CN104168069B - The modulating system of phase controlled rotation in the coherent light communications field and modulator approach - Google Patents

Abstract

The present invention discloses the modulating system and modulator approach that in a kind of coherent light communications field, phase controlled rotates, relate to the coherent light communications field, this system comprises sending end and receiving end, and modulation signal is carried out controlled rotation according to the numerical value of control signal sequence by sending end, produces pseudo-PM-QPSK signal; After receiving end carries out dispersion compensation, clock recovery, use auto adapted filtering device processing digital signal and use constant modulus algorithm to be upgraded by the coefficient of auto adapted filtering device, receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end; Follow-up processing flow is identical with common coherent light signal. The present invention converts BPSK to MR-BPSK, converts PS-QPSK to MR-PS-QPSK, can use constant modulus algorithm, avoids mistake convergence problem.

Description

The modulating system of phase controlled rotation in the coherent light communications field and modulator approach

Technical field

The present invention relates to the coherent light communications field, specifically relate to modulating system and modulator approach that in a kind of coherent light communications field, phase controlled rotates.

Background technology

Theory and the experiment of coherent light communication start from the eighties. Being acknowledged as due to coherent optical communication system and have highly sensitive advantage, a large amount of research work has been done in coherent light transmission technology by various countries. Hereafter, due to the invention of EDFA (Erbium-dopedOpticalFiberAmplifier, erbium-doped fiber amplifier) and the immense success in industry application, coherent light communication research turns cold.

Along with optical communication enters 40G, 100G epoch, coherent light communication research is risen once again. What current people valued is the feature that coherent light communication frequency selectivity is good, spectrum effectiveness is high, and these features are conducive to the raising of message capacity. In addition, in coherent communication, the damage of signal is all linear damage by dispersion and polarization mode dispersion, and now communication channel can be modeled as linear time invariant system. DSP (DigitalSignalProcessing, the digital signal processing) technology complicated by appropriateness just can compensated linear damage.

Due to the progress of electronic technology so that the cost of digital signal processing greatly reduces. The coherent optical communication system of a new generation generally introduces DSP technology, and the auto-adaptive filtering technique based on CMA (ConstantModulusAlgorithms, constant modulus algorithm) is its main integral part. Using after intrinsic light carrier demodulation flashlight, re-using ADC (Analog-DigitalConverter, analog to digital converter) and sample gained electronic signal, finally carry out digital signal processing.

Considering spectrum efficiency and the requirement of light signal to noise ratio tolerance limit, what adopt based on the 100G commercial system of coherent light communication is PM-QPSK (PolarizationMultiplexedQuadriPhaseShiftKeying, polarization multiplexing quadriphase PSK) technology. Shown in Figure 1, the flow process of the digital signal processing of coherent optical communication receiver is generally: dispersion compensation �� clock recovery �� auto adapted filtering (CMA) �� carrier auxiliary (frequency difference estimation and compensation) �� carrier auxiliary (differs and estimate and compensate) �� bit decision. Auto adapted filtering device plays polarization demultiplexing and residual chromatic dispersion compensation effect, is usually made up of linear equalizer and auto adapted filtering coefficient update algorithm, and CMA (constant modulus algorithm) is auto adapted filtering coefficient update algorithm. Because constant modulus algorithm does not need training sequence, and not needing to compensate frequency difference in advance, there is feature that is simple and strong robustness, so being adopted by main flow commercial system.

Relative to the PM-QPSK technology adopted by 100G commercial system, other modulation format has its unique features and advantage. BPSK (BinaryPhaseShiftKeying, binary phase-shift key control) although spectrum efficiency only QPSK (QuadriPhaseShiftKeying, quadriphase PSK) half, but owing to the phase distance of BPSK constellation point is from higher than QPSK mono-times, so more can the phase distortion that causes of anti-non-linear effect. Not high at spectral efficiency requirements, and system transfers distance is by the application scene of non-linear restriction, in transmitting without relaying overlength span, BPSK has certain advantage. And the PS-QPSK of up-to-date proposition (PolarizationSwitchedQuadriPhaseShiftKeying, polarization switch quadriphase PSK), although spectrum efficiency only has 3/4ths of PM-QPSK, but PS-QPSK signal can be used in the modulation format of high speed optical communication all, there is the highest OSNR (OpticalSignalNoiseRatio, light signal to noise ratio) tolerance limit, and non-linear tolerance is higher, can complete to transmit more at a distance.

But, when CMA is used for bpsk signal, owing to it does not meet the establishment condition of CMA algorithm, i.e. Expected [E_m ²]=0, Expected is for asking statistics expectation, E_mFor modulation signal, subscript " 2 " is for asking square, and the coefficient of auto adapted filtering device may converge to ambiguity point, and such as, the last output of auto adapted filtering device may be:

E_out(i)=cos (��) E_m(i)+jsin(��)E_m(i+g)(1)

E_outI () is the output of auto adapted filtering device, E_mI () is i-th modulation code element, i is any integer, E_m(i+g) being the i-th+g modulation code element, g is the integer of the tap number being less than auto adapted filtering device, and cos (��) and sin (��) represent that the coefficient that any sum of squares equals 1, �� are arbitrarily angled, and j is imaginary unit. Easily find out: due to E_m(i) and E_m(i+g) it is all bpsk signal, although output signal E_outI in (), two code elements are superimposed, but still meet permanent mould condition. The output of correct auto adapted filtering device is single code element, and now auto adapted filtering device based on constant modulus algorithm does not export correct result. When classical constant modulus algorithm is used for bpsk signal, there will be the problem of mistake convergence.

