Wavelength division isolation anti-interference method and system for radio frequency optical network front return signal

Abstract

The invention discloses a wavelength division isolation anti-interference method and system for a radio frequency optical network front return signal, and the method comprises the steps: introducing an interference monitoring system which represents the quality of a radio frequency signal and the power optical noise at the same time, and constructing a wavelength interference matrix of the normalized interference intensity between any wavelength channel pairs according to the interference monitoring system; carrying out topology analysis based on the matrix, calculating the interference degree and automatically dividing interference clusters of high-interference channels to realize global perception and quantitative description of a common-fiber link interference relationship; target wavelength configuration parameters of the central wavelength, the wavelength interval, the guard band width and the optical filter bandwidth of each channel are adaptively determined by using the interference matrix and the interference cluster result, and differential widening and frequency shift are performed on the channels in the interference cluster; and finally, by controlling the adjustable light source and the adjustable optical filter, the wavelength division configuration is dynamically reconstructed along with the interference environment. Therefore, in an ARoF + PoF common-fiber transmission scene, both the anti-interference capability of the radio frequency signal and the frequency spectrum utilization rate of the optical fiber can be considered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency optical communication control, and in particular to a wavelength division isolation anti-interference method for front-haul and backhaul signals of a radio frequency optical network, a front-haul and backhaul network and a system. BACKGROUND

[0002] With the evolution of 5G mobile communication networks towards high bandwidth, low latency and large-scale antenna arrays, radio frequency optical transmission (especially analog Radio-over-Fiber, ARoF) gradually becomes an important implementation form of front-haul and backhaul links. By transmitting millimeter wave and higher frequency band radio frequency signals in optical fibers, the structure of remote radio units can be significantly simplified, the flexibility of site deployment can be improved, and the architecture of cloud-based and centralized wireless access networks can be matched. In actual engineering deployment, multiple radio frequency carriers are usually transmitted in the same optical fiber in a wavelength division multiplexing (Wavelength Division Multiplexing, WDM) manner to meet the capacity requirements of multiple sectors, multiple standards, and multiple frequency bands coexisting.

[0003] On the other hand, in order to reduce the power supply cost and wiring complexity of remote active devices, a power-over-fiber (Power-over-Fiber, PoF) scheme is introduced into the front-haul and backhaul system, and a high-power continuous wave light is used to supply power to the remote radio module in the same optical fiber, thereby forming a composite link structure in which multiple radio frequency signals and high-power supply light are co-transmitted. Although this structure improves the system integration and deployment flexibility, it significantly aggravates the coupling of optical fiber nonlinear effects and power light noise on radio frequency data signals.

[0004] In the current design, engineering usually suppresses nonlinear crosstalk such as four-wave mixing (Four-Wave Mixing, FWM) and cross-phase modulation (Cross-Phase Modulation, XPM) by increasing channel spacing, reserving fixed guard bands, configuring static optical filters, and using dispersion compensation, and tries to minimize the impact of supply light on data signals. However, the above suppression strategies are usually based on conservative assumptions about the most unfavorable interference scenarios to configure static margins: on the one hand, a large amount of available spectral resources need to be sacrificed, resulting in low fiber spectral utilization; on the other hand, 5G traffic load and topology are highly dynamic, and the number of channels, service types, and transmission power change over time, so static guard bands and fixed filter configurations are difficult to continuously match real-time interference environments. SUMMARY

[0005] The application provides a wavelength division isolation anti-interference method for a radio frequency optical network front-haul signal, a front-haul network, a system, a storage medium, a computer program product and an electronic device, to at least solve the problem that in the related art, it is difficult to balance nonlinear interference suppression and optical fiber spectrum efficient utilization in a PoF and multi-path radio frequency optical co-fiber transmission scenario.

