of reverse transfers
Optical fiber link Delay, and Delay is transferred to second processing control module 3-8；
The second processing control module 3-8 exports control signal according to Delay and controls second phase compensating module 3-
9；
The second phase compensating module 3-9 receives broadband frequency signals from third Wavelength division multiplexing module 3-2, and to broadband
Frequency signal carries out phase compensation, and exports through third photoelectric conversion module 3-6 to local user.
By the phase information of extraction reference signal, each subscriber unit and distal fiber Frequency Transfer unit connect the present invention
The broadband frequency signals of receipts have the characteristic of phase stabilization；Particularly, respectively output broadband frequency signals can keep Phase synchronization.
With increasing for distribution node, it is bulky, control complexity that the invention avoids central station optical fiber Frequency Transfer cellular systems
Disadvantage；The deficiency of optical fiber link transmitting optical power excessive attenuation is overcome also through two-way optical amplification unit.
Detailed description of the invention
Fig. 1 is specific embodiment of the invention structural schematic diagram；
Fig. 2 is specific embodiment of the invention central station optical fiber Frequency Transfer cellular construction schematic diagram；
Fig. 3 is specific embodiment of the invention distal fiber Frequency Transfer cellular construction schematic diagram；
Fig. 4 is specific embodiment of the invention subscriber unit structural schematic diagram；
Wherein, 1, central station optical fiber Frequency Transfer unit, 1-1, the first light hair module, 1-2, the second light hair module, 1-3,
First Wavelength division multiplexing module, 1-4, first phase compensating module, 1-5, reference frequency source, 1-6, first phase detection module, 1-
7, the first processing and control module, 1-8, the first light receive module；2, distal fiber Frequency Transfer unit, 2-1, the second wavelength-division multiplex mould
Block, 2-2, third light receive module, and 2-3, the 4th light receive module, 2-4, signal processing module, and 2-5, the 4th light send out module；3, user
Unit, 3-1,2 × 2 optical splitters, 3-2, third Wavelength division multiplexing module, 3-3, the 4th Wavelength division multiplexing module, 3-4, the first photoelectricity
Conversion module, 3-5, the second photoelectric conversion module, 3-6, third photoelectric conversion module, 3-7, second phase detection module, 3-8,
Second processing control module, 3-9, second phase compensating module.
Specific embodiment
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, right below in conjunction with attached drawing
Technical solution in the embodiment of the present invention is clearly and completely described, and described embodiment is only that a part of the invention is real
Example is applied, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art are not paying creativeness
Every other embodiment obtained, shall fall within the protection scope of the present invention under the premise of labour.
In order to realize that high-precision distribution type fiber-optic wideband frequency transmits, it is wide that the present invention provides a kind of high-precision distribution type fiber-optic
Band Frequency Transfer system and method, the system is as shown in Figure 1, include broadband frequency source, central station optical fiber Frequency Transfer unit
1, N number of subscriber unit 3, M two-way optical amplification units and distal fiber Frequency Transfer unit 2, the broadband frequency source and center
Optical fiber Frequency Transfer of standing unit 1 is electrically connected, the central station optical fiber Frequency Transfer unit 1, N number of subscriber unit 3, M bi-directional light
Amplifying unit and distal fiber Frequency Transfer unit 2 connect into single fiber bi-directional series via, the central station optical fiber by optical fiber
Frequency Transfer unit 1 and distal fiber Frequency Transfer unit 2 are located at the both ends of the single fiber bi-directional series circuit path, the N
A subscriber unit 3, M sequences of the two-way optical amplification unit in the single fiber bi-directional series circuit path are arbitrary；
The central station optical fiber Frequency Transfer unit 1 receives the broadband frequency signals of broadband frequency source output, and sends this
The reference signal generated inside broadband frequency signals and central station optical fiber Frequency Transfer unit 1 is along single fiber bi-directional series via, warp
It crosses N number of subscriber unit 3 and M bidirectional optical amplifier reaches distal fiber Frequency Transfer unit 2；
The distal fiber Frequency Transfer unit 2 receives broadband frequency signals and reference signal, and reference signal is passed through
Distal fiber Frequency Transfer unit is sent, and reference signal is along single fiber bi-directional series via, reverses through N number of subscriber unit 3 and M
A two-way optical amplification unit loops back to central station optical fiber Frequency Transfer unit 1；
The central station optical fiber Frequency Transfer unit 1 receives the reference signal that distal fiber Frequency Transfer unit 2 is sent, and mentions
The phase information between the reference signal and local reference signal is taken, and according to this information stable fiber tunnel time delay, it is real
The wideband frequency high-precision of existing distal fiber Frequency Transfer unit 2 receives；
The subscriber unit 3 passes respectively from central station optical fiber Frequency Transfer unit 1 and distal fiber frequency according to receiving
The phase information between the reference signal of the transmission of unit 2 is passed, and broadband frequency signals are compensated according to this information, realizes N
The wideband frequency high-precision of a subscriber unit 3 receives.
