CN104977079B - A kind of signal demodulating method and device - Google Patents
A kind of signal demodulating method and device Download PDFInfo
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Abstract
The embodiments of the invention provide a kind of signal demodulating method and device, wherein, methods described includes：Obtain the first signal frame of the first detector detection, and the secondary signal frame of the second detector detection；Determine first signal frame with corresponding at least one weak signal pair of synchronization in the secondary signal frame；When to each weak signal to handling, first signal frame described in current weak signal pair and the weak signal in the secondary signal frame are deployed according to Bessel function of the first kind respectively, respectively obtain the function expansion corresponding with the weak signal of current weak signal centering；By the function expansion, it is determined that currently weak signal is to phase difference caused by corresponding external disturbance signal, by the phase difference to current weak signal to being demodulated.By signal demodulation scheme provided in an embodiment of the present invention, weak signal can accurately be demodulated, and then the position of invader can be positioned exactly.
Description
Technical field
The present invention relates to signal processing technology field, more particularly to a kind of signal demodulating method and device.
Background technology
With the development of society, the raising of people's security protection consciousness, all kinds of security and guard technology means are widely used.It is existing
The conventional safety-protection system solution in generation is for example infrared point-to-point to the scheme of penetrating, fence, power network, induction cable and optical fiber
Safety-protection system.Optical fiber safety-protection system is a kind of sensor-based system for using optical fibers as sensor information, and optical fiber is as sensor information
While the and medium as optical transport.Optical fiber safety-protection system can monitor 40Km in real time with exterior domain at present, and to certain precision
In the range of accident carry out remotely and in real time alarm.
The operation principle of optical fiber safety-protection system is：Optical fiber safety-protection system sends sensor fibre to defence area, is visited by optical signal
Survey the optical signal that device returns fiber reflection to be demodulated, the position of invader is positioned by demodulation result, and sends
Warning message.
The core of optical fiber safety-protection system is the long-distance sensing system based on optical fiber Sagnac (Sagnac) interferometer principle
System, the long-distance sensing system light path structure based on optical fiber Sagnac interferometer principles are as shown in Figure 1.In Fig. 1, SLD is light source,
C1For circulator, C2For 3 × 3 couplers, M is faraday rotation mirror, P1、P2Respectively two-way detector.P1、P2The signal received
Two classes are broadly divided into, the first kind is P1、P2Middle crosspoint is not referred to as strong signal in the signal of null value, such signal；Second class is
P1、P2Middle crosspoint is located at the signal of dead-center position, and such signal is referred to as weak signal.Current signal demodulation scheme, right
P1、P2When the signal detected is demodulated, can't tell the men from the boys signal, but blindly either believe all signals by force
Number or weak signal be demodulated according to differential algorithm or normalization algorithm.
And the method that differential algorithm or normalization algorithm are demodulated to signal, the demodulation of strong signal is only applicable to, it is right
It is low according to this method, resulting demodulation result accuracy in the demodulation of weak signal.This signal is entered it can be seen that existing
The scheme of row demodulation, due to being demodulated all signals all blindnesses according to differential algorithm or normalization algorithm, because
, the problem of low to weak signal demodulation result accuracy be present in this.Further, the existing this side being demodulated to signal
Case, due to low to weak signal demodulation result accuracy, and the demodulation result of weak signal be also invader is positioned it is important
Privacy, therefore, most lead to not exactly position the position of invader at last.
The content of the invention
The embodiments of the invention provide a kind of signal demodulating method and device, to solve current signal demodulating method, because
Weak signal can not accurately be demodulated, caused by the problem of can not being positioned exactly to the position of invader.
In order to solve the above problems, the invention discloses a kind of signal demodulating method, including：Obtain the detection of the first detector
The first signal frame, and the second detector detection secondary signal frame；Determine first signal frame and the secondary signal
Correspond at least one weak signal pair of synchronization in frame；When to each weak signal to handling, by current weak signal
The first signal frame to described in deploys according to Bessel function of the first kind respectively with the weak signal in the secondary signal frame, respectively
Obtain the function expansion corresponding with the weak signal of current weak signal centering；By the function expansion, it is determined that current weak
Signal is to phase difference caused by corresponding external disturbance signal, by the phase difference to current weak signal to being demodulated.
Preferably, it is described to determine first signal frame with corresponding at least the one of synchronization in the secondary signal frame
Individual weak signal includes to step：It is each in signal and the secondary signal frame to each moment in first signal frame
The signal at moment is normalized；Signal to each moment in first signal frame after normalized and
The signal at each moment in the secondary signal frame after normalized is compared；By synchronization and at normalization
The signal for after reason being all null value is defined as a pair of weak signals.
