Adaptive equalization method and apparatus for optical communication systems

Abstract

The application provides an adaptive equalization method and device for an optical communication system, which comprises the following steps: determining a first signal power spectrum envelope curve of a storage signal of a dispersion compensator and a second signal power spectrum envelope curve of an output signal of a linear equalizer; determining a third signal power spectrum envelope curve of an output signal of a post digital filter under each preset tap coefficient group, and determining a target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each third signal power spectrum envelope curve; and updating the tap coefficient group of the post digital filter to the target tap coefficient group, so that the post digital filter completes equalization on high-frequency noise introduced by the linear equalizer. The application can realize adaptive noise equalization, effectively improve the response speed and efficiency of noise equalization of the linear equalizer, reduce the complexity of noise equalization of the linear equalizer, and improve the optical signal-to-noise ratio of the system.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to an adaptive equalization method and apparatus for optical communication systems. Background Technology

[0002] Coherent optical communication technology is currently at the forefront and a hot topic in the field of communication research. Among its key technologies, equalization is one of the crucial techniques for improving the bit error rate performance of optical communication links. Because linear equalizers can provide good performance on channels with favorable spectral characteristics, they are commonly used in coherent optical communication systems to compensate for major linear transmission losses. However, the use of linear equalizers also introduces high-frequency noise enhancement, severely impacting communication quality. Therefore, noise equalization of linear equalizers plays a particularly important role in coherent optical communication systems.

[0003] In typical digital optical coherent receivers, finite impulse response (FIR) followed by digital filters and multi-symbol detection algorithms are usually used to suppress increasing noise and achieve the purpose of linear equalizer noise equalization. However, the implementation of such noise equalization algorithms is complex, the response speed for achieving noise equalization is slow, the efficiency is not high, and the optical signal-to-noise ratio (OSNR) of the system also needs to be improved. Summary of the Invention

[0004] This invention provides an adaptive equalization method and apparatus for optical communication systems, which solves the shortcomings of existing linear equalizer noise equalization methods, such as complex implementation, slow response speed, low efficiency, and the need to improve the optical signal-to-noise ratio of the system.

[0005] This invention provides an adaptive equalization method for an optical communication system, the optical communication system comprising a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter; the received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, and the post-digital filter;

[0006] The method includes:

[0007] Determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer;

[0008] The third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is determined, and the target tap coefficient group is determined from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each of the third signal power spectrum envelope curves.

[0009] The tap coefficient set of the post-digital filter is updated to the target tap coefficient set so that the post-digital filter can perform equalization of the high-frequency noise introduced by the linear equalizer.

[0010] According to the present invention, an adaptive equalization method for an optical communication system is provided, wherein the tap coefficient group includes a first tap coefficient, a second tap coefficient, and a plurality of remaining tap coefficients; based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each of the third signal power spectrum envelope curves, a target tap coefficient group is determined from the preset tap coefficient groups, including:

[0011] Based on the tap coefficient group corresponding to the first target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, multiple candidate values ​​of the first tap coefficient in the target tap coefficient group are determined; the first target signal power spectrum envelope curve is the third signal power spectrum envelope curve distributed between the first signal power spectrum envelope curve and the second signal power spectrum envelope curve in the high frequency range of the signal power spectrum.

[0012] Based on the tap coefficient group corresponding to the second target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, the optimal second tap coefficient and the remaining multiple tap coefficients corresponding to each candidate value of the first tap coefficient are determined; the second target signal power spectrum envelope curve is the third signal power spectrum envelope curve with the highest overlap with the first signal power spectrum envelope curve.

[0013] Based on the multiple candidate values ​​of the first tap coefficient, the optimal second tap coefficient corresponding to each candidate value of the first tap coefficient, and the remaining multiple tap coefficients, multiple pre-selected tap coefficient groups are obtained.

[0014] Based on the multiple pre-selected tap coefficient groups, the target tap coefficient group is determined.

[0015] According to the adaptive equalization method for optical communication systems provided by the present invention, determining the third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups includes:

[0016] The signal power spectrum of the output signal of the post-digital filter under each preset tap coefficient group is determined; the signal power spectrum is the signal power spectrum obtained by fast Fourier transform processing;

[0017] The power spectrum of each signal is divided into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks after the power spectrum of each signal is divided.

[0018] The signal power amplitude of each signal power spectral block in each signal power spectrum is averaged to determine the envelope value corresponding to each signal power spectral block in each signal power spectrum.

[0019] Based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is obtained.

[0020] An adaptive equalization method for an optical communication system according to the present invention determines the target tap coefficient group based on the plurality of pre-selected tap coefficient groups, including:

[0021] The signal power spectrum of the output signal of the post-digital filter under each of the preselected tap coefficient groups is determined, and the signal power spectrum of the output signal under each of the preselected tap coefficient groups is averaged to obtain the mean signal power spectrum of each of the preselected tap coefficient groups.

[0022] The target tap coefficient group is obtained based on the preselected tap coefficient group corresponding to the largest mean of the signal power spectrum.

[0023] According to the adaptive equalization method for optical communication systems provided by the present invention, each preset tap coefficient group includes a plurality of first tap coefficient groups, wherein the first tap coefficient in the plurality of first tap coefficient groups includes a plurality of values, and the second tap coefficient and the remaining plurality of tap coefficients are fixed values.

