CN106052730B - A kind of signal demodulating method and device for distributed fiber-optic sensor system - Google Patents
A kind of signal demodulating method and device for distributed fiber-optic sensor system Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
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- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
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Abstract
The invention discloses a kind of signal demodulating method and device for distributed fiber-optic sensor system, obtains the signal after an optical pulse code sequence and optical pulse code sequence and the impulse response convolution of testing fiber；By the signal after the optical pulse code sequence and convolution of acquisition, respectively by Fourier transform to frequency domain, according to the signal after the optical pulse code sequence and convolution after conversion, the impulse response of the testing fiber under frequency domain is calculated；The obtained impulse response of testing fiber under frequency domain is converted into by time domain by inverse fourier transform, obtains the impulse response of testing fiber.The present invention is used for the signal demodulating method and device of distributed fiber-optic sensor system, is inputted using pulsatile once, and it is this condition of impulse response no at all to consider the sum of complementary Gray code auto-correlation, therefore reduces demodulating error.
Description
Technical field
The invention belongs to signal demodulation techniques field, and in particular to a kind of signal solution for distributed fiber-optic sensor system
Adjust method and device.
Background technology
Distributed fiber-optic sensor system is using light wave as transducing signal, using optical fiber as transmission medium, can perceive and demodulate and is outer
Boundary's measurand is with time and the continuously distributed information in space, since optical fiber itself is not charged, small, light weight, pliable
Song, electromagnetism interference, radiation resistance are good, can particularly be adapted under the adverse circumstances such as inflammable, explosive and strong electromagnetic
Use so that it has extensive in key areas such as following intelligent grid, Oilfield Pipelines security monitoring, communication line attack early warnings
Application demand.Distributed fiber-optic sensor technology is divided into based on Rayleigh scattering, based on Raman scattering, the biography based on Brillouin scattering
Sense technology.
The spatial resolution both direction of distributed fiber-optic sensor technology towards farther distance sensing and higher develops.
Optical pulse code is then an important way of lifting system distance sensing.The core concept of optical pulse code technology, is to use
The length that the symbol " 1 " by intensity modulated of specific rule and " 0 " form (is commonly divided into for L optical pulse code sequences
Simplex is encoded and complementary Gray code), to replace the single pumping pulse in sensing solutions, then the response song that solution is transferred to
Line is decoded using corresponding decoding process, the lifting system signal-to-noise ratio on the premise of time of measuring is not changed, and then is extended
Distance sensing.Optical pulse code technology is widely used in various optical fiber sensing systems, such as optical time domain reflection (OTDR), Raman
Optical time domain reflection (ROTDR), Brillouin light Time Domain Reflectometry (BOTDR), Brillouin optical time domain analysis (BOTDA).
By taking bipolarity Gray code as an example, cataloged procedure is as follows：By specific two code lengths of law generation be L and
The complementary Gray code light pulse sequence A being made of symbol " 1 " and " -1 "kAnd Bk.Due to light arteries and veins in OTDR, ROTDR, BOTDR
Punching cannot be negative, so AkA by being made of accordingly symbol " 1 " and symbol " 0 " againk1,Ak2Make the difference to obtain, BkAgain by corresponding
The B being made of symbol " 1 " and symbol " 0 "k1,Bk2Make the difference to obtain.Can be by gain-type pulse and attenuation type pulse in BOTDA
Form " 1 " and " -1 " code.AkAnd BkRelation should meet：
Ak*Ak+Bk*Bk=2L δk (1)
Wherein * represents related operator, as shown in Figure 1.And δkRepresent discrete impulse function, expression formula is：
By designed complementary Gray code light pulse sequence AkAnd BkIncident optical respectively, the impulse response h with optical fiberk
After carrying out convolution, two groups of different responses are respectively obtained, i.e.,With
The optical fiber impulse response h of corresponding above-mentioned cataloged procedurekDemodulating process it is as follows：By above-mentioned two groups of different responses point
Not with corresponding original, complementary gray-code sequence AkAnd BkRelevant operation is carried out, and two groups of responses after relevant operation are summed,
The optical fiber impulse response of signal-to-noise ratio lifting is can obtain, expression formula is：
According to the characteristic of Complementary Golay sequences, the main peak of the auto-correlation function of the two is identical, and secondary lobe is complementary.Auto-correlation letter
After number summation obtains sensing function, the amplitude of main peak doubles, and secondary lobe is cancelled out each other.
