CN105591690A - Method and device for monitoring polarization-mode dispersion - Google Patents
Method and device for monitoring polarization-mode dispersion Download PDFInfo
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Abstract
The invention provides a method and device for monitoring polarization-mode dispersion. The method for monitoring polarization-mode dispersion is applied to an adaptive filter. The method includes the following steps that: the differential group delay (DGD) matrix of electrical signals entering the adaptive filter is obtained; a DGD curve is obtained according to the amplitude values of the DGD matrix and the sampling time of the adaptive filter corresponding to each amplitude value; the frequency value of the DGD curve is obtained according to the distances between adjacent zero points of the DGD curve; a DGD value is determined according to the frequency value of the DGD curve; and the polarization-mode dispersion value of the electrical signals is determined according to the DGD value of the plurality of different electrical signals. According to the method, the amplitude values of the DGD matrix of the electrical signals entering the adaptive filter are demonstrated in the form of the DGD curve; the frequency value of the DGD curve is obtained according to the distances between the adjacent zero points of the DGD curve; the DGD value is determined; and the polarization-mode dispersion value is determined. With the method according to which the frequency value is calculated through using the distances between the adjacent zero points adopted, the calculation complexity of the DGD value is decreased, and the real-time performance of online monitoring of the polarization-mode dispersion value can be increased.
Description
Technical field
The present invention relates to the communications field, particularly a kind of method and device of monitoring polarization mode dispersion.
Background technology
For the telecommunication service that the meets sustainable growth requirement to network superelevation broadband, the optical fiber transmission of physics bottomThe transfer rate of communication system is in continuous lifting. Single wave speed is from 10Gbit/s, and 40Gbit/s, brings up to100Gbit/s and following super 100G interface. Along with optical fibre transmission distance, transmission speed and spectrum efficiencyImprove constantly, the decay that optical fiber causes signal, distortion distortion, the impact of the transmission result on signal is moreCome larger. Generally speaking, except nonlinear impairments, as from phase-modulation (SPM, self-phasemodulation)/Cross-phase Modulation (XPM, cross-phasemodulation)/four-wave mixing (FWM, four-wavemixing)Outward, the main linear damage that optical fiber causes signal has mainly comprised chromatic dispersion (CD, chromaticDispersion), polarization mode dispersion (PMD, polarizationmodedispersion), Polarization Dependent Loss (PDL,Polarizatondependentloss) etc. Wherein chromatic dispersion refers to the interior generation of an independent fiber modePulse stretching. The light of different wave length is due to the refractive index difference of corresponding fiber core, so pass in optical fiberDefeated speed difference. Light pulse is become to be grouped into by multi-frequency, thereby has caused the pulse through dispersion transmissionCan there is broadening linearity, cause intersymbol interference. Chromatic dispersion value and fiber lengths are directly proportional. Can be with optical fiberThe increase of length reaches several ten thousand ps. In the fixing situation of fiber lengths, chromatic dispersion value remains unchanged substantially.
Polarization mode dispersion PMD refers to that internal stress is not because inside of optical fibre fiber core cross section is not positive circleEvenly, the reason such as outside is subject to external force bending, extruding, two orthogonal polarization modes that transmit in optical fiber itBetween there is certain delay inequality, thereby produced pulse stretching. Polarization mode dispersion value is with its main shaft of optical fiber stateChanging, with respect to chromatic dispersion, the real-time change of polarization mode dispersion brings to accurately estimation and compensation at any timeDifficulty larger.
Along with improving constantly of fibre-optic transmission system (FOTS) speed, individual pulse narrowed width, chromatic dispersion, polarizationThe pulse stretching that mode dispersion produces, increasing on the impact of signal. So in high speed fibre transmission system,The chromatic dispersion that need to produce optical fiber, the various damages such as polarization mode dispersion detect effectively to be estimated and joinsTo compensate exactly, eliminate. Just can recover correct signal at receiving terminal like this, ensure the effective of linkTransmission.
The appearance of coherent light communication, particularly in conjunction with high-speed AD converter (ADC, AnalogtodigitalConverter) and the application of Digital Signal Processing (DSP, DigitalSignalProcessing) technology, makeAccurate detection and the compensation of optical signal damage become possibility. Detect also in order to understand in time line status simultaneously,Realize automatic network diagnosis, repair, dynamic assignment Internet resources, change instant tune according to fiber channel conditionThe various parameters that whole DSP processes, change routing table, repartitions transmission path, realizes intelligent network management,Ensure the reliable and secure operation of optical fiber transmission network, this also needs optical fibre transmission channel to carry out Real-Time Monitoring.Wherein chromatic dispersion, polarization mode dispersion, the various optical fiber damages such as Polarization Dependent Loss are important measurement indexes.
In coherent reception system, utilize the parameter obtaining while carrying out to the received signal DSP processing, meterCalculate various optical fiber impairment values. Realize optical fiber property on-line monitoring (OPM, opticalperformanceMonitoring). This method precision is high, and cost is low, real-time, is widely used gradually. At phase stem graftingIn receipts system, because DSP processing procedure has been similar to the process of channel simulation negate, therefore can be in order toWith the calculation of parameter polarization mode dispersion of processing in DSP algorithm, in processing method, need obtaining at pilot processTo curve carry out Sine-Fitting, according to the sinusoidal frequency values after matching, just calculate polarization modeDispersion values.