Preferably, by the weak signal in the first signal frame of current weak signal centering and the secondary signal frame respectively according to
Bessel function of the first kind deploys, and the step of respectively obtaining the function expansion corresponding with current weak signal centering weak signal wraps
Include：Determine the weak signal in the first expression formula corresponding to the weak signal in first signal frame, and the secondary signal frame
Corresponding second expression formula；It is determined that carry out Bessel function of the first kind expansion, the Taylor's formula deployed under specified point；By institute
The Taylor's formula deployed described in the substitution of the first expression formula under specified point is stated, is obtained and the weak signal in first signal frame
Corresponding first function expansion；The Taylor's formula that will deploy described in second expression formula substitution under specified point, is obtained
The second function expansion corresponding with the weak signal in the secondary signal frame.
Preferably, the first expression formula corresponding to the weak signal in first signal frame is：Second expression formula corresponding to weak signal in the secondary signal frame is：Wherein, the ω represents the normalization angular frequency of the outer signals disturbance of optical fiber sensing
Rate, at the time of t represents that weak signal corresponds to, CnNormalization coefficient is represented, what the first detector of expression and the second detector detected
The initial phase difference of two-way light,Represent external disturbance signal phase difference corresponding to the weak signal of t；By described first
Expression formula substitute into described in the Taylor's formula deployed under specified point, corresponding with the weak signal in the first signal frame the obtained
One function expansion is：Will
Second expression formula substitute into described in the Taylor's formula deployed under specified point, it is obtaining with weak signal phase in secondary signal frame
Corresponding second function expansion is：
Preferably, it is described by function expansion, it is determined that phase caused by external disturbance signal corresponding to current weak signal
The step of difference includes：Only retain in the first function expansion, setting exponent number item and generate the 3rd function expansion, only retain
In the second function expansion, setting exponent number item generates the 4th function expansion；To the 3rd function expansion and
4th function expansion is handled, and obtains the weak signal to the micro- of phase difference caused by corresponding external disturbance signal
Point；Integral and calculating is carried out to the differential, obtains current weak signal to phase difference caused by corresponding external disturbance signal.
In order to solve the above problems, the invention also discloses a kind of signal demodulating equipment, including：Acquisition module, for obtaining
The first signal frame for taking the first detector to detect, and the secondary signal frame of the second detector detection；Determining module, for determining
First signal frame and at least one weak signal pair for corresponding to synchronization in the secondary signal frame；Demodulation module, use
In when to each weak signal to handling, by the first signal frame described in current weak signal pair and the secondary signal frame
Weak signal deploy respectively according to Bessel function of the first kind, respectively obtain corresponding with the weak signal of current weak signal centering
Function expansion；By the function expansion, it is determined that current weak signal is to phase difference caused by corresponding external disturbance signal,
By the phase difference to current weak signal to being demodulated.
Preferably, the determining module includes：Module is normalized, for the letter to each moment in first signal frame
Number and the signal at each moment in the secondary signal frame be normalized；Comparing module, for normalized
Each moment in the secondary signal frame after the signal and normalized at each moment in first signal frame afterwards
Signal be compared；Weak signal to determining module, for by synchronization and the signal that after normalized is all null value
It is defined as a pair of weak signals.
Preferably, the demodulation module by the first signal frame of current weak signal centering with it is weak in the secondary signal frame
Signal deploys according to Bessel function of the first kind respectively, respectively obtains the function exhibition corresponding with current weak signal centering weak signal
During open type：Determine weak in the first expression formula corresponding to the weak signal in first signal frame, and the secondary signal frame
Second expression formula corresponding to signal；It is determined that carry out Bessel function of the first kind expansion, the Taylor's formula deployed under specified point；
The Taylor's formula that will deploy described in first expression formula substitution under specified point, is obtained and the weak letter in first signal frame
Number corresponding first function expansion；The Taylor's formula that will deploy described in second expression formula substitution under specified point, is obtained
To the second function expansion corresponding with the weak signal in the secondary signal frame.
Preferably, the first expression formula corresponding to the weak signal in first signal frame is：Second expression formula corresponding to weak signal in the secondary signal frame is：Wherein, the ω represents the normalization angular frequency of the outer signals disturbance of optical fiber sensing
Rate, at the time of t represents that weak signal corresponds to, CnNormalization coefficient is represented, what the first detector of expression and the second detector detected
The initial phase difference of two-way light,Represent external disturbance signal phase difference corresponding to the weak signal of t；By described first
Expression formula substitute into described in the Taylor's formula deployed under specified point, corresponding with the weak signal in the first signal frame the obtained
One function expansion is：Will
Second expression formula substitute into described in the Taylor's formula deployed under specified point, it is obtaining with weak signal phase in secondary signal frame
Corresponding second function expansion is：
Preferably, the demodulation module is by function expansion, it is determined that external disturbance signal production corresponding to current weak signal
During raw phase difference：Only retain in the first function expansion, setting exponent number item and generate the 3rd function expansion, only retain
In the second function expansion, setting exponent number item generates the 4th function expansion；To the 3rd function expansion and
4th function expansion is handled, and obtains the weak signal to the micro- of phase difference caused by corresponding external disturbance signal
Point；Integral and calculating is carried out to the differential, obtains current weak signal to phase difference caused by corresponding external disturbance signal.