But in actual application system, as shown in Fig. 2, the laser that laser is sent, by by waveform generator
(AWG) electrooptic modulator (EOM) of control, forms the pulse after coding.After amplifying by erbium-doped fiber amplifier (EDFA),
Enter by circulator in testing fiber.
EDFA cannot be guaranteed that identical gain is amplified when to Optical pulse amplification, for continuous light pulse, therefore pass through
After crossing EDFA, relatively after light pulse amplitude can be relatively low, it is inconsistent the symbol power of diverse location occur, as shown in Figure 3.It is difficult at this time
To ensure formula (1), as shown in figure 4, so as to which in demodulation, the sum of complementary Gray code auto-correlation is not impulse response but is rushing
Swash the secondary lobe that response side occurs, cause measurement error.Simulated using the impulse response of 20km optical fiber as Fig. 5.It is demodulated
Afterwards, the response obtained is Fig. 6.It can be found that there is very big shake after demodulation, demodulating error can be bigger.
The content of the invention
The purpose of the embodiment of the present invention be to provide a kind of signal demodulating method for distributed fiber-optic sensor system and
Device, to reduce the demodulating error to optical fiber impulse response.
To reach above-mentioned purpose, the embodiment of the invention discloses a kind of signal solution for distributed fiber-optic sensor system
Tune method, comprises the following steps：
Obtain the letter after an optical pulse code sequence and optical pulse code sequence and the impulse response convolution of testing fiber
Number；
By the signal after the optical pulse code sequence and convolution of acquisition, respectively by Fourier transform to frequency domain, according to change
The signal after optical pulse code sequence and convolution after changing, is calculated the impulse response of the testing fiber under frequency domain；
The obtained impulse response of testing fiber under frequency domain is converted into by time domain by inverse fourier transform, is obtained to be measured
The impulse response of optical fiber.
Preferably, the impulse response that the testing fiber under frequency domain is calculated, calculation formula are：Its
In, H represents the impulse response of the testing fiber under frequency domain, and Y represents the optical pulse code sequence after passing through Fourier transform to frequency domain
Row and the signal after the impulse response convolution of testing fiber, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain
Row.
Preferably, it is described to be converted into the obtained impulse response of testing fiber under frequency domain by inverse fourier transform
Time domain, calculation formula are：Wherein, h represents the impulse response of the testing fiber under time domain, and Y, which is represented, passes through Fourier
Optical pulse code sequence after leaf transformation to frequency domain and the signal after the impulse response convolution of testing fiber, AfRepresentative passes through Fourier
Optical pulse code sequence after leaf transformation to frequency domain.
Preferably, the optical pulse code sequence of the testing fiber is：Original optical pulse coded sequence is by mixing bait light
Fiber amplifier is amplified the optical pulse code sequence after processing.
Preferably, the original optical pulse coded sequence is：Two light pulses obtained using complementary Gray code are compiled
Code sequence in any one.
The embodiment of the invention also discloses, a kind of signal demodulating equipment for distributed fiber-optic sensor system, including,
Signal obtains module, obtains an optical pulse code sequence and the impulse of optical pulse code sequence and testing fiber
Respond the signal after convolution；
Signal conversion module, by the signal after the optical pulse code sequence and convolution of acquisition, passes through Fourier transform respectively
To frequency domain, according to the signal after the optical pulse code sequence and convolution after conversion, rushing under frequency domain testing fiber is calculated
Swash response；
Signal inverse transform module, is converted the obtained impulse response of testing fiber under frequency domain by inverse fourier transform
To time domain, the impulse response of testing fiber is obtained.