Sine-Fitting is a kind of non-linear curve fitting, by the method for iteration, calculates the non-linear of correspondenceThe solution of least squares equation group. Shortcoming is computational process more complicated, if adopt hardware (FPGA, IC) realExisting, take resource many, realize difficulty large; And in the time that received signal quality is poor, treat that the curve of matching is notThe sine curve of one rule, fitting result is easily made mistakes.
Summary of the invention
The object of the present invention is to provide a kind of method and device of monitoring polarization mode dispersion, reduced polarization modeThe complexity of dispersion monitoring, has improved the stability of polarization mode dispersion monitoring.
In order to achieve the above object, the invention provides a kind of method of monitoring polarization mode dispersion, be applied to one certainlyAdaptive filter, comprising:
Obtain the differential group delay DGD matrix of the signal of telecommunication that enters described sef-adapting filter;
According to the sampling time of the amplitude of described DGD matrix and sef-adapting filter corresponding to each amplitude,Obtain DGD curve;
According to the spacing between the adjacent zero point of described DGD curve, obtain the frequency values of described DGD curve;
According to the frequency values of described DGD curve, determine DGD value;
According to the DGD value of multiple different signals of telecommunication, determine the polarization mode dispersion value of the described signal of telecommunication.
Preferably, according to the spacing between the adjacent zero point of described DGD curve, obtain described DGD curveThe step of frequency values comprise:
Described DGD curve is carried out to many times of interpolation, form full curve;
According to the abscissa at all zero points of described full curve, determine between the abscissa at adjacent zero point betweenDistance;
According to the interpolation multiple of described spacing and described many times of interpolation, determine the cycle of described curve, and then reallyThe frequency values of fixed described curve; Wherein, the cycle of described curve is directly proportional to described spacing, described curveCycle and described interpolation multiple are inversely proportional to, and the cycle of described curve and the frequency values of described curve are inversely proportional to.
Preferably, if the zero number of described full curve is greater than or equal to 3, described method also comprises:
Choose 2 adjacent zero points in the centre position at all zero points of described full curve, by described centreSpacing between 2 adjacent zero points of position is determined the frequency values of curve.
Preferably, according to the frequency values of described DGD curve, determine that the step of DGD value comprises:
According to the letter of the tap number of the frequency values of described curve, described sef-adapting filter and the described signal of telecommunicationNumber baud rate, determines DGD value; Wherein, the frequency values of described DGD value and described curve and described adaptiveAnswer the tap number of wave filter to be directly proportional, be inversely proportional to the signal baud rate of the described signal of telecommunication.
Preferably, according to the DGD value of multiple different signals of telecommunication, determine the polarization mode dispersion of the described signal of telecommunicationThe step of value comprises:
By entering the different signal of telecommunication of described adaptivity wave filter in a Preset Time section, determine multipleDifferent DGD matrixes, and then obtain multiple DGD values;
Remove the DGD value differing greatly in described multiple DGD value, remaining DGD value is averagedComputing, obtains the polarization mode dispersion value of the described signal of telecommunication.
Preferably, obtain the step of the differential group delay DGD matrix of the signal of telecommunication that enters described sef-adapting filterSuddenly comprise:
Obtain the coefficient matrix of described sef-adapting filter;
The coefficient matrix of described sef-adapting filter is carried out to discrete Fourier transform, obtain described self adaptation filterThe frequency domain value of the coefficient of ripple device;
According to the frequency domain value of the coefficient of described sef-adapting filter, determine chromatic dispersion CD matrix;
From the frequency domain value of the coefficient of described adaptivity wave filter, isolate described CD matrix, described in obtainingDGD matrix.
Preferably, adopting according to the amplitude of described DGD matrix and sef-adapting filter corresponding to each amplitudeThe sample time, the step that obtains DGD curve comprises:
From the amplitude of described DGD matrix, remove the impact on described amplitude of amplitude wave filter, described in obtainingThe object amplitude of DGD matrix;
Sampling time taking the object amplitude of described DGD matrix as ordinate, sef-adapting filter is as abscissa,Build a two-dimensional coordinate system;
In described two-dimensional coordinate system, the object amplitude of described DGD matrix is represented with curve form, obtainDGD curve.
The embodiment of the present invention also provides a kind of device of monitoring polarization mode dispersion, is applied to a sef-adapting filter,Comprise:
The first acquisition module, for obtaining the differential group delay of the signal of telecommunication that enters described sef-adapting filterDGD matrix;
The first determination module, for according to the amplitude of described DGD matrix and self adaptation corresponding to each amplitudeIn the sampling time of wave filter, obtain DGD curve;
The second acquisition module, for according to the spacing between the adjacent zero point of described DGD curve, described in obtainingThe frequency values of DGD curve;
The second determination module, for according to the frequency values of described DGD curve, determines DGD value;
The 3rd determination module, for according to the DGD value of multiple different signals of telecommunication, determines the described signal of telecommunicationPolarization mode dispersion value.
Preferably, described the second acquisition module comprises:
Interpolating module, for described DGD curve is carried out to many times of interpolation, forms full curve;
Spacing determination module, for according to the abscissa at all zero points of described full curve, determines adjacent zerosSpacing between the abscissa of point;
Frequency determination module, for according to the interpolation multiple of described spacing and described many times of interpolation, described in determiningThe cycle of curve, and then the frequency values of definite described curve; Wherein, the cycle of described curve and described spacingBe directly proportional, the cycle of described curve and described interpolation multiple are inversely proportional to, and the cycle of described curve and described songThe frequency values of line is inversely proportional to.
