CN106301593A - Adaptive blind polarization demultiplexing treating method and apparatus - Google Patents

Abstract

The present invention relates to a kind of adaptive blind polarization demultiplexing treating method and apparatus, the method comprises determining that the auto-adaptive fir filter tap coefficient at current time；According to the tap coefficient of described current time, described auto-adaptive fir filter carries out polarization demultiplexing process to the input signal of current time, and by the signal output after polarization demultiplexing process；Wherein, according to tap coefficient and two polarization state complex signals in a described upper moment, the tap coefficient of described current time was calculated.Due to the present invention by decomposing, coordinate transform can make the multimode signal of different modulating form transform on same circle becomes constant modulus signals, therefore on the premise of not knowing format modulation signal, it can be carried out polarization demultiplexing, therefore the method that the present invention provides is unrelated with modulation format, be applicable to network, modulation format is further flexible, dynamic, the various and uncertain application scenarios of flow.

Description

Adaptive blind polarization demultiplexing processing method and device

Technical Field

The invention relates to the technical field of optical fiber communication, in particular to a self-adaptive blind polarization demultiplexing processing method and a device.

Background

In recent years, with the rapid increase of network traffic and bandwidth requirements, high-speed coherent optical communication technology has become a key technology for realizing long-distance large-capacity information transmission. By the technologies of polarization multiplexing, wavelength division multiplexing and the like, the bandwidth utilization rate of the optical fiber communication system can be effectively improved, and the system capacity is improved. For high-speed coherent optical communication, due to the influence of factors such as optical fiber dispersion and polarization random crosstalk, a multi-tap adaptive butterfly FIR filter is required to perform residual dispersion, polarization film dispersion equalization and polarization demultiplexing.

Currently, polarization demultiplexing methods include both data-aided and blind processing. The data-aided method carries out channel estimation by sending the training sequence, occupies partial frequency spectrum resources and reduces the utilization rate of system bandwidth. However, the blind processing method, as a key technology in the ofdm demodulation system, does not need to periodically transmit the training sequence, and can recover the original transmitted signal only by means of the statistical characteristics of the received signal, so that it does not need to occupy too much bandwidth resources. Therefore, compared with the two methods, the blind processing method has the advantages. Due to the continuous development of data centers and cloud computing, network traffic will become more dynamic, diverse and unpredictable, and an elastic optical transceiver supporting various modulation formats becomes a key for effectively bearing burst dynamic change network traffic, improving spectrum utilization rate and optimizing network resource utilization in an elastic optical network. It is therefore desirable to provide a blind processing method that is independent of the modulation format.

Disclosure of Invention

Aiming at the defects, the invention provides a self-adaptive blind polarization demultiplexing processing method and a device, wherein the processing process is irrelevant to the modulation format, and the method and the device are suitable for application scenes with increasingly dynamic, various and unpredictable network flow.

The self-adaptive blind polarization demultiplexing processing method provided by the invention comprises the following steps:

determining a tap coefficient of the self-adaptive FIR filter at the current moment;

according to the tap coefficient at the current moment, the self-adaptive FIR filter performs polarization demultiplexing on the input signal at the current moment and outputs the signal after the polarization demultiplexing;

wherein the determining the tap coefficient of the adaptive FIR filter at the current time comprises:

decomposing each polarization state complex signal in the output signal of the self-adaptive FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.

Optionally, the output signal of the adaptive butterfly FIR filter at each time includes an x-polarization complex signal and a y-polarization complex signal; in a corresponding manner, the first and second optical fibers are,

and (3) carrying out coordinate transformation on the real part signal of the x polarization state complex signal by adopting the following formula:

x′_i(k)＝x_i(k)-4·sign[x_i(k)]-2·sign{x_i(k)-4·sign[x_i(k)]}

wherein x is_i(k) Is the real part signal x 'of the x polarization state complex signal in the output signal of the adaptive butterfly FIR filter at the time k'_i(k) For the real part signal x_i(k) Obtaining a real number signal after coordinate transformation; and/or