[0024] After dividing each of the signal power spectra into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks after each signal power spectrum block, the method further includes:

[0025] Determine the envelope value corresponding to each signal power spectrum block in the signal power spectrum corresponding to the minimum value in the first tap coefficient and the envelope value corresponding to each signal power spectrum block in the signal power spectrum corresponding to the maximum value in the first tap coefficient;

[0026] The method of linear equations is used to calculate the envelope value of each signal power spectrum block in the signal power spectrum corresponding to each target value in the first tap coefficient; the target value is any value in the first tap coefficient other than the minimum value and the maximum value;

[0027] Based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each first tap coefficient group is obtained.

[0028] According to an adaptive equalization method for an optical communication system provided by the present invention, the optical communication system further includes an inter-symbol interference equalizer.

[0029] The signal input terminal of the inter-symbol interference equalizer is connected to the signal output terminal of the post-digital filter; the inter-symbol interference equalizer is used to equalize the inter-symbol interference introduced by the post-digital filter.

[0030] The present invention also provides an adaptive equalization device for an optical communication system, the optical communication system comprising a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter; the received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, and the post-digital filter;

[0031] The adaptive equalization device includes:

[0032] The first processing module is used to determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer.

[0033] The second processing module is used to determine the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group, and to determine the target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each of the third signal power spectrum envelope curves.

[0034] The first update module is used to update the tap coefficient group of the post-digital filter to the target tap coefficient group, so that the post-digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer.

[0035] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement adaptive equalization for an optical communication system as described above.

[0036] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements adaptive equalization for an optical communication system as described above.

[0037] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements adaptive equalization for an optical communication system as described above.

[0038] The adaptive equalization method and apparatus for optical communication systems provided by this invention considers the influence of the tap coefficients of the post-digital filter on the signal power spectrum in different frequency ranges. It calculates the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer, obtaining the signal power spectrum envelope curves before and after linear equalization. Then, it determines the third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups. Based on the distribution of the signal power spectrum envelope curves before and after linear equalization and the third signal power spectrum envelope curves, it determines the target tap coefficient group to be used by the post-digital filter. This allows the post-digital filter to equalize the high-frequency noise introduced by the linear equalizer under the target tap coefficient group, enabling the post-digital filter to adaptively select the optimal tap coefficient group. While achieving adaptive noise equalization, it effectively improves the response speed and efficiency of the linear equalizer's noise equalization, reduces the complexity of the linear equalizer's noise equalization, and improves the optical signal-to-noise ratio of the system. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a flowchart illustrating the adaptive equalization method for optical communication systems provided by the present invention.

[0041] Figure 2 This is a schematic diagram of the power spectrum envelope curves of the output signal of the digital filter under different tap coefficient groups provided by the present invention;

[0042] Figure 3 This is a schematic diagram illustrating the overlap pattern of the signal power spectrum envelope curves under different tap coefficient groups provided by the present invention.

[0043] Figure 4 This is a schematic diagram illustrating the simulation results provided by the present invention compared with existing technologies;

[0044] Figure 5 This is a schematic diagram of the adaptive equalization device for optical communication systems provided by the present invention.

[0045] Figure 6 This is a schematic diagram of the optical communication system provided by the present invention;

[0046] Figure 7 This is a schematic diagram of the physical structure of the electronic device provided by the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] The following is combined Figures 1-7 The present invention describes an adaptive equalization method and apparatus for optical communication systems.

[0049] Figure 1 This is a flowchart illustrating the adaptive equalization method for optical communication systems provided by the present invention. The optical communication system includes a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter. The received signal is transmitted sequentially through the dispersion compensator, linear equalizer, carrier recovery module, and post-digital filter. Figure 1 As shown, the method includes:

[0050] Step 110: Determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer;

[0051] Step 120: Determine the third signal power spectrum envelope curve of the output signal of the digital filter under each preset tap coefficient group, and determine the target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each third signal power spectrum envelope curve.

[0052] Step 130: Update the tap coefficient group of the digital filter to the target tap coefficient group so that the digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer.

[0053] Specifically, the first signal power spectrum envelope curve described in this embodiment of the invention refers to the envelope curve of the signal power spectrum of the received signal after passing through the signal stored in the dispersion compensator. It can be understood as the signal power spectrum envelope curve before linear equalization. The stored signal refers to the frequency domain signal after Fast Fourier Transform (FFT) stored in the dispersion compensator after the received signal has been processed.

[0054] It should be noted that, in this embodiment of the invention, the signal power spectrum is the signal power spectrum obtained by FFT processing.

[0055] The second signal power spectrum envelope curve described in this embodiment of the invention refers to the envelope curve of the signal power spectrum of the output signal after the output signal of the dispersion compensator has passed through linear equalization.

[0056] The preset tap coefficient groups described in the embodiments of the present invention refer to multiple pre-set tap coefficient groups, which can be set according to theoretical experience values ​​verified by actual simulation.

[0057] Here, the tap coefficient set refers to the tap coefficient set of the post-digital filter, which includes multiple adjustable tap coefficients. For example, for a 3-tap post-digital filter, its tap coefficient set includes two tap coefficients, which can be denoted as tap coefficient a and tap coefficient β.

[0058] The third signal power spectrum envelope curve described in the embodiments of the present invention refers to the envelope curve of the signal power spectrum of the output signal after passing through the post-digital filter by assigning different tap coefficient groups to the post-digital filter.

[0059] The distribution described in the embodiments of the present invention refers to the distribution relationship of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each third signal power spectrum envelope curve in the same signal power spectrum coordinate system. Specifically, it can be expressed as the third signal power spectrum envelope curve being distributed between the first signal power spectrum envelope curve and the second signal power spectrum envelope curve, or the third signal power spectrum envelope curve coinciding with the first signal power spectrum envelope curve, etc.