Preferably, the impulse response that the testing fiber under frequency domain is calculated, calculation formula are：Its
In, H represents the impulse response of the testing fiber under frequency domain, and Y represents the optical pulse code sequence after passing through Fourier transform to frequency domain
Row and the signal after the impulse response convolution of testing fiber, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain
Row.
Preferably, it is described to be converted into the obtained impulse response of testing fiber under frequency domain by inverse fourier transform
Time domain, calculation formula are：Wherein, h represents the impulse response of the testing fiber under time domain, and Y, which is represented, passes through Fourier
Optical pulse code sequence after leaf transformation to frequency domain and the signal after the impulse response convolution of testing fiber, AfRepresentative passes through Fourier
Optical pulse code sequence after leaf transformation to frequency domain.
Preferably, the optical pulse code sequence of the testing fiber is：By original optical pulse coded sequence by mixing bait
Fiber amplifier is amplified the optical pulse code sequence after processing.
Preferably, the original optical pulse coded sequence is：Two light pulses obtained using complementary Gray code are compiled
Code sequence in any one.
As seen from the above technical solutions, the embodiment of the present invention is by obtaining an optical pulse code sequence and light pulse
Signal after the impulse response convolution of coded sequence and testing fiber；By the letter after the optical pulse code sequence and convolution of acquisition
Number, respectively by Fourier transform to frequency domain, according to the signal after the optical pulse code sequence and convolution after conversion, it is calculated
The impulse response of testing fiber under frequency domain；The impulse response of testing fiber under frequency domain that will be obtained by inverse fourier transform
Time domain is converted into, obtains the impulse response of testing fiber.Since the present invention is using pulsatile once input, no at all consider complementary
The sum of Gray code auto-correlation is this condition of optical fiber impulse response, therefore reduces demodulating error.
Certainly, implement any of the products of the present invention or method must be not necessarily required to reach all the above excellent at the same time
Point.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is attached drawing needed in technology description to be briefly described, it should be apparent that, drawings in the following description are only this
Some embodiments of invention, for those of ordinary skill in the art, without creative efforts, can be with
Other attached drawings are obtained according to these attached drawings.
Fig. 1 is using complementary Gray code schematic diagram in background technology；
Fig. 2 is the application system figure that signal demodulates in background technology；
Fig. 3 is to amplify the inconsistent coded light pulses of afterpulse power by EDFA in the application system；
Fig. 4 is the Gray code light pulse auto-correlation summation after EDFA in the application system；
The original transfer function that Fig. 5 is used when being and being simulated in background technology；
Fig. 6 is the transmission function after being demodulated to original transfer function described in Fig. 5 by Gray；
Fig. 7 is the flow chart of the embodiment of the present invention one；
Fig. 8 is optical pulse code and the signal graph after optical fiber impulse response convolution in the embodiment of the present invention one；
The original transfer function that Fig. 9 is used when being using the simulation of one method of the embodiment of the present invention；
Figure 10 is to the transmission function after original transfer function demodulation described in Fig. 9；
Figure 11 is the structure diagram of the embodiment of the present invention two.
Embodiment
Below in conjunction with the attached drawing in the embodiment of the present invention, the technical solution in the embodiment of the present invention is carried out clear, complete
Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained every other without making creative work
Embodiment, belongs to the scope of protection of the invention.
Embodiment one
The present invention is used for a kind of embodiment of the signal demodulating method of distributed fiber-optic sensor system, can be applied to Fig. 2 institutes
In the scene shown, step is as shown in fig. 7, comprises following steps：
Step 701：Obtain an optical pulse code sequence and the impulse response of optical pulse code sequence and testing fiber volume
Signal after product；
It should be noted that the optical pulse code sequence, can be any one of any one coding mode generation
A optical pulse code sequence.
Preferably, the optical pulse code sequence, for the two optical pulse code sequences obtained using complementary Gray code
Any one in row.