[0006] In a first aspect, the embodiments of the application provide a wavelength division isolation anti-interference method for a radio frequency optical network front-haul signal, applied to a front-haul network for transmitting radio frequency optical signals and power light in an optical fiber link through wavelength division multiplexing, the method comprising: obtaining interference monitoring data of each wavelength channel in the optical fiber link, the interference monitoring data at least including a signal quality index for characterizing the quality of each radio frequency optical signal and a power light noise index for characterizing the noise of the power light; determining the interference strength between each wavelength channel based on the interference monitoring data, and constructing a wavelength interference matrix for characterizing the interference relationship between each wavelength channel; the matrix elements in the wavelength interference matrix are used to characterize the normalized interference strength between any two wavelength channels; based on the wavelength interference matrix, the interference strength of each wavelength channel is topologically analyzed, the interference degree index of each wavelength channel is calculated, and at least one interference cluster composed of wavelength channels with interference strength higher than a preset interference threshold is identified according to the interference threshold; based on the wavelength interference matrix and the at least one interference cluster, the target wavelength configuration parameters are adaptively determined according to the interference strength between each wavelength channel, so that in the target wavelength configuration parameters, the wavelength spacing and / or guard band width corresponding to the wavelength channels belonging to the interference cluster are greater than the wavelength spacing and / or guard band width of the wavelength channels not belonging to the interference cluster; wherein the target wavelength configuration parameters include: the center wavelength of each wavelength channel, the wavelength spacing between adjacent wavelength channels, the guard band width on both sides of each wavelength channel, and the optical filter bandwidth for filtering each wavelength channel; the adjustable light source and the adjustable optical filter in the front-haul network are controlled according to the target wavelength configuration parameters, the center wavelength and the optical filter bandwidth of each wavelength channel are adjusted, so that the adjusted each wavelength channel works under the target wavelength configuration parameters.

[0007] In a second aspect, the embodiments of the present application provide a wavelength division isolation anti-interference system for a radio frequency optical network front backhaul signal, the system comprising: an interference monitoring data acquisition unit configured to acquire interference monitoring data of each wavelength channel in an optical fiber link, the interference monitoring data comprising at least a signal quality index for representing a quality of each radio frequency optical signal and a power optical noise index for representing a power optical noise; a wavelength interference matrix construction unit configured to determine interference intensities between each wavelength channel based on the interference monitoring data, and construct a wavelength interference matrix for representing interference relationships between each wavelength channel, wherein a matrix element in the wavelength interference matrix is configured to represent a normalized interference intensity between any two wavelength channels; an interference topology analysis unit configured to perform a topology analysis on the interference intensities of each wavelength channel based on the wavelength interference matrix, calculate an interference degree index of each wavelength channel, and identify at least one interference cluster formed by wavelength channels with interference intensities higher than a preset interference threshold according to the interference threshold; a target wavelength configuration determination unit configured to determine target wavelength configuration parameters adaptively according to the interference intensities between each wavelength channel based on the wavelength interference matrix and the at least one interference cluster, so that in the target wavelength configuration parameters, a wavelength spacing and / or a guard band width corresponding to a wavelength channel belonging to the interference cluster is greater than a wavelength spacing and / or a guard band width of a wavelength channel not belonging to the interference cluster, wherein the target wavelength configuration parameters comprise a center wavelength of each wavelength channel, a wavelength spacing between adjacent wavelength channels, a guard band width on both sides of each wavelength channel, and an optical filter bandwidth for filtering each wavelength channel; and a wavelength and filter control unit configured to control adjustable optical sources and adjustable optical filters in the front backhaul network according to the target wavelength configuration parameters, and adjust the center wavelength and the optical filter bandwidth of each wavelength channel, so that each wavelength channel after adjustment operates under the target wavelength configuration parameters.

[0008] In a third aspect, the embodiments of the present application provide a front-haul network, comprising: integrated photonic chips deployed at each remote radio unit, and a central controller in communication connection with each integrated photonic chip; each integrated photonic chip has an adjustable laser, a micro-ring resonator array and a photodetector integrated thereon; the adjustable laser is configured to emit an optical carrier carrying a radio frequency optical signal and / or power light on a corresponding wavelength channel according to a center wavelength of each wavelength channel in a target wavelength configuration parameter; the micro-ring resonator array is configured to perform band-pass filtering on the optical signal entering each wavelength channel according to an optical filter bandwidth and a guard bandwidth of each wavelength channel in the target wavelength configuration parameter, to form an adjustable wavelength channel filtering characteristic; the photodetector is configured to receive a part of the optical power branched out by an optical splitter in a fiber link where each wavelength channel is located and perform photoelectric conversion to generate interference monitoring data containing a signal quality index and a power light noise index; and the central controller is configured to execute the method according to any one of the above embodiments of the present application to determine the target wavelength configuration parameter based on the interference monitoring data during operation, and control the adjustable laser and the micro-ring resonator array to make the front-haul network work under the target wavelength configuration parameter.