[0060] The target tap coefficient set described in this embodiment of the invention refers to the optimal tap coefficient set ultimately determined by the post-digital filter through adaptive adjustment to meet the requirements of optimal equalization effect. In other words, the post-digital filter, with the target tap coefficient set, can effectively equalize the high-frequency noise introduced by the linear equalizer.

[0061] In embodiments of the present invention, the optimal set of tap coefficients for the post-digital filter is calculated by considering the influence of the tap coefficients of the post-digital filter on the signal power spectrum in different frequency ranges, such as high frequency and intermediate frequency ranges. First, in an optical communication system, such as a Faster-Than-Nyquist (FTN) optical communication system, the stored signal in the dispersion compensator and the output signal of the linear equalizer are obtained. Then, the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer are determined by calculating the signal power spectrum envelope curve.

[0062] Specifically, by acquiring the power spectrum of the signal stored in the dispersion compensator and the power spectrum of the output signal of the linear equalizer, the power spectrum of each signal is divided into blocks to determine multiple power spectrum blocks after each block. Then, the signal power amplitude of each power spectrum block in each power spectrum is averaged to calculate the envelope value corresponding to each power spectrum block in each power spectrum. Based on the envelope value corresponding to each power spectrum block in each power spectrum, the first power spectrum envelope curve of the storage signal of the dispersion compensator and the second power spectrum envelope curve of the output signal of the linear equalizer are obtained.

[0063] Furthermore, in an embodiment of the present invention, different preset tap coefficient groups are assigned to the post-digital filter, and then the corresponding output signals are obtained. The third signal power spectrum envelope curve of the output signal of the post-digital filter under different tap coefficient groups is determined by calculating the signal power spectrum envelope curve. Simultaneously, based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each third signal power spectrum envelope curve, a third signal power spectrum envelope curve that meets the equalization effect requirements is determined. Therefore, the tap coefficient group corresponding to the third signal power spectrum envelope curve can be used to determine the target tap coefficient group from the preset tap coefficient groups.

[0064] Furthermore, the tap coefficient set of the post-digital filter can be automatically updated to the target tap coefficient set. In this way, the optimal tap coefficient set of the post-digital filter can be adaptively selected, enabling the post-digital filter to equalize the high-frequency noise introduced by the linear equalizer, thereby reducing the noise equalization complexity of the linear equalizer and achieving a highly efficient equalization effect.

[0065] The adaptive equalization method for optical communication systems in this invention considers the influence of the tap coefficients of the post-digital filter on the signal power spectrum in different frequency ranges. It calculates the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer, obtaining the signal power spectrum envelope curves before and after linear equalization. Then, it determines the third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups. Based on the distribution of the signal power spectrum envelope curves before and after linear equalization and the third signal power spectrum envelope curves, it determines the target tap coefficient group to be used by the post-digital filter. This allows the post-digital filter to equalize the high-frequency noise introduced by the linear equalizer under the target tap coefficient group, enabling the post-digital filter to adaptively select the optimal tap coefficient group. While achieving adaptive noise equalization, it effectively improves the response speed and efficiency of the linear equalizer's noise equalization, reduces the complexity of the linear equalizer's noise equalization, and improves the optical signal-to-noise ratio of the system.

[0066] Based on the above embodiments, as an optional embodiment, the optical communication system may further include an inter-symbol interference (ISI) equalizer;

[0067] The signal input terminal of the ISI equalizer is connected to the signal output terminal of the post-digital filter; the ISI equalizer is used to equalize the ISI introduced by the post-digital filter.

[0068] In an embodiment of the present invention, by connecting an ISI equalizer after the post-digital filter, the ISI introduced by the post-digital filter can be equalized. At the same time, the residual ISI that is not equalized at the front end can also be equalized, thereby further improving the ISI equalization effect of the entire optical communication system.

[0069] Based on the above embodiments, as an optional embodiment, in step 120, determining the third signal power spectrum envelope curve of the output signal of the digital filter under preset tap coefficient groups includes:

[0070] Once determined, the signal power spectrum of the output signal of the digital filter under each preset tap coefficient group is determined; the signal power spectrum is the signal power spectrum obtained after FFT transformation.

[0071] The power spectrum of each signal is divided into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks after the power spectrum of each signal is divided.

[0072] The signal power amplitude of each signal power spectral block in each signal power spectrum is averaged to determine the envelope value corresponding to each signal power spectral block in each signal power spectrum.

[0073] Based on the envelope values ​​corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is obtained.

[0074] Specifically, the preset number of frequency points described in the embodiments of the present invention can be set according to actual calculation needs.

[0075] In an embodiment of the present invention, the output signal of the post-digital filter under each preset tap coefficient group is acquired, and the signal power spectrum of the output signal corresponding to each tap coefficient group is calculated. Based on the obtained signal power spectrum, the signal power spectrum is divided into blocks of a preset number of consecutive frequency points, and the envelope curve of the signal power spectrum is calculated by averaging the results of the blocks.

[0076] Specifically, the power spectrum of each signal is divided into blocks according to a preset number of frequency points. For example, if the frequency range is 0 to 64 GHz, then 10 blocks are used. 9If each continuous frequency point is considered a block, then the 0-64 GHz range can be divided into 64 signal power spectral blocks, resulting in multiple signal power spectral blocks after each block is formed. By averaging the signal power amplitude of each signal power spectral block within each signal power spectral spectrum, the envelope value corresponding to each signal power spectral block in each signal power spectral spectrum can be calculated.

[0077] Furthermore, based on the envelope values ​​corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is obtained.

