CN104410456B - The hybrid compensation method and device of pattern dependent loss and Polarization Dependent Loss - Google Patents

Abstract

The invention provides a kind of hybrid compensation method of pattern dependent loss and Polarization Dependent Loss, described method includes that S1. carries out constellation modulation to bit signal；S2. the signal after modulating constellation carries out mode polarization time encoding；S3. the signal after mode polarization time encoding is carried out light modulation；S4. the signal after light modulation is carried out light polarization and closes bundle；S5. the signal after light polarization being closed bundle carries out Mode Coupling；S6. Mode Coupling signal is carried out decoupling；S7. the signal after decoupling is carried out light polarization beam splitting；S8. the signal after light polarization beam splitting is carried out coherent demodulation；S9. the signal after coherent demodulation is carried out channel equalization；S10. the signal after channel equalization is carried out the decoding of mode polarization time；S11. signal after decoding is carried out constellation demodulation.The method of the invention can effectively suppress the pattern dependent loss in transmitting procedure and Polarization Dependent Loss, promotes systematic function.

Description

The hybrid compensation method and device of pattern dependent loss and Polarization Dependent Loss

Technical field

The present invention relates to communication technical field, be specifically related to a kind of pattern dependent loss and polarization phase Close the hybrid compensation method and device of loss.

Background technology

Increasing along with the exponential type capacity in past 20 years, wavelength-division multiplex becomes data light net The important technology form of network.The major reason forming this situation is exactly to continue rapidly to promote Data network flux.But the capacity that recent study progress shows WDM optical transmission increases Length is the most substantially slowed down, and its system experimentation is just in the celestial being of fast approaching nonlinear optical fiber transmission The agriculture limit.Mode division multiplexing technology (Mode Division Multiplexing, letter in less fundamental mode optical fibre Claim MDM) it is a kind of brand-new light MIMO transmission form, and it is expected for reality by people Promote the important potential scheme of optical-fiber network capacity the most further.

MDM technology is to utilize the orthogonality between each pattern of optical fiber, each pattern is considered as solely Vertical channel loading signal, formation multiple-input and multiple-output (Multiple Input, Multiple Output, It is called for short MIMO) passage, to improve system transmission capacity and spectrum efficiency.Less fundamental mode optical fibre, turns round and look at name Thinking justice, by appropriate design optical fiber, the most limited pattern is energized and transmits.So, phase Ratio, in single-mode fiber, can use MDM technology to expand simple optical fiber transmission capacity；Compared to Multimode fibre, can number, Optimizing Mode dispersion and crosstalk for controlling the mode.

Although MDM technology is considered as the important method promoting optical-fiber network capacity, but MDM In pattern dependent loss (Mode Dependent Loss, be called for short MDL) and the relevant damage of polarization The existence of consumption (Polarization Dependent Loss is called for short PDL), not only makes fiber-optic transfer During other transmission characteristics change, return transmission system and cause deterioration, as transmission time inclined Polarization state fluctuation causes OSNR to change, thus causes the change of luminous power.It can also cause increasing Benefit fluctuation, and the performance of receiving terminal compensator also can be affected.

Therefore, a kind of pattern dependent loss and the hybrid compensation side of Polarization Dependent Loss how are provided Method, the impact that transmission performance is caused by reduction pattern dependent loss and Polarization Dependent Loss becomes One problem demanding prompt solution.

Summary of the invention

For defect of the prior art, the present invention provides a kind of pattern dependent loss and polarization phase Close the hybrid compensation method and device of loss, reduce pattern dependent loss and Polarization Dependent Loss The impact that transmission performance is caused.

First aspect, the present invention provides a kind of pattern dependent loss and the associating of Polarization Dependent Loss Compensation method, described method includes:

At transmitting terminal,

S1. bit signal is carried out constellation modulation；

S2. the signal after modulating constellation carries out mode polarization time encoding；

S3. the signal after mode polarization time encoding is carried out light modulation；

S4. the signal after light modulation is carried out light polarization and closes bundle；

S5., after the signal after light polarization being closed bundle carries out Mode Coupling, it is sent in less fundamental mode optical fibre pass It is transmitted；

At receiving terminal,

S6. the Mode Coupling signal of transmission in described less fundamental mode optical fibre is carried out decoupling；

S7. the signal after decoupling is carried out light polarization beam splitting；

S8. the signal after light polarization beam splitting is carried out coherent demodulation；

S9. the signal after coherent demodulation is carried out channel equalization；

S10. the signal after channel equalization is carried out the decoding of mode polarization time；

S11. the signal after decoding the mode polarization time carries out constellation demodulation, after obtaining constellation demodulation Bit signal.