[0009] In a fourth aspect, an electronic device is provided, comprising: at least one processor, and a memory in communication connection with the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the wavelength division isolation anti-interference method for a radio frequency optical network front-haul signal according to any one of the embodiments of the present application.

[0010] In a fifth aspect, the embodiments of the present application provide a storage medium having a computer program stored thereon, characterized in that the program is executed by a processor to implement the steps of the wavelength division isolation anti-interference method for a radio frequency optical network front-haul signal according to any one of the embodiments of the present application.

[0011] In a sixth aspect, the embodiments of the present application provide a computer program product, comprising computer programs / instructions, which are executed by a processor to implement the steps of the wavelength division isolation anti-interference method for a radio frequency optical network front-haul signal according to any one of the embodiments of the present application.

[0012] The wavelength division isolation anti-interference method and system for a radio frequency optical network front-haul signal provided by the present application can at least produce the following technical effects:

[0013] (1) By jointly monitoring the radio frequency signal quality indicators and power optical noise indicators of each wavelength channel in the optical fiber link, a wavelength interference matrix is constructed to represent the normalized interference intensity between any two wavelength channels, and on this basis, topology analysis is performed to obtain the interference degree indicators of each channel and identify the interference clusters. Thus, the nonlinear crosstalk relationship between the radio frequency optical channels and the power optical noise coupling relationship are uniformly quantitatively described and globally characterized, not only accurately identifying the channel set with high interference intensity from the overall perspective of the link, but also distinguishing the channels with significantly weaker interference relationship, ensuring the pertinence and effectiveness of interference suppression and resource allocation.

[0014] (2) Based on the above interference matrix and interference clusters, the target wavelength configuration parameters are adaptively determined based on the interference intensity between the wavelength channels, and the center wavelength, adjacent interval, guard band width and optical filter bandwidth of each channel are adjusted cooperatively by controlling the adjustable optical source and adjustable optical filter. Among them, the wavelength channels belonging to the interference cluster adopt relatively larger wavelength interval and / or guard band width, and can be matched with more stringent filter bandwidth configuration, while the channels not belonging to the interference cluster maintain relatively compact interval and bandwidth configuration. Through this differentiated configuration method according to the interference clusters, on the one hand, the nonlinear products and power optical noise between the high interference channels are mainly weakened, which improves the radio frequency transmission quality and link margin of the key channels; on the other hand, the guard band and filter bandwidth of the channels with weak interference are not excessively expanded, fully releasing the available spectrum resources, so that the overall link realizes high spectrum utilization efficiency while ensuring the anti-interference performance, and can be adaptively adjusted with the change of business load and power optical working state.

[0015] Through the technical scheme, in the ARoF and PoF composite co-fiber transmission scenario, the wavelength interference matrix and the interference cluster are taken as the center, the interference relationship is modeled and the interference cluster is identified, and the adjustable devices are adjusted through parameter adaptive configuration, so that the key wavelength division isolation parameters such as wavelength interval, guard band width and filter bandwidth are no longer statically reserved, but are dynamically optimized and configured according to the actual interference environment. Thus, without changing the physical structure of the existing optical fiber link, fine suppression of the interference of multiple radio frequency optical signals and power optical co-fiber transmission and efficient scheduling of spectrum resources are realized, and the stability and expansion capability of the front-haul network under the condition of high bandwidth and high power supply are improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 FIG. 1 shows a flow chart of an example of a wavelength division isolation anti-jamming method for radio over fiber network front-haul signals according to an embodiment of the present application;

[0018] Figure 2 FIG. 2 shows an operation flow chart of an example of a wavelength division isolation anti-jamming method with a periodic iterative closed-loop regulation mechanism according to an embodiment of the present application;

[0019] Figure 3 FIG. 3 shows an operation flow chart of an example of dividing at least one interference cluster based on a wavelength interference matrix according to an embodiment of the present application;

[0020] Figure 4 FIG. 4 shows an operation flow chart of an example of adaptively determining target wavelength configuration parameters based on a wavelength interference matrix and at least one interference cluster according to an embodiment of the present application;

[0021] Figure 5 FIG. 5 shows an operation flow chart of an example of adjusting output power of a power light source according to an embodiment of the present application;

