CN112217570B - Optical amplification transmission device and method applied to optical fiber time transfer network - Google Patents
Optical amplification transmission device and method applied to optical fiber time transfer network Download PDFInfo
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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
- H04B10/29—Repeaters
- H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
- H04B10/297—Bidirectional amplification
- H04B10/2971—A single amplifier for both directions
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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
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0795—Performance monitoring; Measurement of transmission parameters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
- H04J14/0201—Add-and-drop multiplexing
- H04J14/0215—Architecture aspects
- H04J14/0216—Bidirectional architectures
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
- H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
Abstract
The invention provides an optical amplification transmission device applied to an optical fiber time transfer network, which comprises a first detection device, a second detection device, a bidirectional optical amplification device and a time delay measurement device, wherein the first detection device is used for detecting the time delay of a transmission signal; the first detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device and is used for dividing an optical signal transmitted into the first detection device into two paths, wherein one path is connected into the bidirectional optical amplification device, and the other path is connected into the time delay measurement device through the photoelectric conversion device; the bidirectional optical amplification device is used for bidirectional amplification of optical signals; the second detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device; and the time delay measuring device is used for measuring the signal time delay difference between the first detection device and the second detection device, calculating the transmission error of the time signal passing through the optical amplification device according to the signal time delay difference, and transmitting the transmission error data to the optical fiber time transmission equipment for the operation and processing of the time transmission signal, thereby improving the time transmission performance. The technical scheme of the invention can flexibly adjust the parameters of the amplifier according to network planning and application, and is convenient for engineering application. The method has wide application range and application value.
Description
Technical Field
The present invention relates to the field of optical transmission, and in particular, to an optical amplification transmission apparatus and method applied to an optical fiber time transfer network.
Background
The invention relates to the technical field of communication, navigation, astronomical observation, electric power and traffic systems and scientific research, and the requirements on high-precision time transmission are higher and stronger. At present, time service technologies based on satellites, such as a satellite common view method and a satellite bidirectional time comparison method, are interfered by environmental factors on a free space transmission link, and the precision of time transmission only reaches nanosecond level. With the continuous development of new technologies, especially the application of various distributed systems with wide area and stronger time dependence, these wireless channel-based time transfer technologies have been unable to meet the requirements of future time transfer. The optical fiber has the advantages of high bandwidth, low loss, long transmission distance, strong interference resistance and the like, and is widely applied to the field of communication. The time transmission by using the existing widely distributed optical communication network is an effective way for breaking through the limitation of the prior art and realizing high-precision long-distance time transmission.
The time transmission based on the optical fiber faces the problem of transmission noise caused by the change of the transmission delay of the optical fiber link due to external environmental factors such as temperature, stress, transmission wavelength and the like. In order to realize high-precision optical fiber time transmission, the transmission symmetry of a bidirectional link needs to be maintained or the transmission error of the bidirectional link needs to be monitored in real time, and meanwhile, the influence caused by the change of environmental factors is restrained, and a same-fiber same-wave bidirectional transmission scheme can be adopted. When the transmission distance of the optical fiber reaches hundreds of kilometers, the optical signal needs to be amplified and regenerated due to the existence of the transmission loss of the optical fiber. Different from single-fiber unidirectional transmission and optical amplification technologies adopted in the existing optical fiber communication network, single-fiber bidirectional optical amplification is required to be adopted for long-distance optical fiber time transmission, and the single-fiber bidirectional amplification becomes one of key technologies for realizing high-precision bidirectional time transmission in the optical fiber communication network. Some solutions are provided for optical fiber time transmission at home and abroad, and if a two-way optical amplifier scheme adopting a circulator is adopted for inhibiting Rayleigh scattering and other noises, the problem of link asymmetry caused by the use of two one-way optical amplifiers is not solved; the problem of link symmetry of light in different directions passing through an optical amplifier is solved by amplifying the forward or backward transmitted light through the same optical amplifier by adopting an optical switch or a multiplexer, but the problems that the working life of the optical switch and the adjustment of the optical amplifier gain are not flexible, the practical engineering application is influenced and the like exist.
The patent application number 201910023601.7 bidirectional wavelength division multiplexing optical amplifier proposes a bidirectional wavelength division multiplexing optical amplifier for optical fiber time frequency transmission, which is used to solve the problem of bidirectional optical amplification in the single optical fiber bidirectional time frequency transmission process. The forward transmission channel and the backward transmission channel enter a unidirectional optical amplifier with an isolator through a wave separator/combiner, and the bidirectional amplification of the same fiber and different waves of optical signals carrying time frequency signals in a bidirectional wavelength division multiplexing time frequency transmission link is realized. The method avoids the adverse effect caused by single-fiber bidirectional amplification, and ensures the symmetry of forward and backward light passing through the optical amplifier to a certain extent by passing forward and backward transmitted optical signals through the same optical amplifier. However, the forward and backward optical signals are transmitted between the add/drop filters through different optical fibers, so that the transmission delay of the forward and backward optical signals is asymmetric, which will bring adverse effects on the transmission performance of the system; meanwhile, the forward and backward optical signals are optically amplified by one amplifier, that is, the amplification gains of the forward and backward optical signals passing through the amplifying device are the same, which brings great limitation to practical application, because the gain requirements of the forward and backward optical amplifiers in practical application are usually different according to network planning and practical application. Meanwhile, the scheme is only suitable for amplifying light with different wavelengths in the forward direction and the backward direction, namely, single-fiber bidirectional different wavelengths, and is not suitable for a transmission system with high transmission precision, namely, single-fiber bidirectional same wavelength.