Same, for PS-QPSK signal, although the modulation of two polarization states is all QPSK signal, but at any code-element period, the modulation of one of them polarization must equal or in contrast to the modulation of another polarization, namelyWherein,Represent the modulation signal of X polarization,Represent the modulation signal of Y polarization. Having dependency owing to being modulated to the signal of two polarization states, the coefficient of auto adapted filtering device still may converge to ambiguity point, and such as, the last output of auto adapted filtering device may be:

$E_{out}\left(i\right)=cos\left(\mathrm{\α}\right)E_m^X\left(i\right)+jsin\left(\mathrm{\α}\right)E_m^Y\left(i\right)---\left(2\right)$

Equally it may be seen that in last output, the modulation of two polarizations is superimposed, and does not really untie, but still meeting permanent mould condition, now, the auto adapted filtering device based on constant modulus algorithm does not export correct result equally. When classical constant modulus algorithm is used for PS-QPSK signal, there will be the problem of mistake convergence equally.

Summary of the invention

It is an object of the invention to the deficiency in order to overcome above-mentioned background technology, modulating system and modulator approach that in a kind of coherent light communications field, phase controlled rotates are provided, convert common BPSK to MR-BPSK, convert common PS-QPSK to MR-PS-QPSK, can normally use classical constant modulus algorithm, when avoiding applying common BPSK, PS-QPSK, use the wrong convergence problem that classical constant modulus algorithm there will be.

The present invention provides the modulating system that in a kind of coherent light communications field, phase controlled rotates, comprise sending end and receiving end, modulation signal is carried out controlled rotation according to the numerical value of the control signal sequence pre-determined by described sending end: control signal value is 0 or 1, control signal sequence loops is shifted by sending end: when control signal value is 0, sending end non rotating modulation signal; When control signal value is 1, sending end is by modulation signal rotation+pi/2 or-pi/2; After modulation signal is carried out controlled rotation treatment, produce a pseudo-polarization multiplexing quadriphase PSK PM-QPSK signal;

After described receiving end carries out dispersion compensation, clock recovery, use auto adapted filtering device processing digital signal, and use constant modulus algorithm CMA to be upgraded by the coefficient of auto adapted filtering device, receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end: when control signal value is 0, the output signal of receiving end non rotating auto adapted filtering device; When control signal value is 1, if sending end is by modulation signal rotation+pi/2, then receiving end is by the output signal rotation-pi/2 of auto adapted filtering device; If sending end is by modulation signal rotation-pi/2, then receiving end is by the output signal rotation+pi/2 of auto adapted filtering device; Follow-up digital signal processing flow process is identical with the treatment scheme of common coherent light signal.

The present invention also provides the modulator approach that in a kind of coherent light communications field, phase controlled rotates, and comprises the following steps:

Modulation signal is carried out controlled rotation according to the numerical value of the control signal sequence pre-determined by A, sending end: control signal value is 0 or 1, and control signal sequence loops is shifted by sending end, when control signal value is 0, and sending end non rotating modulation signal; When control signal value is 1, sending end is by modulation signal rotation+pi/2 or-pi/2; After modulation signal is carried out controlled rotation treatment, produce a pseudo-polarization multiplexing quadriphase PSK PM-QPSK signal;

After B, receiving end carry out dispersion compensation, clock recovery, it may also be useful to auto adapted filtering device processing digital signal, and constant modulus algorithm CMA is used to be upgraded by the coefficient of auto adapted filtering device; Receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end: when control signal value is 0, the output signal of receiving end non rotating auto adapted filtering device; When control signal value is 1, if sending end is by modulation signal rotation+pi/2 in steps A, then in step B receiving end by the output signal rotation-pi/2 of auto adapted filtering device; If sending end is by modulation signal rotation-pi/2 in steps A, then in step B receiving end by the output signal rotation+pi/2 of auto adapted filtering device; Follow-up digital signal processing flow process is identical with the treatment scheme of common coherent light signal.

Compared with prior art, the advantage of the present invention is as follows:

(1) phase controlled that the present invention proposes rotates technology, common BPSK is converted to MR-BPSK (ManipulatedRotatingBinaryPhaseShiftKeying, controlled rotation binary phase-shift key control), while retaining the anti-non-linear advantage of BPSK, can normally use classical constant modulus algorithm, can continue to continue to use ripe DSP architecture for commercial 100G coherent communication system, avoid the wrong convergence problem using classical constant modulus algorithm there will be when using common BPSK.

(2) phase controlled that the present invention proposes rotates technology, common PS-QPSK is converted to MR-PS-QPSK (ManipulatedRotatingPolarizationSwitchedQuadriPhaseShiftK eying, controlled rotatory polarization switch quaternary phase-shift keying (PSK)) can normally use classical constant modulus algorithm, avoid the wrong convergence problem using classical constant modulus algorithm there will be when using common PS-QPSK.