[0078] The method of this invention calculates the envelope curve of each signal power spectrum by dividing the power spectrum into blocks and averaging the power spectrum. This ensures the accuracy of the calculated signal power spectrum envelope curve and provides a reliable and accurate data source for the tap coefficient group of the digital filter after subsequent adaptive calculation.

[0079] Optionally, each preset tap coefficient group includes multiple first tap coefficient groups. In the multiple first tap coefficient groups, the first tap coefficient includes multiple values, and the second tap coefficient and the remaining multiple tap coefficients are fixed values.

[0080] After dividing the power spectrum of each signal into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks, the method further includes:

[0081] Determine the envelope value of each signal power spectrum block in the signal power spectrum corresponding to the minimum value in the first tap coefficient and the envelope value of each signal power spectrum block in the signal power spectrum corresponding to the maximum value in the first tap coefficient;

[0082] The method of linear equations is used to calculate the envelope value of each signal power spectrum block in the signal power spectrum corresponding to each target value in the first tap coefficient; the target value is any value in the first tap coefficient other than the minimum and maximum values;

[0083] Based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each first tap coefficient group is obtained.

[0084] Specifically, in this embodiment of the invention, the tap coefficient group includes a first tap coefficient, a second tap coefficient, and a plurality of remaining tap coefficients, which can be denoted as the 1st tap coefficient, the 2nd tap coefficient, ..., the Nth tap coefficient, for a total of N tap coefficients.

[0085] In embodiments of the present invention, each preset tap coefficient group includes multiple first tap coefficient groups. In each of the multiple first tap coefficient groups, the first tap coefficient includes multiple values, while the second to Nth tap coefficients have fixed values. Specifically, based on the principle of setting N tap coefficients, within the estimated range of the first tap coefficient, such as between 0 and 1, multiple values ​​of the first tap coefficient are sequentially set at fixed intervals. The second to Nth tap coefficients can be randomly selected and fixed within the estimated range, resulting in multiple sets of tap coefficient groups. The power spectrum of the output signal after FFT transformation of the digital filter with multiple sets of coefficient combinations is then extracted.

[0086] Furthermore, the power spectrum of each signal is divided into blocks according to a preset number of frequency points, resulting in multiple signal power spectrum blocks after each block. Then, within the estimated range, the first tap coefficients are sequentially set. For any signal power spectrum block, the change in the envelope value of the signal power spectrum after the post-digital filter is linear. Therefore, it is only necessary to calculate the envelope value of the signal power spectrum after the post-digital filter for that signal power spectrum block, using the first tap coefficients at the beginning and end of the preset estimated range. This determines the envelope value of the signal power spectrum corresponding to the minimum value among the first tap coefficients and the envelope value of the signal power spectrum corresponding to the maximum value among the first tap coefficients.

[0087] By constructing a two-point linear equation, the target values ​​within the remaining estimated range, i.e., the values ​​between the minimum and maximum values, can be substituted into this linear equation to obtain the envelope value corresponding to the signal power spectral block. Therefore, by using the linear equation method described above, the envelope value corresponding to each signal power spectral block in the signal power spectrum corresponding to each target value in the first tap coefficient can be calculated, thus obtaining the envelope value corresponding to each signal power spectral block in each signal power spectrum.

[0088] Furthermore, in this embodiment, based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the digital filter under each first tap coefficient group is generated.

[0089] The method of this invention, by considering that the change of the envelope value of the signal power spectrum after digital filtering is linear, adopts a linear equation method to quickly calculate the envelope value corresponding to each first tap coefficient, thereby obtaining the third signal power spectrum curve, reducing computational complexity and improving computational efficiency.

[0090] Similarly, in the embodiments of the present invention, each preset tap coefficient group includes multiple second tap coefficient groups. In the multiple second tap coefficient groups, the first tap coefficient is a fixed value. Within the estimated range, the second to the Nth tap coefficients are set in sequence to obtain multiple tap coefficient groups. The power spectrum of the output signal after the digital filter with multiple set coefficient combination values ​​is extracted and FFT transformed.

[0091] Furthermore, the power spectrum of each signal is divided into blocks according to a preset number of frequency points, resulting in multiple signal power spectrum blocks after each block. For the second to Nth tap coefficients, the change in the envelope value of the signal power spectrum after the post-digital filter is linear for any signal power spectrum block. Therefore, it is only necessary to calculate the envelope value of the signal power spectrum after the post-digital filter at the starting position of the second to Nth tap coefficients within the set prediction range, construct a linear equation, and substitute the values ​​within the remaining prediction range into the linear equation to obtain the envelope value of the signal power spectrum. Based on this method, the envelope value of the signal power spectrum corresponding to all signal power spectrum blocks is calculated, thereby obtaining the envelope value corresponding to each signal power spectrum block in each signal power spectrum.

[0092] Furthermore, in this embodiment, based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the digital filter under each second tap coefficient group is generated.

[0093] Based on the above embodiments, as an optional embodiment, the tap coefficient group includes a first tap coefficient, a second tap coefficient, and a plurality of remaining tap coefficients; in step 120, based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each third signal power spectrum envelope curve, a target tap coefficient group is determined from the preset tap coefficient groups, including:

[0094] Based on the tap coefficient group corresponding to the first target signal power spectrum envelope curve in each third signal power spectrum envelope curve, multiple candidate values ​​of the first tap coefficient in the target tap coefficient group are determined; the first target signal power spectrum envelope curve is the third signal power spectrum envelope curve distributed between the first signal power spectrum envelope curve and the second signal power spectrum envelope curve in the high frequency range of the signal power spectrum.