Preferably, the subscriber unit 3 and central station optical fiber Frequency Transfer unit 1 are according between the reference signal received
Phase information broadband frequency signals are compensated, realize that N number of subscriber unit 3 and distal fiber Frequency Transfer unit 2 receive
The phase of broadband frequency signals is consistent.
Preferably, before the transmission direction from central station optical fiber Frequency Transfer unit 1 to distal fiber Frequency Transfer unit 2 is
To transmission；It is reverse transfers from distal fiber Frequency Transfer unit 2 to the transmission direction of central station optical fiber Frequency Transfer unit 1.
Preferably, such as Fig. 2, central station optical fiber Frequency Transfer unit 1 includes the first light hair module 1-1, the second light hair module
1-2, the first Wavelength division multiplexing module 1-3, first phase compensating module 1-4, reference frequency source 1-5, first phase detection module 1-
6, the first processing and control module 1-7 and the first light receive module 1-8；Wherein
The derived reference signal 1-5 sends out module 1-1 and first phase detection module 1-6 for the first light and provides reference signal,
Reference signal is for perceiving optical fiber link Delay Variation；
The first light hair module 1-1 carries out electro-optic conversion to reference signal, and is transmitted to the first Wavelength division multiplexing module 1-
3；
The second light hair module 1-2 carries out electro-optic conversion to broadband frequency signals, and exports to the first wavelength-division multiplex mould
Block 1-3；
The first Wavelength division multiplexing module 1-3 will send out the light that module 1-1 and the second light hair module 1-2 are received from the first light
Signal multiplexing is into an optical fiber, and by the optical signal transmission of multiplexing to first phase compensating module 1-4；It simultaneously will be from the first phase
The optical signal that position compensating module 1-4 is received is sent to the first light after being demultiplexed and receives module 1-8；
First light receive module 1-8 by from the backward reference signal that distal fiber Frequency Transfer unit 2 inversely returns into
Row photoelectric conversion, and input first phase detection module 1-6；
The signal received from the first Wavelength division multiplexing module 1-3 is transmitted to optical fiber by the first phase compensating module 1-4
Link；And phase compensation is carried out to the signal received according to the control signal of the first processing and control module 1-7；
The first phase detection module 1-6 is mentioned according to the phase information between local reference signal and backward reference signal
The Delay of optical fiber link is taken out, and inputs the first processing and control module 1-7；
The first processing and control module 1-7 is according to the input of first phase detection module 1-6, and output is for stable fiber
The control signal of chain circuit transmission time delay is to first phase compensating module 1-4.
Such as Fig. 3, distal fiber Frequency Transfer unit 2 includes that the second Wavelength division multiplexing module 2-1, third light receive module 2-2, the
Four light receive module 2-3, signal processing module 2-4 and the 4th light and send out module 2-5；Wherein
The second Wavelength division multiplexing module 2-1 by from optical fiber link broadband frequency signals and reference signal give respectively
Enter third light and receives module 2-2 and the 4th light receipts module 2-3；Loop back reference signal from the 4th light hair module 2-5 is sent into light
Fine link；
The third light receives module 2-2 and carries out photoelectric conversion to broadband frequency signals, and exports and give distal fiber frequency
The user that transfer unit 2 connects；
4th light receives module 2-3 and carries out photoelectric conversion to reference signal, and is transmitted to signal processing module 2-4；
The signal processing module 2-4 receives the reference signal that module 2-3 is received from the 4th light, and is sent to the 4th light hair
Module 2-5；
The 4th light hair module 2-5 will input the second wavelength-division multiplex from the reference signal of signal processing module 2-4
Module 2-1.