[0022] Figure 6 FIG. 6 shows a structural block diagram of an example of a front-haul network according to an embodiment of the present application;

[0023] Figure 7 FIG. 7 shows an operation mechanism flow chart of an example of a wavelength division isolation anti-jamming method for radio over fiber network front-haul signals according to an embodiment of the present application;

[0024] Figure 8 FIG. 8 shows a schematic diagram of an example of a comparison result of total crosstalk power of different methods changing with iteration number;

[0025] Figure 9 FIG. 9 shows a comparison result of a normalized crosstalk matrix of an 8-channel radio over fiber front-haul system;

[0026] Figure 10 FIG. 10 shows a structural block diagram of an example of a wavelength division isolation anti-jamming system for radio over fiber network front-haul signals according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to clearly and completely describe the technical solutions of the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0028] It should be noted that in the prior art, the processing of fiber nonlinear interference in the front-haul scenario is mostly focused on the local optimization of a certain type of physical mechanism. For example, some researches start from the third-order nonlinear effects such as four-wave mixing, and propose to reduce the crosstalk between different wavelength radio frequency optical carriers by increasing the channel spacing, improving the dispersion coefficient or reducing the transmission power. Some schemes also try to use rectangular optical filters, external modulation structures and the like to suppress the mixing sidelobes. However, the above measures are mostly based on a fixed wavelength grid and a preset worst-case scenario, and the parameters are determined only once at the link planning stage, which is difficult to reflect the changes in business load and power distribution in a timely manner. At the same time, in order to ensure that the indicators can still be met in extreme scenarios, part of the available spectrum resources has to be sacrificed, and the fiber spectrum utilization rate is obviously limited.

[0029] For cross-phase modulation and other nonlinear interferences that vary with power and dispersion, some works try to reduce the phase crosstalk by selecting a specific dispersion map, adding a dispersion compensation module at each span, or optimizing the fiber type. Some researches also discuss the use of multimode fiber or ultra-low loss fiber in the front-haul link to improve the overall transmission performance from the system architecture level. However, such methods often require the introduction of additional devices and complex link design, increasing the construction and maintenance costs, and mainly focus on the nonlinear interaction between signal lights, lacking systematic processing of the beat noise, mode splitting noise and other coupling problems generated when power light and radio frequency data signals are co-transmitted in the fiber.

[0030] In the power fiber power supply aspect, some researches show that the longitudinal mode beat noise and mode splitting noise of high-power continuous wave power supply light will be transferred to the radio frequency data signal through dispersion and nonlinear effects when co-transmitted in the fiber, causing the bit error rate, vector amplitude error and other indicators to deteriorate as the power of the power supply light increases. Existing schemes mostly improve the PoF power supply performance from the perspective of improving the photoelectric conversion efficiency and optimizing the power budget, but pay less attention to the quantitative modeling and suppression mechanism of the "power light noise-wave division radio frequency signal" coupling channel, and usually only use the method of reducing the power of the power supply light or increasing the fixed guard band for coarse-grained isolation, which is difficult to balance the power supply efficiency and interference suppression.

[0031] In addition, in the design of wavelength spacing and guard band width, some WDM systems use fixed spacing, fixed guard band or simple "non-equidistant" rules to reduce the influence of certain nonlinear effects. In the radio frequency optical front-haul scenario, front-haul and backhaul, multi-standard and multi-band services are often configured in pairs, and symmetric wavelength arrangement and static optical filter parameters are often used in engineering. With the change of time, the number of channels carrying radio frequency light, the type of service and the transmission power of each channel will fluctuate significantly. The above static configuration cannot accurately reflect the current inter-channel interference relationship, and can only reserve a large amount of guard bandwidth and filter margin, which not only wastes spectrum, but also is difficult to respond to the interference deterioration caused by the superposition of power light noise and multi-channel crosstalk in a timely manner.

[0032] Overall, the current related technology usually separates the wavelength division multiplexing interference between radio frequency lights and the noise coupling of power light to radio frequency data signal: the former is optimized offline through fixed wavelength planning and linear / nonlinear compensation model, and the latter is isolated through simple power limitation or static guardband configuration, lacking a dynamic anti-interference mechanism that uniformly quantizes, real-time monitors and drives the multi-dimensional parameters such as light source wavelength, guardband width, filter bandwidth and power light output in the same framework. This defect makes it difficult for radio frequency light front-haul systems to meet the comprehensive needs of high bandwidth, high spectrum utilization and low interference in complex and time-varying interference environments.

