CN103098392A - Electro-optical modulation apparatus, method, emitter and electro-optical modulation system - Google Patents

Abstract

The embodiment of the invention discloses an electro-optical modulation apparatus, a method, an emitter and an electro-optical modulation system and relates to the communication field. Nonlinear memory polynomials are adopted to carry out pre-distortion compensation to digital electric signals, so that nonlinearity of the electro-optical modulation apparatus is eliminated. The apparatus has the advantages of high precision and production efficiency, simple structure, easy realization and low cost. The electro-optical modulation apparatus comprises a receiving unit, a compensation unit and an electro-optical modulator successively connected with each other, wherein the receiving unit is used for receiving the digital electric signals u (n), the compensation unit is used for carrying out pre-distortion compensation to the digital electric signals u (n) based on the nonlinear memory polynomials and obtaining the digital electric signals x (n) after pre-distortion compensation, the electro-optical modulator is used for converting the digital electric signals x (n) after pre-distortion compensation to optical signals.

Description

A kind of electro-optic modulation arrangement, method, transmitter and electro-optic modulation system

Technical field

The present invention relates to the communications field, relate in particular to a kind of electro-optic modulation arrangement, method, transmitter and electro-optic modulation system.

Background technology

Light positive is handed over frequency division multiplexing (Optical Orthogonal Frequency Division Multiplexing, abbreviation O-OFDM) system is become signal the fibre channel transmission in light territory by the wireless channel transmission in electric territory, the O-OFDM technology is grown at a high speed the new type of modulation mode of Distance Transmission as the next generation, is the preferred version of realizing 100Gbit/s and above transmission capacity.

Electrooptic modulator is the significant components in the O-OFDM system, be used for the signal of telecommunication is converted into light signal, but electrooptic modulator generally has nonlinear characteristic.Because the O-OFDM system is responsive to the non-linear comparison of electrooptic modulator, and directly use linear modulator to make the complex structure of this system, cost high, therefore need to eliminate nonlinear electro-optic modulation arrangement.

At present, electro-optic modulation arrangement is generally eliminated the non-linear of electrooptic modulator with look-up table or feed-forward technique.Look-up table is mainly that input/output signal is stored into the transfer function that table draws modulator, utilizes and to table look-up to realize to launch or the calibration of receiving end signal; Feed-forward technique is to draw the compensation signal of telecommunication by treating that the signal of telecommunication that modulation signal and light signal through electrooptic modulator output change into compares, to compensate again the signal of telecommunication and be converted into light signal the light signal that electrooptic modulator transforms is carried out nonlinear compensation, improve the nonlinear purpose of system.

The inventor finds that in prior art, there are the following problems at least: the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause cost high.

Summary of the invention

In view of this, the embodiment of the present invention provides a kind of electro-optic modulation arrangement, method, transmitter and electro-optic modulation system, the accuracy that in prior art, electro-optic modulation arrangement adopts look-up table to cause is not high, production efficiency is low to solve, and adopts complex structure that feed-forward technique brings, realizes difficulty, the problem that cost is high.

First aspect provides a kind of electro-optic modulation arrangement, comprising: the receiving element that connects successively, and compensating unit and electrooptic modulator, wherein,

Described receiving element is used for receiving digital electric signal u (n), and described digital electric signal u (n) is transferred to compensating unit;

Described compensating unit, be used for receiving digital electric signal u (n) from described receiving element, and according to the nonlinear memory multinomial, described digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated, and the digital electric signal x (n) after described pre-distortion compensated is transferred to described electrooptic modulator;

Described electrooptic modulator for the digital electric signal x (n) after the described pre-distortion compensated of described compensating unit reception, and is converted into light signal with the digital electric signal x (n) after described pre-distortion compensated.

In the possible implementation of the first, according to first aspect, described nonlinear memory multinomial comprises: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1},$ $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=0}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is the coefficient of nonlinear terms.

In the possible implementation of the second, in conjunction with the possible implementation of the first of first aspect or first aspect, the non linear coefficient of described electrooptic modulator is constant, and is stored in described compensating unit.

In the third possible implementation, the implementation possible according to the second of first aspect, this device also comprises: the optical coupler that connects successively, photoelectric processing device and non-linear estimations unit, wherein,

Described optical coupler is connected with described electrooptic modulator, is used for gathering the light signal of described electrooptic modulator output;

Described photoelectric processing device, be used for receiving the light signal of described optical coupler output, and described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n), and described digital electric signal y (n) is sent to described non-linear estimations unit;

Described non-linear estimations unit is connected with described compensating unit, is used for according to the non linear coefficient of described digital electric signal y (n) and described nonlinear memory polynomial computation electrooptic modulator and is transferred to described compensating unit.