Accompanying drawing explanation

Fig. 1 is the digital signal processing schema of existing coherent optical communication receiver.

Fig. 2 is the digital signal processing schema in the embodiment of the present invention.

Fig. 3 is that the bpsk signal in the embodiment of the present invention carries out the controlled schematic diagram rotating generation MR-BPSK signal at sending end.

Fig. 4 is that the MR-BPSK signal in the embodiment of the present invention carries out reverse controlled rotation at receiving end, and carries out the schematic diagram of follow-up signal process.

Fig. 5 is that the PS-QPSK signal in the embodiment of the present invention carries out the controlled schematic diagram rotating generation MR-PS-QPSK signal at sending end.

Fig. 6 is that the MR-PS-QPSK signal in the embodiment of the present invention carries out reverse controlled rotation at receiving end and carries out the schematic diagram of follow-up signal process.

Embodiment

Below in conjunction with drawings and the specific embodiments, the present invention is described in further detail.

The embodiment of the present invention provides the modulating system that in a kind of coherent light communications field, phase controlled rotates, and comprises sending end and receiving end.

The embodiment of the present invention provides the modulator approach that in a kind of coherent light communications field, phase controlled rotates, and comprises the following steps:

Modulation signal is carried out controlled rotation according to the numerical value of the control signal sequence pre-determined by A, sending end: control signal value is 0 or 1, and control signal sequence loops is shifted by sending end, when control signal value is 0, and sending end non rotating modulation signal; When control signal value is 1, sending end is by modulation signal rotation+pi/2 or-pi/2;

After modulation signal is carried out controlled rotation treatment, produce a pseudo-PM-QPSK signal;

After B, receiving end carry out dispersion compensation, clock recovery, use auto adapted filtering device processing digital signal, and use constant modulus algorithm CMA to be upgraded by the coefficient of auto adapted filtering device, receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end: when control signal value is 0, the output signal of receiving end non rotating auto adapted filtering device; When control signal value is 1, if sending end is by modulation signal rotation+pi/2 in steps A, then in step B receiving end by the output signal rotation-pi/2 of auto adapted filtering device; If sending end is by modulation signal rotation-pi/2 in steps A, then in step B receiving end by the output signal rotation+pi/2 of auto adapted filtering device; Shown in Figure 2, follow-up digital signal processing flow process is identical with the treatment scheme of common coherent light signal: carrier auxiliary-frequency difference estimation and compensation �� carrier auxiliary-differ and estimate and compensation �� bit decision.

Modulation signal can be bpsk signal or PS-QPSK signal, is described in detail for bpsk signal, PS-QPSK signal respectively below.

Embodiment 1, controlled rotation binary phase-shift key control (MR-BPSK)

Shown in Figure 3, for bpsk signal, sending end definition length is control signal sequence C (n) of N, 1��n��N, n, N are positive integer, PRBS (Pseudo-RandomBinarySequence, pseudo-random binary sequence) the code stream of control signal sequence C (n) can be a segment length be N, control signal value is 0 or 1. Control signal sequence loops is shifted by sending end, and each code element moment ring shift is once. To each code element, according to the value of the C (1) in corresponding moment determines whether rotate bpsk signal: when C (1)=0, sending end non rotating bpsk signal; Time C (1)=1, bpsk signal is rotated pi/2 by sending end; Then I/Q modulator is used, modulated light signal.

Shown in Figure 4, receiving end uses the control signal sequence identical with sending end, by the control figure sequence alignment of receiving end and sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence: when C (1)=0, the output signal of receiving end non rotating auto adapted filtering device; Time C (1)=1, receiving end is by the output signal rotation-pi/2 of auto adapted filtering device. Although the receiving end control figure sequence used with sending end is identical, but still requires the control figure sequence alignment of receiving end, sending end, to ensure that receiving end carries out the operation mutually inverse with sending end, this is actual is that receiving end carries out synchronously.

For the bpsk signal of polarization multiplexing, sending end defines the control signal sequence that two length are N respectively: C_X(n) and C_YN (), 1��n��N, n, N are positive integer, C_XN () is the control sequence of X polarization, C_YN () is the control sequence of Y polarization, two polarization signals are carried out controlled rotation respectively. Receiving end uses CMA algorithm to upgrade adaptive filter coefficient, solves X polarization signal and Y polarization signal, more separately according to corresponding control signal sequence retrograde rotation; The process of X polarization signal and Y polarization signal is two independent processes, and treatment process is identical, below Unify legislation, unification E_outI () represents X polarization signal or Y polarization signal, unification represents C with control figure sequence C (n)_X(n) or C_Y(n)��

For the bpsk signal of common bpsk signal and polarization multiplexing, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 101, receiving end carry out dispersion compensation, clock recovery, the output of auto adapted filtering device is done second order difference detection, cancellation receiving end, sending end frequency difference and the impact differed, and carry out quadratic power process, the impact of cancellation BPSK modulating data, calculation formula is:

$E_{out}^{dif2}(i+2)={\{\[E_{out}\left(i\right)\]\[E_{out}\left(i\mathrm{+2}\right)\]/{\[E_{out}\left(i\mathrm{+1}\right)\]}^2\}}^2---\left(3\right)$

E_out(i)��E_out(i+1)��E_out(i+2) output signal being respectively auto adapted filtering device, sequence number is followed successively by i, i+1, i+2, and i is positive integer,For carrying out the numerary signal of two powers again through second order difference detection.