Preferably, the method for obtaining optical pulse code sequence, for the method for generally use in the prior art, is specially：One
The laser that laser is sent, by the electrooptic modulator controlled by arbitrary waveform generator, forms the pulse after coding.After coding
Pulse received after erbium-doped fiber amplifier amplification by photodetector, photodetector is by the pulse after coding
It is changed into electric signal, electric signal is passed in oscillograph and shown, then obtains optical pulse code sequence by computer.
Preferably, the method for obtaining the signal after optical pulse code sequence and the impulse response convolution of testing fiber, is existing
There is the method for generally use in technology, be specially：By the amplified optical pulse code sequence of erbium-doped fiber amplifier, by ring
Row device enters in testing fiber, and the signal after the impulse response convolution of optical pulse code sequence and testing fiber is by photodetector
Received, the signal after the convolution is changed into electric signal by photodetector, and electric signal is passed in oscillograph and shown
Show, then the signal after convolution is obtained by computer, as shown in Figure 8.
Step 702：By the signal after the optical pulse code sequence of the acquisition and the convolution, by Fourier transform extremely
Frequency domain, is calculated the impulse response of the testing fiber under frequency domain；
The impulse response that the testing fiber under frequency domain is calculated, calculation formula are：Wherein, H is represented
The impulse response of testing fiber under frequency domain, Y represent the optical pulse code sequence after passing through Fourier transform to frequency domain and light to be measured
Signal after fine impulse response convolution, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain.
It should be noted that the Fourier transform process is completed in a computer.Fourier transform is ability
General knowledge known to field technique personnel, therefore detailed description will be omitted.
Step 703：The impulse response of the testing fiber under frequency domain is converted into by time domain by inverse fourier transform, is obtained
To the impulse response of testing fiber.
It is described that the impulse response of the testing fiber under frequency domain is converted into by time domain by inverse fourier transform, calculate public
Formula is：Wherein, h represents the impulse response of the testing fiber under time domain, and Y is represented by Fourier transform to frequency
Optical pulse code sequence behind domain and the signal after the impulse response convolution of testing fiber, AfRepresent by Fourier transform to frequency
Optical pulse code sequence behind domain.
It should be noted that the inverse fourier transform process is completed in a computer.Inverse fourier transform is
Well known to a person skilled in the art general knowledge, therefore detailed description will be omitted.
Simulated using the transmission function of 20km optical fiber as Fig. 9, carry out what signal demodulated using the present embodiment method
Transmission function is as shown in Figure 10, it can be seen that error very little.
Using above-described embodiment, following beneficial effect can be reached：Coded format is not required, available for various codings
Demodulation, only need to determine a coded sequence；Pass through the condition of EDFA Erbium-Doped Fiber Amplifier amplification in optical pulse code sequence
Under, the present embodiment is inputted using pulsatile once, and no at all considering the sum of complementary Gray code auto-correlation, whether optical fiber impulse is rung
This condition is answered, therefore reduces demodulating error.
Embodiment two
The present invention is used for a kind of embodiment of the signal demodulating equipment of distributed fiber-optic sensor system, as shown in figure 11, bag
Include,
Signal obtains module 111, obtains an optical pulse code sequence and the optical pulse code sequence and testing fiber
Impulse response convolution after signal；
It should be noted that the optical pulse code sequence, can be any one of any one coding mode generation
A optical pulse code sequence.
Preferably, the optical pulse code sequence, for the two optical pulse code sequences obtained using complementary Gray code
Any one in row.
Preferably, the method for obtaining optical pulse code sequence, for the method for generally use in the prior art, is specially：One
The laser that laser is sent, by the electrooptic modulator controlled by arbitrary waveform generator, forms the pulse after coding.After coding
Pulse by erbium-doped fiber amplifier amplification after, obtained by computer.
