Signal demodulation method and system for multi-core optical fiber multiband signal transmission

Abstract

The invention relates to a signal demodulation method and system for multi-core optical fiber multiband signal transmission, and belongs to the technical field of optical communication. Comprising the steps that an optical signal is injected into an N-core optical fiber to obtain multiple paths of parallel transmission signals, and N is an integer larger than 1; dividing the multiple paths of parallel transmission signals to obtain a plurality of sub-bands; selecting any one sub-band from the plurality of sub-bands to carry out digital signal processing to obtain a tap coefficient; applying the tap coefficients to unselected sub-bands, and performing parallel convolution processing to obtain output signals of the sub-bands; and reconstructing the output signal of each sub-band, and recovering the original multi-channel parallel transmission signal. According to the invention, the inter-core crosstalk is reduced, the channel sampling rate during synchronous processing of multiple paths of signals is improved, and the overall performance and efficiency of signal transmission are enhanced.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technology, and in particular to a signal demodulation method and system for multi-core optical fiber multi-band signal transmission. Background Art

[0002] As the core transmission medium of optical fiber communication, optical fiber has traditionally relied on standard single-mode optical fiber for single-path transmission of optical signals. In order to break through the limitation of transmission capacity, new optical fibers have been gradually invented, among which multi-core optical fiber has emerged as a highlight. Multi-core optical fiber integrates multiple independent cores inside, allowing optical signals to be transmitted simultaneously on multiple parallel channels, such as Figure 1 Specifically, if a 4-core fiber is used, the transmission capacity can be four times that of a standard single-mode fiber; if a 7-core fiber is used, the transmission capacity will be increased to seven times that of a standard single-mode fiber. Multi-core fiber significantly enhances the overall performance and data carrying capacity of the optical fiber communication system.

[0003] However, while multi-core optical fiber improves transmission capacity, it also faces new challenges. Due to the close arrangement of multiple fiber cores, the inevitable inter-core crosstalk phenomenon occurs, which directly affects the purity of signal transmission. In order to solve the inter-core crosstalk phenomenon, it is necessary to use the multi-input multi-output signal processing at the receiving end to suppress the crosstalk to ensure that the signal can be restored without distortion. However, as the signal rate increases, the signal spectrum bandwidth also increases, which puts higher requirements on the bandwidth processing capability of the multiple-input and multiple-output digital signal (Multiple-input and multiple-output DSP, referred to as MIMO-DSP) technology. A multi-core optical fiber MIMO equalizer solution is proposed in the public document "Advanced MIMO Signal Processing Techniques Enabling Long-Haul Dense SDM Transmissions" (from "Journal of Lightwave Technology"), but the solution is difficult to process large-bandwidth signals. Therefore, although the existing technology can alleviate the inter-core crosstalk to a certain extent and improve the reception quality and reliability of the signal, it is difficult to efficiently cope with the complex processing requirements of the signal when facing the complex scenario of large-bandwidth multi-core optical fiber transmission. Especially when processing multiple signals synchronously, the sampling rate of each channel will inevitably be limited, which becomes a bottleneck restricting further performance improvement. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the crosstalk phenomenon between cores in the prior art and the limitation of channel sampling rate when facing the synchronous processing of multi-channel signals.

[0005] In a first aspect, in order to solve the above technical problems, the present invention provides a signal demodulation method for multi-core optical fiber multi-band signal transmission, comprising:

[0006] The optical signal is injected into an N-core optical fiber to obtain a multi-channel parallel transmission signal, where N is an integer greater than 1;

[0007] Splitting the multi-path parallel transmission signal to obtain a plurality of sub-frequency bands;

[0008] Select any one sub-band from the multiple sub-bands to perform digital signal processing to obtain a tap coefficient;

[0009] Applying the tap coefficients to unselected sub-frequency bands and performing parallel convolution processing to obtain output signals of each of the sub-frequency bands;

[0010] The output signals of each of the sub-frequency bands are reconstructed to restore the original multi-channel parallel transmission signals.