Preferably, if the zero number of described full curve is greater than or equal to 3, described device also comprises:
Choose module, for choosing 2 adjacent zero points in centre position at all zero points of described full curve,Determine the frequency values of curve by the spacing between 2 adjacent zero points in described centre position.
Preferably, described the second determination module comprises:
First determines submodule, for according to the tap of the frequency values of described curve, described sef-adapting filterThe signal baud rate of the several and described signal of telecommunication, determines DGD value; Wherein, described DGD value and described songThe frequency values of line and the tap number of described sef-adapting filter are directly proportional, with the signal baud rate of the described signal of telecommunicationBe inversely proportional to.
Preferably, described the 3rd determination module comprises:
Second determines submodule, for by entering described adaptivity wave filter not in a Preset Time sectionThe same signal of telecommunication, determines multiple different DGD matrixes, and then obtains multiple DGD values;
The 3rd determines submodule, and the DGD value differing greatly for removing described multiple DGD value, to surplusRemaining DGD value averages computing, obtains the polarization mode dispersion value of the described signal of telecommunication.
Preferably, described the first acquisition module comprises:
First obtains submodule, for obtaining the coefficient matrix of described sef-adapting filter;
Second obtains submodule, for the coefficient matrix of described sef-adapting filter is carried out to discrete fourier changeChange, obtain the frequency domain value of the coefficient of described sef-adapting filter;
The 3rd obtains submodule, for according to the frequency domain value of the coefficient of described sef-adapting filter, determines colourityDispersion CD matrix;
The 4th obtains submodule, isolates institute for the frequency domain value of the coefficient from described adaptivity wave filterState CD matrix, obtain described DGD matrix.
Preferably, described the first determination module comprises:
Object module, for remove from the amplitude of described DGD matrix amplitude wave filter to described amplitudeAffect, obtain the object amplitude of described DGD matrix;
Build module, for object amplitude the adopting as ordinate, sef-adapting filter taking described DGD matrixThe sample time is abscissa, builds a two-dimensional coordinate system;
Represent module, at described two-dimensional coordinate system by the object amplitude of described DGD matrix with shaped formFormula represents, and obtains DGD curve.
Technique scheme of the present invention at least has following beneficial effect:
In the method for the monitoring polarization mode dispersion of the embodiment of the present invention, first the telecommunications of sef-adapting filter will be enteredNumber the amplitude of differential group delay DGD matrix show with DGD curve form, then according to DGD curveSpacing between adjacent zero point is obtained the frequency values of DGD curve, thereby determines DGD value, further can be trueDetermine polarization mode dispersion value; Utilize the method for the calculated rate value at adjacent zero point to reduce the calculation of complex of DGD valueSpend, increased the real-time of polarization mode dispersion value on-line monitoring simultaneously.
Brief description of the drawings
Fig. 1 represents the basic step schematic diagram of the method for the monitoring polarization mode dispersion of the embodiment of the present invention;
Fig. 2 represents the structure chart of coherent optical heterodyne communicatio system in the embodiment of the present invention;
Fig. 3 represents Digital Signal Processing DSP part in the coherent optical heterodyne communicatio system of the embodiment of the present inventionStructure chart;
Fig. 4 represents the structural representation of the butterfly wave filter of the embodiment of the present invention;
Fig. 5 represents to obtain in the method for monitoring polarization mode dispersion of the embodiment of the present invention concrete steps of DGD valueSchematic diagram;
Fig. 6 represents the concrete steps flow chart of the method for the monitoring polarization mode dispersion of the embodiment of the present invention;
Fig. 7 represents the DGD curve map in the method for monitoring polarization mode dispersion of the embodiment of the present invention;
Fig. 8 represents the full curve figure to the DGD after the DGD curve map interpolation processing in Fig. 7;
Fig. 9 represents the DGD full curve figure after the interpolation of the first embodiment of the present invention;
Figure 10 represents the DGD full curve figure after the interpolation of the second embodiment of the present invention;
Figure 11 represents the structural representation of the device of the monitoring polarization mode dispersion of the embodiment of the present invention.
Detailed description of the invention
For making the technical problem to be solved in the present invention, technical scheme and advantage clearer, below in conjunction with attachedFigure and specific embodiment are described in detail.
The present invention is directed to computational process while utilizing the mode of Sine-Fitting to calculate polarization mode dispersion value in prior artComplexity, takies the problem that resource is many and fitting result is easily made mistakes, and a kind of side that monitors polarization mode dispersion is providedMethod and device in, first by enter sef-adapting filter the signal of telecommunication differential group delay DGD matrix amplitude withDGD curve form is shown, then is obtained DGD curve according to spacing between the adjacent zero point of DGD curveFrequency values, thus determine DGD value, further can determine polarization mode dispersion value; Utilize the calculating at adjacent zero pointThe method of frequency values has reduced the computation complexity of DGD value, has increased the reality of DGD value on-line monitoring simultaneouslyShi Xing.
As shown in Figure 1, the embodiment of the present invention provides a kind of method of monitoring polarization mode dispersion, is applied to one certainlyAdaptive filter, comprising:
Step 10, obtains the differential group delay DGD matrix of the signal of telecommunication that enters described sef-adapting filter;
Step 11, according to adopting of the amplitude of described DGD matrix and sef-adapting filter corresponding to each amplitudeThe sample time, obtain DGD curve;
Step 12, according to the spacing between the adjacent zero point of described DGD curve, obtains described DGD curveFrequency values;
Step 13, according to the frequency values of described DGD curve, determines DGD value;
Step 14, according to the DGD value of multiple different signals of telecommunication, determines the polarization mode dispersion of the described signal of telecommunicationValue.