Directly angle can also be carried out second order difference computing, and �� is sought mould:

${\mathrm{\θ}}_r^{dif2}(i+2)=\left\{\begin{array}{c}angle\[E_{out}\left(i\right)\]+angle\[E_{out}(i+2)\]\\ -2angle\[E_{out}(i+1)\]\end{array}\right\}MOD\mathrm{\π}.---\left(4\right)$

Angle is the function that complex signal is asked angle,For detecting through second order difference and seek the angle signal of mould.

Step 102, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 101 are respectivelyOr

Step 103, paired domination number word sequence C (n) carry out circulation second order difference process, and delivery:

C^dif2(n+2)=[C (n+2)+C (n)-2C (n+1)] MOD2,1��n��N-2,

C^dif2(1)=[C (1)+C (N-1)-2C (N)] MOD2,

C^dif2(2)=[C (2)+C (N)-2C (1)] MOD2, (5)

Obtain the controlled rotary digital sequence C calculated through circulation second order difference^dif2(n),1��n��N��

Step 104, by C^dif2(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\mathrm{\Σ}}_1^N{\mathrm{\θ}}_r^{dif2}\left(n\right)C_k^{dif2}\left(n\right)---\left(6\right)$

K is C^dif2N the figure place of () ring shift, k is positive integer, C^dif2N () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then the k value corresponding to this peak value is by C (n) ring shift, produces C_k(n); By C_k(n) and E_outN () is alignd, complete receiving end synchronous with sending end controlled digital sequence.

Follow-up digital signal processing flow process is identical with common bpsk signal treatment scheme, and concrete steps are: carrier auxiliary-frequency difference estimation and compensation �� carrier auxiliary-differ and estimate and compensation �� bit decision.

Embodiment 2, controlled rotatory polarization switch quaternary phase-shift keying (PSK) (MR-PS-QPSK)

For PS-QPSK signal, although modulation is QPSK signal, but the dependency due to two polarization signals, namelyAs used constant modulus algorithm (CMA), still the modulation signal of one of them polarization is carried out controlled rotation.

Shown in Figure 5, sending end definition length is control signal sequence C (n) of N, and 1��n��N, n, N are positive integer, and control signal sequence C (n) is a segment length is the pseudo-PRBS code stream of N, and control signal value is 0 or 1; Sending end is by control signal sequence C (n) ring shift, and uses C (1) that the modulation signal of Y polarization is carried out controlled rotation, and the modulation signal of X polarization does not make and changes.

Shown in Figure 6, after receiving end carries out dispersion compensation, clock recovery, it may also be useful to CMA algorithm upgrades adaptive filter coefficient, solves two polarization signals. Accordingly, by the control figure sequence alignment of receiving end and sending end, and with sending end controlled digital sequence synchronization ring shift, according to the numerical value retrograde rotation Y polarization signal of control signal sequence: when C (1)=0, receiving end non rotating Y polarization signal; Time C (1)=1, receiving end is by Y polarization signal rotation-pi/2. Same, it is necessary to the control signal sequence alignment of receiving end, sending end, namely receiving end carries out synchronously.

For PS-QPSK signal, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 201, receiving end carry out dispersion compensation, clock recovery, being exported by the XY of auto adapted filtering device and be divided by, then carry out quadratic power process, remove the impact of modulation, calculation formula is:

$E_{out}^{XY}\left(i\right)={\[E_{out}^Y\left(i\right)/E_{out}^X\left(i\right)\]}^2---\left(7\right)$

For the Y polarization numerary signal that auto adapted filtering device exports,For the X polarization numerary signal that auto adapted filtering device exports,For both be divided by produce numerary signal.

Again willDoing first order difference, the impact of the phase differential of two polarization signals that cancellation self-adaptation exports, calculation formula is:

$E_{out}^{XY\_dif}(i+1)=E_{out}^{XY}(i+1)/E_{out}^{XY}\left(i\right)---\left(8\right)$

Wherein,For inciting somebody to actionDo the numerary signal of first order difference gained.

First complex plane signal can also be converted into angle signal, more corresponding calculating:

${\mathrm{\θ}}_{XY}^{dif}(i+1)=\left\{\begin{array}{c}angle\[{E^Y}_{out}(i+1)\]-angle\[{E^X}_{out}(i+1)\]\\ -angle\[{E^Y}_{out}\left(i\right)\]+angle\[{E^X}_{out}\left(i\right)\]\end{array}\right\}\mathrm{mod}\mathrm{\π}.---\left(9\right)$

Angle is for seeking angle calculation, and mod is modulo operation,For x signal and y signal subtract each other, do the angle signal of difference after seeking angle.