[0011] In one embodiment of the present invention, the method for obtaining multiple sub-frequency bands is:

[0012] The multi-channel parallel transmission signal is divided in the frequency domain into M sub-frequency bands of equal width;

[0013] Based on the M sub-bands of equal width, M sub-bands with bandwidth B are generated. i / M baseband signals, and obtaining a frequency response of each of the baseband signals, wherein each of the baseband signals corresponds to a subcarrier;

[0014] The frequency shift is performed for each of the subcarriers, and the mathematical expression of the frequency of each of the subcarriers is:

[0015] f(i,j)=f(i)+j*(B i / M);

[0016] Wherein, f(i,j) is the frequency of the jth subcarrier of the i-th core optical fiber; i = 0, 1, ..., N, j = 0, 1, ..., M, N is the total number of optical fiber cores, and M is the total number of sub-bands; f(i) is the frequency response function of each baseband signal; B i is the bandwidth of the multiplexed parallel transmission signals.

[0017] In one embodiment of the present invention, the method for obtaining the tap coefficient is:

[0018] Extracting a key signal from the selected sub-frequency band, performing channel estimation on the key signal, and obtaining a channel estimation result;

[0019] Based on the channel estimation result, an iterative formula is used to calculate the tap coefficients required to compensate the channel, and the iterative formula is:

[0020] T j =T j +error*u;

[0021] Among them, T j is the tap coefficient, error is the difference between the reference subcarrier signal and the measured signal; u is the iteration step size;

[0022] The error is gradually reduced by iteratively updating the tap coefficients until the error is reduced to a preset range.

[0023] In one embodiment of the present invention, the process of performing channel estimation on the signal includes using a predefined pilot signal or training sequence as a reference.

[0024] In one embodiment of the present invention, the calculation formula for the parallel convolution processing is:

[0025]

[0026] Among them, s1, s2, …, s K Represent the transmission signals of different spatial modes respectively; T (K,K),j are the tap coefficient components, j is the tap coefficient number, K is the total number of transmitted signals; P1, P2, ..., P K are the different output signals obtained respectively.

[0027] In one embodiment of the present invention, reconstructing the output signals of each of the sub-frequency bands includes performing error detection and correction on the reconstructed signals.

[0028] In a second aspect, in order to solve the above technical problems, the present invention provides a signal demodulation system for multi-core optical fiber multi-band signal transmission, comprising:

[0029] A signal receiving module, used for injecting an optical signal into an N-core optical fiber to obtain a multi-channel parallel transmission signal, wherein N is an integer greater than 1;

[0030] A signal segmentation module, used for segmenting the multi-channel parallel transmission signal to obtain multiple sub-frequency bands;

[0031] A signal processing module, configured to select any one sub-band from the plurality of sub-bands for digital signal processing to obtain a tap coefficient; apply the tap coefficient to unselected sub-bands and perform parallel convolution processing to obtain output signals of each of the sub-bands;

[0032] The signal output module is used to reconstruct the output signal of each sub-frequency band to restore the original multi-channel parallel transmission signal.

[0033] In a third aspect, in order to solve the above technical problem, the present invention provides an electronic device, comprising:

[0034] one or more processors;

[0035] A storage device for storing one or more programs;

[0036] When the one or more programs are executed by the one or more processors, the one or more processors implement any one of the above methods.

[0037] In a fourth aspect, in order to solve the above-mentioned technical problem, the present invention provides a multi-core optical fiber, including the above-mentioned signal demodulation system for multi-core optical fiber multi-band signal transmission.

[0038] In a fifth aspect, in order to solve the above technical problem, the present invention provides a multi-port optical fiber transceiver, comprising the above-mentioned multi-core optical fiber.