In the above embodiment of the present invention, utilize in coherent reception system Digital Signal Processing DSP processing procedureAdaptive-filtering equilibrium, the adaptive filter coefficient that polarization demultiplexing link obtains, according to ignoring non-lineProperty when the affecting of optical fiber damage, the impulse response of adaptive filter coefficient equals the impulse of fiber channel damageThe principle of response negate, calculates differential group delay value (DGD, differentialgroupdelay); Simultaneously byA period of time in polarization mode dispersion pmd, the statistical value of the differential group delay DGD of specified wavelength. SoBy the DGD value calculating in a period of time, just can obtain pmd value.
Be illustrated in figure 2 typical PM-QPSK (Polarization-multiplexedQuadraturePhaseShiftKeying palarization multiplexing QPSK) structure of coherent optical heterodyne communicatio system. Transmitted signal informationBe modulated onto in two orthogonal polarization states of light carrier; Through fiber channel, arrive after receiving terminal, pass throughLocal laser instrument carries out coherent reception, demodulation, changes into the signal of telecommunication. The signal of telecommunication is carried out to DSP processing; EliminateFall the various damages that fiber channel causes signal transmission; Signal after being restored, then decode.
As shown in Figure 3, the processing procedure of DSP is divided into chromatic dispersion compensation, clock recovery, adaptive-filteringEquilibrium, carrier wave frequency deviation compensation, the links such as phase compensation and signal decoding. In the above embodiment of the present invention, monitorThe method of polarization mode dispersion is mainly applied the link balanced with sef-adapting filter; Concrete, adaptive-filteringBalance module adopts the method for sef-adapting filter to realize, and can be permanent mode filter (CMA, ConstantModuleAlgorithm) or minimum-mean square error filters (LMS, LeastMeanSquare) etc., existConcrete form in the invention process is a butterfly wave filter. As shown in Figure 4, this butterfly wave filter is by 4Individual fir wave filter forms. Above-mentioned butterfly wave filter, by the method for iteration, makes filter output signal and hopeThe input signal recovering is equal, and the coefficient after butterfly wave filter iteration convergence equals cd, DGD, pdlEtc. the cascade of various optical fiber damages, negate. So first cd, DGD divides the impact of butterfly filter coefficientFrom, the cd matrix that just can obtain according to after separating, DGD matrix computations goes out cd, DGD value.
In specific embodiments of the invention, the complexity of calculating in order to reduce polarization mode dispersion, improves polarization modeThe stability that dispersion is calculated, is obtaining performing step 12 after DGD curve, passes through the adjacent of DGD curveSpacing between zero point is obtained the frequency values of DGD curve, then calculates by the frequency values of DGD curveDGD value, finally determines polarization mode dispersion PMD value by multiple DGD values.
In the above embodiment of the present invention, as shown in Figure 5, step 12 comprises:
Step 121, carries out many times of interpolation to described DGD curve, forms full curve;
Step 122, according to the abscissa at all zero points of described full curve, determines the abscissa at adjacent zero pointBetween spacing;
Step 123, according to the interpolation multiple of described spacing and described many times of interpolation, determines the cycle of described curve,And then the frequency values of definite described curve; Wherein, the cycle of described curve is directly proportional to described spacing, described inThe cycle of curve and described interpolation multiple are inversely proportional to, and the cycle of described curve and the frequency values of described curve becomeInverse ratio.
In the specific embodiment of the invention, because the DGD curve obtaining by step 11 is by multiple discontinuousValue form, this DGD curve is the basic trend of the amplitude of the rough described DGD matrix of expression only, logicalThe method of too much times of interpolation, forms a full curve, and this full curve can represent its DGD comparatively accuratelyThe amplitude size of matrix. It should be noted that, the interpolation multiple of these many times of interpolation is not limited to a fixed value, andThis interpolation multiple is larger, and the expression result of full curve is more accurate.
Further, the spacing between adjacent zero point refers to the spacing between the abscissa at adjacent zero point; SpecificallyMethod be that after utilizing, the abscissa value at a zero point deducts the result that the abscissa value at last zero point obtains and isSpacing between these 2 adjacent zero points. Then, can obtain curve by above-mentioned spacing and interpolation multipleFrequency values; Use the frequency values of the method calculated curve to reduce the complexity of calculating, if while DGD matrixArbitrary amplitude change the variation that can cause curve, curve also can change zero point immediately, can be becomeFrequency values after change, has realized the real-time in DGD observation process.
Concrete, cycle=spacing * 2/ interpolation multiple of DGD curve; Frequency values=the 1/DGD of DGD curveThe cycle of curve.
Concrete, in the above embodiment of the present invention, if the zero number of described full curve is greater than or equal to 3Individual, described method also comprises:
Step 124, chooses 2 adjacent zero points in the centre position at all zero points of described full curve, passes throughSpacing between 2 adjacent zero points in described centre position is determined the frequency values of curve.
In the specific embodiment of the invention, if the zero number of full curve is 2, by these two zero pointsBetween spacing can calculate a frequency values, this frequency values is the frequency values of DGD curve; If bent continuouslyThe zero number of line is greater than or equal to 3 (zero number are integer), due to curve mid portion the mostAccurately, choose 2 adjacent zero points in the centre position at all zero points and calculate spacing, and then calculated rate value.Such as, zero number is 4, by calculating the distance computation between second zero point and the 3rd zero pointFrequency values; Zero number is 5 for another example, by calculate between second zero point and the 3rd zero point betweenApart from calculated rate value or by calculate distance computation frequency values between the 3rd zero point and the 4th zero point orThe frequency values that person obtains above-mentioned two distance computation is averaged and is used as the frequency values of curve.