Compared with prior art, the present invention has advantages below：
Signal demodulation scheme provided in an embodiment of the present invention, getting the first signal of acquisition the first detector detection
Frame, and during the secondary signal frame of the second detector detection, it is first determined the weak signal pair in signal frame.And for weak signal pair
I.e. weak signal is then deployed using Bessel function of the first kind, respectively obtains the letter corresponding with the weak signal of current weak signal centering
Number expansion, then handles function expansion, determines weak signal to phase caused by corresponding external disturbance signal again
Difference.It can be seen that signal demodulation scheme provided in an embodiment of the present invention is when the signal in signal frame is handled, can be by weak letter
Number made a distinction with strong signal, and targetedly to weak signal to being demodulated, due in the embodiment of the present invention using having
Effect ground mode is demodulated to weak signal, therefore, it is possible to accurately be demodulated to weak signal, and then can be exactly to invader
Position positioned.
Brief description of the drawings
Fig. 1 is fibre optic interferometer light channel structure figure；
Fig. 2 is a kind of step flow chart of according to embodiments of the present invention one signal demodulating method；
Fig. 3 is a kind of step flow chart of according to embodiments of the present invention two signal demodulating method；
Fig. 4 is the step flow chart that signal demodulation is carried out using the signal demodulating method shown in embodiment two；
Fig. 5 is the original waveform figure for the signal frame being demodulated using the method shown in Fig. 4；
Fig. 6 is obtained demodulation result after being demodulated using the method shown in Fig. 4 to the signal frame shown in Fig. 5
Curve map；
Fig. 7 is the curve of obtained demodulation result after being demodulated using existing method to the signal frame shown in Fig. 5
Figure；
Fig. 8 is a kind of structured flowchart of according to embodiments of the present invention three signal demodulating equipment.
Embodiment
In order to facilitate the understanding of the purposes, features and advantages of the present invention, it is below in conjunction with the accompanying drawings and specific real
Applying mode, the present invention is further detailed explanation.
Embodiment one
Reference picture 1, show a kind of step flow chart of according to embodiments of the present invention one signal demodulating method.
The signal demodulating method of the embodiment of the present invention comprises the following steps：
Step S102：Obtain the first signal frame of the first detector detection, and the secondary signal of the second detector detection
Frame.
Detector carries out processing after signal is detected, to signal and converts thereof into electric signal, then according to setpoint frequency
To master control set (such as：Computer, processing module, processor, main control module etc.) send signal frame.Optical fiber in the present embodiment
Two detectors are provided with interferometer light path, therefore, master control set can obtain respectively two detectors i.e. the first detector with
The signal frame that second detector is sent.
Step S104：Determine the first signal frame with corresponding at least one weak signal of synchronization in secondary signal frame
It is right.
Multiple signals are included in signal frame, and each signal is corresponding with respective signal intensity and time point is instant
Carve.Strong signal is not referred to as in the signal of null value based on crosspoint in two paths of signals, crosspoint is located at zero point in two paths of signals
The signal of position, such signal are referred to as the principle of weak signal, similarly by synchronization in two signal frames in the present embodiment
Signal is compared, to determine weak signal pair.
It should be noted that identified weak signal be to that may only have a pair, it is possible that multipair, particular number be by
Signal in first signal frame and secondary signal frame determines.
In the present embodiment, determine the first signal frame with each weak signal in secondary signal frame to rear, to each signal
Frame carries out subsequent step S106 and step S108 processing.
Step S106：When to each weak signal to handling, by the current signal frame of weak signal centering first and second
Weak signal in signal frame is deployed according to Bessel function of the first kind respectively, respectively obtains the weak signal with current weak signal centering
Corresponding function expansion.
Preferably, when weak signal is deployed according to Bessel function of the first kind, by corresponding to weak signal expression formula substitute into,
In the Taylor's formula deployed under specified point, then the function for deploying to obtain according to Bessel function of the first kind by weak signal can be realized
Expansion.
Step S108：By function expansion, it is determined that current weak signal is to phase caused by corresponding external disturbance signal
Difference, by the phase difference to weak signal to being demodulated.