[0039] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0040] (1) The signal demodulation method and system for multi-core optical fiber multi-band signal transmission described in the present invention effectively avoids the tedious steps of individual iterative processing of each frequency band through the innovative method of sharing tap coefficients for multiple frequency bands, and directly applies the tap coefficients obtained by processing a sub-band to other frequency bands, greatly improving the efficiency of signal processing. In addition, this method can give full play to the transmission advantages of multi-core optical fiber and realize multi-channel, large-bandwidth multi-core optical fiber signal processing. Through this optimized signal demodulation technology, not only can the overall performance of the multi-core optical fiber communication system be significantly improved to meet the current growing demand for high-speed data transmission, but it can also effectively deal with the problem of crosstalk between cores and the channel sampling rate limitation problem encountered when processing multiple signals simultaneously, bringing technological progress to the field of optical fiber communication.

[0041] (2) The present invention adopts a frequency band splitting strategy to reduce the bandwidth of the measured signal and the reference signal. This optimization directly simplifies the calculation process of the tap coefficients. Processing signals within a narrower bandwidth not only reduces the amount of calculation required, but also reduces the demand for processing resources, thereby improving calculation efficiency. In addition, the combination of frequency domain splitting and subcarrier modulation further improves transmission efficiency and spectrum utilization, making signal transmission more efficient and spectrum resources more reasonably allocated and used. The application of this strategy ensures that the system can achieve higher quality signal transmission and more stable performance under limited spectrum resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0043] Figure 1 A schematic diagram of an existing multi-core optical fiber in a preferred embodiment of the present invention;

[0044] Figure 2 This is a flow chart of a signal demodulation method for multi-core optical fiber multi-band signal transmission in a preferred embodiment of the present invention;

[0045] Figure 3 A spectrum diagram of digital multi-subcarrier modulation in a preferred embodiment of the present invention;

[0046] Figure 4 A structural diagram of a linear multi-input multi-output filter in a preferred embodiment of the present invention;

[0047] Figure 5 This is an example diagram of a signal demodulation method for multi-core optical fiber multi-band signal transmission in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0049] Reference Figure 2 As shown, an embodiment of the present invention provides a signal demodulation method for multi-core optical fiber multi-band signal transmission, including but not limited to the following steps:

[0050] S1. Inject an optical signal into an N-core optical fiber to obtain a multi-channel parallel transmission signal, where N is an integer greater than 1;

[0051] S2, dividing the multi-channel parallel transmission signals to obtain multiple sub-bands;

[0052] S3, selecting any one sub-band from the multiple sub-bands to perform digital signal processing to obtain a tap coefficient;

[0053] S4, applying the tap coefficients to the unselected sub-bands and performing parallel convolution processing to obtain output signals of each sub-band;

[0054] S5. Reconstruct the output signals of each sub-frequency band to restore the original multi-channel parallel transmission signals.

[0055] The embodiment of the present invention provides a signal demodulation method for multi-core optical fiber multi-band signal transmission. By dividing the frequency bands of multi-channel parallel transmission signals and adopting the technology of multi-band shared tap coefficients, the complex process of iterative processing for each frequency band is effectively simplified. By directly applying the tap coefficients obtained by processing a sub-band to other frequency bands, the embodiment of the present invention not only improves the efficiency of signal processing, but also reduces the consumption of computing resources. In addition, the method makes full use of the transmission potential of multi-core optical fiber to realize multi-channel, large-bandwidth multi-core optical fiber signal processing. This optimized signal demodulation technology not only improves the overall performance of the multi-core optical fiber communication system and meets the growing demand for high-speed data transmission, but also effectively solves the problem of crosstalk between cores, and breaks through the limitation of channel sampling rate during synchronous processing of multi-channel signals, further promoting the development of optical fiber communication technology.

[0056] Specifically, in step S1, an optical signal is injected into a multi-core optical fiber by a transmitter to realize multi-path parallel transmission of signals. In this process, the transmitter, which can usually be a laser or an LED, generates unmodulated optical signals. Subsequently, these optical signals will be modulated to carry data information.