In the 4th kind of possible implementation, according to the third possible implementation of first aspect, described photoelectric processing device comprises photodetector, analog-digital converter and the signal synchronous processing unit that connects successively, wherein,

Described photodetector is used for and will be converted into analog electrical signal from the light signal that described optical coupler receives;

Described analog-digital converter is used for the analog electrical signal that described photodetector produces is converted to digital electric signal;

Described signal synchronous processing unit is used for the digital electric signal that described analog-digital converter produces is converted to the digital signal y (n) of synchronizeing with described digital signal.

In the 5th kind of possible implementation, according to the 4th kind of possible implementation of first aspect, described photodetector is the low bandwidth photodetector, and described analog-digital converter is the low speed analog-digital converter,

If service traffics are high band wide data, described photodetector will not be converted into analog electrical signal from the light signal that described optical coupler receives, make described non-linear estimations unit not calculate the non linear coefficient of electrooptic modulator, and then make described compensating unit use a of the last transmission in described non-linear estimations unit _kmDescribed digital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, described photodetector will be converted into analog electrical signal from the light signal that described optical coupler receives, described analog-digital converter is converted to digital electric signal with the analog electrical signal that described photodetector produces, make described non-linear estimations unit according to the non linear coefficient of described nonlinear memory polynomial computation electrooptic modulator, and then make described compensating unit use the non linear coefficient of described electrooptic modulator to carry out pre-distortion compensated to described digital electric signal u (n).

Second aspect provides a kind of elimination non-linear method, is applied to comprise that in the electro-optic modulation arrangement of electrooptic modulator, the method comprises:

Receive digital electric signal u (n);

According to the nonlinear memory multinomial, described digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated;

Digital electric signal x (n) after described pre-distortion compensated is converted into light signal.

In the possible implementation of the first, according to second aspect, described nonlinear memory multinomial comprises: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Perhaps $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is the coefficient of nonlinear terms.

In the third possible implementation, in conjunction with the possible implementation of the first of second aspect or second aspect,, the method also comprises:

Gather the light signal of described electro-optic modulation arrangement output;

Described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n);

Non linear coefficient according to described digital electric signal y (n) and described nonlinear memory polynomial computation electrooptic modulator.

In the 4th kind of possible implementation, according to the third possible implementation of second aspect, described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n), be embodied in:

Described light signal is converted into analog electrical signal;

Described analog electrical signal is converted to digital electric signal;

Described digital electric signal is converted to the digital signal y (n) of synchronizeing with described digital signal.

In the 5th kind of possible implementation, according to the 4th kind of possible implementation of second aspect, the method also comprises:

If service traffics are high band wide data, described electro-optic modulation arrangement is not converted into analog electrical signal with described light signal, make described electro-optic modulation arrangement not calculate the non linear coefficient of electrooptic modulator, and according to the non linear coefficient of the electrooptic modulator of last calculating, described digital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, described electro-optic modulation arrangement is converted into analog electrical signal with described light signal, and described analog electrical signal is converted to digital electric signal, and according to the non linear coefficient of described nonlinear memory polynomial computation electrooptic modulator, and according to the non linear coefficient of described electrooptic modulator, described digital electric signal u (n) is carried out pre-distortion compensated.

The third aspect provides a kind of transmitter, comprises electro-optic modulation arrangement as described above.

Fourth aspect provides a kind of electro-optic modulation system, comprises transmitter as described above and receiver, and wherein said receiver is used for receiving optical signals, and described light signal is converted into digital electric signal.

By such scheme, solved that the accuracy that in the prior art, electro-optic modulation arrangement adopts look-up table to cause is high, production efficiency is low, and adopted complex structure that feed-forward technique brings, realize difficulty, the problem that cost is high.

Description of drawings

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or description of the Prior Art, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

The structural representation of a kind of electro-optic modulation arrangement that Fig. 1 provides for the embodiment of the present invention;

The structural representation of the another kind of electro-optic modulation arrangement that Fig. 2 provides for the embodiment of the present invention;

The structural representation of the another kind of electro-optic modulation arrangement that Fig. 3 provides for the embodiment of the present invention;

The structural representation of the another kind of electro-optic modulation arrangement that Fig. 4 provides for the embodiment of the present invention;

The flow chart of a kind of electrooptical modulation method that Fig. 5 provides for the embodiment of the present invention;

The flow chart of the computational process of the non linear coefficient of a kind of electrooptic modulator that Fig. 6 provides for the embodiment of the present invention;

The structural representation of a kind of transmitter that Fig. 7 provides for the embodiment of the present invention;

The structural representation of a kind of electro-optic modulation system that Fig. 8 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Based on the embodiment in the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

On the one hand, the embodiment of the present invention provides a kind of electro-optic modulation arrangement 100, and referring to Fig. 1, this electro-optic modulation arrangement 100 comprises: the receiving element 10 that connects successively, and compensating unit 20 and electrooptic modulator 30, wherein,

Receiving element 10 is used for receiving digital electric signal u (n), and described digital electric signal u (n) is transferred to compensating unit 20;

Exemplarily, receiving element 10 constantly receives digital electric signal, for example according to the sequencing that receives, digital electric signal can be denoted as respectively u (1), u (2), u (3) ... u (n), because the nonlinear compensation principle of each digital electric signal is all identical, so the present embodiment only elaborates as an example of the process of digital electric signal u (n) being carried out nonlinear compensation example.