In the present embodiment, by above-mentioned signal demodulating method, it can demodulate in the first signal frame and secondary signal frame
Each pair of weak signal corresponding to phase difference caused by external disturbance signal, then demodulate by existing correlation demodulation method
It is each to phase difference caused by external disturbance signal corresponding to strong signal in one signal frame and secondary signal frame, by demodulating
Each phase difference the position of invader is positioned using existing correlation technique.
The signal demodulating method provided by the present embodiment, getting the first signal of acquisition the first detector detection
Frame, and during the secondary signal frame of the second detector detection, it is first determined the weak signal pair in signal frame.And for weak signal pair
I.e. weak signal is then deployed using Bessel function of the first kind, respectively obtains the letter corresponding with the weak signal of current weak signal centering
Number expansion, then handles function expansion, determines weak signal to phase caused by corresponding external disturbance signal again
Difference.It can be seen that the signal demodulating method that the present embodiment provides, has to property to weak signal to being demodulated, due in the present embodiment
Weak signal is demodulated using effectively mode, therefore, it is possible to accurately be demodulated to weak signal, and then can be right exactly
The position of invader is positioned.
Embodiment two
Reference picture 2, show a kind of step flow chart of according to embodiments of the present invention two signal demodulating method.
The signal demodulating method of the embodiment of the present invention specifically includes following steps：
Step S202：First signal frame of main control module acquisition the first detector detection, and the detection of the second detector
Secondary signal frame.
Multiple signals are included in signal frame, and each signal is corresponding with respective signal intensity and time point is instant
Carve.In the present embodiment, by the signal P in the first signal frame1Represent, by the signal P in secondary signal frame2Represent.Wherein,
First detector and the second detector synchronizing detection signal, main control module are receiving the first detector and the spy of the second detector
After measuring signal frame, analyzed after two-way synchronizing signal is combined.
Step S204：When main control module is to each in the signal and secondary signal frame at each moment in the first signal frame
The signal at quarter is normalized.
Wherein, a kind of mode that preferably signal in the first signal frame is normalized is as follows：
S1：Determine maximum signal value in the first signal frame, and minimum signal strength value；
S2：It is poor that the signal at each moment in the first signal frame is made with minimum signal strength value respectively, is then removed with difference
With maximum signal value and the difference of minimum signal strength value, to realize that the signal to each moment in the first signal frame is carried out
Normalized.
Such as：The signal intensity of three signals included in first signal frame is respectively 3,4 and 5, then, to first
Then it is (3-3)/(5-3)=0 when signal is normalized, correspondingly, the result difference after other two signal normalization process
For 1/2,1.
Using with the signal in the first signal frame is normalized by the way of can be to each in secondary signal frame
The signal at moment is normalized.
Step S206：Signal and normalizing of the main control module to each moment in the first signal frame after normalized
The signal at each moment in secondary signal frame after change processing is compared, by synchronization and after normalized be all
The signal of null value is defined as a pair of weak signals.
It should be noted that the first signal frame in secondary signal frame to there may be multiple weak signals pair, it is also possible to only deposits
In a weak signal pair, specific number depends on the first signal frame and the signal intensity in secondary signal frame.
In the present embodiment, during the first signal frame is determined with after each pair of weak signal in secondary signal frame, respectively to each
Weak signal is handled as follows.
Step S208：Main control module to current weak signal to handling when, determine the weak signal pair in the first signal frame
The first expression formula answered, and the second expression formula corresponding to weak signal in secondary signal frame.
The first expression formula is corresponding to weak signal in first signal frame：
The second expression formula is corresponding to weak signal in secondary signal frame：
Wherein, ω represents the normalized radian frequency of the outer signals disturbance of optical fiber sensing, when t is represented corresponding to weak signal
Carve, CnNormalization coefficient is represented, represents the initial phase difference for the two-way light that the first detector and the second detector detect,Represent external disturbance signal phase difference corresponding to the weak signal of t.
It should be noted that during specific implementation, CnValue can be by those skilled in the art according to the actual requirements
It is configured, such as：It is arranged to 1,2,3 etc., the present embodiment is not specifically limited to this.
Step S210：Main control module determines Taylor carrying out Bessel function of the first kind expansion, deploying under specified point
Formula.
Wherein, Taylor's formula is
When the Taylor's formula deployed under specified point is a=0, the expansion after Taylor's formula conversion.
Step S212：Main control module substitutes into the first expression formula the Taylor's formula deployed under specified point, obtains and first
The corresponding first function expansion of weak signal in signal frame；It is public that second expression formula is substituted into the Taylor deployed under specified point
Formula, obtain the second function expansion corresponding with the weak signal in secondary signal frame.