[0057] In the field of signal modulation technology, Digital Subcarrier Modulation (DSCM) is an advanced method that relies on digital signal processing technology to achieve multi-band multiplexing of signals. This technology can distribute data signals to multiple subcarriers, thereby improving spectrum efficiency and enhancing signal transmission capabilities. Figure 3 As shown in the figure, the signal spectrum diagram of DSCM clearly shows how the technology can effectively distribute data signals in multiple frequency bands, thereby optimizing spectrum utilization and reducing interference between signals. Figure 3 In the figure, the leftmost sub-figure shows the continuous spectrum of the traditional signal. By using DSCM to separate the spectrum, Figure 3 The three figures on the right show the DSCM signal spectra of 2, 4, and 8 digital subcarriers respectively. It can be seen that DSCM modulation technology can divide the signal into multiple discrete frequency bands. Since the total spectrum bandwidth remains unchanged, DSCM modulation causes the bandwidth of each subcarrier to be significantly reduced, for example Figure 3 In the rightmost 8 subcarrier modulation examples, the bandwidth of each subcarrier is reduced to 1 / 8 of the original. This subdivision of the frequency band helps to improve spectrum utilization and reduce interference between subcarriers. However, DSCM modulation has not yet been applied to multi-core optical fiber transmission systems. To this end, the embodiment of the present invention innovatively uses digital multi-subcarrier modulation to divide the multi-channel parallel transmission signal to obtain multiple sub-bands, each of which represents a part of the original signal. Specifically, in step S2, the steps of dividing the multi-channel parallel transmission signal are:

[0058] S201, obtain multiple parallel transmission signals from N core optical fibers, that is, the original transmission signals, whose bandwidth is B i (i=0,1,…,N), i represents different fiber cores. In order to solve the bandwidth limitation problem of N-core fiber transmission link, the original bandwidth B i The transmission signal is segmented in the frequency domain with a segmentation factor of M. The segmentation factor M can also be expressed as the original bandwidth B i It is divided into M sub-bands of equal width. Therefore, the bandwidth of each sub-band is B i / M.

[0059] S202: for the i-th core optical fiber, generate M optical fibers with bandwidth B based on step S201. i / M baseband signals. These baseband signals are the result of dividing the original signal in the frequency domain, and each baseband signal corresponds to a subcarrier.

[0060] S203. For each subcarrier j (j=0, 1, ..., M), frequency shift is performed to ensure that they are evenly distributed in the frequency domain and remain orthogonal. The frequency shift amount is j*(B i / M), so the mathematical expression of the frequency of each subcarrier j is:

[0061] f(i,j)=f(i)+j*(B i / M);

[0062] Wherein, f(i) is the frequency response of each baseband signal, which is the fundamental frequency of the subcarrier when no frequency shift is performed.

[0063] Specifically, in step S3, each sub-band can independently transmit signals. A specific sub-band is selected for the next step of digital signal processing. In this embodiment, the digital signal processing preferably uses multiple-input and multiple-output digital signal processing (Multiple-input and multiple-output DSP, referred to as MIMO-DSP) technology. MIMO-DSP technology can use multiple receiving channels to synchronously receive all transmitted signals, and based on the principle of channel correlation, effectively restore and process the original signal. Figure 4. The tap coefficients calculated thereby can accurately map the channel characteristics of the selected sub-band. In addition, this parallel processing strategy significantly reduces the impact of inter-core crosstalk in multi-core optical fibers, thereby greatly improving the signal reception quality and system reliability. At the receiving end, MIMO-DSP technology can cope with complex link impairments including mode coupling, differential mode group delay (DGD), and mode-dependent loss. By fine-tuning the tap coefficients, DSP technology can compensate for these impairments, thereby restoring and improving the quality of the signal. In an embodiment of the present invention, the specific steps for obtaining the tap coefficients are:

[0064] S301 . Extract key signals from the selected sub-frequency bands. The information extraction is mainly achieved by applying filters in the frequency domain, with the purpose of clearly separating the signal components in the sub-frequency bands.

[0065] S302: Perform channel estimation on the key signal to accurately determine the frequency response of the channel. This process includes using predefined pilot signals or training sequences, which are used as references to help accurately estimate channel characteristics.