[0095] Based on the tap coefficient group corresponding to the second target signal power spectrum envelope curve in each third signal power spectrum envelope curve, determine the optimal second tap coefficient and the remaining multiple tap coefficients corresponding to each candidate value of the first tap coefficient; the second target signal power spectrum envelope curve is the third signal power spectrum envelope curve with the highest overlap with the first signal power spectrum envelope curve.

[0096] Based on the multiple candidate values ​​of the first tap coefficient, the optimal second tap coefficient corresponding to each candidate value of the first tap coefficient, and the remaining multiple tap coefficients, multiple pre-selected tap coefficient groups are obtained.

[0097] The target tap coefficient group is determined based on multiple pre-selected tap coefficient groups.

[0098] Specifically, the high-frequency range and intermediate-frequency range described in the embodiments of the present invention are the frequency ranges set in the FTN optical communication system of the present invention. The intermediate-frequency range can be divided into 3.2GHz to 44.8GHz, and the high-frequency range can be divided into 44.8GHz to 64GHz. The specific division can also be made according to actual calculation needs. That is to say, the division of the high-frequency range and intermediate-frequency range may be different in different optical communication systems. This application does not make specific limitations in this regard.

[0099] In an embodiment of the present invention, the first target signal power spectrum envelope curve is a third signal power spectrum envelope curve distributed between the first and second signal power spectrum envelope curves within the high-frequency range of the signal power spectrum. Specifically, the actual value of the first tap coefficient is determined by judging whether the third signal power spectrum envelope curve after the signal passes through the digital filter in the high-frequency range of the signal power spectrum is located between the envelope curves of the signal power spectrum before and after linear equalization, i.e., between the first and second signal power spectrum envelope curves. If the signal power spectrum envelope curve corresponding to a set of tap coefficients is located between the envelope curves of the signal power spectrum before and after linear equalization, i.e., the signal power spectrum envelope curve is the first target signal power spectrum envelope curve, it indicates that the value of the first tap coefficient in the set of tap coefficients meets the requirements. Thus, all possible values ​​of the first coefficient in the target tap coefficient set are obtained.

[0100] In the embodiments of the present invention, a post-digital filter with 3 taps is used as an example to illustrate the method flow of the embodiments of the present invention, but the present invention does not specifically limit the number of taps of the post-digital filter.

[0101] In this embodiment of the invention, the digital filter after the 3 taps has two tap coefficients, a and β. The estimated range of the first tap coefficient a is 0 to 1, and simulation verification shows that, as... Figure 2 As shown in Figure (A), in the signal frequency range of 0 to 64 GHz, the value of the first tap coefficient 'a' can be set between the estimated range of 0.05 and 0.5, and the selection interval can be set to 0.05. The second tap coefficient 'β' is as follows... Figure 2As shown in Figure (B), the phenomenon of intermediate frequency signal loss can be reduced by setting the value to less than 0. Simulation verification shows that when the value of the second tap coefficient β is reduced to -0.2, it is sufficient to meet the requirement of reducing intermediate frequency signal loss. Therefore, the value of the second tap coefficient β can be fixed at -0.2.

[0102] Subsequently, the power spectrum envelope curve of the third signal after passing through the post-digital filter was calculated when the second coefficient was set to -0.2 and the first coefficient was set to 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0.5 respectively.

[0103] Specifically, in the embodiments of the present invention, simulation verification revealed that under a certain frequency condition, the average power spectrum exhibits a linear relationship as the value of the first tap coefficient changes. Therefore, the average power spectrum can be calculated only at a certain frequency when the first tap coefficient is set to its minimum value of 0.05 and its maximum value of 0.5. A linear equation is then constructed, and the average power spectrum corresponding to the target values ​​of the remaining first tap coefficients can be calculated by substituting them into the linear equation. This yields the complete power spectrum envelope curve.

[0104] Furthermore, it is determined that the frequency is within the high-frequency range, and the power spectrum envelope curve after the digital filter lies between the power spectrum envelope curves of the signals after linear equalization and FFT transformation. For example, in this embodiment, after the above steps, the multiple candidate values ​​for the first tap coefficient in the determined target tap coefficient group are 0.05, 0.1, and 0.15, respectively.

[0105] Furthermore, in an embodiment of the present invention, the second target signal power spectrum envelope curve is the third signal power spectrum envelope curve with the highest degree of overlap with the first signal power spectrum envelope curve. Specifically, by determining the degree of overlap between the signal power spectrum envelope curve before linear equalization and the signal power spectrum envelope curve after digital filtering over the entire frequency range of the signal power spectrum, and the degree of overlap between the third signal power spectrum envelope curve and the first signal power spectrum envelope curve, the optimal values ​​of the second to Nth tap coefficients corresponding to each candidate value of the first tap coefficient can be selected. Thus, based on the multiple candidate values ​​of the first tap coefficient and the optimal second to Nth tap coefficients corresponding to each candidate value of the first tap coefficient, multiple sets of suitable combinations of N tap coefficient values ​​can be obtained, i.e., multiple pre-selected tap coefficient sets can be obtained.

[0106] If the third signal power spectrum envelope curve after passing through a digital filter with a set of tap coefficients has the highest overlap with the envelope curve of the signal power spectrum before linear equalization, then the third signal power spectrum envelope curve is determined as the second target signal power spectrum envelope curve. Therefore, based on the tap coefficient set corresponding to the second target signal power spectrum envelope curve in each third signal power spectrum envelope curve, the optimal second to Nth tap coefficients are determined, indicating that under the first tap coefficient of the tap coefficient set, the combination of the second to Nth tap coefficients is optimal.

