CN106888054A - A kind of method of the FIR time domain dispersion equilibrium of weighted optimization - Google Patents

A kind of method of the FIR time domain dispersion equilibrium of weighted optimization Download PDF

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CN106888054A
CN106888054A CN201710133105.8A CN201710133105A CN106888054A CN 106888054 A CN106888054 A CN 106888054A CN 201710133105 A CN201710133105 A CN 201710133105A CN 106888054 A CN106888054 A CN 106888054A
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time domain
dispersion equilibrium
equilibrium
tap coefficient
fir
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CN106888054B (en
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杨爱英
曾紫怡
郭芃
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Beijing Institute of Technology BIT
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/25133—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion including a lumped electrical or optical dispersion compensator
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/616—Details of the electronic signal processing in coherent optical receivers
    • H04B10/6161—Compensation of chromatic dispersion

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
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Abstract

The present invention relates to a kind of method of the FIR time domain dispersion equilibrium of weighted optimization, belong to technical field of photo communication.Including：Step one, coherent demodulation and analog-to-digital conversion are carried out to the light pulse signal after Optical Fiber Transmission, obtain sampled signal electric field, then calculated complex electric field；Step 2, the tap number for calculating FIR time domain dispersion equilibrium methods；Step 3, the tap coefficient for calculating FIR time domain dispersion equilibrium methods；Step 4, by step 3 export tap coefficient be multiplied with majorized function, then optimized functional parameter optimization, the tap coefficient after being optimized；Step 5, carry out balanced dispersion with the tap coefficient after step 4 optimizes.This method can be used for the optical communication link of different transmission speeds and variety classes modulation format, carry out the dispersion equilibrium of optical fiber link.

Description

A kind of method of the FIR time domain dispersion equilibrium of weighted optimization
Technical field
It is excellent the present invention relates to a kind of method of the finite impulse response (FIR) time domain dispersion equilibrium of optimization, more particularly to a kind of weighting The method of the FIR time domain dispersion equilibrium of change, belongs to technical field of photo communication.
Background technology
By that after Optical Fiber Transmission, can there is effect of dispersion in optical signal.In optical fiber digital communication syst, effect of dispersion causes Pulse stretching, the system of limiting can transmission signal flank speed.There are two kinds, when one kind is currently for the balanced way of dispersion Domain dispersion equilibrium, another kind is balanced frequency domain dispersion.
Time domain dispersion equilibrium can be divided into two kinds of FIR time domains dispersion equilibrium and time domain dispersion equilibrium (TDE).During FIR The principle of domain dispersion equilibrium is：According to the frequency response of dispersion in optical fiberDesign one Individual frequency response isWave filter carry out dispersion equilibrium.The corresponding impulse response of the wave filter isAccording to nyquist sampling law and frequency alias is avoided, time domain equalization filter The window time domain scale of ripple device isTs is the sampling period.In view of the feasibility of practical operation, one As use two samplings, the impulse response of endless is generally blocked in digital signal processing with rectangular window, i.e., equivalent to frequency H on domaineqConvolution sampling function Sa (ω), then time domain is transformed to, just obtain the tap coefficient of FIR time domain equalization dispersions.During FIR The tap number N and tap coefficient a of domain equilibrium dispersionkFor Wherein,
The principle of another method TDE of time domain dispersion equilibrium is：To the frequency response function H of wave filter on frequency domaineq Adding window is blocked, and length of window is signal duration corresponding frequency range.H after blockingeqTurned by inverse Fourier transform Change to time domain.The result of conversion is the tap coefficient of TDE.The tap number N of TDE is also calculated by above-mentioned formula.
Equilibrium of the dispersion on frequency domain is main using overlap frequency domain dispersion equilibrium (OFDE) method, and principle is：Input is believed Number it is divided into length for LfftMultiple windows, length of window is the length of Fast Fourier Transform (FFT).There is overlay region between two windows Loverlap, each window by being fourier transformed into frequency domain, and carried out with tap coefficient multiplication balanced.The tap coefficient of OFDE ForWherein,Finally, equilibrium result inverse Fourier transform is returned into time domain, and is lost Fall the data of overlay region.