First expression formula is substituted into the Taylor's formula deployed under specified point, obtain with the weak signal in the first signal frame
Corresponding first function expansion is：
Will the second expression formula substitute into described in the Taylor's formula deployed under specified point, obtain with it is weak in secondary signal frame
The corresponding second function expansion of signal is：
Step S214：Main control module only retains in first function expansion, setting exponent number item and generates the 3rd functional expansion
Formula, only retain in second function expansion, setting exponent number item and generate the 4th function expansion.
Wherein, setting exponent number item can be configured according to the actual requirements by those skilled in the art, such as：It is arranged to only
Retain first three rank item, the later higher order term of three rank items is ignored, then for example：Be arranged to only retain before quadravalence item, by quadravalence item with
High-order afterwards is ignored, it is, of course, also possible to two rank items etc. before only retaining first five rank item or only retaining.
Preferably, it is arranged to only retain first three rank item, the later higher order term of three rank items is ignored, the 3rd generated after ignoring
Function expansion is：
4th function expansion is：
Step S216：Main control module is handled the 3rd function expansion and the 4th function expansion, obtains weak letter
Number to the differential of phase difference caused by corresponding external disturbance signal.
It is a kind of that preferably the 3rd function expansion and the 4th function expansion are handled, weak signal is obtained to corresponding
External disturbance signal caused by phase difference differential mode it is as follows：
S1, the 3rd function expansion is added with the 4th function expansion, obtains first function expression formula；
I.e.：
S2, the 3rd function expansion is subtracted each other with the 4th function expansion, obtains second function expression formula；
I.e.：
S3, second function expression formula is differentiated；
Resulting functional expression is：
S4, obtained using first function expression formula
S5, (10) substitution (11) is obtained
It should be noted that during specific implementation, it is not limited to cited by the present embodiment, by the 3rd function
Expansion and the 4th function expansion make it is poor and.Concrete processing procedure, can be true according to the actual requirements by those skilled in the art
It is fixed.
Step S218：Integral and calculating is carried out to differential, obtains current weak signal to caused by corresponding external disturbance signal
Phase difference.
Current weak signal is to phase difference caused by corresponding external disturbance signalExpression formula be：
In specific calculating process, if the coupler in fibre optic interferometer is 3 × 3 couplers, by φ0It is arranged toPreferably, by Cn1 is arranged to, can so simplify calculating.
In the present embodiment, by above-mentioned signal demodulating method, it can demodulate in the first signal frame and secondary signal frame
Each pair of weak signal corresponding to phase difference caused by external disturbance signal, then demodulate by existing correlation demodulation method
It is each to phase difference caused by external disturbance signal corresponding to strong signal in one signal frame and secondary signal frame, by demodulating
Each phase difference the position of invader is positioned using existing correlation technique.Such as：Each phase difference obtained to demodulation
Following handling processes are performed successively：Digital filtering, spectrum analysis, curve matching, wavelet analysis, depression points are looked for, when it is determined that depression
After point, position corresponding to depression points is the position of invader.
The signal demodulating method provided by the present embodiment, getting the first signal of acquisition the first detector detection
Frame, and during the secondary signal frame of the second detector detection, it is first determined the weak signal pair in signal frame.And for weak signal pair
I.e. weak signal is then deployed using Bessel function of the first kind, respectively obtains the letter corresponding with the weak signal of current weak signal centering
Number expansion, then handles function expansion, determines weak signal to phase caused by corresponding external disturbance signal again
Difference.It can be seen that the signal demodulating method that the present embodiment provides, has to property to weak signal to being demodulated, due in the present embodiment
Weak signal is demodulated using effectively mode, therefore, it is possible to accurately be demodulated to weak signal, and then can be right exactly
The position of invader is positioned.
The demodulation method of the optical fibre vibration sensor small-signal of the present embodiment is illustrated with an instantiation below,
Idiographic flow is referring to accompanying drawing 4.As shown in figure 4, the demodulation method of the optical fibre vibration sensor small-signal of the present embodiment include with
Lower step：
Step S402：Preprocessed data.
First signal frame, and secondary signal frame are pre-processed, wherein, pretreatment can include interception setting time
The the first signal framing and secondary signal framing of section.
Step S404：Each signal in first signal frame is normalized.
Step S406：Each signal in secondary signal frame is normalized.
It should be noted that step S406 is not limited to perform after step S404, can be before step S404
Perform, can also be performed parallel with step S404.
It is as shown in Figure 5 with the oscillogram in secondary signal frame in the first signal frame after normalized.
Correlation process method in embodiment two specifically may refer to the method for signal frame processing.In this instantiation,
It is each in the secondary signal frame after signal and normalized to each moment in the first signal frame after normalized
The signal at moment is compared, by synchronization and the signal that after normalized is all null value be defined as a pair of weak signals.