Such as Fig. 4, each subscriber unit 3 is answered including 2 × 2 optical splitter 3-1, third Wavelength division multiplexing module 3-2, the 4th wavelength-division
With module 3-3, the first photoelectric conversion module 3-4, the second photoelectric conversion module 3-5, third photoelectric conversion module 3-6, the second phase
Position detection module 3-7, second processing control module 3-8 and second phase compensating module 3-9；Wherein
2 × 2 optical splitter 3-1 includes four ports, and port 1 and port 2 are inputted with the forward direction of optical fibre channel respectively
Port is connected with backward input port, and port 3 inputs third Wavelength division multiplexing module to reference signal and broadband frequency signals for preceding
3-2, port 4 input the 4th Wavelength division multiplexing module 3-3 to reference signal by after；
The first photoelectric conversion module 3-4 and the second photoelectric conversion module 3-5 is respectively to rear to reference signal and forward direction
Reference signal carries out photoelectric conversion, and is transferred to second phase detection module 3-7；
The second phase detection module 3-7 is according to the reference signal of fl transmission and the reference signal detecting of reverse transfers
Optical fiber link Delay, and Delay is transferred to second processing control module 3-8；
The second processing control module 3-8 exports control signal according to Delay and controls second phase compensating module 3-
9；
The second phase compensating module 3-9 receives broadband frequency signals from third Wavelength division multiplexing module 3-2, and to broadband
Frequency signal carries out phase compensation, and exports through third photoelectric conversion module 3-6 to local user.
The present invention also provides a kind of high-precision distribution type fiber-optic wideband frequency transmission methods, comprising the following steps:
S1, broadband frequency source are by broadband frequency signals input center station optical fiber Frequency Transfer unit, central station optical fiber frequency
Transfer unit is respectively by the reference of the reference frequency source output inside broadband frequency signals and central station optical fiber Frequency Transfer unit
Signal carries out electro-optic conversion, and through wavelength-division multiplex and phase compensation input optical fibre link；
The reference signal of reference frequency source output can be expressed asWherein ω is the frequency of reference signal
Rate,For initial phase；
S2, i-th (i=1,2 ..., N) a subscriber unit: extract the broadband frequency signals and reference signal of fl transmission,
And photoelectric conversion is carried out respectively；
The reference signal of the received fl transmission of i-th of subscriber unit is expressed as:Wherein
τLUFor the optical fiber link propagation delay time from central station optical fiber Frequency Transfer unit to the i-th subscriber unit；
S3, jth (j=1,2 ..., M) a two-way optical amplification unit: carry out light amplification to the signal of transmitting to preceding；
S4, distal fiber Frequency Transfer unit extract width from the optical signal that central station optical fiber Frequency Transfer unit is sent
Band frequency signal, and export the user for giving the connection of distal fiber Frequency Transfer unit；Meanwhile from central station optical fiber Frequency Transfer
Reference signal is extracted in the optical signal that unit is sent, and is successively sent through photoelectric conversion, signal processing and electro-optic conversion process
Give central station optical fiber Frequency Transfer unit；
The reference signal that distal fiber Frequency Transfer unit receives is expressed as:Wherein
τLRFor from central station optical fiber Frequency Transfer unit to the optical fiber link propagation delay time of distal fiber Frequency Transfer unit；
S5, i-th (i=1,2 ..., N) a subscriber unit: extract the reference signal of reverse transfers, and carry out wavelength-division multiplex,
Photoelectric conversion；
The reference signal for the reverse transfers that i-th of subscriber unit extracts is expressed as:
Wherein τRUFor the optical fiber link propagation delay time from distal fiber Frequency Transfer unit to the i-th subscriber unit；
S6, jth (j=1,2 ..., M) a two-way optical amplification unit: carry out light amplification to the signal of transmitting to rear；
S7, central station optical fiber Frequency Transfer unit receive the reference signal from distal fiber Frequency Transfer unit loopback,
The reference signal after photoelectric conversion and locally sent is compared, and is extracted from central station optical fiber Frequency Transfer unit to distal end light
The optical fiber link Delay of fine Frequency Transfer unit, central station optical fiber Frequency Transfer unit control phase compensation according to formula (1)
Module is with stable fiber chain circuit transmission time delay, so that the wideband frequency letter that distal fiber Frequency Transfer unit output phase is stable
Number；Wherein formula (1) indicates are as follows:
τLR+τRL=c (2)
Wherein, c is constant；
Central station optical fiber Frequency Transfer unit receives the reference signal from distal fiber Frequency Transfer unit loopback and indicates
Are as follows:Wherein τRLTo be passed from distal fiber Frequency Transfer unit to central station optical fiber frequency
Pass the optical fiber link propagation delay time of unit；
S8, under the premise of central station optical fiber frequency cells stable fiber chain circuit transmission time delay, based on the received forward direction and
Backward reference signal, the broadband frequency signals that i-th of subscriber unit control phase compensation block makes output phase stable.