Above method all plays the effect of balanced dispersion.Wherein, the application of FIR time domains dispersion equilibrium method is more universal. The shortcoming of the method is that tap coefficient modulus value is constant, and this can cause equilibrium result not good.Therefore, it is how equal in FIR time domain dispersions On the basis of weighing apparatus, further optimize tap coefficient, be the problem for needing to solve at present to reach optimal equalization effect.
The content of the invention
It is an object of the invention to overcome traditional FIR time domains dispersion equilibrium to exist, tap coefficient modulus value is constant causes balanced effect Really undesirable technological deficiency, dispersion equilibrium effect is necessary further raising, it is proposed that a kind of FIR time domain colors of weighted optimization Dissipate method in a balanced way.
The purpose of invention is achieved through the following technical solutions.
A kind of method of the FIR time domain dispersion equilibrium of weighted optimization, central idea is constant with modulus value with majorized function FIR time domain dispersion equilibrium tap coefficient be multiplied mode, optimize tap coefficient weight, then with optimize after tap coefficient it is equal Weighing apparatus dispersion, so as to change the constant situation of tap coefficient modulus value, reaches the purpose for improving dispersion equilibrium effect.
Specifically include following steps：
Step one, coherent demodulation and analog-to-digital conversion are carried out to the light pulse signal after Optical Fiber Transmission, obtain sampled signal electricity , then calculated complex electric field；
The real part of sampling electric field, is designated as EI(n)；Imaginary part, is designated as EQ(n), then calculated complex electric field, by equation below (1) Calculate：
E (n)=EI(n)+jEQ(n)(1)；
Wherein, E (n) represents plural electric field, and j represents imaginary unit；
Step 2, the tap number for calculating FIR time domain dispersion equilibrium methods；
Calculated especially by equation below (2)：
Wherein, N is the tap number of FIR time domain dispersion equilibrium methods, and D is dispersion parameter, and λ is laser center wavelength, and L is Fiber lengths, c is the light velocity, and Ts is the sampling period,Expression is rounded downwards；
Step 3, the tap coefficient for calculating FIR time domain dispersion equilibrium methods；
Calculated especially by equation below (3)：
Wherein, akIt is tap coefficient,π is pi；
Step 4, the tap coefficient that step 3 is exported is multiplied with majorized function, then to the optimized parameter of majorized function, obtained To the tap coefficient of weighting；
Concretely comprise the following steps：
Step 4.1 is by akIt is multiplied with majorized function, to reach optimization akThe effect of weight；
Step 4.2 is based on the functional parameter of optimization, to ensure the tap coefficient C after optimizationkOptimal equalization effect can be reached；
Wherein, majorized function is chosen as raised cosine, is also called Raised Cosine functions, referred to as RC functions, i.e., RC-FIR time domain dispersion equilibrium；Then Gaussian function, referred to as Gaussian functions, i.e. G-FIR time domains dispersion equilibrium can also be selected； Or select other majorized functions.
For RC functions, functional parameter is halfwidthWith rolloff-factor α, Wherein, TwindowIt is the length of window of FIR time domain dispersion equilibrium methods.For different X1With α values, according to C-FIR time domain colors The balanced portfolio effect to the optic communication signal after different length Optical Fiber Transmission is dissipated, parameter X under different condition is obtained1With α most Good value is constant, thereby determines that X1With the value of α；
For Gaussian function, functional parameter to be optimized is halfwidth TG_FWHM=X2·Twindow,
Contrast X2When taking different numerical value, according to G-FIR time domains dispersion equilibrium to the optic communication after different length Optical Fiber Transmission The portfolio effect of signal, can obtain parameter X under different condition2Optimal value it is constant, thereby determine that X2Optimal value；
To other majorized functions, the optimization of its parameter is also according to the optic communication signal after different length Optical Fiber Transmission Portfolio effect is carried out.
Step 5, carry out balanced dispersion with the tap coefficient after step 4 optimizes；
Dispersion equilibrium is carried out especially by equation below (4)：
Wherein, E (n-k) is sampling electric field, EeqN () is output electric field,Represent ckWith E's (n-k) N of product is with the excursion of k is sued for peace from 0 to N-1；
So far, from step one to step 5, the method for completing a kind of FIR time domain dispersion equilibrium of weighted optimization.
