Method and system for suppressing inter-core crosstalk of multi-core optical fiber, and storage medium

Abstract

The invention relates to the technical field of multi-core optical fiber inter-core crosstalk suppression, and provides a multi-core optical fiber inter-core crosstalk suppression method and system and a storage medium, and the method comprises the steps: carrying out the orthogonal component signal diversity processing of a 2N polarization state signal transmitted through an N-core optical fiber at a receiving side, and obtaining a 4N-dimensional vector signal; performing statistical calculation to obtain a cluster mean value and a covariance of each dimension of the 4N-dimensional vector signals; a multi-dimensional Gaussian space is constructed based on the cluster mean value and the covariance, and a multi-dimensional space probability density function is obtained; calculating the multi-dimensional space probability density function to obtain a corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multi-dimensional Gaussian space; determining symbols of clusters to which the signal points are most likely to belong based on the corresponding probabilities; and performing symbol judgment to obtain a judgment result. According to the method, the inter-core crosstalk can be mapped to the multi-dimensional Gaussian space for soft decision, so that the calculation complexity and the bit error rate are reduced, and the reliability and the stability of a communication system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-core optical fiber core crosstalk suppression, and in particular to a method, system and computer-readable storage medium for suppressing multi-core optical fiber core crosstalk. Background Art

[0002] With the rapid development of information technology, the requirements for communication technology are also increasing. Improving the information capacity of optical fiber transmission and reducing the optical nonlinear effects in optical fiber communication are important issues in the development of the optical fiber communication field.

[0003] Space Division Multiplexing (SDM) technology is one of the breakthroughs to achieve the above needs. This technology uses multiple receiving channels to simultaneously receive all transmitted signals and uses signal processing algorithms to recover and process them, which can reduce the optical power per unit area of ​​the fiber cross section and reduce the optical nonlinear effects during transmission. However, although the multi-core fiber (MCF) used in this technology has good adaptability, due to problems such as spatial mode coupling, it will inevitably produce crosstalk between cores, which will cause correlation between signals in different channels and cause signal distortion.

[0004] At present, the industry mainly uses Multiple-Input Multiple-Output Digital Signal Processing (MIMO-DSP) technology to compensate for signal distortion caused by inter-core crosstalk. However, when using strongly coupled multi-core fibers (CC-MCF), the inter-core crosstalk is highly random, and MIMO-DSP is difficult to reduce the high bit error rate caused by this. In addition, although increasing the tap length of MIMO-DSP can reduce the bit error rate, it is impossible to completely eliminate the residual inter-core crosstalk, and the calculation complexity is high. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem that the method for eliminating core-to-core crosstalk in the prior art has a high bit error rate and is particularly obvious when CC-MCF is used. A method, system and computer-readable storage medium for suppressing core-to-core crosstalk of a multi-core optical fiber are provided. While having low computational complexity, signal distortion is effectively compensated, the bit error rate is reduced, and the reliability and stability of the communication system are improved.

[0006] In a first aspect, in order to solve the above technical problems, the present invention provides a method for suppressing crosstalk between cores of a multi-core optical fiber, comprising the following steps:

[0007] The 2N polarization state signals transmitted through the N-core optical fiber are subjected to orthogonal component signal diversity processing at the receiving side to obtain a 4N-dimensional vector signal;

[0008] Performing statistical calculations on the 4N-dimensional vector signal to obtain cluster means and covariances of respective dimensions of the 4N-dimensional vector signal;

[0009] Constructing a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function;

[0010] Calculating the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space;

[0011] The symbols of the cluster to which each of the signal points most likely belongs are determined based on the corresponding probabilities; and symbol decisions are performed based on the symbols to obtain decision results.

[0012] In one embodiment of the present invention, a 2N polarization state signal transmitted through an N-core optical fiber is obtained based on MIMO processing at the receiving side, the 2N polarization state signal is regarded as 2N groups of complex-valued sequence signals, and signal diversity processing of orthogonal components is performed on the 2N groups of complex-valued sequence signals to obtain the 4N-dimensional vector signal.

[0013] In one embodiment of the present invention, the method for performing signal diversity processing of orthogonal components on the 2N groups of complex-valued sequence signals is: separating the real part and the imaginary part of the 2N groups of complex-valued sequence signals to obtain 4N groups of real-valued sequences, and treating each group of real-valued sequences in the 4N groups of real-valued sequences as a new dimension to obtain the 4N-dimensional vector signal.