The patent application number 201610073321.3 "high-precision optical fiber time transfer bidirectional optical amplification method and device" proposes a high-precision optical fiber time transfer bidirectional optical amplification method and device in the field of optical fiber time frequency transfer, which is used for solving the problem of optical amplification in an optical fiber time transfer link based on same-fiber same-wave bidirectional time division multiplexing. The method separates a time transmission channel from an optical fiber wavelength channel through a wave separator/combiner, and leads optical signals transmitted in the forward direction and the backward direction on the time transmission channel and other one-way transmission wavelength channels to pass through 1 one-way optical amplifier by controlling the state of a 2 multiplied by 2 optical switch, thereby realizing the same-fiber same-wave two-way amplification of the optical signals carrying timing signals in the same-fiber same-wave two-way time division multiplexing time transmission link, ensuring the symmetry of the link to the maximum extent and effectively avoiding the influence of the multiple amplification of noise such as Rayleigh scattering and the like on the optical fiber time transmission performance. The method switches the forward and backward optical fiber channel connection through optical switch light, so that the forward and backward light passes through the same optical amplifier, and the passing optical fiber links are the same, thereby greatly ensuring the symmetry of the links. The switching noise of the optical switch is also amplified by the optical amplifier, which adversely affects the stable operation of the system, and the switching time of the optical switch also occupies the effective transmission time.
Disclosure of Invention
Aiming at the problems in the prior art, an optical amplification transmission device and method applied to an optical fiber time transmission network are provided, which are used for solving the adverse effect of transmission errors brought by the optical amplification device in a long-distance optical fiber time transmission link on the transmission performance and expanding the coverage range of the optical fiber time transmission network. Meanwhile, the transmission error of the bidirectional amplifier for transmitting the optical signal by the optical fiber time is monitored in real time and transmitted to the optical fiber time transmission equipment to improve the performance of the optical fiber time transmission system.
The technical scheme adopted by the invention is as follows: an optical amplification transmission device applied to an optical fiber time transfer network comprises a first detection device, a second detection device, a bidirectional optical amplification device and a time delay measurement device;
the first detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device and is used for dividing an optical signal transmitted into the first detection device into two paths, wherein one path is connected into the bidirectional optical amplification device, and the other path is connected into the time delay measurement device through the photoelectric conversion device;
the bidirectional optical amplification device comprises a first optical circulator, a first optical amplifier, a second optical circulator and a second optical amplifier, wherein the first optical circulator is connected with the first detection device, and the second optical circulator is connected with the second detection device; the first optical circulator is connected to a second optical circulator through a first optical amplifier, the second optical circulator is connected to the first optical circulator through a second optical amplifier, the first optical amplifier amplifies signals transmitted to the second optical circulator by the first optical circulator, and the second optical amplifier amplifies signals transmitted to the first optical circulator by the second optical circulator;
the second detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device;
and the time delay measuring device is used for measuring the time delay difference between the first detection device and the second detection device, calculating the transmission error of the time signal passing through the bidirectional optical amplification device according to the signal time delay difference, and transmitting the transmission error data to the optical fiber time transmission equipment for the operation and processing of the time transmission signal.
Furthermore, the first detection device includes a first optical beam splitter, a second optical beam splitter, a third optical beam splitter, and a first photoelectric conversion module, one exit end of the first optical beam splitter is connected to one exit end of the second optical beam splitter, another exit end of the first optical beam splitter is connected to one exit end of the third optical beam splitter, and another exit end of the second optical beam splitter is connected to another exit end of the third optical beam splitter; the incident end of the first optical splitter is connected with the optical fiber link, the incident end of the second optical splitter is connected with the bidirectional optical amplification device, the incident end of the third optical splitter is connected with the input end of the first photoelectric conversion module, and the output end of the first photoelectric conversion module is connected to the time delay measuring device.
Furthermore, the second detection device includes a fourth optical beam splitter, a fifth optical beam splitter, a sixth optical beam splitter, and a second photoelectric conversion module, one exit end of the fourth optical beam splitter is connected to one exit end of the fifth optical beam splitter, another exit end of the fourth optical beam splitter is connected to one exit end of the sixth optical beam splitter, and another exit end of the fifth optical beam splitter is connected to another exit end of the sixth optical beam splitter; the incident end of the fourth optical beam splitter is connected with the optical fiber link, the incident end of the fifth optical beam splitter is connected with the bidirectional optical amplification device, the incident end of the sixth optical beam splitter is connected with the input end of the second photoelectric conversion module, and the output end of the second photoelectric conversion module is connected to the time delay measuring device.