Beneficial effect
A kind of method of the FIR time domain dispersion equilibrium of weighted optimization of the present invention, compared with existing balanced dispersion method, has Following beneficial outcomes：
1. this method can apply to the optical communication link system of variety classes modulation format, and the dispersion for carrying out optical fiber link is equal Weighing apparatus；
2. this method can effectively improve the effect of time domain equalization dispersion, it is adaptable to different optic communication modulation format and various Character rate, wherein, the effect of optimization of RC-FIR time domain dispersion equilibrium is more more significantly than G-FIR time domain dispersion equilibrium；
3. pair by the QPSK signals that length is the Optical Fiber Transmission within 1000km, RC-FIR time domain dispersion equilibrium EVM values Smaller by 4% to 6% than FIR time domain dispersion equilibrium, 3%, G-FIR time domains dispersion equilibrium EVM values smaller than TDE are more equal than FIR time domain dispersions Weigh small 2% to 5%, it is smaller than TDE by about 1%；
4. it is pair the QPSK signals of the Optical Fiber Transmission of 1000km-2000km, RC-FIR time domain dispersion equilibrium EVM by length Value about 3%, G-FIR time domain dispersion equilibrium EVM values lower than FIR time domains dispersion equilibrium and TDE are than FIR time domains dispersion equilibrium and TDE It is low by about 2%.
Brief description of the drawings
Fig. 1 is that the simulation dispersion in the method and embodiment 1 of a kind of FIR time domain dispersion equilibrium of weighted optimization of the invention is equal The used system block diagram of weighing apparatus；
Fig. 2 is the DSP basic flows in a kind of embodiment of the method 1 and 2 of the FIR time domain dispersion equilibrium of weighted optimization of the invention Cheng Tu；
Fig. 3 is a kind of method schematic of the FIR time domain dispersion equilibrium of weighted optimization of the invention；
Fig. 4 be a kind of FIR time domain dispersion equilibrium of weighted optimization of the invention embodiment of the method 1 in RC-FIR time domain dispersions The calculation flow chart of equalization methods；
During Fig. 5 is for the embodiment 1 of specific implementation method, the QPSK signals of 40Gb/s are by 500km, X1With α spans With the relation of equilibrium result EVM；
During Fig. 6 is for the embodiment 1 of specific implementation method, the QPSK signals of 40Gb/s are by 1000km, X1With α spans With the relation of equilibrium result EVM；
During Fig. 7 is for the embodiment 1 of specific implementation method, the QPSK signals of 40Gb/s are by 1500km, X1With α spans With the relation of equilibrium result EVM；
Fig. 8 for specific implementation method embodiment 1 in, RC-FIR time domains dispersion equilibrium, FIR time domains dispersion equilibrium and TDE Three kinds of tap coefficient comparison diagrams of method；
During Fig. 9 is the embodiment 1 in specific embodiment, the QPSK signals of 40Gb/s through different length standard single mode light After fibre transmission, the EVM Comparative results that time domain dispersion equilibrium is obtained are carried out with three kinds of methods.X-axis is fiber lengths, Y-axis in figure (a) It is the EVM after balanced dispersion, three curves in figure represent equal using FIR time domains dispersion equilibrium, TDE and RC-FIR time domain dispersions EVM values obtained by weighing apparatus three kinds of methods equilibrium dispersions, figure (b), figure (c), when scheming (d) and being respectively optical fiber 500km long, through FIR time domains Signal constellation (in digital modulation) figure after dispersion equilibrium, TDE and RC-FIR time domain dispersion equilibrium；
Figure 10 is in the embodiment 1 in specific embodiment, 16QAM signals are transmitted through the standard single-mode fiber of different length The EVM Comparative results that time domain dispersion equilibrium is obtained are carried out with three kinds of methods afterwards, wherein, symbol rate and the QPSK of 16QAM signals believe It is number identical；
Figure 11 is in the embodiment 1 in specific embodiment, 32QAM signals are transmitted through the standard single-mode fiber of different length The EVM Comparative results that time domain dispersion equilibrium is obtained are carried out with three kinds of methods afterwards, wherein, symbol rate and the QPSK of 32QAM signals believe It is number identical；
Figure 12 for specific implementation method embodiment 2 in, the parameter X of G-FIR time domain dispersion equilibrium2Optimization process；
Figure 13 for specific embodiment embodiment 2 in, RC-FIR time domains dispersion equilibrium, FIR time domains dispersion equilibrium, TDE Tap coefficient with four kinds of methods of G-FIR time domains dispersion equilibrium is contrasted；