Compensating unit 20, be used for receiving digital electric signal u (n) from receiving element 10, and according to the nonlinear memory multinomial, described digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated, and the digital electric signal x (n) after described pre-distortion compensated is transferred to electrooptic modulator 30;

Exemplarily, because there is nonlinear distortion in electrooptic modulator 30 in the electric light transfer process, so, if directly digital electric signal u (n) is carried out the electric light conversion through electrooptic modulator 30, the light signal meeting distortion that obtains, so, need to carry out suitable compensation to digital electric signal u (n), make digital electric signal x (n) after compensation carry out through electrooptic modulator 30 light signal and digital electric signal u (n) that the electric light conversion obtains linear, thereby avoid the nonlinear distortion in the electric light transfer process.

Optionally, described nonlinear memory multinomial can comprise: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1},$ $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is non linear coefficient.

In order to make the nonlinear memory multinomial simple, and then reduce calculation procedure, preferred, the nonlinear memory multinomial can comprise: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1},$ Following examples comprise the nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Be elaborated.

Exemplarily, M is natural number, the expression memory span, when M=0, the memoryless multinomial of above-mentioned non-linear polynomial repressentation is when M＞0, above-mentioned non-linear polynomial table is shown with the memory multinomial, and the M value is larger, and the accuracy of the compensation of 20 couples of digital electric signal u of compensating unit (n) is higher; K is the natural number greater than 1, represents high non-linearity exponent number, is stored in compensating unit 20, and in electrooptic modulator, K generally can be set to 1≤K≤5, and the value of K is larger, and the accuracy of the compensation of 20 couples of digital electric signal u of compensating unit (n) is higher; a _kmBe the non linear coefficient of electrooptic modulator 30, wherein, a _kmSize can change because of the kind of electrooptic modulator 30 and the variation of residing external environment thereof, when the kind one of electrooptic modulator 30 regularly, mainly be subjected to the impact of ambient temperature larger.

Exemplary, $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Can be converted into by inverting: $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1}),$ Due to compensating unit 20

Obtain the digital electric signal x (n) be through pre-distortion compensated, therefore generally according to multinomial $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1})$ Digital electric signal x (n) is carried out pre-distortion compensated.

Electrooptic modulator 30 for the digital electric signal x (n) after the compensating unit 20 described pre-distortion compensateds of reception, and is converted into light signal with the digital electric signal x (n) after described pre-distortion compensated.

Exemplarily, electrooptic modulator 30 is converted to light signal with the digital electric signal x (n) after pre-distortion compensated, transmits by optical-fibre channel.

Embodiments of the invention provide a kind of electro-optic modulation arrangement 100, by the nonlinear memory multinomial, digital electric signal is carried out pre-distortion compensated, thereby eliminate the non-linear of electro-optic modulation arrangement, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity

Below by three specific embodiments, described nonlinear memory multinomial is comprised $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ The time electro-optic modulation arrangement describe.

Embodiment one

Referring to Fig. 2, the electro-optic modulation arrangement 100 that the present embodiment provides comprises: the receiving element 10, compensating unit 20, the electrooptic modulator 30 that connect successively, also comprise successively the feedback loop that the optical coupler 40 that connects, photoelectric processing device 50 and non-linear estimations unit 60 consist of, wherein, optical coupler 40 is connected connection with electrooptic modulator, connection is connected in non-linear estimations unit 60 with compensating unit.

The effect of receiving element described in the present embodiment 10, compensating unit 20, electrooptic modulator 30 is same as the previously described embodiments, repeats no more herein, and the present embodiment calculates a in real time by feedback loop _km, make compensating unit 20 according to a that calculates in real time _kmDigital electric signal u (n) is compensated, and then improve compensation precision.The below calculates a in real time to feedback loop _kmProcess be elaborated.Wherein feedback loop comprises:

Optical coupler 40 is used for gathering the light signal that electrooptic modulator 30 is exported;

Exemplarily, optical coupler 40 is divided into two parts with the light signal of electrooptic modulator 30 outputs according to certain ratio, wherein, the more a part of light signal of ratio transmits by optical-fibre channel, the less a part of optical signal transmission of ratio is used for analyzing and calculating the nonlinear parameter a of electrooptic modulator to photoelectric processing device 50 and non-linear estimations unit 60 _km, and then digital electric signal u (n) is carried out pre-distortion compensated.The ratio that adopts in the present embodiment is 90: 10, certainly, also can be set to other ratios.