Preferably, the signal after constellation is modulated by described step S2 carries out mode polarization time encoding Including:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& {-s}_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states.

Preferably, described step S9 carries out channel equalization to the signal after coherent demodulation and includes:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\mathrm{\Σ}{r}_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal.

Preferably, described step S10 carries out the mode polarization time and translates the signal after channel equalization Code includes:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Preferably, described step S1 bit signal is carried out constellation modulation include bit signal is entered Row quadriphase PSK QPSK, eight phase-shift keying (PSK) 8PSK, quadrature amplitude modulation 16QAM or just Hand over the constellation modulation of amplitude modulation(PAM) 64QAM.

Second aspect, the present invention provides a kind of pattern dependent loss and the associating of Polarization Dependent Loss Compensation device, described device includes:

Transmitting terminal includes:

Constellation manipulator, for carrying out constellation modulation to bit signal；

Mode polarization clock coder, when the signal after modulating constellation carries out mode polarization Between encode；

Photomodulator, for carrying out light modulation to the signal after mode polarization time encoding；

Light polarization beam combiner, closes bundle for the signal after light modulation carries out light polarization；

Mode coupler, the signal after light polarization is closed bundle carries out Mode Coupling, and by mould Signal after formula coupling is sent in less fundamental mode optical fibre pass and is transmitted；

Receiving terminal includes:

Pattern decoupler, for carrying out the Mode Coupling signal of transmission in described less fundamental mode optical fibre Decoupling；

Optical polarization beam splitter, for carrying out light polarization beam splitting to the signal after decoupling；

Coherent demodulator, for carrying out coherent demodulation to the signal after light polarization beam splitting；

Channel equalizer, for carrying out channel equalization to the signal after coherent demodulation；

Mode polarization time decoder, in time carrying out mode polarization to the signal after channel equalization Between decode；

Constellation demodulator, the signal after decoding the mode polarization time carries out constellation demodulation, Obtain the bit signal after constellation demodulation.

Preferably, described mode polarization clock coder specifically for:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& {-s}_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states.

Preferably, described channel equalizer specifically for:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\mathrm{\&Sigma;}{r}_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal.

Preferably, described mode polarization time decoder specifically for:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Preferably, described constellation manipulator includes for bit signal carries out constellation modulation: right Bit signal carries out quadriphase PSK QPSK, eight phase-shift keying (PSK) 8PSK, quadrature amplitude modulation The constellation modulation of 16QAM or quadrature amplitude modulation 64QAM.

As shown from the above technical solution, the pattern dependent loss of the present invention and Polarization Dependent Loss Hybrid compensation method, Land use models polarization time encoding, by pattern, polarisation transfer signal and time Between transmit signal and combine, it is ensured that signal transmission orthogonality temporally and spatially, this Bright described method can effectively suppress the damage relevant with polarization of the pattern dependent loss in transmitting procedure Consumption, promotes systematic function.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below The accompanying drawing used required in embodiment or description of the prior art will be briefly described, aobvious and Easily insight, the accompanying drawing in describing below is some embodiments of the present invention, common for this area From the point of view of technical staff, on the premise of not paying creative work, it is also possible to according to these accompanying drawings Obtain other accompanying drawing.

Fig. 1 is pattern dependent loss and the connection of Polarization Dependent Loss of the embodiment of the present invention one offer Close the flow chart of compensation method；

Fig. 2 is pattern dependent loss and the connection of Polarization Dependent Loss of the embodiment of the present invention two offer Close the structural representation of compensation device.

Detailed description of the invention

For making the purpose of the embodiment of the present invention, technical scheme and advantage clearer, below will knot Close the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, Complete description, it is clear that described embodiment be a part of embodiment of the present invention rather than Whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not having Make the every other embodiment obtained under creative work premise, broadly fall into present invention protection Scope.

Fig. 1 shows the pattern dependent loss and Polarization Dependent Loss that the embodiment of the present invention one provides The flow chart of hybrid compensation method, as it is shown in figure 1, the pattern dependent loss of the present embodiment and The hybrid compensation method of Polarization Dependent Loss is as described below.