Preferably, the method for obtaining the signal after optical pulse code sequence and the impulse response convolution of testing fiber, is existing
There is the method for generally use in technology, be specially：By the amplified optical pulse code sequence of erbium-doped fiber amplifier, by ring
Row device enters in testing fiber, and the signal after the impulse response convolution of optical pulse code sequence and testing fiber is by photodetector
Received, the signal after the convolution is changed into electric signal by photodetector, and electric signal is passed in oscillograph and shown
Show, then the signal after convolution is obtained by computer.
Signal conversion module 112, by the signal after the optical pulse code sequence of the acquisition and the convolution, passes through Fourier
The impulse response of the testing fiber under frequency domain is calculated to frequency domain in leaf transformation；
The impulse response that the testing fiber under frequency domain is calculated, calculation formula are：Wherein, H is represented
The impulse response of testing fiber under frequency domain, Y represent the optical pulse code sequence after passing through Fourier transform to frequency domain and light to be measured
Signal after fine impulse response convolution, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain.
It should be noted that the Fourier transform process is completed in a computer.Fourier transform is ability
General knowledge known to field technique personnel, therefore detailed description will be omitted.
Signal inverse transform module 113, is become the impulse response of the testing fiber under frequency domain by inverse fourier transform
Time domain is shifted to, obtains the impulse response of testing fiber.
It is described that the impulse response of the testing fiber under frequency domain is converted into by time domain by inverse fourier transform, calculate public
Formula is：Wherein, h represents the impulse response of the testing fiber under time domain, and Y is represented by Fourier transform to frequency
Optical pulse code sequence behind domain and the signal after the impulse response convolution of testing fiber, AfRepresent by Fourier transform to frequency
Optical pulse code sequence behind domain.
It should be noted that the inverse fourier transform process is completed in a computer.Inverse fourier transform is
Well known to a person skilled in the art general knowledge, therefore detailed description will be omitted.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any this actual relation or order.Moreover, term " comprising ", "comprising" or its any other variant are intended to
Non-exclusive inclusion, so that process, method, article or equipment including a series of elements not only will including those
Element, but also including other elements that are not explicitly listed, or further include as this process, method, article or equipment
Intrinsic key element.In the absence of more restrictions, the key element limited by sentence "including a ...", it is not excluded that
Also there are other identical element in process, method, article or equipment including the key element.
Each embodiment in this specification is described using relevant mode, identical similar portion between each embodiment
Divide mutually referring to what each embodiment stressed is the difference with other embodiment.It is real especially for system
For applying example, since it is substantially similar to embodiment of the method, so description is fairly simple, related part is referring to embodiment of the method
Part explanation.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the scope of the present invention.It is all
Any modification, equivalent replacement, improvement and so within the spirit and principles in the present invention, are all contained in protection scope of the present invention
It is interior.
Claims (10)
1. a kind of signal demodulating method for distributed fiber-optic sensor system, it is characterised in that comprise the following steps：
Obtain the signal after an optical pulse code sequence and optical pulse code sequence and the impulse response convolution of testing fiber；
By the signal after the optical pulse code sequence and convolution of acquisition, respectively by Fourier transform to frequency domain, after conversion
Optical pulse code sequence and convolution after signal, the impulse response of the testing fiber under frequency domain is calculated；
The obtained impulse response of testing fiber under frequency domain is converted into by time domain by inverse fourier transform, obtains testing fiber
Impulse response.
2. the signal demodulating method according to claim 1 for distributed fiber-optic sensor system, it is characterised in that described
The impulse response that the testing fiber under frequency domain is calculated, calculation formula is：Wherein, H is represented and treated under frequency domain
The impulse response of optical fiber is surveyed, Y represents the impulse of optical pulse code sequence and testing fiber after passing through Fourier transform to frequency domain
Respond the signal after convolution, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain.
3. the signal demodulating method according to claim 2 for distributed fiber-optic sensor system, it is characterised in that described
The obtained impulse response of testing fiber under frequency domain is converted into by time domain by inverse fourier transform, calculation formula is：Wherein, h represents the impulse response of the testing fiber under time domain, and Y is represented by after Fourier transform to frequency domain
Signal after optical pulse code sequence and the impulse response convolution of testing fiber, AfRepresent by after Fourier transform to frequency domain
Optical pulse code sequence.