[0014] In one embodiment of the present invention, after obtaining the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space, I and Q component synthesis processing is performed to obtain the corresponding probability between each signal point in the 2N polarization state signal and each cluster in the multidimensional Gaussian space, and the symbol of the cluster to which each signal point in the 2N polarization state signal most likely belongs is determined based on the corresponding probability, and symbol decision is performed based on the symbol to obtain the decision result of each signal point in the 2N polarization state signal.

[0015] In one embodiment of the present invention, the method for performing statistical calculation on the 4N-dimensional vector signal is: combining the reference signal provided by the signal sending side, performing covariance matrix calculation on the 4N-dimensional vector signal, and then processing it based on the clustering algorithm to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal.

[0016] In one embodiment of the present invention, the clustering algorithm is an M-dimensional clustering algorithm, the cluster mean and the covariance are obtained by processing based on the M-dimensional clustering algorithm, and the multidimensional Gaussian space constructed based on the cluster mean and the covariance is an M-dimensional Gaussian space; the number of the M-dimensional Gaussian spaces is A, and M*A=4N.

[0017] In one embodiment of the present invention, after constructing the multidimensional Gaussian space based on the cluster mean and the covariance, the reference signal and the 4N-dimensional vector signal are combined to calculate the covariance matrix of each constellation symbol to obtain the multidimensional space probability density function, and the multidimensional space probability density function f(x) is:

[0018]

[0019] Wherein, Cov is the covariance matrix, e is a natural constant, μ is the cluster mean, x is the unprocessed 4N-dimensional vector signal, and T represents transposition; the cluster mean μ is:

[0020]

[0021] Wherein, data(i) is an n*4N dimensional data cluster group, and n is the number of data points within the cluster of the n*4N dimensional data cluster group.

[0022] In one embodiment of the present invention, a log-likelihood ratio is calculated for the multidimensional space probability density function to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space.

[0023] In a second aspect, in order to solve the above technical problems, the present invention also provides a system for suppressing crosstalk between cores of a multi-core optical fiber, comprising:

[0024] The signal diversity processing module performs orthogonal component signal diversity processing on the 2N polarization state signals transmitted through the N-core optical fiber at the receiving side to obtain a 4N-dimensional vector signal;

[0025] A cluster mean and covariance calculation module performs statistical calculation on the 4N-dimensional vector signal to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal;

[0026] A probability density function calculation module constructs a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function;

[0027] A corresponding probability calculation module calculates the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space;

[0028] A symbol decision module determines the symbol of the cluster to which each of the signal points is most likely to belong based on the corresponding probability; and performs symbol decision based on the symbol to obtain a decision result.

[0029] In the third aspect, in order to solve the above-mentioned technical problem, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for suppressing crosstalk between cores of multi-core optical fibers are implemented.

[0030] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0031] The present invention provides a method, system and computer-readable storage medium for suppressing inter-core crosstalk of a multi-core optical fiber. Based on signal diversity processing of orthogonal components, the 2N polarization state signals transmitted by N-core optical fibers are processed into 4N-dimensional vector signals, and the inter-core crosstalk is mapped to a multi-dimensional space to simulate a Gaussian distribution for soft decision. While the calculation complexity is low, the signal distortion is effectively compensated, the bit error rate is reduced, and the reliability and stability of the communication system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0033] Figure 1 A step diagram of a method for suppressing inter-core crosstalk of a multi-core optical fiber in a preferred embodiment of the present invention;

[0034] Figure 2 This is a suppression flow chart taking a four-core DP-16QAM signal as an example in a preferred embodiment of the present invention;

[0035] Figure 3 It is a module diagram of a system for suppressing inter-core crosstalk of a multi-core optical fiber according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0038] At present, the industry mainly uses MIMO-DSP technology to compensate for inter-core crosstalk, but when CC-MCF is used, the inter-core crosstalk is highly random, and MIMO-DSP is difficult to reduce the high bit error rate caused by inter-core crosstalk. Although measures such as increasing the tap length of MIMO-DSP can reduce the bit error rate, it cannot completely eliminate the residual inter-core crosstalk, and the calculation complexity is high.

[0039] Considering that the traditional hard decision method will increase the bit error rate due to signal distortion when facing complex channels, and the soft decision method can use the probability distribution function model to simulate the signal distribution in detail to reduce the bit error rate, the inventor of the embodiment of the present application chose to use the soft decision method. However, the soft decision method is aimed at the standard single-mode optical fiber communication system, and how to apply it to the multi-core optical fiber communication system is the difficulty that the embodiment of the present application needs to solve.