Furthermore, a time division multiplexing mechanism is adopted for transmission, and when forward transmission optical signals are transmitted, backward optical signals are not transmitted; when backward optical signal transmission is carried out, forward optical signals are not transmitted.
Furthermore, two optical amplifiers are adopted to amplify the forward optical signal and the backward optical signal respectively in the optical signal transmission process, the time delay measuring device measures time signals at two ends during the transmission of the forward optical signal to obtain forward time delay difference, measures time signals at two ends during the transmission of the backward optical signal to obtain backward time delay difference, calculates according to the forward time delay difference, the backward time delay difference and system errors in real time to obtain transmission error data, and transmits the transmission error data to the optical fiber time transmission equipment for operation and processing of the time transmission signal.
The invention also provides a transmission error elimination method based on the optical amplification transmission device applied to the optical fiber time transmission network, which is characterized in that two optical amplifiers are adopted between the detectors at the two ends to amplify the forward optical signal and the backward optical signal respectively, the transmitted optical signal is divided into two parts in the detectors at the two ends through the optical beam splitter, one part of the two parts is transmitted, and the other part of the two parts is converted into an electric signal through the photoelectric converter and is transmitted to the time delay measuring device; when the forward optical signal is transmitted, the time delay measuring device obtains a forward time delay difference by receiving the electric signals transmitted by the detectors at the two ends; when backward optical signals are transmitted, the time delay measuring device obtains backward time delay difference by receiving electric signals transmitted by the detectors at the two ends; and the transmission error is obtained by combining the forward delay difference and the backward delay difference with the system error, and the transmission error data is transmitted to the optical fiber time transmission equipment for the operation and processing of the time transmission signal.
Further, the method for acquiring the forward delay difference comprises the following steps: the optical signal is divided into two parts of light by the first optical beam splitter, one part of light enters the third optical beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after the first electric signal is obtained; the other part of light enters a second optical beam splitter and is sent to the bidirectional optical amplifying device through the second optical beam splitter; in the bidirectional optical amplifier, the optical signal is sent to the first optical amplifier after passing through the first optical circulator, sent to the second optical circulator after being amplified by the first optical amplifier, and then output to the fifth optical beam splitter in the second detection device by the second optical circulator to be divided into two partsSplitting light, wherein a part of light enters a sixth optical beam splitter and then is sent to a second photoelectric converter, the part of light is converted into an electric signal through the second photoelectric converter, and the electric signal is sent to a time delay measuring device after the second electric signal is obtained; the other part of light enters a fourth optical beam splitter, and the light is output and continuously transmitted after passing through the fourth optical beam splitter; the time delay measuring device measures the time delay difference of the first electric signal and the second electric signal to obtain the forward time delay difference delta TFORWARD。
Further, the method for acquiring the backward delay difference comprises the following steps: the optical signal is divided into two parts of light by the fourth beam splitter, one part of light enters the sixth beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a third electric signal is obtained; the other part of light enters a fifth optical beam splitter, and is sent to a bidirectional light amplification device through the fifth optical beam splitter, in the bidirectional light amplification device, the light is sent to a second optical amplifier after passing through a second optical circulator, the light is sent to a first optical circulator after being sent to the second optical amplifier, the second light which is output to a first detection device through the first optical circulator is split into two parts of light through the optical beam splitter, one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the two parts of light are converted into electric signals through the first photoelectric converter, and the electric signals are sent to a time delay measurement device after fourth electric signals are obtained; the other part of light enters the first optical beam splitter, and the light is output and continuously transmitted after passing through the optical beam splitter; the time delay measuring device measures the time delay difference between the third electric signal and the fourth electric signal to obtain the backward time delay difference delta TBACK。
Further, the system error calculation method comprises: replacing a bidirectional optical amplification device in the measuring device by a fixed-length optical fiber, and respectively performing forward system delay measurement and backward system delay measurement;
and (3) forward system time delay measurement: the optical signal is divided into two parts of light by the first beam splitter, one part of light enters the third beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after a fifth electric signal is obtained; the other part of light enters the second optical beam splitter, enters one end of the optical fiber with the fixed length L after passing through the second optical beam splitter, and enters a fifth detection device in the second detection device through the other end of the optical fiberThe optical beam splitter is divided into two parts of light, one part of light enters the sixth optical beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal through the second photoelectric converter, and the electric signal is sent to the time delay measuring device after the sixth electric signal is obtained; the time delay measuring device measures the time delay difference between the fifth electric signal and the sixth electric signal to obtain the time delay difference delta T 'of the forward system'FORWARD。
And (3) backward system time delay measurement: the fourth optical signal is divided into two parts of light by the beam splitter, one part of light enters the sixth optical beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a seventh electric signal is obtained; the other part of light enters a fifth optical beam splitter, enters one end of an optical fiber with a fixed length L after passing through the fifth optical beam splitter, and is divided into two parts of light by a second light entering the first detection device through the other end of the optical fiber, wherein one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the first photoelectric converter is used for converting the light into an electric signal, and the eighth electric signal is obtained and then is sent to a time delay measurement device; the time delay measuring device measures the time delay difference between the seventh electric signal and the eighth electric signal to obtain the time delay difference delta T 'of the backward system'BACK；
The system error delta T can be obtainedSYS＝ΔT′FORWARD-ΔT′BACK。
Further, the calibration value is calculated by the following method: Δ T ═ Δ TFORWARD-ΔTBACK-ΔTSYSWhere Δ T is a calibrated value.