In the above embodiment of the present invention, step 13 comprises:
Step 131, according to the tap number of the frequency values of described curve, described sef-adapting filter and described electricityThe signal baud rate of signal, determines DGD value; Wherein, the frequency values of described DGD value and described curve andThe tap number of described sef-adapting filter is directly proportional, and is inversely proportional to the signal baud rate of the described signal of telecommunication.
In the specific embodiment of the invention, DGD value=DGD curve frequency values * butterfly filter tap number/letterNumber baud rate.
In the above embodiment of the present invention, step 14 comprises:
Step 141, by entering the different signal of telecommunication of described adaptivity wave filter in a Preset Time section,Determine multiple different DGD matrixes, and then obtain multiple DGD values;
Step 142, removes the DGD value differing greatly in described multiple DGD value, to remaining DGD valueAverage computing, obtain described polarization mode dispersion value.
In the specific embodiment of the invention, because polarization mode dispersion PMD value is the poor of interior specified wavelength between a sectionDivide the statistical value of group delay DGD value, multiple DGD values are averaged and can be obtained PMD value; WithTime owing to may having larger error in measuring process, DGD value that need to will differ greatly be asked after rejecting againOn average, obtain polarization mode dispersion value.
In the above embodiment of the present invention, step 10 comprises:
Step 101, obtains the coefficient matrix of described sef-adapting filter;
Step 102, carries out discrete Fourier transform to the coefficient matrix of described sef-adapting filter, described in obtainingThe frequency domain value of the coefficient of sef-adapting filter;
Step 103, according to the frequency domain value of the coefficient of described sef-adapting filter, determines chromatic dispersion CD matrix;
Step 104 is isolated described CD matrix from the frequency domain value of the coefficient of described adaptivity wave filter,Obtain described DGD matrix.
And in specific embodiments of the invention, step 11 comprises:
Step 111 is removed the impact on described amplitude of amplitude wave filter from the amplitude of described DGD matrix,Obtain the object amplitude of described DGD matrix;
Step 112, when sampling taking the object amplitude of described DGD matrix as ordinate, sef-adapting filterBetween be abscissa, build a two-dimensional coordinate system;
Step 113, in described two-dimensional coordinate system by the object amplitude of described DGD matrix with curve form exhibitionExisting, obtain DGD curve.
For the method for the above-mentioned monitoring polarization mode dispersion of clearer description, real to the present invention below in conjunction with Fig. 6Executing routine method is described further:
Step S601, known butterfly filter coefficient.
Through DFT conversion, obtain the frequency domain value of filter coefficient.
Step S602, by calculating, obtains CD matrix D from the frequency domain value of butterfly filter coefficient-1(f)2；
Step S603 by calculating, separates CD matrix from the frequency domain value of butterfly filter coefficientD-1(f)2, obtain DGD matrix u-1(f)2; And then obtain u-1(f)2Amplitude | u-1(f)2|；
Step S604, removes the impact of amplitude wave filter amplitudefilter;
Step S605, removes the matrix of skew | u-1(f)2| be an array that length is filter tap number. WillThis array prints, and is a frequency and the linear sine curve of DGD value. Just calculateThe frequency values of chord curve, just can obtain DGD value;
Fig. 7 is | u-1(f)2| curve, butterfly filter tap number 25, so there are 25 DGD amplitudes.
The calculation procedure that calculates sine curve frequency values according to the distance between curve adjacent zero point is:
A. right | u-1(f)2| many times of interpolation of curve, Fig. 8 is through 32 times of interpolation | u-1(f)2| curve.
B. calculate the spacing L between all adjacent zero points; Such as Fig. 8 has 8 zero points.Abscissa position is respectively 114,154, and 218,288,357,426,496,559.Spacing between adjacent 2 zero points is respectively 40,64,70,69,69,70,63.
C. calculate sine curve cycle T=L*2/ interpolation multiple; Sine curve frequency f=1/T.The sine curve cycle that adopts 7 distance computation of Fig. 8 to go out is respectively:
2.5000，4.0000，4.3750，4.3125，4.3125，4.3750，3.9375。
Only choose | u-1(f)2| adjacent 2 zero points in the abscissa centre position of curve. Calculate periodic quantity, useIn next step calculating. Because the mid portion of curve is the most accurately.
Such as choosing Fig. 8 | u-1(f)2| at two zero points of centre of curve, the periodic quantity calculating is 4.3125.
Step S606, DGD calculated value=f* butterfly filter tap number/signal baud rate; According toFig. 7 curve, in the middle of adopting, two periodic quantities that calculate zero point are 4.3125, the DGD value that calculates=1/4.3125*25/64*1000＝90.5797ps。
Step S607, by average the repeatedly DGD calculated value obtaining within a period of time, removes individual differenceHigher value, can obtain result more accurately, can obtain polarization mode dispersion value.
In order better to describe the process of obtaining DGD frequency by the spacing between adjacent zero point, below in conjunction withFig. 9, Figure 10 illustrate its concrete steps:
The DGD curve of Fig. 9 the first embodiment after interpolation, has 10 zero points.
Spacing is respectively 50,50, and 53,52,52,51,53,50,37.