Exemplarily, when electro-optic modulation arrangement 100 is started working, the non linear coefficient a of store electricity optical modulator 30 not yet in compensating unit 20 _km, namely compensating unit 20 is not yet worked, and in the case, x (n) equates with digital electric signal u (n), and the light signal z (n) of x (n) after electrooptic modulator 30 modulation becomes non-linear relation with digital electric signal u (n).

Calculate the non linear coefficient a of electrooptic modulator 30 when non-linear estimations unit 60 _kmAnd after sending to compensating unit 20, compensating unit 20 is started working, in the case, the output electrical signals x (n) of compensating unit 20 is the signal after digital electric signal u (n) is compensated, and the light signal z (n) of x (n) after electrooptic modulator 30 modulation is linear with digital electric signal u (n).

Photoelectric processing device 50, be used for receiving the light signal of optical coupler 40 outputs, and this light signal is converted to the digital electric signal y (n) of synchronizeing with digital electric signal u (n), and this digital electric signal y (n) is sent to non-linear estimations unit 60.

Exemplarily, photoelectric processing device 50 can comprise: the photodetector 501, analog-digital converter 502 and the signal synchronous processing unit 503 that connect successively, wherein,

Photodetector 501 is used for and will be converted into analog electrical signal from the light signal that optical coupler 40 receives, and wherein, this photodetector 501 can be the high bandwidth photodetector;

Analog-digital converter 502 is used for the analog electrical signal that photodetector 501 produces is converted to digital electric signal, and wherein, this analog-digital converter 502 can be the high speed analog-digital converter;

Exemplarily, when electro-optic modulation arrangement 100 is started working, the light signal z (n) of x (n) after electrooptic modulator 30 modulation becomes non-linear relation with digital electric signal u (n), and light signal z (n) is the digital electric signal of nonlinear distortion through the digital electric signal y (n) that photodetector 501, analog-digital converter 502 are modulated into;

Signal synchronous processing unit 503 is used for the digital electric signal that analog-digital converter 502 produces is converted to the digital signal y (n) of synchronizeing with digital signal u (n).

exemplarily, because receiving digital electric signal u (n), receiving element 10 needs the regular hour through a series of processing arriving signal synchronous processing unit 503, so, synchronization, the digital electric signal that the digital electric signal that synchronous processing unit 503 receives and receiving element 10 receive is asynchronous, that is to say, when digital electric signal u (n) that receiving element 10 receives, the digital electric signal that synchronous processing unit 503 receives may be y (n-1) or y (n-2) or the signal of telecommunication of other n before the moment, being specially which signal of telecommunication constantly can determine according to delay time.For the non-linear of electrooptic modulator 30 compensated, need to do registration process to the digital electric signal that synchronous processing unit 503 receives, make the digital electric signal of synchronous processing unit 503 outputs synchronize with the digital electric signal that receiving element 10 receives.

For example, suppose according to delay time, the digital electric signal that current time receiving element 10 receives is u (7), the digital electric signal that signal synchronous processing unit 503 receives is y (5), need so y (5) is processed making y (5) synchronize with u (7), and the digital electric signal after synchronous processing unit is expressed as y (7).

Exemplarily, signal synchronous processing unit 503 can comprise OFDM processing unit and inverse fast fourier transform (Inverse Fast Fourier Transform the is called for short IFFT) converting unit that connects successively, wherein,

OFDM processing unit 5031, be connected with analog-digital converter 502, be used for receiving the digital electric signal of analog-digital converter 502 outputs, and this digital electric signal is done registration process be converted under frequency domain and receive with current time receiving element 10 signal that digital electric signal u (n) is synchronizeed, and this signal is transferred to the IFFT converting unit;

IFFT converting unit 5032, be connected with non-linear estimations unit 60, the digital electric signal that is used for synchronizeing with the digital electric signal u (n) that current time receiving element 10 receives under the frequency domain with the output of OFDM processing unit is converted into the synchronous digital electric signal y (n) of digital electric signal u (n) that receives with current time receiving element 10 under time domain.

Calculate the non linear coefficient a of electrooptic modulator 30 when non-linear estimations unit 60 _kmAnd after sending to compensating unit 20, compensating unit 20 is started working, the light signal z (n) of x (n) after electrooptic modulator 30 modulation is linear with digital electric signal u (n), and the digital electric signal y (n) that light signal z (n) is modulated into through photodetector 501, analog-digital converter 502 is undistorted digital electric signal.Need to prove, after compensating unit 20 work, under perfect condition, digital electric signal y (n) equates with digital electric signal u (n), but can there be certain admissible error in actual capabilities, for example, this admissible error can for, in actual signal transmission is used, do not affect user's experience etc., can think that namely digital electric signal y (n) equates in error range with digital electric signal u (n).