[0107] Specifically, in this embodiment, when the first tap coefficient 'a' is set to a fixed value, the value of the second tap coefficient 'β' is set within the estimated range of -0.2 to 0 at a certain frequency. It can be found that the average power spectrum shows a linear law. Only the average power spectrum at a certain frequency when the second tap coefficient 'β' is set to -0.2 and 0 can be calculated, and then a linear equation can be constructed. The average power spectrum of the remaining values ​​of the second coefficient 'β' can be calculated by substituting them into the linear equation, thereby obtaining the complete power spectrum envelope curve.

[0108] Furthermore, the degree of overlap between the first signal power spectrum envelope curve before linear equalization and the third signal power spectrum envelope curve after digital filtering is determined, with the first tap coefficient fixed at 0.05. The degree of overlap is obtained by calculating the correlation coefficient between the power spectrum envelopes of the signal after digital filtering and the signal before linear equalization for different tap coefficient sets. A larger correlation coefficient indicates a greater degree of overlap.

[0109] For example, when the first tap coefficient a is a candidate value of 0.05 and the second tap coefficient β is -0.14, the overlap of the signal power spectrum envelope curve is the largest, and a set of pre-selected tap coefficients a = 0.05 / β = -0.14 can be determined; and so on, the optimal tap coefficient β corresponding to each candidate value of the first tap coefficient a can be obtained, thus obtaining each set of pre-selected tap coefficients.

[0110] Figure 3 This is a schematic diagram illustrating the overlap pattern of the signal power spectrum envelope curves under different tap coefficient groups provided by the present invention, as shown in the figure. Figure 3 As shown, the tap coefficient groups with the largest correlation coefficients corresponding to the first tap coefficient 'a' in each tap coefficient group are a = 0.05 / β = -0.14, a = 0.1 / β = -0.13, and a = 0.15 / β = -0.17, respectively. These tap coefficient groups are the pre-selected tap coefficient groups.

[0111] Furthermore, in this embodiment, the target tap coefficient group of the digital filter is determined from the multiple pre-selected tap coefficient groups calculated above.

[0112] Based on the above embodiments, as an optional embodiment, determining the target tap coefficient group based on multiple pre-selected tap coefficient groups includes:

[0113] Once the signal power spectrum of the output signal of the digital filter under each preselected tap coefficient group is determined, the average signal power spectrum of the output signal under each preselected tap coefficient group is calculated to obtain the mean signal power spectrum corresponding to each preselected tap coefficient group.

[0114] The target tap coefficient set is obtained based on the preselected tap coefficient set corresponding to the maximum mean signal power spectrum.

[0115] Specifically, in the embodiments of the present invention, the signal power spectrum of the output signal of the digital filter under each pre-selected tap coefficient group is extracted, and the signal power spectrum of the output signal under each pre-selected tap coefficient group is averaged to calculate the mean of the signal power spectrum. Based on the magnitude of the mean, the optimal combination of N tap coefficients is selected.

[0116] In an embodiment of the present invention, the preselected tap coefficient group corresponding to the maximum mean of the signal power spectrum is the optimal combination of N tap coefficients, which is the target tap coefficient group of the post-digital filter. In an embodiment of the present invention, the target tap coefficient group corresponding to the maximum mean of the signal power spectrum selected from the preselected tap coefficient groups a = 0.05 / β = -0.14, a = 0.1 / β = -0.13, and a = 0.15 / β = -0.17 is a = 0.1 / β = -0.13.

[0117] In this embodiment of the invention, by calculating the mean of the signal power spectrum to determine the optimal combination of N tap coefficients, it can be ensured that the post-digital filter obtains the best noise equalization effect under the optimal tap coefficient group.

[0118] The method of this invention, by considering the different patterns of each tap coefficient of the post-digital filter on the signal power spectrum in the high-frequency and mid-frequency ranges, and based on the distribution relationship between the signal power spectrum envelope curve of the output signal before and after linear equalization and the signal power spectrum envelope curve after the post-digital filter, finds the optimal combination of tap coefficients that can be adjusted to achieve better noise equalization effect of the post-digital filter, which greatly improves the noise equalization performance of the post-digital filter.

[0119] In an embodiment of the present invention, simulation verification was performed in a BTB-128Gbaud system with a channel spacing of 137.5GHz. The ISI equalizer uses the Maximum-Likelihood Sequence Detection (MLSD) algorithm and sets the number of taps to 3 or 5. Figure 4Figures (A), (B), and (C) show the simulation performance comparison results of the method of this embodiment and three prior art methods under system speedup factors of 0.95, 0.9, and 0.85, respectively. The system structure of the method of this embodiment is the structure of a 3-tap post-digital filter and a 3-tap ISI equalizer that can achieve adaptive equalization in the aforementioned embodiments. Prior art 1 is a method without a post-digital filter and MLSD algorithm; prior art 2 is a structure of a traditional 2-tap post-digital filter and a 5-tap ISI equalizer; and prior art 3 is a structure of a traditional 3-tap post-digital filter and a 3-tap ISI equalizer.

[0120] Continue to refer to Figure 4 ,like Figure 4 As shown in Figures (A), (B), and (C), compared to the method of prior art 1, the method of the embodiments of the present invention achieves OSNR improvements of 0.1 dB, 0.35 dB, and 0.9 dB at acceleration factors of 0.95, 0.9, and 0.85, respectively; compared to the method of prior art 2, the method of the embodiments of the present invention achieves OSNR improvements of 0.04 dB, 0.15 dB, and 0.2 dB at acceleration factors of 0.95, 0.9, and 0.85, respectively; compared to the method of prior art 3, the method of the embodiments of the present invention shows no significant performance loss at acceleration factors of 0.95, 0.9, and 0.85, but its complexity is 3.7% of that of prior art 3.