The spacing 52 at two zero points of center, corresponding periodic quantity 3.25.
DGD value=1/3.25*25/64*1000=120.1923ps.
Figure 10 is the DGD curve of the second embodiment after interpolation, has 4 zero points.
Spacing is respectively 109,205, and 152.
The spacing 205 at two zero points of center, corresponding periodic quantity 12.8125.
DGD value=1/12.8125*25/64*1000=30.4878ps.
In order better to realize above-mentioned purpose, as shown in figure 11, the embodiment of the present invention also provides a kind of monitoring partiallyThe device of polarization mode dispersion, is applied to a sef-adapting filter, comprising:
The first acquisition module 501, for obtaining the differential group delay of the signal of telecommunication that enters described sef-adapting filterDGD matrix;
The first determination module 502, for according to the amplitude of described DGD matrix and each amplitude corresponding fromIn the sampling time of adaptive filter, obtain DGD curve;
The second acquisition module 503, for according to the spacing between the adjacent zero point of described DGD curve, obtainsThe frequency values of described DGD curve;
The second determination module 504, for according to the frequency values of described DGD curve, determines DGD value;
The 3rd determination module 505, for according to the DGD value of multiple different signals of telecommunication, determines described polarizationMode dispersion value.
Concrete, in the above embodiment of the present invention, described the second acquisition module 503 comprises:
Interpolating module, for described DGD curve is carried out to many times of interpolation, forms full curve;
Spacing determination module, for according to the abscissa at all zero points of described full curve, determines adjacent zerosSpacing between the abscissa of point;
Frequency determination module, for according to the interpolation multiple of described spacing and described many times of interpolation, described in determiningThe cycle of curve, and then the frequency values of definite described curve; Wherein, the cycle of described curve and described spacingBe directly proportional, the cycle of described curve and described interpolation multiple are inversely proportional to, and the cycle of described curve and described songThe frequency values of line is inversely proportional to.
Further, in the above embodiment of the present invention, if the zero number of described full curve is greater than or etc.In 3, described device also comprises:
Choose module, for choosing 2 adjacent zero points in centre position at all zero points of described full curve,Determine the frequency values of curve by the spacing between 2 adjacent zero points in described centre position.
Concrete, in the above embodiment of the present invention, described the second determination module 504 comprises:
First determines submodule, for according to the tap of the frequency values of described curve, described sef-adapting filterThe signal baud rate of the several and described signal of telecommunication, determines DGD value; Wherein, described DGD value and described songThe frequency values of line and the tap number of described sef-adapting filter are directly proportional, with the signal baud rate of the described signal of telecommunicationBe inversely proportional to.
Concrete, in the above embodiment of the present invention, described the 3rd determination module 505 comprises:
Second determines submodule, for by entering described adaptivity wave filter not in a Preset Time sectionThe same signal of telecommunication, determines multiple different DGD matrixes, and then obtains multiple DGD values;
The 3rd determines submodule, and the DGD value differing greatly for removing described multiple DGD value, to surplusRemaining DGD value averages computing, obtains described polarization mode dispersion value.
Concrete, in the above embodiment of the present invention, described the first acquisition module 501 comprises:
First obtains submodule, for obtaining the coefficient matrix of described sef-adapting filter;
Second obtains submodule, for the coefficient matrix of described sef-adapting filter is carried out to discrete fourier changeChange, obtain the frequency domain value of the coefficient of described sef-adapting filter;
The 3rd obtains submodule, for according to the frequency domain value of the coefficient of described sef-adapting filter, determines colourityDispersion CD matrix;
The 4th obtains submodule, isolates institute for the frequency domain value of the coefficient from described adaptivity wave filterState CD matrix, obtain described DGD matrix.
Concrete, in the above embodiment of the present invention, described the first determination module 502 comprises:
Object module, for remove from the amplitude of described DGD matrix amplitude wave filter to described amplitudeAffect, obtain the object amplitude of described DGD matrix;
Build module, for object amplitude the adopting as ordinate, sef-adapting filter taking described DGD matrixThe sample time is abscissa, builds a two-dimensional coordinate system;
Represent module, at described two-dimensional coordinate system by the object amplitude of described DGD matrix with shaped formFormula represents, and obtains DGD curve.
In the method for the above embodiment of the present invention monitoring polarization mode dispersion, first the electricity of sef-adapting filter will be enteredThe amplitude of the differential group delay DGD matrix of signal is shown with DGD curve form, then according to DGD curveAdjacent zero point between spacing obtain the frequency values of DGD curve, thereby determine DGD value, further canDetermine polarization mode dispersion value; Utilize the method for the calculated rate value at adjacent zero point to reduce the calculating of DGD value multipleAssorted spending increased the real-time of polarization mode dispersion value on-line monitoring simultaneously.
It should be noted that, the device of the monitoring polarization mode dispersion that the embodiment of the present invention provides is the above-mentioned side of applicationThe device of method, all embodiment of said method are all applicable to this device, and all can reach same or similarBeneficial effect.
In the device that the embodiment of the present invention provides by simplify the method that obtains DGD curve frequency, i.e. basisSpacing between the adjacent zero point of DGD curve, calculates frequency values, obtains DGD value; Reduce DGDThe complexity of calculating, has improved the accuracy of DGD result of calculation; Because computational process is simple, can be moreThe short time obtains result, has strengthened the real-time of on-line monitoring; And these computational methods are applicable to various polarizationsMultiplexing coherent reception system, such as PM-QPSK, PM-BPSK system, applicability is wide.