Figure 14 (a) for specific embodiment embodiment 2 in, QPSK signals through standard single-mode fiber transmit after, use RC- FIR time domains dispersion equilibrium, FIR time domains dispersion equilibrium, that four kinds of methods of TDE and G-FIR time domains dispersion equilibrium carry out time domain dispersion is equal The comparison diagram of EVM after weighing apparatus；When Figure 14 (b), 14 (c), 14 (d), 14 (e) are respectively fiber lengths 500km, FIR time domain dispersions are equal Weighing apparatus, TDE, RC-FIR time domain dispersion equilibrium and FIR time domains dispersion equilibrium gained signal constellation (in digital modulation) figure；
Figure 15 is in the embodiment 2 of specific embodiment, 16QAM signals are transmitted through standard single-mode fiber, when using RC-FIR After domain dispersion equilibrium, FIR time domains dispersion equilibrium, four kinds of methods of TDE and G-FIR time domains dispersion equilibrium carry out time domain dispersion equilibrium EVM is contrasted；
Figure 16 is in the embodiment 2 of specific embodiment, 32QAM signals are transmitted through standard single-mode fiber, when using RC-FIR After domain dispersion equilibrium, FIR time domains dispersion equilibrium, four kinds of methods of TDE and G-FIR time domains dispersion equilibrium carry out time domain dispersion equilibrium EVM is contrasted.
Specific embodiment
In order to better illustrate objects and advantages of the present invention, the content of the invention is described further below in conjunction with the accompanying drawings.
The time domain dispersion equilibrium system block diagram of the inventive method is as shown in Figure 1.Wherein, I/Q modulator produces signal, and mixes Doped fiber amplifier (EDFA) is connected, and EDFA is used for controlled output power, then is transmitted by standard single-mode fiber, often transmits 100km places an EDFA and is used for compensating decay, by after coherent reception and analog-to-digital conversion, into Digital Signal Processing flow. Fig. 2 is day numeral signal processing flow figure, wherein, by the data of analog-to-digital conversion, respectively through clock and data recovery, dispersion is equal Weighing apparatus, polarization equilibrium and carrier phase recovery, finally, make decisions and error rate calculation.Time domain dispersion equilibrium method schematic is such as Shown in Fig. 3, wherein, by being multiplied with tap coefficient after delay, addition is equalized result to signal.
Embodiment 1
The present embodiment originally realizes a kind of FIR time domain colors of weighted optimization of the invention using raised cosine as majorized function Dissipate method in a balanced way.
The calculation process of this method is as shown in Figure 4.First pass around analog-to-digital conversion and obtain E (n), then according to formula (2) and Formula (3) calculates the tap number N and tap coefficient a of FIR time domain dispersion equilibriumk.Again by tap coefficient akIt is multiplied with RC functions, is obtained To the tap coefficient C of RC-FIR time domain dispersion equilibrium methodsk, then according to formula (4) equilibrium dispersion, finally, calculate output letter Number EVM.
It is expressed as by the sampled signal after analog to digital conversion
E (n)=EI(n)+jEQ(n)
The tap number and tap coefficient of FIR time domain dispersion equilibrium are calculated first, can be obtained according to formula
Wherein, akIt is tap coefficient,N is tap number.
In order to tap coefficient akOptimization, needing will be with akRaised cosine is multiplied.The halfwidth of raised cosineOptimum value should be reached with rolloff-factor α, the tap coefficient after optimization can be made Reach optimal equalization chromatic dispersion effects.In order to X1Optimized with α, X1Take scope 0.5-1.5, α and take scope 0-1, simulate to QPSK Signal is carried out at RC-FIR time domain dispersion equilibrium after the standard single-mode fiber transmission of tri- length of 500km, 1000km, 1500km Reason.Result such as Fig. 5, Fig. 6, and Fig. 7.Fig. 5 conveying lengths are 500km, and Fig. 6 is 1000km, and Fig. 7 is 1500km.Wherein, Fig. 5, figure The X-axis of 6 and Fig. 7 is halfwidth parameter X1, Y-axis is rolloff-factor α, and Z axis are the EVM values after equilibrium.In figure, color is brighter, then EVM values are bigger, and portfolio effect is poorer；Color is deeper, and EVM values are smaller, and portfolio effect is better.As can be seen that different long at three Under degree, there is position consistency in the maximum and minimum value of EVM.Minimum value (black region) appears in X1The position of=0.7, α=0.3 Put；Maximum (red area) concentrates on X1The position of=0.5, α=0.6.Therefrom it was determined that equal in RC-FIR time domain dispersions Parameter X in weighing apparatus method10.7 and 0.3 are respectively with the value of α.