Step 202, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 201 are respectivelyOr

Step 203, paired domination number word sequence carry out circulation first order difference process, and delivery,

C^dif(n+1)=[C (n+1)-C (n)] MOD2,1��n��N-1,

C^dif(1)=[C (1)-C (N)] MOD2, (10)

Obtain the controlled rotary digital sequence C calculated through circulation first order difference^dif(n),1��n��N��

Step 204, by C^dif(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\mathrm{\Σ}}_1^N{\mathrm{\θ}}_{XY}^{dif}\left(n\right)C_k^{dif}\left(n\right)---\left(11\right)$

K is C^difN the figure place of () ring shift, k is positive integer, C^difN () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then C (n) is carried out ring shift k position by the k value corresponding to peak value, produce C_k(n); By C_k(n) withAlignment, complete receiving end, sending end control figure sequence synchronous.

Follow-up digital signal processing flow process is identical with common PS-QPSK signal processing flow, and concrete steps are: carrier auxiliary-frequency difference estimation and compensation �� carrier auxiliary-differ and estimate and compensation �� bit decision.

In sum, the present invention realizes simply, and whole Received signal strength treating processes can inherit the ripe processing mode of polarization multiplexing QPSK completely, has very strong practicality. The present invention is directed to BPSK and PS-QPSK modulation technology can not use the problem of classical constant modulus algorithm to propose, but the use of the present invention is not limited to this two kinds of modulation formats.

The embodiment of the present invention can be carried out various modifications and variations by the technician of this area, if these amendments and modification are within the scope of the claims in the present invention and equivalent technologies thereof, then these amendments and modification are also within protection scope of the present invention.

The prior art that the content not described in detail in specification sheets is known to the skilled person.

Claims (8)

1. the modulating system that in a coherent light communications field, phase controlled rotates, comprise sending end and receiving end, it is characterized in that: modulation signal is carried out controlled rotation according to the numerical value of the control signal sequence pre-determined by described sending end: modulation signal is binary phase-shift key control bpsk signal or polarization switch quadriphase PSK PS-QPSK signal, control signal value is 0 or 1, control signal sequence loops is shifted by sending end: when control signal value is 0, sending end non rotating modulation signal; When control signal value is 1, sending end is by modulation signal rotation+pi/2 or-pi/2; After modulation signal is carried out controlled rotation treatment, produce a pseudo-polarization multiplexing quadriphase PSK PM-QPSK signal;

After described receiving end carries out dispersion compensation, clock recovery, use auto adapted filtering device processing digital signal, and use constant modulus algorithm CMA to be upgraded by the coefficient of auto adapted filtering device, receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end: when control signal value is 0, the output signal of receiving end non rotating auto adapted filtering device; When control signal value is 1, if sending end is by modulation signal rotation+pi/2, then receiving end is by the output signal rotation-pi/2 of auto adapted filtering device; If sending end is by modulation signal rotation-pi/2, then receiving end is by the output signal rotation+pi/2 of auto adapted filtering device; Follow-up digital signal processing flow process is identical with the treatment scheme of common coherent light signal.

2. the modulating system that in the coherent light communications field as claimed in claim 1, phase controlled rotates, it is characterized in that: when described modulation signal is binary phase-shift key control bpsk signal, sending end definition length is control signal sequence C (n) of N, 1��n��N, n, N are positive integer, the pseudo-random binary sequence PRBS code stream of described control signal sequence C (n) to be a segment length be N, control signal value is 0 or 1; Control signal sequence loops is shifted by sending end, each code element moment ring shift is once, to each code element, according to the value of the C (1) in corresponding moment determines whether rotate bpsk signal: when C (1)=0, sending end non rotating bpsk signal; Time C (1)=1, bpsk signal is rotated pi/2 by sending end; Then I/Q modulator is used, modulated light signal;

Receiving end uses the control signal sequence identical with sending end, by the control figure sequence alignment of receiving end and sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence: when C (1)=0, the output signal of receiving end non rotating auto adapted filtering device; Time C (1)=1, receiving end is by the output signal rotation-pi/2 of auto adapted filtering device;

For the bpsk signal of polarization multiplexing, sending end defines the control signal sequence that two length are N respectively: C_X(n) and C_YN (), 1��n��N, n, N are positive integer, C_XN () is the control sequence of X polarization, C_YN () is the control sequence of Y polarization, two polarization signals are carried out controlled rotation respectively; Receiving end uses CMA algorithm to upgrade adaptive filter coefficient, solves X polarization signal and Y polarization signal, more separately according to corresponding control signal sequence retrograde rotation; The process of X polarization signal and Y polarization signal is two independent processes, and treatment process is identical, below Unify legislation, unification E_outI () represents X polarization signal or Y polarization signal, unification represents C with control figure sequence C (n)_X(n) or C_Y(n);

For the bpsk signal of common bpsk signal and polarization multiplexing, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 101, receiving end carry out dispersion compensation, clock recovery, the output of auto adapted filtering device is done second order difference detection, cancellation receiving end, sending end frequency difference and the impact differed, and carry out quadratic power process, the impact of cancellation BPSK modulating data, calculation formula is:

$E_{out}^{dif2}(i+2)={\{\[E_{out}\left(i\right)\]\[E_{out}(i+2)\]/{\[E_{out}(i+1)\]}^2\}}^2,$

E_out(i)��E_out(i+1)��E_out(i+2) output signal being respectively auto adapted filtering device, sequence number is followed successively by i, i+1, i+2, and i is positive integer,For carrying out the numerary signal of two powers again through second order difference detection;

Or directly angle is carried out second order difference computing, and �� is sought mould:

${\mathrm{\θ}}_r^{dif2}(i+2)=\left\{\begin{array}{c}angle\[E_{out}\left(i\right)\]+angle\[E_{out}(i+2)\]\\ -2angle\[E_{out}(i+1)\]\end{array}\right\}MOD\mathrm{\π}.,$

Angle is the function that complex signal is asked angle,For detecting through second order difference and seek the angle signal of mould;

Step 102, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 101 are respectivelyOr

Step 103, paired domination number word sequence C (n) carry out circulation second order difference process, and delivery:

C^dif2(n+2)=[C (n+2)+C (n)-2C (n+1)] MOD2,1��n��N-2,

C^dif2(1)=[C (l)+C (N-l)-2C (N)] MOD2,

C^dif2(2)=[C (2)+C (N)-2C (1)] MOD2,

Obtain the controlled rotary digital sequence C calculated through circulation second order difference^dif2(n), 1��n��N;

Step 104, by C^dif2(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\Σ}_1^N{\mathrm{\θ}}_r^{dif2}\left(n\right)C_k^{dif2}\left(n\right),$

K is C^dif2N the figure place of () ring shift, k is positive integer, C^dif2N () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then the k value corresponding to this peak value is by C (n) ring shift, produces C_k(n); By C_k(n) and E_outN () is alignd, complete receiving end synchronous with sending end controlled digital sequence; Follow-up digital signal processing flow process is identical with common bpsk signal treatment scheme.

3. the modulating system that in the coherent light communications field as claimed in claim 1, phase controlled rotates, it is characterized in that: when described modulation signal is polarization switch quadriphase PSK PS-QPSK signal, sending end definition length is control signal sequence C (n) of N, 1��n��N, n, N are positive integer, described control signal sequence C (n) is a segment length is the pseudo-PRBS code stream of N, and control signal value is 0 or 1; Sending end is by control signal sequence C (n) ring shift, and uses C (1) that the modulation signal of Y polarization is carried out controlled rotation, and the modulation signal of X polarization does not make and changes;

After receiving end carries out dispersion compensation, clock recovery, CMA algorithm is used to upgrade adaptive filter coefficient, solve two polarization signals, receiving end uses the control signal sequence identical with sending end, by the control figure sequence alignment of receiving end and sending end, and with sending end controlled digital sequence synchronization ring shift, and the numerical value retrograde rotation Y polarization signal according to control signal sequence: when C (1)=0, receiving end non rotating Y polarization signal; Time C (1)=1, receiving end is by Y polarization signal rotation-pi/2;

For PS-QPSK signal, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 201, receiving end carry out dispersion compensation, clock recovery, being exported by the XY of auto adapted filtering device and be divided by, then carry out quadratic power process, remove the impact of modulation, calculation formula is:

$E_{out}^{XY}\left(i\right)={\[E_{out}^Y\left(i\right)/E_{out}^X\left(i\right)\]}^2,$

For the Y polarization numerary signal that auto adapted filtering device exports,For the X polarization numerary signal that auto adapted filtering device exports,For both be divided by produce numerary signal;

Again willDoing first order difference, the impact of the phase differential of two polarization signals that cancellation self-adaptation exports, calculation formula is:

$E_{out}^{XY\_dif}(i+1)=E_{out}^{XY}(i+1)/E_{out}^{XY}\left(i\right),$

Wherein,For inciting somebody to actionDo the numerary signal of first order difference gained;

Or first complex plane signal is converted into angle signal, more corresponding calculating:

${\mathrm{\θ}}_{XY}^{dif}(i+1)=\left\{\begin{array}{c}angle\[{E^Y}_{out}(i+1)\]-angle\[{E^X}_{out}(i+1)\]\\ -angle\[{E^Y}_{out}\left(i\right)\]+angle\[{E^X}_{out}\left(i\right)\]\end{array}\right\}\mathrm{mod}\mathrm{\π}.,$

Angle is for seeking angle calculation, and mod is modulo operation,For x signal and y signal subtract each other, do the angle signal of difference after seeking angle;

Step 202, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 201 are respectivelyOr

Step 203, paired domination number word sequence carry out circulation first order difference process, and delivery,

C^dif(n+1)=[C (n+1)-C (n)] MOD2,1��n��N-1,

C^dif(1)=[C (1)-C (N)] MOD2,

Obtain the controlled rotary digital sequence C calculated through circulation first order difference^dif(n), 1��n��N;

Step 204, by C^dif(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\Σ}_1^N{\mathrm{\θ}}_{XY}^{dif}\left(n\right)C_k^{dif}\left(n\right),$

K is C^difN the figure place of () ring shift, k is positive integer, C^difN () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then C (n) is carried out ring shift k position by the k value corresponding to peak value, produce C_k(n); By C_k(n) withAlignment, complete receiving end, sending end control figure sequence synchronous; Follow-up digital signal processing flow process is identical with common PS-QPSK signal processing flow.