The above is the preferred embodiment of the present invention, it should be pointed out that the common skill for the artArt personnel, not departing under the prerequisite of principle of the present invention, can also make some improvements and modifications,These improvements and modifications also should be considered as protection scope of the present invention.
Claims (14)
1. monitor a method for polarization mode dispersion, be applied to a sef-adapting filter, it is characterized in that, bagDraw together:
Obtain the differential group delay DGD matrix of the signal of telecommunication that enters described sef-adapting filter;
According to the sampling time of the amplitude of described DGD matrix and sef-adapting filter corresponding to each amplitude,Obtain DGD curve;
According to the spacing between the adjacent zero point of described DGD curve, obtain the frequency values of described DGD curve;
According to the frequency values of described DGD curve, determine DGD value;
According to the DGD value of multiple different signals of telecommunication, determine the polarization mode dispersion value of the described signal of telecommunication.
2. the method for monitoring polarization mode dispersion according to claim 1, is characterized in that, according to describedSpacing between the adjacent zero point of DGD curve, the step of obtaining the frequency values of described DGD curve comprises:
Described DGD curve is carried out to many times of interpolation, form full curve;
According to the abscissa at all zero points of described full curve, determine between the abscissa at adjacent zero point betweenDistance;
According to the interpolation multiple of described spacing and described many times of interpolation, determine the cycle of described curve, and then reallyThe frequency values of fixed described curve; Wherein, the cycle of described curve is directly proportional to described spacing, described curveCycle and described interpolation multiple are inversely proportional to, and the cycle of described curve and the frequency values of described curve are inversely proportional to.
3. the method for monitoring polarization mode dispersion according to claim 2, is characterized in that, if described companyThe zero number of continuous curve is greater than or equal to 3, and described method also comprises:
Choose 2 adjacent zero points in the centre position at all zero points of described full curve, by described centreSpacing between 2 adjacent zero points of position is determined the frequency values of curve.
4. the method for monitoring polarization mode dispersion according to claim 1, is characterized in that, according to describedThe frequency values of DGD curve, determine that the step of DGD value comprises:
According to the letter of the tap number of the frequency values of described curve, described sef-adapting filter and the described signal of telecommunicationNumber baud rate, determines DGD value; Wherein, the frequency values of described DGD value and described curve and described adaptiveAnswer the tap number of wave filter to be directly proportional, be inversely proportional to the signal baud rate of the described signal of telecommunication.
5. the method for monitoring polarization mode dispersion according to claim 1, is characterized in that, according to multipleThe DGD value of the different signals of telecommunication, determine that the step of the polarization mode dispersion value of the described signal of telecommunication comprises:
By entering the different signal of telecommunication of described adaptivity wave filter in a Preset Time section, determine multipleDifferent DGD matrixes, and then obtain multiple DGD values;
Remove the DGD value differing greatly in described multiple DGD value, remaining DGD value is averagedComputing, obtains the polarization mode dispersion value of the described signal of telecommunication.
6. the method for monitoring polarization mode dispersion according to claim 1, is characterized in that, obtains and entersThe step of the differential group delay DGD matrix of the signal of telecommunication of described sef-adapting filter comprises:
Obtain the coefficient matrix of described sef-adapting filter;
The coefficient matrix of described sef-adapting filter is carried out to discrete Fourier transform, obtain described self adaptation filterThe frequency domain value of the coefficient of ripple device;
According to the frequency domain value of the coefficient of described sef-adapting filter, determine chromatic dispersion CD matrix;
From the frequency domain value of the coefficient of described adaptivity wave filter, isolate described CD matrix, described in obtainingDGD matrix.
7. the method for monitoring polarization mode dispersion according to claim 1, is characterized in that, according to describedIn the sampling time of sef-adapting filter corresponding to the amplitude of DGD matrix and each amplitude, obtain DGD songThe step of line comprises:
From the amplitude of described DGD matrix, remove the impact on described amplitude of amplitude wave filter, described in obtainingThe object amplitude of DGD matrix;
Sampling time taking the object amplitude of described DGD matrix as ordinate, sef-adapting filter is as abscissa,Build a two-dimensional coordinate system;
In described two-dimensional coordinate system, the object amplitude of described DGD matrix is represented with curve form, obtainDGD curve.
8. monitor a device for polarization mode dispersion, be applied to a sef-adapting filter, it is characterized in that, bagDraw together:
The first acquisition module, for obtaining the differential group delay of the signal of telecommunication that enters described sef-adapting filterDGD matrix;
The first determination module, for according to the amplitude of described DGD matrix and self adaptation corresponding to each amplitudeIn the sampling time of wave filter, obtain DGD curve;
The second acquisition module, for according to the spacing between the adjacent zero point of described DGD curve, described in obtainingThe frequency values of DGD curve;
The second determination module, for according to the frequency values of described DGD curve, determines DGD value;
The 3rd determination module, for according to the DGD value of multiple different signals of telecommunication, determines the described signal of telecommunicationPolarization mode dispersion value.
9. the device of monitoring polarization mode dispersion according to claim 8, is characterized in that, described secondAcquisition module comprises:
Interpolating module, for described DGD curve is carried out to many times of interpolation, forms full curve;
Spacing determination module, for according to the abscissa at all zero points of described full curve, determines adjacent zerosSpacing between the abscissa of point;
Frequency determination module, for according to the interpolation multiple of described spacing and described many times of interpolation, described in determiningThe cycle of curve, and then the frequency values of definite described curve; Wherein, the cycle of described curve and described spacingBe directly proportional, the cycle of described curve and described interpolation multiple are inversely proportional to, and the cycle of described curve and described songThe frequency values of line is inversely proportional to.