[0121] The adaptive equalization device for optical communication systems provided by the present invention is described below. The adaptive equalization device for optical communication systems described below and the adaptive equalization method for optical communication systems described above can be referred to in correspondence.

[0122] Figure 5 This is a schematic diagram of the adaptive equalization device for an optical communication system provided by the present invention. The optical communication system includes a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter. The received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, and the post-digital filter. As shown in the figure, the adaptive equalization device includes:

[0123] The first processing module 510 is used to determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer.

[0124] The second processing module 520 is used to determine the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group, and to determine the target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each third signal power spectrum envelope curve.

[0125] The first update module 530 is used to update the tap coefficient group of the digital filter to the target tap coefficient group so that the digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer.

[0126] The adaptive equalization device for optical communication systems described in this embodiment can be used to execute the adaptive equalization method embodiment for optical communication systems described above. Its principle and technical effects are similar, and will not be repeated here.

[0127] The adaptive equalization device for optical communication systems in this invention considers the influence of the tap coefficients of the post-digital filter on the signal power spectrum in different frequency ranges. It calculates the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer, obtaining the signal power spectrum envelope curves before and after linear equalization. Then, it determines the third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups. Based on the distribution of the signal power spectrum envelope curves before and after linear equalization and the third signal power spectrum envelope curves, it determines the target tap coefficient group to be used by the post-digital filter. This allows the post-digital filter to equalize the high-frequency noise introduced by the linear equalizer under the target tap coefficient group, enabling the post-digital filter to adaptively select the optimal tap coefficient group. While achieving noise equalization, it effectively improves the response speed and efficiency of the linear equalizer's noise equalization, reduces the complexity of the linear equalizer's noise equalization, and improves the optical signal-to-noise ratio of the system.

[0128] Figure 6 This is a schematic diagram of the optical communication system provided by the present invention, as shown below. Figure 6 As shown, the optical communication system includes a dispersion compensator, a linear equalizer, a carrier recovery module, a post-digital filter, an ISI equalizer, and an adaptive equalizer. The received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, the post-digital filter, and the ISI equalizer.

[0129] The adaptive equalization device is used to execute the adaptive equalization method for optical communication systems in the above embodiments, including: determining the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer; determining the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group, and determining the target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each third signal power spectrum envelope curve; updating the tap coefficient group of the post-digital filter to the target tap coefficient group, so that the post-digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer.

[0130] The ISI equalizer is used to further equalize the ISI introduced by the post-digital filter and the residual ISI from the front end, thereby improving the ISI equalization effect of the system.

[0131] Figure 7 This is a schematic diagram of the physical structure of the electronic device provided by the present invention, such as... Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other through the communication bus 740. The processor 710 can call logic instructions in the memory 730 to execute the adaptive equalization method for optical communication systems provided by the above methods. The method includes: determining a first signal power spectrum envelope curve of the stored signal of the dispersion compensator and a second signal power spectrum envelope curve of the output signal of the linear equalizer; determining a third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups, and determining a target tap coefficient group from the preset tap coefficient groups based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each of the third signal power spectrum envelope curves; updating the tap coefficient group of the post-digital filter to the target tap coefficient group, so that the post-digital filter can complete the equalization of high-frequency noise introduced by the linear equalizer.

[0132] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0133] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the adaptive equalization method for optical communication systems provided by the above methods. The method includes: determining a first signal power spectrum envelope curve of the stored signal of the dispersion compensator and a second signal power spectrum envelope curve of the output signal of the linear equalizer; determining a third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups, and determining a target tap coefficient group from the preset tap coefficient groups based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each of the third signal power spectrum envelope curves; updating the tap coefficient group of the post-digital filter to the target tap coefficient group, so that the post-digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer.

[0134] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements an adaptive equalization method for an optical communication system provided by the methods described above. This method includes: determining a first signal power spectrum envelope curve of the stored signal of the dispersion compensator and a second signal power spectrum envelope curve of the output signal of the linear equalizer; determining a third signal power spectrum envelope curve of the output signal of the post-digital filter under preset tap coefficient groups, and, based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each of the third signal power spectrum envelope curves, determining a target tap coefficient group from the preset tap coefficient groups; updating the tap coefficient group of the post-digital filter to the target tap coefficient group, so that the post-digital filter can complete the equalization of high-frequency noise introduced by the linear equalizer.

[0135] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive equalization method for optical communication systems, characterized in that, The optical communication system includes a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter; the received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, and the post-digital filter. The method includes: Determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer; The third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is determined, and the target tap coefficient group is determined from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each of the third signal power spectrum envelope curves. The tap coefficient group of the post-digital filter is updated to the target tap coefficient group so that the post-digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer. The tap coefficient group includes a first tap coefficient, a second tap coefficient, and multiple remaining tap coefficients; determining the target tap coefficient group from the preset tap coefficient groups based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each of the third signal power spectrum envelope curves includes: Based on the tap coefficient group corresponding to the first target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, multiple candidate values ​​of the first tap coefficient in the target tap coefficient group are determined; the first target signal power spectrum envelope curve is the third signal power spectrum envelope curve distributed between the first signal power spectrum envelope curve and the second signal power spectrum envelope curve in the high frequency range of the signal power spectrum. Based on the tap coefficient group corresponding to the second target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, the optimal second tap coefficient and the remaining multiple tap coefficients corresponding to each candidate value of the first tap coefficient are determined; the second target signal power spectrum envelope curve is the third signal power spectrum envelope curve with the highest overlap with the first signal power spectrum envelope curve. Based on the multiple candidate values ​​of the first tap coefficient, the optimal second tap coefficient corresponding to each candidate value of the first tap coefficient, and the remaining multiple tap coefficients, multiple pre-selected tap coefficient groups are obtained. Based on the multiple pre-selected tap coefficient groups, the target tap coefficient group is determined.