Preferably, when the offset of the second phase compensating module of subscriber unit passes for subscriber unit to distal fiber frequency
Pass the optical fiber link propagation delay time τ between unitRUWhen, realize what distal fiber Frequency Transfer unit and each subscriber unit exported
Broadband frequency signals Phase synchronization.
In addition, term " first ", " second ", " third ", " the 4th " are used for description purposes only, and should not be understood as instruction or
It implies relative importance or implicitly indicates the quantity of indicated technical characteristic, define " first ", " second ", " the as a result,
Three ", the feature of " the 4th " can explicitly or implicitly include at least one of the features, and should not be understood as to limit of the invention
System.
Embodiment provided above has carried out further detailed description, institute to the object, technical solutions and advantages of the present invention
It should be understood that embodiment provided above is only the preferred embodiment of the present invention, be not intended to limit the invention, it is all
Any modification, equivalent substitution, improvement and etc. made for the present invention, should be included in the present invention within the spirit and principles in the present invention
Protection scope within.
Claims (7)
1. high-precision distribution type fiber-optic wideband frequency transmission system, which is characterized in that including broadband frequency source, central station optical fiber frequency
Rate transfer unit (1), distal fiber Frequency Transfer unit (2), M two-way optical amplification units and N number of subscriber unit (3), it is described
Broadband frequency source is electrically connected with central station optical fiber Frequency Transfer unit (1), the central station optical fiber Frequency Transfer unit (1), N number of
Subscriber unit (3), M two-way optical amplification units and distal fiber Frequency Transfer unit (2) connect into single fiber bi-directional by optical fiber
Series via, the central station optical fiber Frequency Transfer unit (1) and distal fiber Frequency Transfer unit (2) are located at the single fiber
The both ends of two-way series circuit path, N number of subscriber unit (3), M two-way optical amplification units are in the single fiber bi-directional series circuit path
Sequence be arbitrary；
The central station optical fiber Frequency Transfer unit (1) receives the broadband frequency signals of broadband frequency source output, and sends this width
With the reference signal generated inside frequency signal and central station optical fiber Frequency Transfer unit (1), along single fiber bi-directional series via,
Distal fiber Frequency Transfer unit (3) are reached by N number of subscriber unit (3) and M two-way optical amplification units；
The distal fiber Frequency Transfer unit (2) receives broadband frequency signals and reference signal, and reference signal is passed through far
Optical fiber Frequency Transfer unit is held to send, reference signal is along single fiber bi-directional series via, reverses through N number of subscriber unit (3) and M
A two-way optical amplification unit loops back to central station optical fiber Frequency Transfer unit (1)；
The central station optical fiber Frequency Transfer unit (1) receives the reference signal that distal fiber Frequency Transfer unit (2) are sent, and mentions
The phase information between the reference signal and local reference signal is taken, and according to this information stable fiber tunnel time delay, it is real
The wideband frequency high-precision of existing distal fiber Frequency Transfer unit (2) receives；
Subscriber unit (3) basis receives to be passed from central station optical fiber Frequency Transfer unit (1) and distal fiber frequency respectively
The phase information between the reference signal of unit (2) transmission is passed, and broadband frequency signals are compensated according to this information, is realized
The wideband frequency high-precision of N number of subscriber unit (3) receives.
2. high-precision distribution type fiber-optic wideband frequency transmission system according to claim 1, which is characterized in that the user
Unit (3) and central station optical fiber Frequency Transfer unit (1) according to the phase information between reference signal to broadband frequency signals into
Row compensation realizes that N number of subscriber unit (3) is consistent with distal fiber Frequency Transfer unit (2) the reception phase of broadband frequency signals.