10. the device of monitoring polarization mode dispersion according to claim 9, is characterized in that, if described companyThe zero number of continuous curve is greater than or equal to 3, and described device also comprises:
Choose module, for choosing 2 adjacent zero points in centre position at all zero points of described full curve,Determine the frequency values of curve by the spacing between 2 adjacent zero points in described centre position.
The device of 11. monitoring polarization mode dispersions according to claim 8, is characterized in that, described secondDetermination module comprises:
First determines submodule, for according to the tap of the frequency values of described curve, described sef-adapting filterThe signal baud rate of the several and described signal of telecommunication, determines DGD value; Wherein, described DGD value and described songThe frequency values of line and the tap number of described sef-adapting filter are directly proportional, with the signal baud rate of the described signal of telecommunicationBe inversely proportional to.
The device of 12. monitoring polarization mode dispersions according to claim 8, is characterized in that, the described the 3rdDetermination module comprises:
Second determines submodule, for by entering described adaptivity wave filter not in a Preset Time sectionThe same signal of telecommunication, determines multiple different DGD matrixes, and then obtains multiple DGD values;
The 3rd determines submodule, and the DGD value differing greatly for removing described multiple DGD value, to surplusRemaining DGD value averages computing, obtains the polarization mode dispersion value of the described signal of telecommunication.
The device of 13. monitoring polarization mode dispersions according to claim 8, is characterized in that, described firstAcquisition module comprises:
First obtains submodule, for obtaining the coefficient matrix of described sef-adapting filter;
Second obtains submodule, for the coefficient matrix of described sef-adapting filter is carried out to discrete fourier changeChange, obtain the frequency domain value of the coefficient of described sef-adapting filter;
The 3rd obtains submodule, for according to the frequency domain value of the coefficient of described sef-adapting filter, determines colourityDispersion CD matrix;
The 4th obtains submodule, isolates institute for the frequency domain value of the coefficient from described adaptivity wave filterState CD matrix, obtain described DGD matrix.
The device of 14. monitoring polarization mode dispersions according to claim 8, is characterized in that, described firstDetermination module comprises:
Object module, for remove from the amplitude of described DGD matrix amplitude wave filter to described amplitudeAffect, obtain the object amplitude of described DGD matrix;
Build module, for object amplitude the adopting as ordinate, sef-adapting filter taking described DGD matrixThe sample time is abscissa, builds a two-dimensional coordinate system;
Represent module, at described two-dimensional coordinate system by the object amplitude of described DGD matrix with shaped formFormula represents, and obtains DGD curve.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107204803A (en) * | 2017-05-16 | 2017-09-26 | 华中科技大学 | A kind of polarization mode dispersion monitoring method and system based on PPM Transmission systems |
| CN109560867A (en) * | 2017-09-27 | 2019-04-02 | 富士通株式会社 | Monitor method, apparatus, receiver and the communication system of Polarization Dependent Loss |
| CN111698026A (en) * | 2019-03-12 | 2020-09-22 | 富士通株式会社 | Polarization state change monitoring method and device and receiver |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7587142B1 (en) * | 2005-12-29 | 2009-09-08 | At&T Intellectual Property Ii, Lp | Method for estimating the polarization mode dispersion compliant capacity fraction of the total optical frequency transmission window of a transport system |
| CN101688819A (en) * | 2007-03-28 | 2010-03-31 | 爱斯福光电工程公司 | Be used for determining the method and the facility of Differential Group Delay and polarization mode dispersion |
| CN103580758A (en) * | 2012-07-26 | 2014-02-12 | 富士通株式会社 | Optical transmission system and method for monitoring polarization dependent characteristics of optical transmission line |
-
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-
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- 2015-03-20 WO PCT/CN2015/074784 patent/WO2016061998A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7587142B1 (en) * | 2005-12-29 | 2009-09-08 | At&T Intellectual Property Ii, Lp | Method for estimating the polarization mode dispersion compliant capacity fraction of the total optical frequency transmission window of a transport system |
| CN101688819A (en) * | 2007-03-28 | 2010-03-31 | 爱斯福光电工程公司 | Be used for determining the method and the facility of Differential Group Delay and polarization mode dispersion |
| CN103580758A (en) * | 2012-07-26 | 2014-02-12 | 富士通株式会社 | Optical transmission system and method for monitoring polarization dependent characteristics of optical transmission line |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107204803A (en) * | 2017-05-16 | 2017-09-26 | 华中科技大学 | A kind of polarization mode dispersion monitoring method and system based on PPM Transmission systems |
| CN109560867A (en) * | 2017-09-27 | 2019-04-02 | 富士通株式会社 | Monitor method, apparatus, receiver and the communication system of Polarization Dependent Loss |
| CN109560867B (en) * | 2017-09-27 | 2022-05-17 | 富士通株式会社 | Method, device, receiver and communication system for monitoring polarization dependent loss |
| CN111698026A (en) * | 2019-03-12 | 2020-09-22 | 富士通株式会社 | Polarization state change monitoring method and device and receiver |
| CN111698026B (en) * | 2019-03-12 | 2023-05-12 | 富士通株式会社 | Polarization state change monitoring method, device and receiver |
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| WO2016061998A1 (en) | 2016-04-28 |
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