After determining the parameter of raised cosine, by itself and akIt is multiplied, obtains the tap coefficient of RC-FIR time domain dispersion equilibrium Ck.QPSK signals to transmitting 1000km in standard single-mode fiber, Fig. 8 compared for RC-FIR time domains dispersion equilibrium, FIR respectively The modulus value of the tap coefficient needed for time domain dispersion equilibrium and TDE；Wherein, X-axis is tap number, and Y-axis is tap coefficient amplitude.From figure In as can be seen that the tap coefficient modulus value of FIR time domain dispersion equilibrium methods is constant, and RC-FIR time domain dispersion equilibrium methods are to taking out The weight of head coefficient has obvious optimization function.
RC-FIR time domain dispersion equilibrium method equilibrium dispersion used by formula be
Wherein, EeqN () is the signal after equilibrium.
The optical signal that Fig. 9, Figure 10 and Figure 11 compared for different modulating form transmits certain length in standard single-mode fiber Afterwards, signal after dispersion equilibrium is carried out using RC-FIR time domains dispersion equilibrium, tri- kinds of equalization methods of FIR time domains dispersion equilibrium and TDE EVM.Optical signal modulation form is respectively QPSK, 16QAM and 32QAM, and conveying length scope is 200km to 2000km.Fig. 9 A in (), X-axis is Optical Fiber Transmission length, Y-axis is EVM values after equilibrium.Fig. 9 (b), 9 (c), 9 (d) are passed through after transmitting 500km The QPSK signal constellation (in digital modulation) figures of FIR time domains dispersion equilibrium, TDE and RC-FIR time domain dispersion equilibrium.Can be obvious from three planispheres Find out, the portfolio effect of RC-FIR time domain dispersion equilibrium is compared with other two method more preferably.The X-axis of Figure 10 and Figure 11 is fiber lengths, Y Axle is EVM values after equilibrium.Complex chart 9-11 can be seen that the signal less than 500km to transmission range, and RC-FIR time domain dispersions are equal Weighing apparatus gained EVM is than FIR time domains dispersion equilibrium and the small 4%-6% of TDE；To the long range transmission signal of 1000km-2000km, RC- The EVM of FIR time domain dispersion equilibrium can reduce about 3%.
Embodiment 2
The present embodiment realizes that a kind of FIR time domain dispersions of weighted optimization of the invention are equal using Gaussian function as majorized function The method of weighing apparatus.
Figure 12 is the halfwidth parameter optimisation procedure of G-FIR time domain dispersion equilibrium, wherein, X-axis is X2, Y-axis is EVM values, Three curve represents Optical Fiber Transmission 500km, 1000km and 1500km respectively.Gaussian function halfwidth is according to TG_FWHM=X2· TwindowIt is determined that.In order to X2Analysis is optimized, by X2Span is set to 0.5-1.5, simulates QPSK signals point in the range of this After not transmitting 500km, 1000km, 1500km in standard single-mode fiber, using the result of G-FIR time domain dispersion equilibrium.Can be with Find out, under three kinds of Optical Fiber Transmission length, halfwidth parameter X2Optimal value be all 0.7, parameter X2Value thereby determine that. QPSK signal transmissions 1000km, four kinds of methods distinguish corresponding tap coefficient modulus value such as Figure 13.As can be seen that G-FIR time domain colors Dissipating equalization methods also has effect of optimization to the weight of tap coefficient, but be not as obvious as RC-FIR time domain dispersion equilibrium.