And (3) carrying out coordinate transformation on the imaginary part signal of the x polarization state complex signal by adopting the following formula:

x′_q(k)＝x_q(k)-4·sign[x_q(k)]-2·sign{x_q(k)-4·sign[x_q(k)]}

wherein x is_q(k) Is the imaginary part signal x 'of the x polarization state complex signal in the output signal of the adaptive butterfly FIR filter at the time point of k'_q(k) For the imaginary signal x_q(k) Carrying out coordinate transformation to obtain a real number signal; and/or

And (3) carrying out coordinate transformation on the real part signal of the y polarization state complex signal by adopting the following formula:

y′_i(k)＝y_i(k)-4·sign[y_i(k)]-2·sign{y_i(k)-4·sign[y_i(k)]}

wherein, y_i(k) Is the real part signal, y 'of the y polarization state complex signal in the output signal of the adaptive butterfly FIR filter at the time point of k'_i(k) For the real part signal y_i(k) Carrying out coordinate transformation to obtain a real number signal; and/or

And (3) carrying out coordinate transformation on the imaginary part signal of the y polarization state complex signal by adopting the following formula:

y′_q(k)＝y_q(k)-4·sign[y_q(k)]-2·sign{y_q(k)-4·sign[y_q(k)]}

wherein, y_q(k) Y-bias in output signal of the adaptive butterfly FIR filter at time kImaginary signal, y 'of the oscillatory complex signals'_q(k) For the imaginary signal y_q(k) And carrying out coordinate transformation to obtain a real number signal.

Optionally, the error of the real part signal of the x-polarization complex signal is calculated by using the following formula:

_xi(k)＝x′_i(k)(|R_x′i|²-|x′_i(k)|²)

wherein R is_x′iIs a real part signal x_i(k) Is determined by the reference modulus value of (a),_xi(k) is a real part signal x_i(k) An error of (2); and/or

The error of the imaginary signal of the complex signal of x polarization state is calculated using the following formula:

_xq(k)＝x′_q(k)(|R_x′q|²-|x′_q(k)|²)

wherein R is_x′qAs an imaginary signal x_q(k) Is determined by the reference modulus value of (a),_xq(k) as an imaginary signal x_q(k) An error of (2); and/or

And calculating the error of the real part signal of the y polarization state complex signal by adopting the following formula:

_yi(k)＝y′_i(k)(|R_y′i|²-|y′_i(k)|²)

wherein R is_y′iAs a real part signal y_i(k) Is determined by the reference modulus value of (a),_yi(k) as a real part signal y_i(k) An error of (2); and/or

And calculating the error of the imaginary part signal of the y polarization state complex signal by adopting the following formula:

_yq(k)＝y′_q(k)(|R_y′q|²-|y′_q(k)|²)

wherein R is_y′qIs an imaginary signal y_q(k) Is determined by the reference modulus value of (a),_yq(k) is an imaginary signal y_q(k) The error of (2).

Optionally, the complex error of the x polarization state is calculated using the following formula:

_x(k)＝_xi(k)+j_xq(k)

wherein,_x(k) complex error for x polarization; and/or

The complex error of the y polarization state is calculated using the following equation:

_y(k)＝_yi(k)+j_yq(k)

wherein,_y(k) is the complex error of the y polarization state.

Optionally, the tap coefficient at the k +1 th time is calculated by using the following formula:

H_k+1,xx(m)＝H_k,xx(m)+μ·_x(k)·x_in(k-m)^*

H_k+1,xy(m)＝H_k,xy(m)+μ·_x(k)·y_in(k-m)^*

H_k+1,yx(m)＝H_k,yx(m)+μ·_y(k)·x_in(k-m)^*

H_k+1,yy(m)＝H_k,yy(m)+μ·_y(k)·y_in(k-m)^*

where μ is the step size of the tap update, H_k,xx(m)、H_k,xy(m)、H_k,yx(m)、H_k,yy(m) is the coefficient of the m tap at time k, H_k+1,xx(m)、H_k+1,xy(m)、H_k+1,yx(m)、H_k+1,yy(m) is the coefficient of the m tap at time k +1, x_in(k-m)^*Is the conjugate of the input signal in the x-polarization state at time k, y_in(k-m)^*Is the conjugate of the input signal at the y-polarization state at time instant k.