Compared with the prior art, the beneficial effects of adopting the technical scheme are as follows:
1) the bidirectional optical signal is prevented from being amplified by a bidirectional amplifier, the system amplification noise is reduced, forward and backward optical signals are respectively amplified, the parameters of the amplifier can be flexibly adjusted according to network planning and application, and engineering application is facilitated. The method has wide application range and application value.
2) The method and the device for measuring the time delay of the symmetrical optical signals are adopted, and the error of a measuring system is eliminated through system calibration, so that the aim of improving the measuring precision is fulfilled. Because different amplifiers are adopted in the forward direction and the backward direction, the erbium fibers of different amplifiers have different material characteristics, lengths and the like, and the time delay of an optical signal passing through different amplifiers is different, the optical signal has asymmetry after passing through the forward amplifier device and the backward amplifier device, and the asymmetry can be changed after being influenced by factors such as electricity, environment and the like. However, the manufacturing parameters of the two symmetrical measuring devices are the same, so the error of the system is less influenced by factors such as environment, and the variation of the calibrated parameters is negligible. Therefore, the measurement error of the system can be eliminated by a calibration method, so that the real-time measurement performance of the system is ensured.
3) The optical monitoring channel of the optical network is utilized to transmit real-time measurement data, the transmission problem of the measurement data is effectively solved, and the feasibility of the method is ensured. Generally, an optical network with optical amplifiers has an optical monitoring channel for monitoring and collecting the operating states of the amplifiers, so that the optical monitoring channel can be used for collecting the operating states of the amplifiers at all stages, transmitting the monitored real-time transmission error data of the bidirectional amplifier for optical signal transmission in optical fiber time to corresponding optical fiber time transmission equipment through the optical monitoring channel, and eliminating the transmission noise of the optical amplification device through a correlation algorithm by using the data, thereby improving the performance of the optical fiber time transmission system.
Drawings
Fig. 1 is a schematic structural diagram of an optical amplification transmission device of the present invention.
Fig. 2 is a schematic diagram of forward optical amplification delay measurement of the optical amplification transmission apparatus of the present invention.
Fig. 3 is a schematic diagram of backward optical amplification delay measurement of the optical amplification transmission apparatus of the present invention.
Fig. 4 is a schematic diagram of the forward system delay measurement of the present invention.
Fig. 5 is a schematic diagram of the backward system delay measurement of the present invention.
Reference numerals: 1-a first detection device, 2-a second detection device, 3-a bidirectional optical amplification device, 4-a time delay measurement device, 11-a first optical beam splitter, 12-a second optical beam splitter, 13-a third optical beam splitter, 14-a first photoelectric conversion module, 21-a fourth optical beam splitter, 22-a fifth optical beam splitter, 23-a sixth optical beam splitter, 24-a second photoelectric conversion module, 31-a first optical circulator, 32-a first optical amplifier, 33-a second optical circulator and 34-a second optical amplifier.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
The technical scheme of the invention solves the following problems:
1) because the high-precision time transfer adopts single-fiber same-wavelength bidirectional transfer, forward and backward optical signals need to be amplified, and the forward and backward optical amplification parameter settings are usually different by combining an amplification node in practical network application, the forward and backward optical signals need to be separated from the single fiber, and the forward and backward optical signals need to be amplified by adopting two amplifiers respectively, and the high-precision time transfer has independent setting or adjustment performance so as to adapt to different network environments and application requirements;
2) because different amplifiers are adopted in the forward direction and the backward direction, the erbium fibers of different amplifiers have different material characteristics, lengths and the like, and the time delay of an optical signal passing through different amplifiers is different, the optical signal has asymmetry after passing through the forward amplifier device and the backward amplifier device, and the asymmetry can be changed after being influenced by factors such as electricity, environment and the like. Therefore, asymmetry caused by the forward and backward optical amplification devices needs to be monitored, collected and transmitted to the equipment end, and the influence of noise of the bidirectional optical amplification device on the optical fiber time transmission performance is eliminated through corresponding algorithm processing.
3) Generally, an optical network with optical amplifiers has an optical monitoring channel for monitoring and collecting the operating states of the amplifiers, so that the optical monitoring channel can be used for collecting the operating states of the amplifiers at all stages, and simultaneously transmitting the measured real-time transmission error data of the bidirectional amplifier for optical signals transmitted by optical fiber time to corresponding optical fiber time transmission equipment through the optical monitoring channel, and eliminating the noise of an optical amplification device through a correlation algorithm by using the data, thereby improving the performance of the optical fiber time transmission system.