[0066] S303: Based on the channel estimation result, an equalizer is designed to compensate for the influence of the channel. The equalizer generally adopts a finite impulse response (FIR) filter structure, and the determination of its tap coefficients depends on the characteristics of the channel.

[0067] S304, using an iterative method to calculate the tap coefficient T of the equalizer j , the iteration formula is:

[0068] T j =T j +error*u;

[0069] Wherein, error is the difference between the reference subcarrier signal and the measured signal, and u is the iteration step, which can be adjusted as needed.

[0070] S305, updating the tap coefficient T through iteration j , gradually reducing the error and optimizing the performance of the equalizer. This process may require multiple iterations until the error is reduced to a preset range.

[0071] The frequency band division strategy of steps S301 to S305 is adopted to reduce the bandwidth of the measured signal and the reference signal. This optimization directly simplifies the tap coefficient T jThe calculation process of the signal is simplified. Processing the signal within a narrower bandwidth not only reduces the amount of calculation required, but also reduces the demand for processing resources, thereby improving the calculation efficiency. In addition, the combination of frequency domain segmentation and subcarrier modulation further improves the transmission efficiency and spectrum utilization, making signal transmission more efficient and spectrum resources more reasonably allocated and used. The application of this strategy ensures that the system can achieve higher quality signal transmission and more stable performance under limited spectrum resources.

[0072] Specifically, in step S4, it is assumed that all sub-bands experience the same channel. Based on this assumption, the tap coefficients (such as T j ) is applied to other sub-bands. Therefore, in this embodiment, the obtained tap coefficients are applied to other unselected sub-bands to achieve parallel convolution of multi-channel signal matrices, thereby suppressing the core-to-core crosstalk of multi-band signals. The specific method is as follows:

[0073] Get the tap coefficient T finally obtained in step S305 j , and apply it to other unselected sub-bands. Using the tap coefficient T j Perform parallel convolution processing on multiple signals. The calculation formula for parallel convolution processing is:

[0074]

[0075] Among them, s1, s2, …, s K Represent the transmission signals of different spatial modes respectively; T (K,K),j are the tap coefficient components, j is the tap coefficient number, K is the total number of transmitted signals; P1, P2, ..., P K are the different output signals obtained respectively.

[0076] Furthermore, in order to better illustrate the parallel convolution processing process, taking a matrix with a dimension of 2x2 as an example, the specific calculation formula for parallel convolution is:

[0077]

[0078] Where s1 and s2 represent the transmission signals of two spatial modes. By using the MIMO tap T of any frequency band j Perform matrix operations (the matrix dimension is 2x2) to obtain output signals P1 and P2.

[0079] In order to more intuitively demonstrate the implementation process of the method provided by the embodiment of the present invention, a detailed description will be given below through specific examples.

[0080] For example, refer to Figure 5 The specific steps of the method provided in the embodiment of the present invention are:

[0081] Step 1: Optical signal transmission and acquisition, the dual-polarization optical signal with a bandwidth of 20GHz is transmitted through a 4-core optical fiber and reaches the optical receiver. At this time, the signal has 8 spatial modes. These parallel transmitted signals are collected using a coherent receiver and a multi-channel analog-to-digital converter (AD) to prepare data for subsequent processing.

[0082] Step 2: Signal segmentation and sub-band generation. For the 8 parallel transmission signals, the spectrum segmentation technology (DSCM) is used to segment each signal into the original 4 parts, so that the signal bandwidth of each sub-band is reduced to 5GHz. This step actually separates the signal through filtering methods to ensure that the information carried by all four sub-bands on the DSCM is independent, providing a basis for subsequent crosstalk suppression.

[0083] Step 3: Remove the inter-core crosstalk. For sub-band 1 (5 GHz bandwidth), use the MIMO-DSP with the minimum mean square error-decision-directed (LMS-DD) algorithm to remove the inter-core crosstalk. Through this step, the MIMO-DSP tap coefficients for band 1 can be obtained, which are key parameters for subsequent signal processing.