At transmitting terminal,

Step 101: bit signal is carried out constellation modulation.

Step 102: the signal after modulating constellation carries out mode polarization time encoding.

Step 103: the signal after mode polarization time encoding is carried out light modulation.

Step 104: the signal after light modulation is carried out light polarization and closes bundle.

Step 105: after the signal after light polarization is closed bundle carries out Mode Coupling, be sent to few mould light Fibre passes and is transmitted.

At receiving terminal,

Step 106: the Mode Coupling signal of transmission in described less fundamental mode optical fibre is carried out decoupling.

Step 107: the signal after decoupling is carried out light polarization beam splitting.

Step 108: the signal after light polarization beam splitting is carried out coherent demodulation.

Step 109: the signal after coherent demodulation is carried out channel equalization.

Step 110: the signal after channel equalization is carried out the decoding of mode polarization time.

Step 111: the signal after decoding the mode polarization time carries out constellation demodulation, obtains constellation Bit signal after demodulation.

Wherein, described step 101 bit signal is carried out constellation modulation include bit signal is entered Row quadriphase PSK (Quadrature Phase Shift Keying is called for short QPSK), eight phase shift keys Control (8Phase Shift Keying is called for short 8PSK), 16 quadrature amplitude modulation (Quadrature Amplitude Modulation, is called for short 16QAM) or the constellation modulation of 64QAM.

Wherein, the signal after constellation is modulated by described step 102 carries out mode polarization time encoding Including:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& {-s}_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states.

From the above it can be seen that original signal s₁、s₂、s₃And s₄It is encoded as a matrix S. In the matrix S of transmission, the every a line of matrix represents a transmission path, namely in optic communication In spatial model LP_11aTwo polarization states P_x、P_yAnd LP_11bTwo polarization states Q_x、Q_y。 In the matrix S of transmission, each list shows that a signal period T, each matrix S need The 8T time launches.Through mode polarization time encoding signal will in the different time and Space is launched simultaneously, carries out the transmission of signal.The signal launched on any two polarization direction Inner product is 0, so, within the 8T time, the signal of any two-way is mutually orthogonal, just by In this orthogonality, it is ensured that mode polarization time encoding can provide the maximum diversity of signal to increase Benefit.

The signal loading launched, to after different mode, closes bundle and pattern through light modulation, light polarization Coupling, the signal after coupling transmits in less fundamental mode optical fibre.At receiving terminal, to described less fundamental mode optical fibre The Mode Coupling signal of middle transmission carries out decoupling, then the signal after decoupling is carried out light inclined Shake beam splitting and coherent demodulation, after converting optical signals to the signal of telecommunication, carry out the equilibrium of channel effect, Last carrying out again decodes demodulation process.

Wherein, described step 107 carries out channel equalization to the signal after coherent demodulation and includes:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\mathrm{\&Sigma;}{r}_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal.

Wherein, h₁、h₂、h₃And h₄Can obtain by the way of transmitting terminal launches training sequence.

Wherein, described step 108 carries out the decoding of mode polarization time to the signal after channel equalization Including:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Wherein, willRespectively with s_iSeek distance, if meetingThen Then willIt is decoded as s_i。

Thus, the pattern dependent loss of the present embodiment and the hybrid compensation method of Polarization Dependent Loss, Land use models polarization time encoding, ties with time tranfer signal mutually by pattern, polarisation transfer signal Closing, it is ensured that signal transmission orthogonality temporally and spatially, method described in the present embodiment can With the pattern dependent loss in effectively suppression transmitting procedure and Polarization Dependent Loss, promote systematicness Energy.