In this instantiation, during the first signal frame is determined with after each pair of weak signal in secondary signal frame, it is right respectively
Each pair of weak signal is handled as follows.
Step S408：To the weak signal in the first signal frame according to series expansion.
Step S410：To the weak signal in secondary signal frame according to series expansion.
For the specific method in step S408 and step S410 to weak signal according to series expansion, embodiment may refer to
Step S208 will not be repeated here to step S214 in two.
Step S412：The series expansion obtained in step S408 and step S410 is added.
In this step, first function is obtained after the series expansion obtained in step S408 and step S410 is added
Expression formula.
Step S414：The series expansion obtained in step S408 and step S410 is subtracted each other.
In this step, second function is obtained after the series expansion obtained in step S408 and step S410 is added
Expression formula.
Step S416：Obtained using first function expression formula
For how to obtainThe associated expression that may refer in embodiment two obtains.
Step S418：Second function expression formula is differentiated.
Step S420：Obtained by step S416 and step S418Expression formula and differential expressions obtain
Arrive
Step S422：To obtained differentialIntegral and calculating is carried out, current weak signal is obtained and the corresponding external world is disturbed
Phase difference caused by dynamic signal.
In this instantiation, by above-mentioned signal demodulating method, the first signal frame and secondary signal frame can be demodulated
In each pair of weak signal corresponding to phase difference caused by external disturbance signal, then demodulated by existing correlation demodulation method
It is each to phase difference caused by external disturbance signal corresponding to strong signal in first signal frame and secondary signal frame, pass through demodulation
Each phase difference gone out is positioned using existing correlation technique to the position of invader.Such as：Each phase obtained to demodulation
Difference performs following handling processes successively：Digital filtering, spectrum analysis, curve matching, wavelet analysis, depression points are looked for, when it is determined that recessed
After trapping spot, position corresponding to depression points is the position of invader.Using the method shown in Fig. 4 to the signal shown in Fig. 5
After frame is demodulated, the curve map of obtained demodulation result is as shown in Figure 6.Correspondingly, if using existing method in Fig. 5
Shown signal frame is demodulated, then, the curve map of obtained demodulation result is as shown in Figure 7.
Embodiment three
Reference picture 8, show a kind of structured flowchart of signal demodulating equipment of the embodiment of the present invention three.
Signal demodulating equipment in the present embodiment can apply to optical fiber warning system, the signal demodulation dress in the present embodiment
Put including：Acquisition module 802, for obtaining the first signal frame of the first detector detection, and the of the detection of the second detector
Binary signal frame；Determining module 804, for determining the first signal frame with corresponding at least one of synchronization in secondary signal frame
Weak signal pair；Demodulation module 806, for when to each weak signal to handling, by the current signal of weak signal centering first
Frame deploys according to Bessel function of the first kind respectively with the weak signal in secondary signal frame, respectively obtains and current weak signal centering
The corresponding function expansion of weak signal；By function expansion, it is determined that current weak signal is to corresponding external disturbance signal
Caused phase difference, by phase difference to current weak signal to being demodulated.
Preferably, determining module 804 includes：Module 8042 is normalized, for the letter to each moment in the first signal frame
Number and the signal at each moment in secondary signal frame be normalized；Comparing module 8044, for normalized
The signal at each moment in secondary signal frame after the signal and normalized at each moment in the first signal frame afterwards enters
Row compares；Weak signal to determining module 8046, for by synchronization and the signal that after normalized is all null value determine
For a pair of weak signals.
Preferably, demodulation module 806 is by the weak signal in the first signal frame of current weak signal centering and secondary signal frame
Deploy respectively according to Bessel function of the first kind, respectively obtain the function expansion corresponding with current weak signal centering weak signal
When：Determine corresponding to the weak signal in the first expression formula, and secondary signal frame corresponding to the weak signal in the first signal frame
Two expression formulas；It is determined that carry out Bessel function of the first kind expansion, the Taylor's formula deployed under specified point；By the first expression formula
The Taylor's formula deployed under specified point is substituted into, obtains the first function expansion corresponding with the weak signal in the first signal frame
Formula；Second expression formula is substituted into the Taylor's formula deployed under specified point, obtained corresponding with the weak signal in secondary signal frame
Second function expansion.