Optionally, the polarization demultiplexing processing is performed on the input signal at the k +1 th time by using the following formula:

$\left[\begin{array}{c}x(k+1)\\ y(k+1)\end{array}\right]=\left[\begin{array}{c}\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,xx}\left(m\right)\·x_{in}(k+1-m)+\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,xy}\left(m\right)\·y_{in}(k+1-m)\\ \underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,yx}\left(m\right)\·x_{in}(k+1-m)+\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,yy}\left(m\right)\·y_{in}(k+1-m)\end{array}\right]$

wherein x is_in(k +1-m) is the input signal for the x polarization state at time k +1, y_in(k +1-m) is an input signal of y polarization state at the k +1 moment, x (k +1) is a signal obtained by polarization demultiplexing processing on the x polarization state input signal at the k +1 moment, and y (k +1) is polarization demultiplexing processing on the y polarization state input signal at the k +1 moment2N +1 is the number of taps of the signal obtained after multiplexing.

Optionally, the real part signal x is calculated using the following formula_i(k) Reference modulus value R_x′i：

$R_{x^{\′}i}=\sqrt{\frac{E\left\{{|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\left\}\right|}^2\right\}}}$

Wherein s is_xi(k) The real part of the complex signal under the x polarization state ideal constellation at the k time; and/or

The imaginary signal x is calculated using the equation_q(k) Reference modulus value R_x′q：

$R_{x^{\′}q}=\sqrt{\frac{E\left\{{|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{x_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{x_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\left\}\right|}^2\right\}}}$

Wherein s is_xq(k) The imaginary part of the complex signal under the ideal constellation of the x polarization state at the k time; and/or

The real part is calculated using the following equationSignal y_i(k) Reference modulus value R_y′i：

$R_{y^{\′}i}=\sqrt{\frac{E\left\{{|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\left\}\right|}^2\right\}}}$

Wherein s is_yi(k) The real part of the complex signal under the ideal constellation of the y polarization state at the kth moment; and/or

The imaginary signal y is calculated using the formula_q(k) Reference modulus value R_y′q：

$R_{y^{\′}q}=\sqrt{\frac{E\left\{{|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\left\}\right|}^2\right\}}}$

Wherein s is_yq(k) The imaginary part of the complex signal in the ideal constellation of the y polarization state at the k time.

The invention provides an adaptive blind polarization demultiplexing processing device, which comprises:

the tap coefficient determining module is used for determining the tap coefficient of the self-adaptive FIR filter at the current moment;

the self-adaptive FIR filter is used for carrying out polarization demultiplexing processing on the input signal at the current moment according to the tap coefficient at the current moment and outputting the signal after the polarization demultiplexing processing;

wherein the tap coefficient determining module is specifically configured to:

decomposing each polarization state complex signal in the output signal of the self-adaptive butterfly FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.

The adaptive blind polarization demultiplexing processing method provided by the invention needs to decompose each polarization state complex signal in the output signal of the previous moment of the next moment into a real part signal and an imaginary part signal when calculating the tap coefficient of the next moment, perform coordinate transformation and error calculation on the decomposed signals, combine the errors to obtain a complex error, calculate the tap coefficient of the next moment according to the complex error, and perform polarization demultiplexing processing by using the tap coefficient of the next moment when the adaptive FIR filter receives the input signal of the next moment. Because the invention can transform the multimode signals with different modulation formats to the same circle into the constant modulus signals through decomposition and coordinate transformation, the polarization demultiplexing can be carried out on the signals under the premise of not knowing the modulation formats of the signals, and therefore, the method provided by the invention is irrelevant to the modulation formats, and is suitable for application scenes that the modulation formats in networks are more flexible, and the flow is more dynamic, diversified and unpredictable.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a flowchart illustrating an adaptive blind polarization demultiplexing method according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

The invention provides an adaptive blind polarization demultiplexing processing method, as shown in fig. 1, the method includes:

determining a tap coefficient of the self-adaptive FIR filter at the current moment;

according to the tap coefficient at the current moment, the self-adaptive FIR filter performs polarization demultiplexing on the input signal at the current moment and outputs the signal after the polarization demultiplexing;

wherein the determining the tap coefficient of the adaptive butterfly FIR filter at the current time comprises:

decomposing each polarization state complex signal in the output signal of the self-adaptive butterfly FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.