Exemplarily, this photodetector 501, analog-digital converter 502 and signal synchronous processing unit 503 can be integrated into a device, also can be set to respectively a device, and the embodiment of the present invention does not limit this.

Non-linear estimations unit 60 is used for according to digital electric signal y (n) and non-linear multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Calculate a of current time _kmAnd be transferred to compensating unit 20.

Exemplarily, are connected with the photoelectric processing device with compensating unit 20 respectively and are connected in non-linear estimations unit 60, each constantly compensating unit 20 and photoelectric processing device 50 respectively the digital electric signal x (n) of output and y (n) are sent to non-linear estimations unit 60, make the non-linear estimations unit according to digital electric signal x (n) and y (n) and the non-linear multinomial of reception $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Calculate a _km, and with a that calculates _kmSend to compensating unit 20, be used for next pre-distortion compensated of 20 pairs of digital electric signals of compensating unit constantly, at this moment, upper one is stored in a in compensating unit 20 constantly _kmBe replaced.

Exemplarily, the electro-optic modulation arrangement 100 that provides due to the present embodiment can real-time update electrooptic modulator 30 non linear coefficient a _km, namely work as the non linear coefficient a that environment change causes electrooptic modulator 30 _kmDuring change, electro-optic modulation arrangement 100 can be made compensation in real time to digital electric signal x (n), so this electrooptic modulator 100 is applied widely.

Embodiments of the invention provide a kind of electro-optic modulation arrangement 100, the non linear coefficient a of the electrooptic modulator 30 by real-time calculating and renewal _kmAnd non-linear multinomial $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1})$ Digital electric signal u (n) is carried out pre-distortion compensated in real time, thereby eliminate the non-linear of electro-optic modulation arrangement, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity.

Embodiment two:

Referring to Fig. 3, the electro-optic modulation arrangement 100 that the present embodiment provides comprises: the receiving element 10 that connects successively, compensating unit 20, electrooptic modulator 30.

Exemplarily, the receiving element 10 of the electro-optic modulation arrangement 100 that the present embodiment provides, compensating unit 20 are identical with previous embodiment with electrooptic modulator 30 functions, repeat no more herein.

The present embodiment does not need to increase feedback loop and calculates in real time a _km, because when the kind of electrooptic modulator 30 and residing external environment thereof are stablized, the non linear coefficient a of electrooptic modulator 30 _kmGenerally also more stable (can think steady state value in error range, for example, during this error range can be used according to actual signal transmission, do not affect the user experience etc. determine), therefore, a in the present embodiment _kmThe electrooptic modulator 30 that uses according to reality in advance calculates and is stored in compensating unit 20, compensates for 20 couples of digital electric signal u of compensating unit (n), to eliminate the nonlinear distortion in the electric light transfer process.

Exemplarily, calculate the non linear coefficient a of electrooptic modulator 30 in advance _kmThe time, concrete device can comprise: the feedback loop that the photodetector 501 that connects successively that provides as embodiment one, analog-digital converter 502, synchronous processing unit 503 and non-linear estimations unit 60 consist of, and this feedback loop can be connected with the electro-optic modulation arrangement 100 that the present embodiment provides.The calculating a that utilizes embodiment one to provide _kmMethod ask for a when stablizing _km, and with this a _kmNon linear coefficient as default electrooptic modulator 30 is stored in compensating unit 20.

The electro-optic modulation arrangement 100 that embodiments of the invention provide is by the non linear coefficient a of default electrooptic modulator 30 _kmAnd non-linear multinomial $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1})$ Digital electric signal u (n) is carried out pre-distortion compensated, thereby eliminate the non-linear of electro-optic modulation arrangement, that adopt due to the present embodiment is the non linear coefficient a of the electrooptic modulator 30 preset _km, can not be to the non linear coefficient a of electrooptic modulator 30 _kmTherefore carry out real-time update, be adapted at using in more stable environment, and only need to or use for the first time when this electro-optic modulation arrangement 100 is dispatched from the factory the time, with the non linear coefficient a of above-mentioned default electrooptic modulator 30 _kmDevice to a _kmPreset, and be stored in compensating unit 20 and get final product, work as a _kmCan remove preinstall apparatus after presetting successfully, have advantage simple in structure, that cost is low.

Embodiment three

Referring to Fig. 4, the electro-optic modulation arrangement 100 that the present embodiment provides comprises: the receiving element 10 that connects successively, compensating unit 20, electrooptic modulator 30, also comprise successively the feedback loop that the optical coupler 40 that connects, photoelectric processing device 50 and non-linear estimations unit 60 consist of, wherein, optical coupler 40 is connected connection with electrooptic modulator, connection is connected in non-linear estimations unit 60 with compensating unit.

The structure of the present embodiment and principle are identical with embodiment one, only describe for different piece herein.Be that what use in the present embodiment is low bandwidth photodetector 501 and low speed analog-digital converter 502.