Fig. 2 shows the pattern dependent loss and Polarization Dependent Loss that the embodiment of the present invention two provides The structural representation of hybrid compensation device, as in figure 2 it is shown, described device includes:

Transmitting terminal includes:

Constellation manipulator 21, for carrying out constellation modulation to bit signal；

Mode polarization clock coder 22, the signal after modulating constellation carries out mode polarization Time encoding；

Photomodulator 23, for carrying out light modulation to the signal after mode polarization time encoding；

Light polarization beam combiner 24, closes bundle for the signal after light modulation carries out light polarization；

Mode coupler 25, the signal after light polarization is closed bundle carries out Mode Coupling, and will Signal after Mode Coupling is sent in less fundamental mode optical fibre pass and is transmitted；

Receiving terminal includes:

Pattern decoupler 26, for entering the Mode Coupling signal of transmission in described less fundamental mode optical fibre Row is decoupling；

Optical polarization beam splitter 27, for carrying out light polarization beam splitting to the signal after decoupling；

Coherent demodulator 28, for carrying out coherent demodulation to the signal after light polarization beam splitting；

Channel equalizer 29, for carrying out channel equalization to the signal after coherent demodulation；

Mode polarization time decoder 290, for carrying out mode polarization to the signal after channel equalization Time decodes；

Constellation demodulator 291, the signal after decoding the mode polarization time carries out constellation solution Adjust, obtain the bit signal after constellation demodulation.

Wherein, described mode polarization clock coder 22 specifically for:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& {-s}_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states.

Wherein, described channel equalizer 29 specifically for:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\mathrm{\&Sigma;}{r}_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal.

Wherein, described mode polarization time decoder 290 specifically for:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Wherein, described constellation manipulator 21 includes for bit signal carries out constellation modulation: right Bit signal carries out quadriphase PSK QPSK, eight phase-shift keying (PSK) 8PSK, quadrature amplitude modulation The constellation modulation of 16QAM or quadrature amplitude modulation 64QAM.

Device described in the present embodiment, may be used for the technology of embodiment of the method shown in Fig. 1 that performs Scheme, it is similar with technique effect that it realizes principle, and here is omitted.

Above example is merely to illustrate technical scheme, is not intended to limit；Although With reference to previous embodiment, the present invention is described in detail, those of ordinary skill in the art It is understood that the technical scheme described in foregoing embodiments still can be modified by it, Or wherein portion of techniques feature is carried out equivalent；And these amendments or replacement, do not make The essence of appropriate technical solution departs from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (4)

1. a hybrid compensation method for pattern dependent loss and Polarization Dependent Loss, its feature exists In, described method includes:

At transmitting terminal,

S1. bit signal is carried out constellation modulation；

S2. the signal after modulating constellation carries out mode polarization time encoding；

S3. the signal after mode polarization time encoding is carried out light modulation；

S4. the signal after light modulation is carried out light polarization and closes bundle；

S5., after the signal after light polarization being closed bundle carries out Mode Coupling, it is sent in less fundamental mode optical fibre pass It is transmitted；

At receiving terminal,

S6. the Mode Coupling signal of transmission in described less fundamental mode optical fibre is carried out decoupling；

S7. the signal after decoupling is carried out light polarization beam splitting；

S8. the signal after light polarization beam splitting is carried out coherent demodulation；

S9. the signal after coherent demodulation is carried out channel equalization；

S10. the signal after channel equalization is carried out the decoding of mode polarization time；

S11. the signal after decoding the mode polarization time carries out constellation demodulation, after obtaining constellation demodulation Bit signal；

Wherein, described constellation is modulated after signal carry out mode polarization time encoding and include:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& -s_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states；

Described signal after coherent demodulation carried out channel equalization include:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\&Sigma;r_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal；

Described signal after channel equalization is carried out the mode polarization time decoding include:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Method the most according to claim 1, it is characterised in that described bit signal is entered Planetary modulation include bit signal is carried out quadriphase PSK QPSK, eight phase-shift keying (PSK) 8PSK, The constellation modulation of quadrature amplitude modulation 16QAM or quadrature amplitude modulation 64QAM.

3. a hybrid compensation device for pattern dependent loss and Polarization Dependent Loss, its feature exists In, described device includes:

Transmitting terminal includes:

Constellation manipulator, for carrying out constellation modulation to bit signal；

Mode polarization clock coder, when the signal after modulating constellation carries out mode polarization Between encode；

Photomodulator, for carrying out light modulation to the signal after mode polarization time encoding；

Light polarization beam combiner, closes bundle for the signal after light modulation carries out light polarization；

Mode coupler, the signal after light polarization is closed bundle carries out Mode Coupling, and by mould Signal after formula coupling is sent in less fundamental mode optical fibre pass and is transmitted；

Receiving terminal includes:

Pattern decoupler, for carrying out the Mode Coupling signal of transmission in described less fundamental mode optical fibre Decoupling；