In order to solve the problems, an optical amplification transmission device and method applied to an optical fiber time transmission network are provided, and aiming at the characteristic that an optical fiber time transmission signal is sensitive to bidirectional transmission asymmetry (the asymmetry greatly affects the transmission performance), the asymmetry of a bidirectional optical amplifier except a manufacturing process is considered, and the asymmetry is also changed under the influence of factors such as electricity and environment, so that a real-time measurement method is provided for monitoring the transmission error of the bidirectional amplification device and transmitting the transmission error data to optical fiber time transmission equipment in a link in real time, and the optical fiber time transmission equipment performs algorithm processing according to a time transmission algorithm and the transmission error of the amplification device in the optical fiber link, so that the transmission precision of the optical fiber time transmission equipment is improved, and the performance of an optical fiber time transmission system is finally improved; the time signal transmitted in single fiber two-way shares the same optical fiber physical link with other optical signals in a wavelength division multiplexing mode, when the optical fiber link needs to be provided with an amplifier, the optical signal of the transmission time and other optical signals are separated by using a wavelength division device, the time delay values of the forward and backward transmitted time optical signals after passing through respective optical amplifiers are respectively measured, and then the forward time delay value and the backward time delay value are subtracted to obtain the transmission error of the two-way amplifier. And finally, transmitting the transmission error data to an optical fiber time transmission device on a link through an optical monitoring channel for operation and processing of time transmission signals, and finally improving the performance of the optical fiber time transmission system, wherein the specific scheme is as follows:
as shown in fig. 1, an optical amplification transmission apparatus applied to an optical fiber time transfer network includes a first detection device 1, a second detection device 2, a bidirectional optical amplification device 3, and a time delay measurement device 4;
the first detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device and is used for dividing an optical signal transmitted into the first detection device into two paths, wherein one path is connected into the bidirectional optical amplification device, and the other path is connected into the time delay measurement device through the photoelectric conversion device;
the bidirectional optical amplification device comprises a first optical circulator 31, a first optical amplifier 32, a second optical circulator 33 and a second optical amplifier 34, wherein the first optical circulator is connected with the first detection device, and the second optical circulator is connected with the second detection device; the first optical circulator is connected to a second optical circulator through a first optical amplifier, the second optical circulator is connected to the first optical circulator through a second optical amplifier, the first optical amplifier amplifies signals transmitted to the second optical circulator by the first optical circulator, and the second optical amplifier amplifies signals transmitted to the first optical circulator by the second optical circulator;
the second detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device;
and the time delay measuring device is used for measuring the signal time delay difference between the first detection device and the second detection device, calculating the transmission error of the time signal passing through the bidirectional optical amplification device according to the signal time delay difference, and transmitting the transmission error data to the optical fiber time transmission equipment for the operation and processing of the time transmission signal.
In a preferred embodiment, the first detection device includes a first optical beam splitter 11, a second optical beam splitter 12, a third optical beam splitter 13, and a first photoelectric conversion module 14, one exit end of the first optical beam splitter is connected to one exit end of the second optical beam splitter, another exit end of the first optical beam splitter is connected to one exit end of the third optical beam splitter, and another exit end of the second optical beam splitter is connected to another exit end of the third optical beam splitter; the incident end of the first optical splitter is connected with the optical fiber link, the incident end of the second optical splitter is connected with the bidirectional optical amplification device, the incident end of the third optical splitter is connected with the input end of the first photoelectric conversion module, and the output end of the first photoelectric conversion module is connected to the time delay measuring device.
In a preferred embodiment, the second detection device includes a fourth optical beam splitter 21, a fifth optical beam splitter 22, a sixth optical beam splitter 23, and a second photoelectric conversion module 24, one exit end of the fourth optical beam splitter is connected to one exit end of the fifth optical beam splitter, another exit end of the fourth optical beam splitter is connected to one exit end of the sixth optical beam splitter, and another exit end of the fifth optical beam splitter is connected to another exit end of the sixth optical beam splitter; the incident end of the fourth optical beam splitter is connected with the optical fiber link, the incident end of the fifth optical beam splitter is connected with the bidirectional optical amplification device, the incident end of the sixth optical beam splitter is connected with the input end of the second photoelectric conversion module, and the output end of the second photoelectric conversion module is connected to the time delay measuring device.
The optical amplification transmission device adopts a time division multiplexing mechanism for transmission, and when the forward transmission optical signal is transmitted, the backward optical signal is not transmitted; when backward optical signal transmission is carried out, forward optical signals are not transmitted.
Specifically, two optical amplifiers are adopted to amplify forward optical signals and backward optical signals respectively in the optical signal transmission process, the time delay measuring device measures time signals at two ends during forward optical signal transmission to obtain forward time delay difference, measures time signals at two ends during backward optical signal transmission to obtain backward time delay difference, transmission error data are obtained by calculating according to the forward time delay difference, the backward time delay difference and system errors in real time, and the transmission error data are transmitted to optical fiber time transmission equipment to be used for operation and processing of time transmission signals.