It will be appreciated that the adaptive FIR filter is an adaptive finite long single bit impulse response filter.

It can be understood that the current tap coefficient adopted when the adaptive FIR filter performs polarization demultiplexing on the input signal at the current time is obtained by performing a certain processing on the output signal of the adaptive FIR filter at the previous time, for example, the tap coefficient adopted when the input signal of the adaptive FIR filter at the 2 nd time is subjected to polarization demultiplexing is obtained by processing the output signal of the adaptive FIR filter at the 1 st time, the tap coefficient adopted when the input signal of the adaptive FIR filter at the 3 rd time is subjected to polarization demultiplexing is obtained by processing the output signal of the adaptive FIR filter at the 2 nd time, and so on … …. The initial tap coefficient adopted when the input signal of the adaptive FIR filter is subjected to polarization demultiplexing at the 1 st moment is self-set. It can be seen that the tap coefficient at each subsequent time is derived from the output signal at the previous time. The tap coefficient is continuously updated in the mode, so that the requirement of polarization demultiplexing is met.

The adaptive blind polarization demultiplexing processing method provided by the invention needs to decompose each polarization state complex signal in the output signal of the previous moment of the next moment into a real part signal and an imaginary part signal when calculating the tap coefficient of the next moment, perform coordinate transformation and error calculation on the decomposed signals, combine the errors to obtain a complex error, calculate the tap coefficient of the next moment according to the complex error, and perform polarization demultiplexing processing by using the tap coefficient of the next moment when the adaptive FIR filter receives the input signal of the next moment. As the invention decomposes the complex signal into a real part and an imaginary part, and then carries out coordinate transformation, the signals with different modulation formats (such as PM-BPSK, PM-QPSK, PM-4PAM, PM-8PAM, PM-16QAM, PM-32QAM and PM-64QAM) can be transformed to the same circle, therefore, the polarization demultiplexing can be carried out on the signals under the premise of not knowing the modulation format of the signals, and the method provided by the invention has nothing to do with the modulation format, and is suitable for application scenes with increasingly dynamic, various and unpredictable network flow. Compared with the traditional RDA, the method provided by the invention has the advantages of simplicity, strong noise resistance and strong robustness, and compared with the traditional DD-LMS, the method has the advantages of easiness in implementation and no need of carrier phase recovery. Therefore, the method provided by the invention is not only suitable for a coherent optical communication system, but also suitable for the whole optical communication system or other specific application scenes.

It will be appreciated that the output signal of the adaptive FIR filter at each instant may include both the x-and y-polarization complex signals.

In a specific implementation, the real part signal of the x-polarization complex signal may be subjected to coordinate transformation by using the following formula:

x′_i(k)＝x_i(k)-4·sign[x_i(k)]-2·sign{x_i(k)-4·sign[x_i(k)]} (1)

wherein x is_i(k) Is the real part signal, x 'of the x polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_i(k) For the real part signal x_i(k) And (5) obtaining a real number signal after coordinate transformation.

Similarly, the imaginary signal of the x-polarization complex signal may be transformed using the following equation:

x′_q(k)＝x_q(k)-4·sign[x_q(k)]-2·sign{x_q(k)-4·sign[x_q(k)]} (2)

wherein x is_q(k) Is the imaginary part signal, x 'of the x polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_q(k) For the imaginary signal x_q(k) And carrying out coordinate transformation to obtain a real number signal.

Similarly, the real part signal of the y-polarization complex signal can be transformed by the following formula:

y′_i(k)＝y_i(k)-4·sign[y_i(k)]-2·sign{y_i(k)-4·sign[y_i(k)]} (3)

wherein, y_i(k) Is the real part signal, y 'of the y polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_i(k) For the real part signal y_i(k) And carrying out coordinate transformation to obtain a real number signal.

Similarly, the imaginary signal of the complex signal of y polarization state can be transformed by the following formula:

y′_q(k)＝y_q(k)-4·sign[y_q(k)]-2·sign{y_q(k)-4·sign[y_q(k)]} (4)

wherein, y_q(k) Is the imaginary part signal y 'of the y polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_q(k) For the imaginary signal y_q(k) And carrying out coordinate transformation to obtain a real number signal.

It is understood that sign () is a sign taking function.