[0040] To this end, embodiments of the present application provide a method, system, and computer-readable storage medium for suppressing crosstalk between cores of a multi-core optical fiber.

[0041] Embodiment 1

[0042] This embodiment provides a method for suppressing crosstalk between multi-core optical fibers. Figure 1 As shown, the following steps are included:

[0043] The 2N polarization state signals transmitted through the N-core optical fiber are subjected to orthogonal component signal diversity processing at the receiving side to obtain a 4N-dimensional vector signal;

[0044] Performing statistical calculations on the 4N-dimensional vector signal to obtain cluster means and covariances of respective dimensions of the 4N-dimensional vector signal;

[0045] Construct a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function;

[0046] Calculating the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space;

[0047] The symbols of the cluster to which each of the signal points most likely belongs are determined based on the corresponding probabilities; and symbol decisions are performed based on the symbols to obtain decision results.

[0048] The present embodiment provides a method for suppressing inter-core crosstalk in a multi-core optical fiber. The 2N polarization state signals transmitted by the N-core optical fiber are processed into 4N-dimensional vector signals through signal diversity of orthogonal components at the receiving side. The inter-core crosstalk is mapped to a multi-dimensional space to simulate a Gaussian distribution for soft decision based on the 4N-dimensional vector signal, thereby reducing the inter-core crosstalk during signal transmission, effectively reducing the bit error rate while reducing the computational complexity, and improving the reliability and stability of the communication system.

[0049] Next, a method for suppressing crosstalk between cores of a multi-core optical fiber provided in this embodiment is introduced in detail:

[0050] Step 1

[0051] Specifically, orthogonal component signal diversity processing is performed on the 2N polarization state signals transmitted through the N-core optical fiber at the receiving side to obtain a 4N-dimensional vector signal.

[0052] Optionally, at the receiving side, 2N polarization state signals transmitted through N-core optical fibers are obtained based on MIMO processing, the 2N polarization state signals are regarded as 2N groups of complex-valued sequence signals, and signal diversity processing of orthogonal components is performed on the 2N groups of complex-valued sequence signals to obtain the 4N-dimensional vector signal.

[0053] Optionally, the MIMO processing includes linear filtering processing and demodulation processing.

[0054] Specifically, the method for performing signal diversity processing of orthogonal components on the 2N groups of complex-valued sequence signals is: separating the real part and the imaginary part of the 2N groups of complex-valued sequence signals to obtain 4N groups of real-valued sequences, and treating each group of real-valued sequences in the 4N groups of real-valued sequences as a new dimension to obtain the 4N-dimensional vector signal.

[0055] Step 2

[0056] Specifically, statistical calculation is performed on the 4N-dimensional vector signal to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal.

[0057] Optionally, in combination with the reference signal provided by the signal sending side, the covariance matrix of the 4N-dimensional vector signal is calculated, and then processed based on a clustering algorithm to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal.

[0058] Specifically, the cluster mean μ is:

[0059]

[0060] Wherein, data(i) is an n*4N dimensional data cluster group, and n is the number of data points within the cluster of the n*4N dimensional data cluster group.

[0061] Step 3

[0062] Specifically, a multidimensional Gaussian space is constructed based on the cluster mean and the covariance to obtain a multidimensional space probability density function.

[0063] Optionally, after constructing the multidimensional Gaussian space based on the cluster mean and the covariance, the reference signal and the 4N-dimensional vector signal are combined to calculate the covariance matrix of each constellation symbol to obtain the multidimensional space probability density function.

[0064] Specifically, the multidimensional space probability density function f(x) is:

[0065]

[0066] Wherein, Cov is the covariance matrix, e is a natural constant, x is the unprocessed 4N-dimensional vector signal, and T represents transpose.

[0067] Optionally, the clustering algorithm is an M-dimensional clustering algorithm, the cluster mean and the covariance are obtained by processing based on the M-dimensional clustering algorithm, and the multidimensional Gaussian space constructed based on the cluster mean and the covariance is an M-dimensional Gaussian space; the number of the M-dimensional Gaussian spaces is A, and M*A=4N.

[0068] Step 4

[0069] Specifically, the probability density function of the multidimensional space is calculated to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space.

[0070] Specifically, the number of clusters is N^M.

[0071] Exemplarily, a four-dimensional Gaussian space simulation is performed on a signal in a 16QAM modulation format, where N=4, M=4, and there are 4^4=256 clusters in total.

[0072] Optionally, a log-likelihood ratio calculation is performed on the multidimensional space probability density function to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space.