The invention also provides a transmission error elimination method based on the optical amplification transmission device applied to the optical fiber time transmission network, which is characterized in that two optical amplifiers are adopted between the detectors at the two ends to amplify the forward optical signal and the backward optical signal respectively, the transmitted optical signal is divided into two parts in the detectors at the two ends through the optical beam splitter, one part of the two parts is transmitted, and the other part of the two parts is converted into an electric signal through the photoelectric converter and is transmitted to the time delay measuring device; when the forward optical signal is transmitted, the time delay measuring device obtains a forward time delay difference by receiving the electric signals transmitted by the detectors at the two ends; when backward optical signals are transmitted, the time delay measuring device obtains backward time delay difference by receiving electric signals transmitted by the detectors at the two ends; and obtaining transmission error data by combining the forward delay difference and the backward delay difference with the system error, and transmitting the transmission error data to optical fiber time transmission equipment for operation and processing of time transmission signals.
Specifically, as shown in fig. 2, the method for obtaining the forward delay difference includes: the optical signal is divided into two parts of light by the first optical beam splitter, one part of light enters the third optical beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after the first electric signal is obtained; another portion of the light enters the second beam splitter,sending the optical signals to a bidirectional optical amplifying device through a second optical beam splitter; in the bidirectional optical amplification device, an optical signal passes through a first optical circulator and then is sent to a first optical amplifier, is amplified by the first optical amplifier and then is sent to a second optical circulator, and then is output to a fifth optical beam splitter in a second detection device by the second optical circulator to be divided into two parts of light, wherein one part of light enters a sixth optical beam splitter and then is sent to a second photoelectric converter, and is converted into an electrical signal by the second photoelectric converter, and the electrical signal is sent to a time delay measurement device after the second electrical signal is obtained; the other part of light enters a fourth optical beam splitter, and the light is output and continuously transmitted after passing through the fourth optical beam splitter; the time delay measuring device measures the time delay difference of the first electric signal and the second electric signal to obtain the forward time delay difference delta TFORWARD。
As shown in fig. 3, the method for obtaining the backward delay difference includes: the optical signal is divided into two parts of light by the fourth beam splitter, one part of light enters the sixth beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a third electric signal is obtained; the other part of light enters a fifth optical beam splitter, and is sent to a bidirectional light amplification device through the fifth optical beam splitter, in the bidirectional light amplification device, the light is sent to a second optical amplifier after passing through a second optical circulator, the light is sent to a first optical circulator after being sent to the second optical amplifier, the second light which is output to a first detection device through the first optical circulator is split into two parts of light through the optical beam splitter, one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the two parts of light are converted into electric signals through the first photoelectric converter, and the electric signals are sent to a time delay measurement device after fourth electric signals are obtained; the other part of light enters the first optical beam splitter, and the light is output and continuously transmitted after passing through the optical beam splitter; the time delay measuring device measures the time delay difference between the third electric signal and the fourth electric signal to obtain the backward time delay difference delta TBACK。
In order to improve the measurement accuracy of the optical amplification device in the optical fiber time transfer network, the system error of the measurement system needs to be measured, and the specific implementation method is to adopt an optical fiber with a fixed length at one end to replace the bidirectional optical amplification device, complete one-time forward optical delay and backward optical delay measurement, and calculate according to the measured forward optical delay difference and backward optical delay difference to obtain the error of the measurement system. When the system runs, the obtained error value is used for correcting the measured value in normal working to improve the measurement precision, so that the system performance is improved.
Specifically, the system error calculation method comprises the following steps: replacing a bidirectional optical amplification device in the measuring device by a fixed-length optical fiber, and respectively performing forward system delay measurement and backward system delay measurement;
as shown in fig. 4, the forward system delay measurement: the optical signal is divided into two parts of light by the first beam splitter, one part of light enters the third beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after a fifth electric signal is obtained; the other part of light enters a second optical beam splitter, enters one end of an optical fiber with the fixed length L after passing through the second optical beam splitter, enters a fifth optical beam splitter in a second detection device through the other end of the optical fiber and is divided into two parts of light, and one part of light enters a sixth optical beam splitter and is sent to a second photoelectric converter, is converted into an electric signal through the second photoelectric converter, and is sent to a time delay measurement device after the sixth electric signal is obtained; the time delay measuring device measures the time delay difference between the fifth electric signal and the sixth electric signal to obtain the time delay difference delta T 'of the forward system'FORWARD。
As shown in fig. 5, the backward system delay measurement: the fourth optical signal is divided into two parts of light by the beam splitter, one part of light enters the sixth optical beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a seventh electric signal is obtained; the other part of light enters a fifth optical beam splitter, enters one end of an optical fiber with a fixed length L after passing through the fifth optical beam splitter, and is divided into two parts of light by a second light entering the first detection device through the other end of the optical fiber, wherein one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the first photoelectric converter is used for converting the light into an electric signal, and the eighth electric signal is obtained and then is sent to a time delay measurement device; the time delay measuring device 4 measures the time delay difference between the seventh electric signal and the eighth electric signal to obtain the time delay difference delta' T of the backward systemBACK；
Obtaining a forward system delay difference delta T 'through forward and backward system delay measurement'FORWARDAnd backward system delay difference delta T'BACKThen the system error Delta T of the measuring system can be obtainedSYS＝ΔT′FORWARD-ΔT′BACK。
When the optical amplification device of the optical fiber time transfer network works normally, forward and backward optical signals lambda are subjected to real-time alignmentTMeasuring to obtain the forward time delay difference delta TFORWARDAnd backward delay difference Δ TBACKCombined with the systematic error Δ TSYSThe measurement result, i.e. the transmission error value, can be obtained as: Δ T ═ Δ TFORWARD-ΔTBACK-ΔTSYSWherein Δ T is a transmission error value; and finally, completing data transmission through the optical monitoring channel.