4. the signal demodulating method for distributed fiber-optic sensor system according to claim 1-3 any one, it is special
Sign is that the optical pulse code sequence of the testing fiber is：The optical pulse code sequence of acquisition is amplified by erbium-doped fiber
Device is amplified the optical pulse code sequence after processing.
5. the signal demodulating method according to claim 4 for distributed fiber-optic sensor system, it is characterised in that described
The optical pulse code sequence of acquisition be：It is any one in the two optical pulse code sequences obtained using complementary Gray code
It is a.
A kind of 6. signal demodulating equipment for distributed fiber-optic sensor system, it is characterised in that including,
Signal obtains module, obtains an optical pulse code sequence and the impulse response of optical pulse code sequence and testing fiber
Signal after convolution；
Signal conversion module, by the signal after the optical pulse code sequence and convolution of acquisition, passes through Fourier transform to frequency respectively
Domain, according to the signal after the optical pulse code sequence and convolution after conversion, the impulse that the testing fiber under frequency domain is calculated is rung
Should；
Signal inverse transform module, will be obtained when the impulse response of testing fiber is converted under frequency domain by inverse fourier transform
Domain, obtains the impulse response of testing fiber.
7. the signal demodulating equipment according to claim 6 for distributed fiber-optic sensor system, it is characterised in that described
The impulse response that the testing fiber under frequency domain is calculated, calculation formula is：Wherein, H is represented and treated under frequency domain
The impulse response of optical fiber is surveyed, Y represents the impulse of optical pulse code sequence and testing fiber after passing through Fourier transform to frequency domain
Respond the signal after convolution, AfRepresent the optical pulse code sequence after passing through Fourier transform to frequency domain.
8. the signal demodulating equipment according to claim 7 for distributed fiber-optic sensor system, it is characterised in that described
The obtained impulse response of testing fiber under frequency domain is converted into by time domain by inverse fourier transform, calculation formula is：Wherein, h represents the impulse response of the testing fiber under time domain, and Y is represented by after Fourier transform to frequency domain
Signal after optical pulse code sequence and the impulse response convolution of testing fiber, AfRepresent by after Fourier transform to frequency domain
Optical pulse code sequence.
9. the signal demodulating equipment for distributed fiber-optic sensor system according to claim 6-8 any one, it is special
Sign is that the optical pulse code sequence of the testing fiber is：The optical pulse code sequence of acquisition is put by erbium-doped fiber
Big device is amplified the optical pulse code sequence after processing.
10. the signal demodulating equipment according to claim 9 for distributed fiber-optic sensor system, it is characterised in that institute
The optical pulse code sequence for the acquisition stated is：It is any one in the two optical pulse code sequences obtained using complementary Gray code
It is a.
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| CN107782346B (en) * | 2017-10-27 | 2019-08-27 | 武汉理工大学 | Large-scale optical fiber grating sensing network demodulation system and method based on Gray code |
| CN109506686B (en) * | 2018-12-19 | 2021-03-23 | 武汉理工光科股份有限公司 | Method for improving detection performance of isotactic fiber bragg grating |
| US10727937B1 (en) * | 2019-03-01 | 2020-07-28 | Huawei Technologies Co., Ltd. | Multi-layer encoding of optical signals |
| CN110568439B (en) * | 2019-09-25 | 2023-08-22 | 中南大学 | Deconvolution-based impulse type through-wall radar antenna ringing suppression method |
| CN112444959B (en) * | 2020-11-20 | 2023-01-17 | 中电科思仪科技(安徽)有限公司 | Device and method for processing optical fiber image ghost |
| CN114061736B (en) * | 2021-11-18 | 2022-11-25 | 北京邮电大学 | Rayleigh distributed phase demodulation optical fiber sensing method and system based on frequency and intensity encoding and decoding |
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