After Figure 14, Figure 15 and Figure 16 are transmitted for the optical signal of different modulating form in standard single-mode fiber, using RC- FIR time domains dispersion equilibrium, FIR time domains dispersion equilibrium, four kinds of results of method equilibrium dispersion of TDE and G-FIR time domains dispersion equilibrium Contrast, format modulation signal is respectively QPSK, 16QAM and 32QAM, conveying length 200km-2000km.Figure 14 (a), Tu15He The X-axis of Figure 16 is fiber lengths, and Y-axis is the EVM values after signal equalization.It is equal when Figure 14 (b) -14 (e) is Optical Fiber Transmission 500km Signal constellation (in digital modulation) figure after weighing apparatus, equalization methods are respectively FIR time domain dispersion equilibrium, when TDE, RC-FIR time domain dispersion equilibrium and G-FIR Domain dispersion equilibrium.Complex chart 14-16, as Optical Fiber Transmission 200km-1000km, when G-FIR time domain dispersion equilibrium EVM values are than FIR The small 4%-2% of domain dispersion equilibrium, as Optical Fiber Transmission 1000km-2000km, G-FIR time domain dispersion equilibrium EVM can reduce about 1%.
Major technique advantage of the present invention：
" a kind of method of the FIR time domain dispersion equilibrium of weighted optimization " of the invention has been described in detail above, but this The specific implementation form of invention is not limited thereto.The explanation of the implementation is only intended to help and understands the method for the present invention and its core Thought is thought；Simultaneously for those of ordinary skill in the art, according to thought of the invention, in specific embodiment and model is applied Place and will change, in sum, this specification content should not be construed as limiting the invention.Without departing substantially from this hair Bright methods described spirit and right in the case of to it carry out it is various obvious change all in the present invention Protection domain within.

Claims (7)

1. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization, it is characterised in that：It is constant with majorized function and modulus value The mode that FIR time domain dispersion equilibrium tap coefficient is multiplied, optimizes the weight of tap coefficient, then balanced with the tap coefficient after optimization Dispersion, so as to change the constant situation of tap coefficient modulus value, reaches the purpose for improving dispersion equilibrium effect；Specifically include following step Suddenly：
Step one, coherent demodulation and analog-to-digital conversion are carried out to the light pulse signal after Optical Fiber Transmission, obtain sampled signal electric field, then Calculated complex electric field；
Step 2, the tap number for calculating FIR time domain dispersion equilibrium methods；
Step 3, the tap coefficient for calculating FIR time domain dispersion equilibrium methods；
Step 4, the tap coefficient that step 3 is exported is multiplied with majorized function, then optimized function optimization, after being optimized Tap coefficient；
Step 5, carry out balanced dispersion with the tap coefficient after step 4 optimizes；
So far, from step one to step 5, the method for completing a kind of FIR time domain dispersion equilibrium of weighted optimization.
2. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 1, it is characterised in that：Step The real part of sampling electric field, is designated as E in oneI(n)；Imaginary part, is designated as EQN (), then calculated complex electric field, are counted by equation below (1) Calculate：
E (n)=EI(n)+jEQ(n) (1)；
Wherein, E (n) represents plural electric field, and j represents imaginary unit.
3. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 1, it is characterised in that：Step The tap number of FIR time domain dispersion equilibrium methods is calculated in two, is calculated especially by equation below (2)：
Wherein, N is the tap number of FIR time domain dispersion equilibrium methods, and D is dispersion parameter, and λ is laser center wavelength, and L is optical fiber Length, c is the light velocity, and Ts is the sampling period,Expression is rounded downwards.
4. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 1, it is characterised in that：Step The tap coefficient of FIR time domain dispersion equilibrium methods is calculated in three, is calculated especially by equation below (3)：
a k = j c T s Dλ 2 L exp ( - j π c Dλ 2 L k 2 ) - - - ( 3 ) ;
Wherein, akIt is tap coefficient,π is pi.
5. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 1, it is characterised in that：Step Four are multiplied the tap coefficient that step 3 is exported with majorized function, then optimized function optimization, the tap coefficient after being optimized, Concretely comprise the following steps：
Step 4.1 is by akIt is multiplied with majorized function, to reach optimization akThe effect of weight；
Step 4.2 is based on majorized function parameter, to ensure the tap coefficient C after optimizationkOptimal equalization effect can be reached.
6. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 5, it is characterised in that：Step In four, majorized function is chosen as raised cosine, is also called Raised Cosine functions, referred to as RC functions, i.e. during RC-FIR Domain dispersion equilibrium；Then Gaussian function, referred to as Gaussian functions, i.e. G-FIR time domains dispersion equilibrium can also be selected；Or selection Other majorized functions；For RC functions, functional parameter is halfwidth TFWHM=X1·Twindow,It is with roll-offing Number α, wherein, TwindowIt is the length of window of FIR time domain dispersion equilibrium methods.For different X1With α values, according to RC-FIR Time domain dispersion equilibrium can obtain parameter X under different condition to the portfolio effect of the optic communication signal after different length Optical Fiber Transmission1 Optimal value with α is constant, thereby determines that X1With the value of α；
For Gaussian function, functional parameter to be optimized is halfwidth TG_FWHM=X2·Twindow,
Contrast X2When taking different numerical value, according to G-FIR time domains dispersion equilibrium to the optic communication signal after different length Optical Fiber Transmission Portfolio effect, can obtain parameter X under different condition2Optimal value it is constant, thereby determine that X2Optimal value.
7. the method for the FIR time domain dispersion equilibrium of a kind of weighted optimization according to claim 1, it is characterised in that：Step Five carry out balanced dispersion with the tap coefficient after step 4 optimizes, and dispersion equilibrium is carried out especially by equation below (4)：
E e q ( n ) = Σ k = 0 N - 1 c k E ( n - k ) - - - ( 4 ) ;
Wherein, E (n-k) is sampling electric field, EeqN () is output electric field,Represent ckWith the product of E (n-k) N and, the excursion of k is sued for peace from 0 to N-1.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023273478A1 (en) * 2021-06-28 2023-01-05 烽火通信科技股份有限公司 Chromatic dispersion compensation method and system for light intensity information of synthesised single sideband signals

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120189319A1 (en) * 2011-01-22 2012-07-26 Viasat, Inc. Adaptive pmd equalizer and implementation
CN103338171A (en) * 2013-06-27 2013-10-02 北京大学 Receiving end equilibrium method and system based on frequency domain communication channel estimation
CN103346839A (en) * 2013-07-09 2013-10-09 温州大学 Coherent light communication dispersion compensation method based on ridge regression analysis
CN103812806A (en) * 2014-02-24 2014-05-21 北京大学 Channel equalization method and system based on time domain channel estimation
CN103973614A (en) * 2013-01-31 2014-08-06 富士通株式会社 Adaptive equalizer tap coefficient correction method and optical receiver
CN104115423A (en) * 2012-02-20 2014-10-22 泰科电子海底通信有限责任公司 System and method for blind equalization and carrier phase recovery in a quadrature amplitude modulated system
US20150256267A1 (en) * 2014-03-07 2015-09-10 Alcatel-Lucent Usa Inc. Optical receiver having a digital chromatic-dispersion compensator based on real-valued arithmetic

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120189319A1 (en) * 2011-01-22 2012-07-26 Viasat, Inc. Adaptive pmd equalizer and implementation
CN104115423A (en) * 2012-02-20 2014-10-22 泰科电子海底通信有限责任公司 System and method for blind equalization and carrier phase recovery in a quadrature amplitude modulated system
CN103973614A (en) * 2013-01-31 2014-08-06 富士通株式会社 Adaptive equalizer tap coefficient correction method and optical receiver
CN103338171A (en) * 2013-06-27 2013-10-02 北京大学 Receiving end equilibrium method and system based on frequency domain communication channel estimation
CN103346839A (en) * 2013-07-09 2013-10-09 温州大学 Coherent light communication dispersion compensation method based on ridge regression analysis
CN103812806A (en) * 2014-02-24 2014-05-21 北京大学 Channel equalization method and system based on time domain channel estimation
US20150256267A1 (en) * 2014-03-07 2015-09-10 Alcatel-Lucent Usa Inc. Optical receiver having a digital chromatic-dispersion compensator based on real-valued arithmetic

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SEB J. SAVORY: "Digital filters for coherent optical receivers", 《OPTICS EXPRESS》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023273478A1 (en) * 2021-06-28 2023-01-05 烽火通信科技股份有限公司 Chromatic dispersion compensation method and system for light intensity information of synthesised single sideband signals

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