In a preferred embodiment, the measurement result transmission can be transmitted by using other service wavelength channels or special wavelength channels besides the own optical monitoring channel in the network with optical amplification.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed. Those skilled in the art to which the invention pertains will appreciate that insubstantial changes or modifications can be made without departing from the spirit of the invention as defined by the appended claims.
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.
Claims (10)
1. An optical amplification transmission device applied to an optical fiber time transfer network is characterized by comprising a first detection device, a second detection device, a bidirectional optical amplification device and a time delay measurement device;
the first detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device and is used for dividing an optical signal transmitted into the first detection device into two paths, wherein one path is connected into the bidirectional optical amplification device, and the other path is connected into the time delay measurement device through the photoelectric conversion device;
the bidirectional optical amplification device comprises a first optical circulator, a first optical amplifier, a second optical circulator and a second optical amplifier, wherein the first optical circulator is connected with the first detection device, and the second optical circulator is connected with the second detection device; the first optical circulator is connected to a second optical circulator through a first optical amplifier, the second optical circulator is connected to the first optical circulator through a second optical amplifier, the first optical amplifier amplifies signals transmitted to the second optical circulator by the first optical circulator, and the second optical amplifier amplifies signals transmitted to the first optical circulator by the second optical circulator;
the second detection device is respectively connected with the bidirectional optical amplification device and the time delay measurement device;
and the time delay measuring device is used for measuring the signal time delay difference between the first detection device and the second detection device, calculating the transmission error of the time signal passing through the bidirectional optical amplification device according to the signal time delay difference and the system error, and transmitting the transmission error data to the optical fiber time transmission equipment for the operation and processing of the time transmission signal.
2. The optical amplification transmission device applied to the optical fiber time transfer network according to claim 1, wherein the first detection device comprises a first optical splitter, a second optical splitter, a third optical splitter, and a first photoelectric conversion module, one exit end of the first optical splitter is connected to one exit end of the second optical splitter, the other exit end of the first optical splitter is connected to one exit end of the third optical splitter, and the other exit end of the second optical splitter is connected to the other exit end of the third optical splitter; the incident end of the first optical splitter is connected with the optical fiber link, the incident end of the second optical splitter is connected with the bidirectional optical amplification device, the incident end of the third optical splitter is connected with the input end of the first photoelectric conversion module, and the output end of the first photoelectric conversion module is connected to the time delay measuring device.
3. The optical amplification transmission device applied to the optical fiber time transfer network according to claim 1 or 2, wherein the second detection device comprises a fourth optical beam splitter, a fifth optical beam splitter, a sixth optical beam splitter, and a second photoelectric conversion module, one exit end of the fourth optical beam splitter is connected to one exit end of the fifth optical beam splitter, another exit end of the fourth optical beam splitter is connected to one exit end of the sixth optical beam splitter, and another exit end of the fifth optical beam splitter is connected to another exit end of the sixth optical beam splitter; the incident end of the fourth optical beam splitter is connected with the optical fiber link, the incident end of the fifth optical beam splitter is connected with the bidirectional optical amplification device, the incident end of the sixth optical beam splitter is connected with the input end of the second photoelectric conversion module, and the output end of the second photoelectric conversion module is connected to the time delay measuring device.
4. The optical amplification transmission apparatus applied to the optical fiber time transfer network according to claim 1, wherein the optical amplification transmission apparatus uses a time division multiplexing mechanism for transfer, and when the forward optical signal is transferred, the backward optical signal is not transferred; when backward optical signal transmission is carried out, forward optical signals are not transmitted.
5. The optical amplification transmission apparatus applied to the optical fiber time transfer network according to claim 1, wherein two optical amplifiers are adopted to amplify the forward optical signal and the backward optical signal respectively in the optical signal transfer process, the delay measurement apparatus measures time signals at two ends during the forward optical signal transfer to obtain a forward delay difference, measures time signals at two ends during the backward optical signal transfer to obtain a backward delay difference, calculates a transmission error of the bidirectional optical amplification apparatus according to the forward delay difference, the backward delay difference and a system error in real time, and transfers the transmission error data to the optical fiber time transfer device for the operation and processing of the time transfer signal.