[0084] Step 4: Application of tap coefficients to multi-band signal processing, apply the MIMO-DSP tap coefficients obtained for band 1 to the other three bands. By directly performing matrix operations, the core crosstalk suppression of multi-band signals can be achieved. This step utilizes the correlation between bands and simplifies the processing flow of other bands through the obtained tap coefficients, improving the processing efficiency.

[0085] Step 5: Signal reconstruction and output, after completing the inter-core crosstalk suppression of all sub-bands, the processed signal is reconstructed and the information of each sub-band is combined to restore the original signal. Finally, the reconstructed signal is output, which has removed the inter-core crosstalk and improved the signal quality and reliability.

[0086] Furthermore, in step 5, after reconstructing the output signal of each sub-band, error detection and correction of the reconstructed signal is also performed. Error detection and correction methods can be flexibly selected and applied according to specific application scenarios and requirements, such as parity check, cyclic redundancy check and automatic repeat request.

[0087] The embodiment of the present invention provides an efficient multi-core fiber multi-band signal demodulation scheme, which uses digital multi-subcarrier modulation technology and the application of tap coefficients to achieve fast signal demodulation and effective suppression of inter-core crosstalk. This method is applicable to a variety of high-speed optical communication networks, short-distance optical interconnection in big data centers, distributed optical fiber acoustic wave sensing systems, and wireless optical communication systems, and demonstrates wide applicability and technical advantages.

[0088] In addition, in the case of limited hardware resources, such as in sampling devices, hardware resources usually include a fixed number of sampling channels and a sampling rate for each channel. Due to the limitation of hardware resources, increasing the number of sampling channels often leads to a decrease in the sampling rate of a single channel. For multi-channel parallel signals transmitted by multi-core optical fibers, the acquisition requirements of multiple channels will further reduce the sampling rate of each channel, thereby affecting the bandwidth of multi-core optical fiber signals. The signal demodulation method provided in an embodiment of the present invention effectively solves this problem. By optimizing signal processing technology, the efficiency and bandwidth of multi-core optical fiber signal transmission are improved, ensuring high-quality transmission of signals.

[0089] Embodiment 2

[0090] Based on the same inventive concept, this embodiment provides a signal demodulation system for multi-core optical fiber multi-band signal transmission. The principle of solving the problem is similar to the signal demodulation method for multi-core optical fiber multi-band signal transmission provided in Example 1, and the repeated parts will not be repeated.

[0091] This embodiment provides a signal demodulation system for multi-core optical fiber multi-band signal transmission, including:

[0092] A signal receiving module, used for injecting an optical signal into an N-core optical fiber to obtain a multi-channel parallel transmission signal, wherein N is an integer greater than 1;

[0093] A signal segmentation module is used to segment the multi-channel parallel transmission signals to obtain multiple sub-frequency bands;

[0094] A signal processing module is used to select any one sub-band from multiple sub-bands for digital signal processing to obtain tap coefficients; apply the tap coefficients to unselected sub-bands and perform parallel convolution processing to obtain output signals of each sub-band;

[0095] The signal output module is used to reconstruct the output signals of each sub-band and restore the original multi-channel parallel transmission signals.

[0096] Embodiment 3

[0097] This embodiment provides an electronic device, including:

[0098] one or more processors;

[0099] A storage device for storing one or more programs;

[0100] When one or more programs are executed by one or more processors, the one or more processors implement the method as described in any one of the first embodiments.

[0101] Embodiment 4

[0102] This embodiment provides a multi-core optical fiber, including a signal demodulation system for multi-core optical fiber multi-band signal transmission provided in the second embodiment.