In particular implementation, the error of the real part signal of the x-polarization complex signal can be calculated by using the following formula:

_xi(k)＝x′_i(k)(|R_x′i|²-|x′_i(k)|²) (5)

wherein R is_x′iIs a real part signal x_i(k) Is determined by the reference modulus value of (a),_xi(k) is a real part signal x_i(k) The error of (2).

Similarly, the error of the imaginary signal of the complex signal of x polarization state can be calculated using the following formula:

_xq(k)＝x′_q(k)(|R_x′q|²-|x′_q(k)|²) (6)

wherein R is_x′qAs an imaginary signal x_q(k) Is determined by the reference modulus value of (a),_xq(k) as an imaginary signal x_q(k) The error of (2).

Similarly, the error of the real part signal of the y-polarization complex signal can be calculated by the following formula:

_yi(k)＝y′_i(k)(|R_y′i|²-|y′_i(k)|²) (7)

wherein R is_y′iAs a real part signal y_i(k) Is determined by the reference modulus value of (a),_yi(k) as a real part signal y_i(k) The error of (2).

Similarly, the error of the imaginary signal of the complex signal in the y polarization state can be calculated by using the following formula:

_yq(k)＝y′_q(k)(|R_y′q|²-|y′_q(k)|²) (8)

wherein R is_y′qIs an imaginary signal y_q(k) Is determined by the reference modulus value of (a),_yq(k) is an imaginary signal y_q(k) The error of (2).

R in the above formula_x′i、R_x′q、R_y′i、R_y′qThe calculation method of (2) is as follows:

wherein the real part signal x can be calculated using the following formula_i(k) Reference modulus value R_x′i：

$R_{x^{\′}i}=\sqrt{\frac{E\left\{{|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\left\}\right|}^2\right\}}}---\left(9\right)$

In the formula, s_xi(k) The real part of the complex signal under the x polarization state ideal constellation at the k time; and/or

Wherein the imaginary signal x is calculated using the following formula_q(k) Reference modulus value R_x′q：

$R_{x^{\′}q}=\sqrt{\frac{E\left\{{|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\left\}\right|}^2\right\}}}---\left(10\right)$

In the formula, s_xq(k) The imaginary part of the complex signal under the ideal constellation of the x polarization state at the k time; and/or

Wherein the real part signal y is calculated using the following formula_i(k) Reference modulus value R_y′i：

$R_{y^{\′}i}=\sqrt{\frac{E\left\{{|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\left\}\right|}^2\right\}}}---\left(11\right)$

In the formula, s_yi(k) The real part of the complex signal under the ideal constellation of the y polarization state at the kth moment; and/or

Wherein the imaginary signal y is calculated using the following formula_q(k) Reference modulus value R_y′q：

$R_{y^{\′}q}=\sqrt{\frac{E\left\{{|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\left\}\right|}^4\right\}}{E\left\{{|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\left\}\right|}^2\right\}}}---\left(12\right)$

In the formula, s_yq(k) The imaginary part of the complex signal in the ideal constellation of the y polarization state at the k time.

In particular implementations, the complex error of the x-polarization state can be calculated using the following equation:

_x(k)＝_xi(k)+j_xq(k) (13)

wherein,_x(k) is the complex error of the x polarization state.

Likewise, the complex error of the y polarization state can be calculated using the following equation:

_y(k)＝_yi(k)+j_yq(k) (14)

wherein,_y(k) is the complex error of the y polarization state.

In specific implementation, the tap coefficient at the k +1 th time can be calculated by the following formula:

H_k+1,xx(m)＝H_k,xx(m)+μ·_x(k)·x_in(k-m)^*(15)

H_k+1,xy(m)＝H_k,xy(m)+μ·_x(k)·y_in(k-m)^*(16)

H_k+1,yx(m)＝H_k,yx(m)+μ·_y(k)·x_in(k-m)^*(17)

H_k+1,yy(m)＝H_k,yy(m)+μ·_y(k)·y_in(k-m)^*(18)

where μ is the step size of the tap update, H_k,xx(m)、H_k,xy(m)、H_k,yx(m)、H_k,yy(m) is the coefficient of the m tap at time k, H_k+1,xx(m)、H_k+1,xy(m)、H_k+1,yx(m)、H_k+1,yy(m) is the coefficient of the m tap at time k +1, x_in(k-m)^*Is the conjugate of the input signal in the x-polarization state at time k, y_in(k-m)^*Is the conjugate of the input signal at the y-polarization state at time instant k.