[0073] Step 5

[0074] Specifically, the symbol of the cluster to which each of the signal points most likely belongs is determined based on the corresponding probability; and symbol decision is performed based on the symbol to obtain a decision result.

[0075] Optionally, after obtaining the correspondence probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space, I and Q component synthesis processing is performed to obtain the correspondence probability between each signal point in the 2N polarization state signal and each cluster in the multidimensional Gaussian space, and the symbol of the cluster to which each signal point in the 2N polarization state signal most likely belongs is determined based on the corresponding probability, and symbol decision is performed based on the symbol to obtain the decision result of each signal point in the 2N polarization state signal.

[0076] Specifically, the symbol of the cluster is represented by the bit group corresponding to the cluster, and the correspondence between the cluster and its corresponding bit group is determined according to the coding table; the correspondence probability between each signal point and each cluster is represented by the correspondence probability between each signal point and each bit group.

[0077] Specifically, the decision value corresponding to the corresponding probability is determined according to the specific modulation format of the 4N-dimensional vector signal; the sizes of the corresponding probabilities are compared, and the decision value corresponding to the maximum probability is used as the decision result of the corresponding signal point in the 4N-dimensional vector signal.

[0078] For example, please refer to Figure 2 As shown, a method for suppressing inter-core crosstalk of a multi-core optical fiber described in this embodiment is further described by taking a four-core DP-16QAM signal as an example.

[0079] Specifically, after being transmitted through the four-core optical fiber, the DP-16QAM signal is subjected to the MIMO processing to obtain an 8-polarization state signal.

[0080] Further, the 8 polarization state signals are subjected to signal diversity processing of the orthogonal components at the receiving side to obtain a 16-dimensional vector signal; Figure 2 As shown, the 8 polarization state signals are complex-valued sequence signals, and the 16-dimensional vector signals are real-valued sequence signals.

[0081] Furthermore, in combination with the reference signal provided by the signal transmitting side of the DP-16QAM signal, the covariance matrix of the 16-dimensional vector signal is calculated, and then processed based on a four-dimensional clustering algorithm to obtain the cluster mean and covariance of each dimension of the 16-dimensional vector signal.

[0082] Further, constructing a four-dimensional Gaussian space based on the cluster mean and the covariance to obtain a four-dimensional space probability density function; wherein the number of the four-dimensional Gaussian spaces is 4, and the number of the clusters is 256;

[0083] Further, a log-likelihood ratio is calculated for the probability density function of the four-dimensional space to obtain a corresponding probability between each signal point in the 16-dimensional vector signal and each cluster in the four-dimensional Gaussian space;

[0084] Further, I and Q component synthesis processing is performed to obtain the corresponding probability between each signal point in the 8 polarization state signals and each cluster in the four-dimensional Gaussian space;

[0085] Further, determining the symbol of the cluster to which each signal point in the 8 polarization state signals most likely belongs;

[0086] Furthermore, the symbol decision is performed to obtain the decision result of each signal point in the 8 polarization state signals.

[0087] Specifically, for a signal in 16QAM modulation format, the decision values ​​corresponding to the corresponding probabilities P1, P2, P3 and P4 are -3, -1, 1, and 3 respectively; if P1 is the maximum value, the decision result of the corresponding signal point is -3.

[0088] Embodiment 2

[0089] This embodiment provides a system for suppressing crosstalk between multi-core optical fibers. Figure 3 As shown, including:

[0090] The signal diversity processing module performs orthogonal component signal diversity processing on the 2N polarization state signals transmitted through the N-core optical fiber at the receiving side to obtain a 4N-dimensional vector signal;

[0091] A cluster mean and covariance calculation module performs statistical calculation on the 4N-dimensional vector signal to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal;

[0092] A probability density function calculation module constructs a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function;

[0093] A corresponding probability calculation module calculates the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space;

[0094] A symbol decision module determines the symbol of the cluster to which each of the signal points is most likely to belong based on the corresponding probability; and performs symbol decision based on the symbol to obtain a decision result.

[0095] For an introduction to a system for suppressing crosstalk between cores of a multi-core optical fiber provided in this embodiment, please refer to the first embodiment, and this embodiment will not be described in detail here.

[0096] This embodiment provides a system for suppressing crosstalk between cores of a multi-core optical fiber, which has the same beneficial effects as the above-mentioned method for suppressing crosstalk between cores of a multi-core optical fiber.

[0097] Embodiment 3

[0098] This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of a method for suppressing inter-core crosstalk of a multi-core optical fiber as described in the first embodiment are implemented.