4. the modulating system that as claimed any one in claims 1 to 3 phase controlled rotates in the coherent light communications field, it is characterised in that: described follow-up digital signal processing flow process is: carrier auxiliary-frequency difference estimation and compensation �� carrier auxiliary-differ estimation and compensation �� bit decision.

5. the modulator approach that in a coherent light communications field, phase controlled rotates, it is characterised in that, comprise the following steps:

Modulation signal is carried out controlled rotation according to the numerical value of the control signal sequence pre-determined by A, sending end: modulation signal is binary phase-shift key control bpsk signal or polarization switch quadriphase PSK PS-QPSK signal, control signal value is 0 or 1, control signal sequence loops is shifted by sending end, when control signal value is 0, sending end non rotating modulation signal; When control signal value is 1, sending end is by modulation signal rotation+pi/2 or-pi/2; After modulation signal is carried out controlled rotation treatment, produce a pseudo-polarization multiplexing quadriphase PSK PM-QPSK signal;

After B, receiving end carry out dispersion compensation, clock recovery, it may also be useful to auto adapted filtering device processing digital signal, and constant modulus algorithm CMA is used to be upgraded by the coefficient of auto adapted filtering device; Receiving end uses the control signal sequence identical with sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence, remove the impact in the controlled rotation of sending end: when control signal value is 0, the output signal of receiving end non rotating auto adapted filtering device; When control signal value is 1, if sending end is by modulation signal rotation+pi/2 in steps A, then in step B receiving end by the output signal rotation-pi/2 of auto adapted filtering device; If sending end is by modulation signal rotation-pi/2 in steps A, then in step B receiving end by the output signal rotation+pi/2 of auto adapted filtering device; Follow-up digital signal processing flow process is identical with the treatment scheme of common coherent light signal.

6. the modulator approach that in the coherent light communications field as claimed in claim 5, phase controlled rotates, it is characterized in that: when described modulation signal is binary phase-shift key control bpsk signal, sending end definition length is control signal sequence C (n) of N, 1��n��N, n, N are positive integer, the pseudo-random binary sequence PRBS code stream of described control signal sequence C (n) to be a segment length be N, control signal value is 0 or 1; Control signal sequence loops is shifted by sending end, each code element moment ring shift is once, to each code element, according to the value of the C (1) in corresponding moment determines whether rotate bpsk signal: when C (1)=0, sending end non rotating bpsk signal; Time C (1)=1, bpsk signal is rotated pi/2 by sending end; Then I/Q modulator is used, modulated light signal;

Receiving end uses the control signal sequence identical with sending end, by the control figure sequence alignment of receiving end, sending end, and with sending end controlled digital sequence synchronization ring shift, again according to the output signal of the numerical value retrograde rotation auto adapted filtering device of control signal sequence: when C (1)=0, the output signal of receiving end non rotating auto adapted filtering device; Time C (1)=1, receiving end is by the output signal rotation-pi/2 of auto adapted filtering device;

For the bpsk signal of polarization multiplexing, sending end defines the control signal sequence that two length are N respectively: C_X(n) and C_YN (), 1��n��N, n, N are positive integer, C_XN () is the control sequence of X polarization, C_YN () is the control sequence of Y polarization, two polarization signals are carried out controlled rotation respectively; Receiving end uses CMA algorithm to upgrade adaptive filter coefficient, solves X polarization signal and Y polarization signal, more separately according to corresponding control signal sequence retrograde rotation; The process of X polarization signal and Y polarization signal is two independent processes, and treatment process is identical, below Unify legislation, unification E_outI () represents X polarization signal or Y polarization signal, unification represents C with control figure sequence C (n)_X(n) or C_Y(n);

For the bpsk signal of common bpsk signal and polarization multiplexing, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 101, receiving end carry out dispersion compensation, clock recovery, the output of auto adapted filtering device is done second order difference detection, cancellation receiving end, sending end frequency difference and the impact differed, and carry out quadratic power process, the impact of cancellation BPSK modulating data, calculation formula is:

$E_{out}^{dif2}(i+2)={\{\[E_{out}\left(i\right)\]\[E_{out}(i+2)\]/{\[E_{out}(i+1)\]}^2\}}^2,$

E_out(i)��E_out(i+1)��E_out(i+2) output signal being respectively auto adapted filtering device, sequence number is followed successively by i, i+1, i+2, and i is positive integer,For carrying out the numerary signal of two powers again through second order difference detection;

Or directly angle is carried out second order difference computing, and �� is sought mould:

${\mathrm{\θ}}_r^{dif2}(i+2)=\left\{\begin{array}{c}angle\[E_{out}\left(i\right)\]+angle\[E_{out}(i+2)\]\\ -2angle\[E_{out}(i+1)\]\end{array}\right\}MOD\mathrm{\π}.,$

Angle is the function that complex signal is asked angle,For detecting through second order difference and seek the angle signal of mould;