In a specific implementation, the polarization demultiplexing process may be performed on the input signal at the k +1 th time by using the following formula:

$\left[\begin{array}{c}x(k+1)\\ y(k+1)\end{array}\right]=\left[\begin{array}{c}\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,xx}\left(m\right)\·x_{in}(k+1-m)+\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,xy}\left(m\right)\·y_{in}(k+1-m)\\ \underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,yx}\left(m\right)\·x_{in}(k+1-m)+\underset{m=-N}{\overset{N}{\Σ}}{H}_{k+1,yy}\left(m\right)\·y_{in}(k+1-m)\end{array}\right]---\left(19\right)$

wherein x is_in(k +1-m) is the input signal for the x polarization state at time k +1, y_inAnd (k +1-m) is an input signal in a y polarization state at the k +1 moment, x (k +1) is a signal obtained by performing polarization demultiplexing on the x polarization state input signal at the k +1 moment, y (k +1) is a signal obtained by performing polarization demultiplexing on the y polarization state input signal at the k +1 moment, and 2N +1 is the number of taps.

It is understood that m has a value range of [ -N, N ].

In specific implementation, the signal may be subjected to preprocessing such as quadrature imbalance compensation, fixed dispersion compensation, and clock synchronization before being input to the filter, and then the preprocessed signal is input to the filter for processing and output, and of course, the output signal may be subjected to processing such as frequency offset estimation and compensation, phase offset estimation and compensation, and symbol demapping, so as to obtain the originating original bit sequence.

Experiments prove that the method provided by the invention has the characteristic of excellent performance compared with the traditional CMA, RDE and other methods when used for carrying out polarization-splitting vibration processing on signals.

Based on the same inventive concept, the invention also provides an adaptive blind polarization demultiplexing processing device, which comprises:

the tap coefficient determining module is used for determining the tap coefficient of the self-adaptive FIR filter at the current moment;

the self-adaptive FIR filter is used for carrying out polarization demultiplexing processing on the input signal at the current moment according to the tap coefficient at the current moment and outputting the signal after the polarization demultiplexing processing;

wherein the tap coefficient determining module is specifically configured to:

decomposing each polarization state complex signal in the output signal of the self-adaptive FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, and the program can be stored in a computer readable storage medium, and when the program is executed, the steps comprising the method embodiments are executed.

In the description of the present invention, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art; the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (8)

1. An adaptive blind polarization demultiplexing method, comprising:

determining a tap coefficient of the self-adaptive butterfly FIR filter at the current moment;

according to the tap coefficient at the current moment, the self-adaptive butterfly FIR filter carries out polarization demultiplexing processing on the input signal at the current moment and outputs the signal after the polarization demultiplexing processing;

wherein the determining the tap coefficient of the adaptive butterfly FIR filter at the current time comprises:

decomposing each polarization state complex signal in the output signal of the self-adaptive butterfly FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.

2. The method of claim 1, wherein the output signal of the adaptive FIR filter at each time instant comprises an x-polarization state complex signal and a y-polarization state complex signal; in a corresponding manner, the first and second optical fibers are,

and (3) carrying out coordinate transformation on the real part signal of the x polarization state complex signal by adopting the following formula:

x′_i(k)＝x_i(k)-4·sign[x_i(k)]-2·sign{x_i(k)-4·sign[x_i(k)]}

wherein x is_i(k) Is the real part signal x 'of the x polarization state complex signal in the output signal of the adaptive butterfly FIR filter at the time k'_i(k) For the real part signal x_i(k) Obtaining a real number signal after coordinate transformation; and/or

And (3) carrying out coordinate transformation on the imaginary part signal of the x polarization state complex signal by adopting the following formula:

x′_q(k)＝x_q(k)-4·sign[x_q(k)]-2·sign{x_q(k)-4·sign[x_q(k)]}

wherein x is_q(k) For the adaptive FIR filter at time kImaginary signal, x 'of complex signal of x polarization state in output signal'_q(k) For the imaginary signal x_q(k) Carrying out coordinate transformation to obtain a real number signal; and/or