[0103] Embodiment 5

[0104] This embodiment provides a multi-port optical fiber transceiver, including a multi-core optical fiber provided in the fourth embodiment.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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 signal demodulation method for multi-core optical fiber multi-band signal transmission, characterized in that: include: The optical signal is injected into an N-core optical fiber to obtain a multi-channel parallel transmission signal, where N is an integer greater than 1; Splitting the multi-path parallel transmission signal to obtain a plurality of sub-frequency bands; Select any one sub-band from the multiple sub-bands to perform digital signal processing to obtain a tap coefficient; Applying the tap coefficients to unselected sub-frequency bands and performing parallel convolution processing to obtain output signals of each of the sub-frequency bands; The output signals of each of the sub-frequency bands are reconstructed to restore the original multi-channel parallel transmission signals.

2. A signal demodulation method for multi-core optical fiber multi-band signal transmission according to claim 1, characterized in that: The method for obtaining multiple sub-frequency bands is: The multi-channel parallel transmission signal is divided in the frequency domain into sub-frequency bands of equal width; Based on the M sub-bands of equal width, M sub-bands with bandwidth B are generated. i / M baseband signals, and obtaining a frequency response of each of the baseband signals, wherein each of the baseband signals corresponds to a subcarrier; The frequency shift is performed for each of the subcarriers, and the mathematical expression of the frequency of each of the subcarriers is: f(i,j)=f(i)+j*(B i / M); Wherein, f(i,j) is the frequency of the jth subcarrier of the i-th fiber core; i = 0, 1, ..., N, j = 0, 1, ..., M, N is the total number of fiber cores, and M is the total number of sub-bands; f(i) is the frequency response function of each baseband signal; i is the bandwidth of the multi-path parallel transmission signal.

3. A signal demodulation method for multi-core optical fiber multi-band signal transmission according to claim 1, characterized in that: The method for obtaining the tap coefficient is: Extracting a key signal from the selected sub-frequency band, performing channel estimation on the key signal, and obtaining a channel estimation result; Based on the channel estimation result, an iterative formula is used to calculate the tap coefficients required to compensate the channel, and the iterative formula is: T j =T j +error*u; Among them, T j is the tap coefficient, error is the difference between the reference subcarrier signal and the measured signal; u is the iteration step size; The error is gradually reduced by iteratively updating the tap coefficients until the error is reduced to a preset range.

4. A signal demodulation method for multi-core optical fiber multi-band signal transmission according to claim 3, characterized in that: The process of performing channel estimation on the signal includes using a predefined pilot signal or training sequence as a reference.

5. The signal demodulation method for multi-core optical fiber multi-band signal transmission according to claim 1, characterized in that: The calculation formula for the parallel convolution processing is: Among them, s1, s2, …, s K Represent the transmission signals of different spatial modes respectively; T (K,K),j are the tap coefficient components, j is the tap coefficient number, K is the total number of transmitted signals; P1, P2, ..., P K are the different output signals obtained respectively.

6. The signal demodulation method for multi-core optical fiber multi-band signal transmission according to claim 1, characterized in that: Reconstructing the output signals of each of the sub-frequency bands includes performing error detection and correction on the reconstructed signals.

7. A signal demodulation system for multi-core optical fiber multi-band signal transmission, characterized in that: include: A signal receiving module, used for injecting an optical signal into an N-core optical fiber to obtain a multi-channel parallel transmission signal, wherein N is an integer greater than 1; A signal segmentation module, used for segmenting the multi-channel parallel transmission signal to obtain multiple sub-frequency bands; A signal processing module, configured to select any one sub-band from the plurality of sub-bands for digital signal processing to obtain a tap coefficient; Applying the tap coefficients to unselected sub-frequency bands and performing parallel convolution processing to obtain output signals of each of the sub-frequency bands; The signal output module is used to reconstruct the output signal of each sub-frequency band to restore the original multi-channel parallel transmission signal.

8. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 6.

9. A multi-core optical fiber, characterized in that: It includes a signal demodulation system for multi-core optical fiber multi-band signal transmission as described in claim 7.

10. A multi-port optical fiber transceiver, characterized in that: A multi-core optical fiber comprising the multi-core optical fiber described in claim 9.

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