If service traffics are high band wide data, low bandwidth photodetector 501 will not be converted into analog electrical signal from the light signal that optical coupler 40 receives, and make non-linear estimations unit 60 not calculate a _km, and then make compensating unit 20 use a of non-linear estimations unit 60 last transmission _kmDigital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, low bandwidth photodetector 501 will be converted into analog electrical signal from the light signal that optical coupler 40 receives, low speed analog-digital converter 502 is converted to digital electric signal with the analog electrical signal that low bandwidth photodetector 501 produces, and makes non-linear estimations unit 60 bases $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Calculate a _km, and then make compensating unit 20 use described a _kmDigital electric signal u (n) is carried out pre-distortion compensated.

The present embodiment only when low bandwidth data to the non linear coefficient a of electrooptic modulator 30 _kmCalculate and real-time update, will upgrade the non linear coefficient a of electrooptic modulator 30 _kmSeparate with high band wide data, neither affect the non linear coefficient a of the electrooptic modulator 30 of this elimination non-linear device 100 _kmRenewal, also provide cost savings simultaneously, compare with the electro-optic modulation arrangement 100 that embodiment two provides, advantage is: the scope of application is wide, accuracy is high; Compare with the electro-optic modulation arrangement 100 that embodiment one provides, advantage is: cost is low.

The below is to comprising when the nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The time electro-optic modulation arrangement describe.

When the nonlinear memory multinomial comprises $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The time and the difference of above-described embodiment one to embodiment three described electro-optic modulation arrangement 100 only be, $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The conversion of can not inverting, so compensating unit 20 is by right

$y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The mode of training obtains the digital electric signal x (n) after pre-distortion compensated.

Embodiments of the invention provide a kind of electro-optic modulation arrangement, by to the nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The mode of training is carried out pre-distortion compensated to digital electric signal, thereby eliminate the non-linear of electro-optic modulation arrangement, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity.

On the one hand, the embodiment of the present invention provides a kind of method of electrooptic modulation, is applied to comprise that in the electro-optic modulation arrangement of electrooptic modulator, referring to Fig. 5, the method comprises:

S501: receiving element receives digital electric signal u (n);

Exemplarily, receiving element constantly receives digital electric signal, for example can be denoted as respectively u (1), u (2), u (3) according to the sequencing digital electric signal that receives ... u (n), because the nonlinear compensation principle of each digital electric signal constantly is all identical, so the present embodiment is only to elaborate as example to the process of digital electric signal u (n) nonlinear compensation.

S502: according to the nonlinear memory multinomial, digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated;

Exemplarily, because there is nonlinear distortion in electrooptic modulator in the electric light transfer process, so, if directly digital electric signal u (n) is carried out the electric light conversion through electrooptic modulator, the light signal meeting distortion that obtains, so, need to carry out suitable compensation to digital electric signal u (n), make digital electric signal x (n) after compensation carry out through electrooptic modulator light signal and digital electric signal u (n) that the electric light conversion obtains linear, thereby avoid the nonlinear distortion in the electric light transfer process.

Optionally, described nonlinear memory multinomial can comprise: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1},$ $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is non linear coefficient.

Preferably, referring to Fig. 6, for calculating in real time the method for electrooptic modulator non linear coefficient, comprising:

S601: the light signal that gathers electrooptic modulator output;

S602: light signal is converted to the digital electric signal y (n) of synchronizeing with digital electric signal u (n);

Exemplarily, described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n), can comprise:

1, described light signal is converted into analog electrical signal;

2, described analog electrical signal is converted to digital electric signal;

3, described digital electric signal is converted to the digital signal y (n) of synchronizeing with described digital signal.

S603: according to digital electric signal y (n) and described non-linear memoryless polynomial computation electrooptic modulator non linear coefficient.

Preferably, the nonlinear memory multinomial can comprise: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}.$ The below comprises the nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Describe.

Exemplarily, M is natural number, the expression memory span, when M=0, the memoryless multinomial of above-mentioned non-linear polynomial repressentation is when M＞0, above-mentioned non-linear polynomial table is shown with the memory multinomial, and the M value is larger, and the accuracy of the compensation of 20 couples of digital electric signal u of compensating unit (n) is higher; K is the natural number greater than 1, represents high non-linearity exponent number, is stored in compensating unit 20, and in electrooptic modulator, K generally can be set to 1≤K≤5, and the value of K is larger, and the accuracy of the compensation of 20 couples of digital electric signal u of compensating unit (n) is higher; a _kmBe the non linear coefficient of electrooptic modulator 30, wherein, a _kmSize can change because of the kind of electrooptic modulator 30 and the variation of residing external environment thereof, when the kind one of electrooptic modulator 30 regularly, mainly be subjected to the impact of ambient temperature larger.