And (3) carrying out coordinate transformation on the real part signal of the y polarization state complex signal by adopting the following formula:

y′_i(k)＝y_i(k)-4·sign[y_i(k)]-2·sign{y_i(k)-4·sign[y_i(k)]}

wherein, y_i(k) Is the real part signal, y 'of the y polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_i(k) For the real part signal y_i(k) Carrying out coordinate transformation to obtain a real number signal; and/or

And (3) carrying out coordinate transformation on the imaginary part signal of the y polarization state complex signal by adopting the following formula:

y′_q(k)＝y_q(k)-4·sign[y_q(k)]-2·sign{y_q(k)-4·sign[y_q(k)]}

wherein, y_q(k) Is the imaginary part signal y 'of the y polarization state complex signal in the output signal of the adaptive FIR filter at the time point of k'_q(k) For the imaginary signal y_q(k) And carrying out coordinate transformation to obtain a real number signal.

3. The method of claim 2,

calculating the error of the real part signal of the x-polarization state complex signal by adopting the following formula:

_xi(k)＝x′_i(k)(|R_x′i|²-|x′_i(k)|²)

wherein R is_x′iIs a real part signal x_i(k) Is determined by the reference modulus value of (a),_xi(k) is a real part signal x_i(k) An error of (2); and/or

The error of the imaginary signal of the complex signal of x polarization state is calculated using the following formula:

_xq(k)＝x′_q(k)(|R_x′q|²-|x′_q(k)|²)

wherein R is_x′qIs an imaginary partSignal x_q(k) Is determined by the reference modulus value of (a),_xq(k) as an imaginary signal x_q(k) An error of (2); and/or

And calculating the error of the real part signal of the y polarization state complex signal by adopting the following formula:

_yi(k)＝y′_i(k)(|R_y′i|²-|y′_i(k)|²)

wherein R is_y′iAs a real part signal y_i(k) Is determined by the reference modulus value of (a),_yi(k) as a real part signal y_i(k) An error of (2); and/or

And calculating the error of the imaginary part signal of the y polarization state complex signal by adopting the following formula:

_yq(k)＝y′_q(k)(|R_y′q|²-|y′_q(k)|²)

wherein R is_y′qIs an imaginary signal y_q(k) Is determined by the reference modulus value of (a),_yq(k) is an imaginary signal y_q(k) The error of (2).

4. The method of claim 3,

the complex error for the x-polarization state is calculated using the following equation:

_x(k)＝_xi(k)+j_xq(k)

wherein,_x(k) complex error for x polarization; and/or

The complex error of the y polarization state is calculated using the following equation:

_y(k)＝_yi(k)+j_yq(k)

wherein,_y(k) is the complex error of the y polarization state.

5. The method of claim 4, wherein the tap coefficient at time k +1 is calculated using the following equation:

H_k+1,xx(m)＝H_k,xx(m)+μ·_x(k)·x_in(k-m)^*

H_k+1,xy(m)＝H_k,xy(m)+μ·_x(k)·y_in(k-m)^*

H_k+1,yx(m)＝H_k,yx(m)+μ·_y(k)·x_in(k-m)^*

H_k+1,yy(m)＝H_k,yy(m)+μ·_y(k)·y_in(k-m)^*

where μ is the step size of the tap update, H_k,xx(m)、H_k,xy(m)、H_k,yx(m)、H_k,yy(m) is the coefficient of the m tap at time k, H_k+1,xx(m)、H_k+1,xy(m)、H_k+1,yx(m)、H_k+1,yy(m) is the coefficient of the m tap at time k +1, x_in(k-m)^*Is the conjugate of the input signal in the x-polarization state at time k, y_in(k-m)^*Is the conjugate of the input signal at the y-polarization state at time instant k.