Preferably, the first expression formula corresponding to the weak signal in the first signal frame is：
The second expression formula is corresponding to weak signal in secondary signal frame：Wherein, ω tables
Show the normalized radian frequency of the outer signals disturbance of optical fiber sensing, at the time of t represents that weak signal corresponds to, CnRepresent normalizing
Change coefficient, represent the initial phase difference for the two-way light that the first detector and the second detector detect,Represent
External disturbance signal phase difference corresponding to the weak signal of t；First expression formula is substituted under specified point and opened up
The Taylor's formula opened, the obtained first function expansion corresponding with the weak signal in the first signal frame are：Second expression formula is substituted into
The Taylor's formula deployed under specified point, the obtained second function expansion corresponding with the weak signal in secondary signal frame are
Preferably, demodulation module 806 is by function expansion, it is determined that external disturbance signal corresponding to current weak signal produces
Phase difference when：Only retain in first function expansion, setting exponent number item and generate the 3rd function expansion, only retain the second letter
In number expansion, setting exponent number item generates the 4th function expansion；To the 3rd function expansion and the 4th function expansion
Handled, obtain differential of the weak signal to phase difference caused by corresponding external disturbance signal；Integral and calculating is carried out to differential,
Current weak signal is obtained to phase difference caused by corresponding external disturbance signal.
The signal demodulating equipment of the present embodiment is used to realize corresponding signal demodulation side in previous embodiment one, embodiment two
Method, and the beneficial effect with corresponding embodiment of the method, will not be repeated here.
Each embodiment in this specification is described by the way of progressive, what each embodiment stressed be with
The difference of other embodiment, between each embodiment identical similar part mutually referring to.For system embodiment
For, because it is substantially similar to embodiment of the method, so description is fairly simple, referring to the portion of embodiment of the method in place of correlation
Defend oneself bright.
Above to a kind of signal demodulating method provided by the present invention and device, it is described in detail, it is used herein
Specific case is set forth to the principle and embodiment of the present invention, and the explanation of above example is only intended to help and understands
The method and its core concept of the present invention；Meanwhile for those of ordinary skill in the art, according to the thought of the present invention, having
There will be changes in body embodiment and application, in summary, this specification content should not be construed as to the present invention
Limitation.
Claims (2)
- A kind of 1. signal demodulating method, it is characterised in that including：Obtain the first signal frame of the first detector detection, and the secondary signal frame of the second detector detection；Determine first signal frame with corresponding at least one weak signal pair of synchronization, bag in the secondary signal frame Include：Signal to each moment in first signal frame and the signal at each moment in the secondary signal frame are returned One change is handled；The institute after signal and normalized to each moment in first signal frame after normalized The signal for stating each moment in secondary signal frame is compared；By synchronization and the letter that after normalized is all null value Number it is defined as a pair of weak signals；When to each weak signal to handling, by the first signal frame described in current weak signal pair and the secondary signal frame In weak signal deploy respectively according to Bessel function of the first kind, respectively obtain corresponding with the weak signal of current weak signal centering Function expansion；By the function expansion, it is determined that current weak signal is to phase caused by corresponding external disturbance signal Difference, by the phase difference to current weak signal to being demodulated；Wherein, by the weak signal in the first signal frame of current weak signal centering and the secondary signal frame respectively according to the first kind Bessel function deploys, and the step of respectively obtaining the function expansion corresponding with current weak signal centering weak signal includes：Really Corresponding to weak signal in first expression formula, and the secondary signal frame corresponding to weak signal in fixed first signal frame Second expression formula；It is determined that carry out Bessel function of the first kind expansion, the Taylor's formula deployed under specified point；By described first The Taylor's formula deployed described in expression formula substitution under specified point, is obtained corresponding with the weak signal in first signal frame First function expansion；Will second expression formula substitute into described in the Taylor's formula deployed under specified point, obtain and described the The corresponding second function expansion of weak signal in binary signal frame；First expression formula corresponding to weak signal in first signal frame is：It is described The second expression formula is corresponding to weak signal in secondary signal frame：Wherein, the ω Represent the normalized radian frequency of the outer signals disturbance of optical fiber sensing, at the time of t represents that weak signal corresponds to, CnExpression is returned One changes coefficient, represents the initial phase difference for the two-way light that the first detector and the second detector detect,When representing t External disturbance signal phase difference corresponding to the weak signal at quarter；It will deploy described in first expression formula substitution under specified point Taylor's formula, the obtained first function expansion corresponding with the weak signal in the first signal frame be：By the second expression formula generation Enter the Taylor's formula deployed under specified point, the obtained second function exhibition corresponding with the weak signal in secondary signal frame Open type is：It is described by function expansion, it is determined that being wrapped corresponding to current weak signal caused by external disturbance signal the step of phase difference Include：Only retain in the first function expansion, setting exponent number item and generate the 3rd function expansion, only retain second letter In number expansion, setting exponent number item generates the 4th function expansion；To the 3rd function expansion and the 4th letter Number expansion is handled, and obtains differential of the weak signal to phase difference caused by corresponding external disturbance signal；To described Differential carries out integral and calculating, obtains current weak signal to phase difference caused by corresponding external disturbance signal.