Exemplary, $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Can be converted into by inverting: $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1}),$ Due in this step, that obtain after pre-distortion compensated is digital electric signal x (n), therefore generally according to multinomial $x\left(n\right)=\frac{1}{\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_{k0}{\left|u\left(n\right)\right|}^{k-1}}(u\left(n\right)-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m)\·{\left|x(n-m)\right|}^{k-1})$ Digital electric signal x (n) is carried out pre-distortion compensated.

The below comprises the nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The time, comprise with above-mentioned nonlinear memory multinomial $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ The time the difference of pre-distortion compensated process describe.

Exemplary, due to $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The conversion of can not inverting, so be by to the nonlinear memory multinomial in this step $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ The mode of training obtains the digital electric signal x (n) after pre-distortion compensated.

S503: the digital electric signal x (n) after pre-distortion compensated is converted into light signal.

Embodiments of the invention provide a kind of electrooptical modulation method, by the nonlinear memory multinomial, digital electric signal is carried out pre-distortion compensated, thereby eliminate the non-linear of electro-optic modulation arrangement, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity.

Exemplarily, described method can also comprise:

If service traffics are high band wide data, described electro-optic modulation arrangement is not converted into analog electrical signal with described light signal, make described electro-optic modulation arrangement not calculate the non linear coefficient of electrooptic modulator, and according to the non linear coefficient of the electrooptic modulator of last calculating, described digital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, described electro-optic modulation arrangement is converted into analog electrical signal with described light signal, and described analog electrical signal is converted to digital electric signal, and according to the non linear coefficient of described nonlinear memory polynomial computation electrooptic modulator, and according to the non linear coefficient of described electrooptic modulator, described digital electric signal u (n) is carried out pre-distortion compensated.

Only can realize like this that the non linear coefficient to electrooptic modulator calculates and real-time update when low bandwidth data, non linear coefficient and the high band wide data of upgrading electrooptic modulator are separated, neither affect the renewal of non linear coefficient of the electrooptic modulator of this elimination non-linear device, also provide cost savings simultaneously.

On the one hand, the embodiment of the present invention provides a kind of transmitter 7, referring to Fig. 7, comprising: any electro-optic modulation arrangement 100 that above-described embodiment provides.

The transmitter that the embodiment of the present invention provides, by the nonlinear memory multinomial, digital electric signal is carried out pre-distortion compensated, thereby eliminate the non-linear of electro-optic modulation arrangement, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity.

On the one hand, the embodiment of the present invention provides a kind of electro-optic modulation system, referring to Fig. 8, comprising: the described transmitter 7 of above-described embodiment and receiver 8, wherein, described receiver 8 is used for receiving optical signals, and described light signal is converted into digital electric signal.

The electro-optic modulation system that the embodiment of the present invention provides, by the nonlinear memory multinomial, digital electric signal is carried out pre-distortion compensated, thereby eliminate non-linear in the electric light transfer process of transmitter, accuracy is high, production efficiency is high, simple in structure, realize easily, cost is low, solved in prior art, the look-up table accuracy is not high, production efficiency is low; Feed-forward technique complex structure, realization difficulty need to increase an extra photo-translating system of cover, cause the problem of cost complexity.

One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can be completed by the hardware that program command is correlated with, aforesaid program can be stored in a computer read/write memory medium, this program is carried out the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: the various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited to this, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of described claim.

Claims (14)

1. an electro-optic modulation arrangement, is characterized in that, comprising: the receiving element that connects successively, and compensating unit and electrooptic modulator, wherein,

Described receiving element is used for receiving digital electric signal u (n), and described digital electric signal u (n) is transferred to compensating unit;

Described compensating unit, be used for receiving digital electric signal u (n) from described receiving element, and according to the nonlinear memory multinomial, described digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated, and the digital electric signal x (n) after described pre-distortion compensated is transferred to described electrooptic modulator;

Described electrooptic modulator for the digital electric signal x (n) after the described pre-distortion compensated of described compensating unit reception, and is converted into light signal with the digital electric signal x (n) after described pre-distortion compensated.

2. electro-optic modulation arrangement according to claim 1, is characterized in that, described nonlinear memory multinomial comprises: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1},$ $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is the coefficient of nonlinear terms.

3. electro-optic modulation arrangement according to claim 1 and 2, is characterized in that, the non linear coefficient of described electrooptic modulator is constant, and be stored in described compensating unit.

4. electro-optic modulation arrangement according to claim 3, is characterized in that, also comprises: the optical coupler that connects successively, photoelectric processing device and non-linear estimations unit, wherein,

Described optical coupler is connected with described electrooptic modulator, is used for gathering the light signal of described electrooptic modulator output;

Described photoelectric processing device, be used for receiving the light signal of described optical coupler output, and described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n), and described digital electric signal y (n) is sent to described non-linear estimations unit;

Described non-linear estimations unit is connected with described compensating unit, is used for according to the non linear coefficient of described digital electric signal y (n) and described nonlinear memory polynomial computation electrooptic modulator and is transferred to described compensating unit.