6. The method of claim 5, wherein the polarization demultiplexing is performed on the input signal at time k +1 using the following equation:

$\left[\begin{array}{c}x\left(k+1\right)\\ y\left(k+1\right)\end{array}\right]=\left[\begin{array}{c}\underset{m=-N}{\overset{N}{\mathrm{\Σ}}}{H}_{k+1,xx}\left(m\right)\·x_{in}\left(k+1-m\right)+\underset{m=-N}{\overset{N}{\mathrm{\Σ}}}{H}_{k+1,xy}\left(m\right)\·y_{in}\left(k+1-m\right)\\ \underset{m=-N}{\overset{N}{\mathrm{\Σ}}}{H}_{k+1,yx}\left(m\right)\·x_{in}\left(k+1-m\right)+\underset{m=-N}{\overset{N}{\mathrm{\Σ}}}{H}_{k+1,yy}\left(m\right)\·y_{in}\left(k+1-m\right)\end{array}\right]$

wherein x is_in(k +1-m) is the input signal for the x polarization state at time k +1, y_inAnd (k +1-m) is an input signal of y polarization state at the k +1 moment, x (k +1) is an x polarization state signal obtained by performing polarization demultiplexing on the input signals of the two polarization states at the k +1 moment, y (k +1) is a y polarization state signal obtained by performing polarization demultiplexing on the input signals of the two polarization states at the k +1 moment, and 2N +1 is the number of taps.

7. The method of claim 3,

calculating the real part signal x using the following equation_i(k) Reference modulus value R_x′i：

$R_{x^{\′}i}=\sqrt{\frac{E\left\{\right|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\}{|}^4\}}{E\left\{\right|s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]-2\·sign\{s_{xi}\left(k\right)-4\·sign\[s_{xi}\left(k\right)\]\}{|}^2\}}}$

Wherein s is_xi(k) The real part of the complex signal under the x polarization state ideal constellation at the k time; and/or

The imaginary signal x is calculated using the equation_q(k) Reference modulus value R_x′q：

$R_{x^{\′}q}=\sqrt{\frac{E\left\{\right|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\}{|}^4\}}{E\left\{\right|s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]-2\·sign\{s_{xq}\left(k\right)-4\·sign\[s_{xq}\left(k\right)\]\}{|}^2\}}}$

Wherein s is_xq(k) The imaginary part of the complex signal under the ideal constellation of the x polarization state at the k time; and/or

Calculating the real part signal y using the following equation_i(k) Reference modulus value R_y′i：

$R_{y^{\′}i}=\sqrt{\frac{E\left\{\right|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\}{|}^4\}}{E\left\{\right|s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]-2\·sign\{s_{yi}\left(k\right)-4\·sign\[s_{yi}\left(k\right)\]\}{|}^2\}}}$

Wherein s is_yi(k) The real part of the complex signal under the ideal constellation of the y polarization state at the kth moment; and/or

The imaginary signal y is calculated using the formula_q(k) Reference modulus value R_y′q：

$R_{y^{\′}q}=\sqrt{\frac{E\left\{\right|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\}{|}^4\}}{E\left\{\right|s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]-2\·sign\{s_{yq}\left(k\right)-4\·sign\[s_{yq}\left(k\right)\]\}{|}^2\}}}$

Wherein s is_yq(k) The imaginary part of the complex signal in the ideal constellation of the y polarization state at the k time.

8. An adaptive blind polarization demultiplexing device, comprising:

the tap coefficient determining module is used for determining the tap coefficient of the self-adaptive FIR filter at the current moment;

the self-adaptive FIR filter is used for carrying out polarization demultiplexing processing on the input signal at the current moment according to the tap coefficient at the current moment and outputting the signal after the polarization demultiplexing processing;

wherein the tap coefficient determining module is specifically configured to:

decomposing each polarization state complex signal in the output signal of the self-adaptive FIR filter at the last moment to obtain a real part signal and an imaginary part signal of the polarization state complex signal;

respectively carrying out coordinate transformation on a real part signal and an imaginary part signal of the polarization state complex signal;

calculating the error of the real part signal according to the reference module value of the real part signal of the polarization state complex signal and the real signal obtained after coordinate transformation, and calculating the error of the imaginary part signal according to the reference module value of the imaginary part signal of the polarization state complex signal and the real signal obtained after coordinate transformation;

synthesizing the error of the real part signal and the error of the imaginary part signal to obtain a complex error of the polarization state complex signal;

and calculating the tap coefficient of the current moment according to the tap coefficient of the previous moment and each polarization state complex signal.