3. high-precision distribution type fiber-optic wideband frequency transmission system according to claim 1, which is characterized in that central station light
Fine Frequency Transfer unit (1) includes the first light hair module (1-1), the second light hair module (1-2), the first Wavelength division multiplexing module (1-
3), first phase compensating module (1-4), reference frequency source (1-5), first phase detection module (1-6), the first processing control mould
Block (1-7) and the first light receive module (1-8)；Wherein
The derived reference signal (1-5) is that the first light sends out module (1-1) and first phase detection module (1-6) is provided with reference to letter
Number, reference signal is for perceiving optical fiber link Delay Variation；
First light hair module (1-1) carries out electro-optic conversion to reference signal, and is transmitted to the first Wavelength division multiplexing module (1-
3)；
Second light hair module (1-2) carries out electro-optic conversion to broadband frequency signals, and exports to the first Wavelength division multiplexing module
(1-3)；
What first Wavelength division multiplexing module (1-3) will receive from the first light hair module (1-1) and the second light hair module (1-2)
Optical signal is multiplexed into an optical fiber, and by the optical signal transmission of multiplexing to first phase compensating module (1-4)；It simultaneously will be from the
The optical signal that one phase compensation block (1-4) receives is sent to the first light and receives module (1-8) after being demultiplexed；
First light receive module (1-8) will from the backward reference signal that distal fiber Frequency Transfer unit (2) inversely returns into
Row photoelectric conversion, and input first phase detection module (1-6)；
The signal received from the first Wavelength division multiplexing module (1-3) is transmitted to optical fiber by the first phase compensating module (1-4)
Link；And phase compensation is carried out to the signal received according to the control signal of the first processing and control module (1-7)；
The first phase detection module (1-6) is extracted according to the phase information between local reference signal and backward reference signal
The Delay of optical fiber link out, and input the first processing and control module (1-7)；
First processing and control module (1-7) is according to the input of first phase detection module (1-6), and output is for stable fiber
The control signal of chain circuit transmission time delay is to first phase compensating module (1-4).
4. high-precision distribution type fiber-optic wideband frequency transmission system according to claim 1, which is characterized in that distal fiber
Frequency Transfer unit (2) include the second Wavelength division multiplexing module (2-1), third light receive module (2-2), the 4th light receive module (2-3),
Signal processing module (2-4) and the 4th light hair module (2-5)；Wherein
Second Wavelength division multiplexing module (2-1) by from optical fiber link broadband frequency signals and reference signal be respectively fed to
Third light receives module (2-2) and the 4th light receives module (2-3)；Loop back reference signal from the 4th light hair module (2-5) is sent
Enter optical fiber link；
The third light receives module (2-2) and carries out photoelectric conversion to broadband frequency signals, and exports and give distal fiber frequency biography
Pass the user of unit (2) connection；
4th light receives module (2-3) and carries out photoelectric conversion to reference signal, and is transmitted to signal processing module (2-4)；
The signal processing module (2-4) receives the reference signal that module (2-3) is received from the 4th light, and is sent to the 4th light hair
Module (2-5)；
4th light hair module (2-5) will input the second wavelength-division multiplex from the reference signal of signal processing module (2-4)
Module (2-1).
5. high-precision distribution type fiber-optic wideband frequency transmission system according to claim 1, which is characterized in that each user
Unit (3) includes 2 × 2 optical splitters (3-1), third Wavelength division multiplexing module (3-2), the 4th Wavelength division multiplexing module (3-3), first
Photoelectric conversion module (3-4), the second photoelectric conversion module (3-5), third photoelectric conversion module (3-6), second phase detect mould
Block (3-7), second processing control module (3-8) and second phase compensating module (3-9)；Wherein
2 × 2 optical splitter (3-1) includes four ports, port 1 and port 2 respectively with the forward direction input terminal of optical fibre channel
Mouth is connected with backward input port, and port 3 inputs third Wavelength division multiplexing module (3- to reference signal and broadband frequency signals for preceding
2), port 4 inputs the 4th Wavelength division multiplexing module (3-2) to reference signal by after；
First photoelectric conversion module (3-4) and the second photoelectric conversion module (3-5) are respectively to rear to reference signal and forward direction
Reference signal carries out photoelectric conversion, and is transferred to second phase detection module (3-7)；
The second phase detection module (3-7) is according to the reference signal of fl transmission and the reference signal detecting light of reverse transfers
Fine chain-circuit time delay information, and Delay is transferred to second processing control module (3-8)；
The second processing control module (3-8) exports control signal according to Delay and controls second phase compensating module (3-
9)；
The second phase compensating module (3-9) receives broadband frequency signals from third Wavelength division multiplexing module (3-2), and to broadband
Frequency signal carries out phase compensation, and exports through third photoelectric conversion module (3-6) to local user.