5. electro-optic modulation arrangement according to claim 4, is characterized in that, described photoelectric processing device comprises photodetector, analog-digital converter and the signal synchronous processing unit that connects successively, wherein,

Described photodetector is used for and will be converted into analog electrical signal from the light signal that described optical coupler receives;

Described analog-digital converter is used for the analog electrical signal that described photodetector produces is converted to digital electric signal;

Described signal synchronous processing unit is used for the digital electric signal that described analog-digital converter produces is converted to the digital signal y (n) of synchronizeing with described digital signal.

6. electro-optic modulation arrangement according to claim 5, is characterized in that,

Described photodetector is the low bandwidth photodetector, and described analog-digital converter is the low speed analog-digital converter,

If service traffics are high band wide data, described photodetector will not be converted into analog electrical signal from the light signal that described optical coupler receives, make described non-linear estimations unit not calculate the non linear coefficient of electrooptic modulator, and then make described compensating unit use a of the last transmission in described non-linear estimations unit _kmDescribed digital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, described photodetector will be converted into analog electrical signal from the light signal that described optical coupler receives, described analog-digital converter is converted to digital electric signal with the analog electrical signal that described photodetector produces, make described non-linear estimations unit according to the non linear coefficient of described nonlinear memory polynomial computation electrooptic modulator, and then make described compensating unit use the non linear coefficient of described electrooptic modulator to carry out pre-distortion compensated to described digital electric signal u (n).

7. the method for an electrooptic modulation, be applied to comprise in the electro-optic modulation arrangement of electrooptic modulator, it is characterized in that, comprising:

Receive digital electric signal u (n);

According to the nonlinear memory multinomial, described digital electric signal u (n) is carried out pre-distortion compensated, obtain the digital electric signal x (n) after pre-distortion compensated;

Digital electric signal x (n) after described pre-distortion compensated is converted into light signal.

8. the method for electrooptic modulation according to claim 7, is characterized in that, described nonlinear memory multinomial comprises: $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{m=0}{\overset{M}{\mathrm{\Σ}}}{a}_{\mathrm{km}}x(n-m){\left|x(n-m)\right|}^{k-1}$ Perhaps $y\left(n\right)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{\left[\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)x(n-m)\right]}^k$ Perhaps $y\left(n\right)=\underset{m=0}{\overset{M}{\mathrm{\Σ}}}h\left(m\right)\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{a}_k{x}^k(n-m)$ Any one, wherein, described K is high non-linearity exponent number, M is memory span, a _kmBe the non linear coefficient of electrooptic modulator, a _k0The non linear coefficient of electrooptic modulator during for M=0, m, n are natural number, h (m), a _kBe the non linear coefficient of electrooptic modulator, wherein, h (m) is the coefficient of memory term, a _kIt is the coefficient of nonlinear terms.

9. the method for according to claim 7 or 8 described electrooptic modulation, is characterized in that, the non linear coefficient of described electrooptic modulator is default constant.

10. the method for electrooptic modulation according to claim 9, is characterized in that, described method also comprises:

Gather the light signal of described electro-optic modulation arrangement output;

Described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n);

Non linear coefficient according to described digital electric signal y (n) and described nonlinear memory polynomial computation electrooptic modulator.

11. the method for electrooptic modulation according to claim 10 is characterized in that, described light signal is converted to the digital electric signal y (n) of synchronizeing with described digital electric signal u (n), comprising:

Described light signal is converted into analog electrical signal;

Described analog electrical signal is converted to digital electric signal;

Described digital electric signal is converted to the digital signal y (n) of synchronizeing with described digital signal.

12. the method for electrooptic modulation according to claim 11 is characterized in that, described method also comprises:

If service traffics are high band wide data, described electro-optic modulation arrangement is not converted into analog electrical signal with described light signal, make described electro-optic modulation arrangement not calculate the non linear coefficient of electrooptic modulator, and according to the non linear coefficient of the electrooptic modulator of last calculating, described digital electric signal u (n) is carried out pre-distortion compensated;

If service traffics are low bandwidth data, described electro-optic modulation arrangement is converted into analog electrical signal with described light signal, and described analog electrical signal is converted to digital electric signal, and according to the non linear coefficient of described nonlinear memory polynomial computation electrooptic modulator, and according to the non linear coefficient of described electrooptic modulator, described digital electric signal u (n) is carried out pre-distortion compensated.

13. a transmitter comprises as the described electro-optic modulation arrangement of claim 1-6 any one.

14. an electro-optic modulation system comprises transmitter as claimed in claim 13 and receiver, wherein, described receiver is used for receiving optical signals, and described light signal is converted into digital electric signal.

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