Optical polarization beam splitter, for carrying out light polarization beam splitting to the signal after decoupling；

Coherent demodulator, for carrying out coherent demodulation to the signal after light polarization beam splitting；

Channel equalizer, for carrying out channel equalization to the signal after coherent demodulation；

Mode polarization time decoder, in time carrying out mode polarization to the signal after channel equalization Between decode；

Constellation demodulator, the signal after decoding the mode polarization time carries out constellation demodulation, Obtain the bit signal after constellation demodulation；

Described mode polarization clock coder specifically for:

Signal after modulating constellation is grouped, wherein, and the signal s in every 4T time interval₁、 s₂、s₃And s₄It is divided into one group, described s₁It is the signal in the first signal period, described s₂It is Signal in the binary signal cycle, described s₃It is the signal in the 3rd signal period, described s₄It is Signal in four signal periods；

Described s₁、s₂、s₃And s₄After mode polarization time encoding, become an information matrix S,

$S=\left[\begin{array}{cccccccc}{s}_1& -s_2& -s_3& -s_4& s_1^{*}& -s_2^{*}& -s_3^{*}& -s_4^{*}\\ s_2& s_1& s_4& -s_3& s_2^{*}& s_1^{*}& s_4^{*}& -s_3^{*}\\ s_3& -s_4& s_1& s_2& s_3^{*}& -s_4^{*}& s_1^{*}& s_2^{*}\\ s_4& s_3& s_2& s_1& s_4^{*}& s_3^{*}& -s_2^{*}& s_1^{*}\end{array}\right]$

For above-mentioned information matrix S, respectively from two polarization totally four channels of two patterns eight The individual time cycle launches, at first signal period T₁In, pattern LP_11aP_xLaunch Signal s₁, pattern LP_11aP_yLaunch signal s₂, pattern LP_11bQ_xLaunch signal s₃, mould Formula LP_11bQ_yLaunch signal s₄, at second signal period T₂In, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch the secondary series of above-mentioned matrix S successively, in like manner, n-th Individual signal period T_nIn, pattern LP_11aP_x, P_y, pattern LP_11bQ_x, Q_yLaunch successively N-th row of above-mentioned matrix S, n=(1,2,3,4,5,6,7,8)；Wherein, s₁ ^*For s₁Conjugated signal, LP_11aAnd LP_11bIt is two spatial models of optical fiber, P_xAnd P_yIt it is pattern LP_11aTwo polarizations State, Q_xAnd Q_yIt it is pattern LP_11bTwo polarization states；

Described channel equalizer specifically for:

If the signal after coherent demodulation is r_t, t=1,2,3,4, represent first signal respectively Cycle T₁To the 4th signal period T₄Signal after coherent demodulation, then to the letter after coherent demodulation Number r_tCarry out channel equalization to include:

${\tilde{s}}_t=\&Sigma;r_t{h}_t^{*}$

Wherein,Represent signal r_tSignal after channel equalization, h_tRepresent that channel status is estimated Coefficient, t=1,2,3,4, h_t ^*It is h_tConjugation, wherein, h₁Represent from pattern LP_11aP_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₂Represent from pattern LP_11aP_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₃Represent from pattern LP_11bQ_x Polarization state is transmitted into the channel status estimation coefficient of receiving terminal, h₄Represent from pattern LP_11bQ_y Polarization state is transmitted into the channel status estimation coefficient of receiving terminal；

Described mode polarization time decoder specifically for:

To the signal after channel equalizationT=1,2,3,4, decode according to formula below, If meeting following formula, then willIt is decoded as s_i:

$d^2({\tilde{s}}_t,s_i)<d^2({\tilde{s}}_t,s_k)$

Wherein, s_iFor pattern LP_11aP_xPolarization, pattern LP_11aP_yPolarization, pattern LP_11b Q_xPolarization or pattern LP_11bQ_yThe signal of polarizing emission, i value is 1,2,3,4；s_k It is default threshold signal, i ≠ k.

Device the most according to claim 3, it is characterised in that described constellation manipulator is used In bit signal is carried out constellation modulation include: bit signal is carried out quadriphase PSK QPSK, Eight phase-shift keying (PSK) 8PSK, quadrature amplitude modulation 16QAM or quadrature amplitude modulation 64QAM Constellation is modulated.