Step 102, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 101 are respectivelyOr

Step 103, paired domination number word sequence C (n) carry out circulation second order difference process, and delivery:

C^dif2(n+2)=[C (n+2)+C (n)-2C (n+1)] MOD2,1��n��N-2,

C^dif2(1)=[C (1)+C (N-1)-2C (N)] MOD2,

C^dif2(2)=[C (2)+C (N)-2C (1)] MOD2,

Obtain the controlled rotary digital sequence C calculated through circulation second order difference^dif2(n), 1��n��N;

Step 104, by C^dif2(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\Σ}_1^N{\mathrm{\θ}}_r^{dif2}\left(n\right)C_k^{dif2}\left(n\right),$

K is C^dif2N the figure place of () ring shift, k is positive integer, C^dif2N () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then the k value corresponding to this peak value is by C (n) ring shift, produces C_k(n); By C_k(n) and E_outN () is alignd, complete receiving end synchronous with sending end controlled digital sequence; Follow-up digital signal processing flow process is identical with common bpsk signal treatment scheme.

7. the modulator approach that in the coherent light communications field as claimed in claim 5, phase controlled rotates, it is characterized in that: when described modulation signal is polarization switch quadriphase PSK PS-QPSK signal, sending end definition length is control signal sequence C (n) of N, 1��n��N, n, N are positive integer, described control signal sequence C (n) is a segment length is the pseudo-PRBS code stream of N, and control signal value is 0 or 1; Sending end is by control signal sequence C (n) ring shift, and uses C (1) that the modulation signal of Y polarization is carried out controlled rotation, and the modulation signal of X polarization does not make and changes;

After receiving end carries out dispersion compensation, clock recovery, CMA algorithm is used to upgrade adaptive filter coefficient, solve two polarization signals, by the control figure sequence alignment of receiving end and sending end, and with sending end controlled digital sequence synchronization ring shift, and the numerical value retrograde rotation Y polarization signal according to control signal sequence: when C (1)=0, receiving end non rotating Y polarization signal; Time C (1)=1, receiving end is by Y polarization signal rotation-pi/2;

For PS-QPSK signal, receiving end is as follows with the synchronous flow process of the control figure sequence alignment of sending end:

After step 201, receiving end carry out dispersion compensation, clock recovery, being exported by the XY of auto adapted filtering device and be divided by, then carry out quadratic power process, remove the impact of modulation, calculation formula is:

$E_{out}^{XY}\left(i\right)={\[E_{out}^Y\left(i\right)/E_{out}^X\left(i\right)\]}^2,$

For the Y polarization numerary signal that auto adapted filtering device exports,For the X polarization numerary signal that auto adapted filtering device exports,For both be divided by produce numerary signal;

Again willDoing first order difference, the impact of the phase differential of two polarization signals that cancellation self-adaptation exports, calculation formula is:

$E_{out}^{XY\_dif}(i+1)=E_{out}^{XY}(i+1)/E_{out}^{XY}\left(i\right),$

Wherein,For inciting somebody to actionDo the numerary signal of first order difference gained;

Or first complex plane signal is converted into angle signal, more corresponding calculating:

${\mathrm{\θ}}_{XY}^{dif}(i+1)=\left\{\begin{array}{c}angle\[{E^Y}_{out}(i+1)\]-angle\[{E^X}_{out}(i+1)\]\\ -angle\[{E^Y}_{out}\left(i\right)\]+angle\[{E^X}_{out}\left(i\right)\]\end{array}\right\}\mathrm{mod}\mathrm{\π}.,$

Angle is for seeking angle calculation, and mod is modulo operation,For x signal and y signal subtract each other, do the angle signal of difference after seeking angle;

Step 202, by E_outI the data framing of (), every N number of data are a frame, appoint and get a frame, and the data that two kinds of modes process in step 201 are respectivelyOr

Step 203, paired domination number word sequence carry out circulation first order difference process, and delivery,

C^dif(n+1)=[C (n+1)-C (n)] MOD2,1��n��N-1,

C^dif(1)=[C (1)-C (N)] MOD2,

Obtain the controlled rotary digital sequence C calculated through circulation first order difference^dif(n), 1��n��N;

Step 204, by C^dif(n) ring shift, displacement after withOrCarry out related calculation:

$SUM\left(k\right)={\Σ}_1^N{\mathrm{\θ}}_{XY}^{dif}\left(n\right)C_k^{dif}\left(n\right),$

K is C^difN the figure place of () ring shift, k is positive integer, C^difN () ring shift k position obtains

Find the peak value of SUM (k) absolute value, then C (n) is carried out ring shift k position by the k value corresponding to peak value, produce C_k(n); By C_k(n) withAlignment, complete receiving end, sending end control figure sequence synchronous; Follow-up digital signal processing flow process is identical with common PS-QPSK signal processing flow.

8. the modulator approach that in the coherent light communications field as according to any one of claim 5 to 7, phase controlled rotates, it is characterised in that: described follow-up digital signal processing flow process is: carrier auxiliary-frequency difference estimation and compensation �� carrier auxiliary-differ estimation and compensation �� bit decision.