[0099] For an introduction to a computer-readable storage medium provided in this embodiment, please refer to Embodiment 1, and this embodiment will not be described in detail here.

[0100] The computer-readable storage medium provided in this embodiment has the same beneficial effects as the method for suppressing crosstalk between cores of a multi-core optical fiber.

[0101] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0102] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0105] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for suppressing crosstalk between cores of a multi-core optical fiber, characterized in that: The following steps are involved: The 2N polarization state signals transmitted through the N-core optical fiber are subjected to orthogonal component signal diversity processing at the receiving side to obtain a 4N-dimensional vector signal; Performing statistical calculations on the 4N-dimensional vector signal to obtain cluster means and covariances of respective dimensions of the 4N-dimensional vector signal; Construct a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function; Calculating the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space; The symbols of the cluster to which each of the signal points most likely belongs are determined based on the corresponding probabilities; and symbol decisions are performed based on the symbols to obtain decision results.

2. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 1, characterized in that: At the receiving side, 2N polarization state signals transmitted through N-core optical fibers are obtained based on MIMO processing, the 2N polarization state signals are regarded as 2N groups of complex-valued sequence signals, and signal diversity processing of orthogonal components is performed on the 2N groups of complex-valued sequence signals to obtain the 4N-dimensional vector signal.

3. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 2, characterized in that: The method for performing signal diversity processing of orthogonal components on the 2N groups of complex-valued sequence signals is: The real part and the imaginary part of the 2N groups of complex-valued sequence signals are separated to obtain 4N groups of real-valued sequences. Each group of real-valued sequences in the 4N groups of real-valued sequences is regarded as a new dimension to obtain the 4N-dimensional vector signal.

4. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 1, characterized in that: After obtaining the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space, I and Q component synthesis processing is performed to obtain the corresponding probability between each signal point in the 2N polarization state signal and each cluster in the multidimensional Gaussian space, and the symbol of the cluster to which each signal point in the 2N polarization state signal most likely belongs is determined based on the corresponding probability, and symbol decision is performed based on the symbol to obtain the decision result of each signal point in the 2N polarization state signal.

5. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 1, characterized in that: The method for performing statistical calculation on the 4N-dimensional vector signal is: Combined with the reference signal provided by the signal sending side, the covariance matrix of the 4N-dimensional vector signal is calculated, and then processed based on the clustering algorithm to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal.

6. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 5, characterized in that: The clustering algorithm is an M-dimensional clustering algorithm. The cluster mean and the covariance are obtained by processing based on the M-dimensional clustering algorithm. The multidimensional Gaussian space constructed based on the cluster mean and the covariance is an M-dimensional Gaussian space. The number of the M-dimensional Gaussian spaces is A, and M*A=4N.

7. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 5, characterized in that: After constructing the multidimensional Gaussian space based on the cluster mean and the covariance, the covariance matrix of each constellation symbol is calculated in combination with the reference signal and the 4N-dimensional vector signal to obtain the multidimensional space probability density function, and the multidimensional space probability density function f(x) is: Wherein, Cov is the covariance matrix, e is a natural constant, μ is the cluster mean, x is the unprocessed 4N-dimensional vector signal, and T represents transposition; the cluster mean μ is: Wherein, data(i) is an n*4N dimensional data cluster group, and n is the number of data points within the cluster of the n*4N dimensional data cluster group.

8. A method for suppressing crosstalk between cores of a multi-core optical fiber according to claim 1, characterized in that: A log-likelihood ratio is calculated for the multidimensional space probability density function to obtain a corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space.

9. A system for suppressing crosstalk between cores of a multi-core optical fiber, characterized in that: include: The signal diversity processing module performs orthogonal component signal diversity processing on the 2N polarization state signals transmitted through the N-core optical fiber at the receiving side to obtain a 4N-dimensional vector signal; A cluster mean and covariance calculation module performs statistical calculation on the 4N-dimensional vector signal to obtain the cluster mean and covariance of each dimension of the 4N-dimensional vector signal; A probability density function calculation module constructs a multidimensional Gaussian space based on the cluster mean and the covariance to obtain a multidimensional space probability density function; A corresponding probability calculation module calculates the probability density function of the multidimensional space to obtain the corresponding probability between each signal point in the 4N-dimensional vector signal and each cluster in the multidimensional Gaussian space; The symbol decision module determines the symbol of the cluster to which each of the signal points is most likely to belong based on the corresponding probability; and performs symbol decision based on the symbol to obtain a decision result.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of a method for suppressing inter-core crosstalk of a multi-core optical fiber as described in any one of claims 1 to 8 are implemented.

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