- A kind of 2. signal demodulating equipment, it is characterised in that including：Acquisition module, for obtaining the first signal frame of the first detector detection, and the secondary signal of the second detector detection Frame；Determining module, for determining first signal frame with corresponding at least one of synchronization in the secondary signal frame Weak signal pair；The determining module includes：Normalize module, for the signal to each moment in first signal frame, with And the signal at each moment in the secondary signal frame is normalized；Comparing module, after to normalized The letter at each moment in the secondary signal frame after the signal and normalized at each moment in first signal frame Number it is compared；Weak signal to determining module, for by synchronization and the signal that after normalized is all null value determine For a pair of weak signals；Demodulation module, for when to each weak signal to handling, by the first signal frame described in current weak signal pair with Weak signal in the secondary signal frame is deployed according to Bessel function of the first kind respectively, respectively obtains and current weak signal centering The corresponding function expansion of weak signal；By the function expansion, it is determined that current weak signal is to corresponding external disturbance Phase difference caused by signal, by the phase difference to current weak signal to being demodulated；Wherein, the demodulation module divides the weak signal in the first signal frame of current weak signal centering and the secondary signal frame Do not deploy according to Bessel function of the first kind, respectively obtain the function expansion corresponding with current weak signal centering weak signal When：Determine the weak signal in the first expression formula corresponding to the weak signal in first signal frame, and the secondary signal frame Corresponding second expression formula；It is determined that carry out Bessel function of the first kind expansion, the Taylor's formula deployed under specified point；By institute The Taylor's formula deployed described in the substitution of the first expression formula under specified point is stated, is obtained and the weak signal phase in first signal frame Corresponding first function expansion；Second expression formula is substituted into the Taylor's formula deployed under specified point, obtain and The corresponding second function expansion of weak signal in the secondary signal frame；First expression formula corresponding to weak signal in first signal frame is：Described The second expression formula is corresponding to weak signal in binary signal frame：Wherein, the ω tables Show the normalized radian frequency of the outer signals disturbance of optical fiber sensing, at the time of t represents that weak signal corresponds to, CnRepresent normalization Coefficient, the initial phase difference for the two-way light that the first detector and the second detector detect is represented,Represent t External disturbance signal phase difference corresponding to the weak signal at moment；It will be opened up described in first expression formula substitution under specified point The Taylor's formula opened, the obtained first function expansion corresponding with the weak signal in the first signal frame are：By the second expression formula generation Enter the Taylor's formula deployed under specified point, the obtained second function exhibition corresponding with the weak signal in secondary signal frame Open type is：The demodulation module is by function expansion, it is determined that phase difference caused by external disturbance signal corresponding to current weak signal When：Only retain in the first function expansion, setting exponent number item and generate the 3rd function expansion, only retain second letter In number expansion, setting exponent number item generates the 4th function expansion；To the 3rd function expansion and the 4th letter Number expansion is handled, and obtains differential of the weak signal to phase difference caused by corresponding external disturbance signal；To described Differential carries out integral and calculating, obtains current weak signal to phase difference caused by corresponding external disturbance signal.
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| JP3088330B2 (en) * | 1997-03-28 | 2000-09-18 | エヌイーシーワイヤレスネットワークス株式会社 | Demodulator |
| WO2008050532A1 (en) * | 2006-10-17 | 2008-05-02 | Pioneer Corporation | Diversity receiver apparatus and diversity reception method |
| CN101378381A (en) * | 2007-08-29 | 2009-03-04 | 三洋电机株式会社 | Demodulation method for receiving OFDM signals, and demodulation apparatus and receiving apparatus using the same |
| CN103983342A (en) * | 2014-05-26 | 2014-08-13 | 北京航天易联科技发展有限公司 | Method for determining shaking position of sensing optical fiber and optical fiber sensing system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP3088330B2 (en) * | 1997-03-28 | 2000-09-18 | エヌイーシーワイヤレスネットワークス株式会社 | Demodulator |
| WO2008050532A1 (en) * | 2006-10-17 | 2008-05-02 | Pioneer Corporation | Diversity receiver apparatus and diversity reception method |
| CN101378381A (en) * | 2007-08-29 | 2009-03-04 | 三洋电机株式会社 | Demodulation method for receiving OFDM signals, and demodulation apparatus and receiving apparatus using the same |
| CN103983342A (en) * | 2014-05-26 | 2014-08-13 | 北京航天易联科技发展有限公司 | Method for determining shaking position of sensing optical fiber and optical fiber sensing system |
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