6. high-precision distribution type fiber-optic wideband frequency transmission method, distributed including any high-precision of claim 1-5
Fiber broadband Frequency Transfer system characterized by comprising
S1, broadband frequency source are by broadband frequency signals input center station optical fiber Frequency Transfer unit, central station optical fiber Frequency Transfer
Unit is respectively by the reference signal of the reference frequency source output inside broadband frequency signals and central station optical fiber Frequency Transfer unit
Electro-optic conversion is carried out, and through wavelength-division multiplex and phase compensation input optical fibre link；
The reference signal of reference frequency source output can be expressed asWherein ω is the frequency of reference signal,
For initial phase；
S2, i-th (i=1,2 ..., N) a subscriber unit: extract the broadband frequency signals and reference signal of fl transmission, and point
It carry out not photoelectric conversion；
The reference signal of the received fl transmission of i-th of subscriber unit is expressed as:Wherein τLUFor
From central station optical fiber Frequency Transfer unit to the optical fiber link propagation delay time of the i-th subscriber unit；
S3, jth (j=1,2 ..., M) a two-way optical amplification unit: carry out light amplification to the signal of transmitting to preceding；
S4, distal fiber Frequency Transfer unit extract broadband frequency from the optical signal that central station optical fiber Frequency Transfer unit is sent
Rate signal, and export the user for giving the connection of distal fiber Frequency Transfer unit；Meanwhile from central station optical fiber Frequency Transfer unit
Reference signal is extracted in the optical signal of transmission, and successively through photoelectric conversion, signal processing and electro-optic conversion process, be sent to
Center station optical fiber Frequency Transfer unit；
The reference signal that distal fiber Frequency Transfer unit receives is expressed as:Wherein τLRFor from
Optical fiber link propagation delay time of the central station optical fiber Frequency Transfer unit to distal fiber Frequency Transfer unit；
S5, i-th (i=1,2 ..., N) a subscriber unit: extract the reference signal of reverse transfers, and carry out wavelength-division multiplex, photoelectricity
Conversion；
The reference signal for the reverse transfers that i-th of subscriber unit extracts is expressed as:Wherein
τRUFor the optical fiber link propagation delay time from distal fiber Frequency Transfer unit to the i-th subscriber unit；
S6, jth (j=1,2 ..., M) a two-way optical amplification unit: carry out light amplification to the signal of transmitting to rear；
S7, central station optical fiber Frequency Transfer unit receive the reference signal from distal fiber Frequency Transfer unit loopback, through light
The reference signal sent after electricity conversion and locally is compared, and extracts the frequency from central station optical fiber Frequency Transfer unit to distal fiber
The optical fiber link Delay of rate transfer unit, central station optical fiber Frequency Transfer unit control phase compensation block according to formula (1)
With stable fiber chain circuit transmission time delay, so that the broadband frequency signals that distal fiber Frequency Transfer unit output phase is stable；Its
Chinese style (1) indicates are as follows:
τLR+τRL=c (1)
Wherein, c is constant；
Central station optical fiber Frequency Transfer unit receives the reference signal from distal fiber Frequency Transfer unit loopback and is expressed as:Wherein τRLFor from distal fiber Frequency Transfer unit to central station optical fiber Frequency Transfer list
The optical fiber link propagation delay time of member；
S8, under the premise of central station optical fiber frequency cells stable fiber chain circuit transmission time delay, forward and backward based on the received
Reference signal, the broadband frequency signals that i-th of subscriber unit control phase compensation block makes output phase stable.
7. high-precision distribution type fiber-optic wideband frequency transmission method according to claim 6, which is characterized in that when user's list
The offset of the second phase compensating module of member is the subscriber unit to the optical fiber link between distal fiber Frequency Transfer unit
Propagation delay time τRUWhen, realize that the broadband frequency signals phase of distal fiber Frequency Transfer unit and the output of each subscriber unit is same
Step.
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