2. The adaptive equalization method for optical communication systems according to claim 1, characterized in that, Determining the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group includes: The signal power spectrum of the output signal of the post-digital filter under each preset tap coefficient group is determined; the signal power spectrum is the signal power spectrum obtained by fast Fourier transform processing; The power spectrum of each signal is divided into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks after the power spectrum of each signal is divided. The signal power amplitude of each signal power spectral block in each signal power spectrum is averaged to determine the envelope value corresponding to each signal power spectral block in each signal power spectrum. Based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group is obtained.

3. The adaptive equalization method for optical communication systems according to claim 1, characterized in that, Based on the multiple pre-selected tap coefficient groups, the target tap coefficient group is determined, including: The signal power spectrum of the output signal of the post-digital filter under each of the preselected tap coefficient groups is determined, and the signal power spectrum of the output signal under each of the preselected tap coefficient groups is averaged to obtain the mean signal power spectrum of each of the preselected tap coefficient groups. The target tap coefficient group is obtained based on the preselected tap coefficient group corresponding to the largest mean of the signal power spectrum.

4. The adaptive equalization method for optical communication systems according to claim 2, characterized in that, The preset tap coefficient groups include multiple first tap coefficient groups. In the multiple first tap coefficient groups, the first tap coefficient includes multiple values, and the second tap coefficient and the remaining multiple tap coefficients are fixed values. After dividing each of the signal power spectra into blocks according to a preset number of frequency points to obtain multiple signal power spectrum blocks after each signal power spectrum block, the method further includes: Determine the envelope value corresponding to each signal power spectrum block in the signal power spectrum corresponding to the minimum value in the first tap coefficient and the envelope value corresponding to each signal power spectrum block in the signal power spectrum corresponding to the maximum value in the first tap coefficient; The method of linear equations is used to calculate the envelope value of each signal power spectrum block in the signal power spectrum corresponding to each target value in the first tap coefficient; the target value is any value in the first tap coefficient other than the minimum value and the maximum value; Based on the envelope value corresponding to each signal power spectrum block in each signal power spectrum, the third signal power spectrum envelope curve of the output signal of the post-digital filter under each first tap coefficient group is obtained.

5. The adaptive equalization method for optical communication systems according to any one of claims 1-4, characterized in that, The optical communication system also includes an inter-symbol interference equalizer; The signal input terminal of the inter-symbol interference equalizer is connected to the signal output terminal of the post-digital filter; the inter-symbol interference equalizer is used to equalize the inter-symbol interference introduced by the post-digital filter.

6. An adaptive equalization device for an optical communication system, characterized in that, The optical communication system includes a dispersion compensator, a linear equalizer, a carrier recovery module, and a post-digital filter; the received signal is transmitted sequentially through the dispersion compensator, the linear equalizer, the carrier recovery module, and the post-digital filter. The adaptive equalization device includes: The first processing module is used to determine the first signal power spectrum envelope curve of the stored signal of the dispersion compensator and the second signal power spectrum envelope curve of the output signal of the linear equalizer. The second processing module is used to determine the third signal power spectrum envelope curve of the output signal of the post-digital filter under each preset tap coefficient group, and to determine the target tap coefficient group from each preset tap coefficient group based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve and each of the third signal power spectrum envelope curves. The first update module is used to update the tap coefficient group of the post-digital filter to the target tap coefficient group so that the post-digital filter can complete the equalization of the high-frequency noise introduced by the linear equalizer. The tap coefficient group includes a first tap coefficient, a second tap coefficient, and multiple remaining tap coefficients; determining the target tap coefficient group from the preset tap coefficient groups based on the distribution of the first signal power spectrum envelope curve, the second signal power spectrum envelope curve, and each of the third signal power spectrum envelope curves includes: Based on the tap coefficient group corresponding to the first target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, multiple candidate values ​​of the first tap coefficient in the target tap coefficient group are determined; the first target signal power spectrum envelope curve is the third signal power spectrum envelope curve distributed between the first signal power spectrum envelope curve and the second signal power spectrum envelope curve in the high frequency range of the signal power spectrum. Based on the tap coefficient group corresponding to the second target signal power spectrum envelope curve in each of the third signal power spectrum envelope curves, the optimal second tap coefficient and the remaining multiple tap coefficients corresponding to each candidate value of the first tap coefficient are determined; the second target signal power spectrum envelope curve is the third signal power spectrum envelope curve with the highest overlap with the first signal power spectrum envelope curve. Based on the multiple candidate values ​​of the first tap coefficient, the optimal second tap coefficient corresponding to each candidate value of the first tap coefficient, and the remaining multiple tap coefficients, multiple pre-selected tap coefficient groups are obtained. Based on the multiple pre-selected tap coefficient groups, the target tap coefficient group is determined.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the adaptive equalization method for optical communication systems as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the adaptive equalization method for optical communication systems as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the adaptive equalization method for optical communication systems as described in any one of claims 1 to 5.

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