6. A transmission error elimination method applied to the optical amplification transmission device of the optical fiber time transmission network is characterized in that two optical amplifiers are adopted between detectors at two ends to amplify a forward optical signal and a backward optical signal respectively, an optical beam splitter divides the transmitted optical signal into two parts in the detectors at the two ends, one part of the transmitted optical signal is transmitted, and the other part of the transmitted optical signal is converted into an electric signal through an optical-to-electrical converter and is transmitted to a time delay measuring device; when the forward optical signal is transmitted, the time delay measuring device obtains a forward time delay difference by receiving the electric signals transmitted by the detectors at the two ends; when backward optical signals are transmitted, the time delay measuring device obtains backward time delay difference by receiving electric signals transmitted by the detectors at the two ends; and the transmission error of the optical amplification device is obtained by combining the forward delay difference and the backward delay difference with the system error, and the transmission error data is transmitted to the optical fiber time transmission equipment for the operation and processing of the time transmission signal.
7. The method for eliminating the transmission error of the optical amplification transmission device applied to the optical fiber time transfer network as claimed in claim 6, wherein the method for obtaining the forward delay difference comprises: the optical signal is divided into two parts of light by the first optical beam splitter, one part of light enters the third optical beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after the first electric signal is obtained; the other part of light enters a second optical beam splitter and is sent to the bidirectional optical amplifying device through the second optical beam splitter; in the bidirectional optical amplification device, an optical signal passes through a first optical circulator and then is sent to a first optical amplifier, is amplified by the first optical amplifier and then is sent to a second optical circulator, and then is output to a fifth optical beam splitter in a second detection device by the second optical circulator to be divided into two parts of light, wherein one part of light enters a sixth optical beam splitter and then is sent to a second photoelectric converter, and is converted into an electrical signal by the second photoelectric converter, and the electrical signal is sent to a time delay measurement device after the second electrical signal is obtained; the other part of light enters a fourth optical beam splitter, and the light is output and continuously transmitted after passing through the fourth optical beam splitter; the time delay measuring device measures the time delay difference of the first electric signal and the second electric signal to obtain the forward time delay difference delta TFORWARD。
8. The method for eliminating the transmission error of the optical amplification transmission apparatus applied to the optical fiber time transfer network according to claim 6 or 7, wherein the method for obtaining the backward delay difference comprises: the optical signal is divided into two parts of light by the fourth beam splitter, one part of light enters the sixth beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a third electric signal is obtained; the other part of light enters a fifth optical beam splitter, and is sent to a bidirectional light amplification device through the fifth optical beam splitter, in the bidirectional light amplification device, the light is sent to a second optical amplifier after passing through a second optical circulator, the light is sent to a first optical circulator after being sent to the second optical amplifier, the second light which is output to a first detection device through the first optical circulator is split into two parts of light through the optical beam splitter, one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the two parts of light are converted into electric signals through the first photoelectric converter, and the electric signals are sent to a time delay measurement device after fourth electric signals are obtained; the other part of light enters the first optical beam splitter, and the light is output and continuously transmitted after passing through the optical beam splitter; the time delay measuring device measures the time delay difference between the third electric signal and the fourth electric signal to obtain the backward time delay difference delta TBACK。
9. The transmission error removing method of claim 6, wherein the system error calculating method comprises: replacing a bidirectional optical amplification device in the measuring device by a fixed-length optical fiber, and respectively performing forward system delay measurement and backward system delay measurement;
and (3) forward system time delay measurement: the optical signal is divided into two parts of light by the first beam splitter, one part of light enters the third beam splitter and is sent to the first photoelectric converter, the light is converted into an electric signal by the first photoelectric converter, and the electric signal is sent to the time delay measuring device after a fifth electric signal is obtained; the other part of light enters the second optical beam splitter, enters one end of the optical fiber with the fixed length L after passing through the second optical beam splitter, enters the fifth optical beam splitter in the second detection device through the other end of the optical fiber and is divided into two parts of light, and one part of light enters the sixth optical beam splitter and is sent to the sixth optical beam splitterThe second photoelectric converter is used for converting the second photoelectric converter into an electric signal to obtain a sixth electric signal and then sending the sixth electric signal to the time delay measuring device; the time delay measuring device measures the time delay difference between the fifth electric signal and the sixth electric signal to obtain the time delay difference delta T 'of the forward system'FORWARD；
And (3) backward system time delay measurement: the fourth optical signal is divided into two parts of light by the beam splitter, one part of light enters the sixth optical beam splitter and is sent to the second photoelectric converter, the light is converted into an electric signal by the second photoelectric converter, and the electric signal is sent to the time delay measuring device after a seventh electric signal is obtained; the other part of light enters a fifth optical beam splitter, enters one end of an optical fiber with a fixed length L after passing through the fifth optical beam splitter, and is divided into two parts of light by a second light entering the first detection device through the other end of the optical fiber, wherein one part of light enters a third optical beam splitter and is sent to a first photoelectric converter, the first photoelectric converter is used for converting the light into an electric signal, and the eighth electric signal is obtained and then is sent to a time delay measurement device; the time delay measuring device measures the time delay difference between the seventh electric signal and the eighth electric signal to obtain the time delay difference delta T 'of the backward system'BACK；
The system error delta T can be obtainedSYS＝ΔT′FORWARD-ΔT′BACK。
10. The transmission error removing method of claim 9, wherein the transmission error is calculated by: Δ T ═ Δ TFORWARD-ΔTBACK-ΔTSYSWhere Δ T is the transmission error value.
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