[0033] It should be understood that the purpose of the above description of the current related technology is only to facilitate the public to better understand the spirit and motives of the application, and is not considered as a limitation of the application. In addition, the technical solutions described in the above current related technology are not prior art, and can also be undisclosed technical solutions, such as solutions under research or in the laboratory stage.

[0034] In the technical solutions of the present application, the collection, storage, use, processing, transmission, provision and disclosure of user personal information, etc. involved in the technical solutions comply with the relevant legal regulations and do not violate public order and good customs.

[0035] Figure 1 A flowchart of an example of a wavelength division isolation anti-interference method for radio frequency light network front-haul signals according to an embodiment of the present application is shown.

[0036] Regarding the execution subject of the method of the present application, it can be any controller or processor with computing or processing capability, which can be a front-haul network that transmits radio frequency light signals and power light through wavelength division multiplexing in a fiber link, such as a centralized wavelength resource management controller in the front-haul network, which obtains interference monitoring data of each wavelength channel in the fiber link, constructs a wavelength interference matrix and identifies an interference cluster by executing program instructions stored in its storage medium, and then issues target wavelength configuration parameters to adjustable light sources and adjustable optical filters, so that the front-haul network adaptively adjusts the center wavelength, wavelength interval and guardband width of each wavelength channel during the co-fiber transmission of multiple radio frequency light signals and power light, thereby enhancing the anti-interference ability of the link and improving the utilization efficiency of the fiber spectrum resource.

[0037] In some examples, it can be integrated and configured in an electronic device or terminal by software, hardware or a combination of software and hardware, and the type of terminal or electronic device can be diversified.

[0038] As Figure 1As shown, in step S110, interference monitoring data of each wavelength channel in the fiber link is acquired, and the interference monitoring data at least includes a signal quality index for characterizing the quality of each radio frequency optical signal and a power optical noise index for characterizing the power optical noise.

[0039] In some embodiments, an interference monitoring module can be arranged at a centralized side device or a convergence node of the front backhaul fiber link, and online monitoring is performed by leading out a small part of optical power on the optical path of each wavelength channel (for example, using a 1:99 or 2:98 optical splitter). For each wavelength channel carrying a radio frequency optical signal, a signal quality index for characterizing the link transmission quality can be acquired after photoelectric conversion, such as a bit error rate (BER), a block error rate (BLER), an error vector magnitude (EVM), a carrier-to-noise ratio (CNR), a distortion index (such as a third-order intermodulation product power), and the like, and a comprehensive evaluation can also be performed in combination with parameters such as a received signal strength indicator (RSSI) and a level margin. For a wavelength channel carrying power light, a relative intensity noise (RIN), a low-frequency amplitude fluctuation, a stray modulation component superimposed on the power light, and the like can be measured by a high-speed photoelectric detection and power sampling circuit, and a power optical noise index is obtained, and statistics are performed in a time window to balance instantaneous fluctuations and long-term trends, so as to form a noise characteristic quantity that can be used for subsequent analysis.

[0040] It should be understood that, in the context description of the embodiments of the present application, “wavelength channel” is used, and if the type of the carried signal is not explicitly distinguished, it can be both a wavelength channel carrying a radio frequency optical signal and a wavelength channel carrying power light, and should not be limited in type.

[0041] In step S120, the interference strength between each wavelength channel is determined based on the interference monitoring data, and a wavelength interference matrix for characterizing the interference relationship between each wavelength channel is constructed.

[0042] In some embodiments, a channel interference evaluation module is established in a network management control unit. For a target radio frequency wavelength channel, the change amount of the signal quality index is compared in the case that other channels are sequentially turned on / off or the power is changed, and then the additional degradation degree caused by different channel combinations to the channel is estimated; the correlation or regression coefficient between the quality fluctuation and the power optical noise between different channels can also be calculated based on long-time sequence monitoring data, so as to obtain an interference metric value reflecting the coupling relationship between the channels. For the power light channel, the influence of the noise index on the quality index of the radio frequency channel in the adjacent and specific frequency offset range can be evaluated, and such coupling is also taken into account in the interference strength evaluation.

[0043] Specifically, the signal quality indicators and the power optical noise indicators of each wavelength channel can be taken as input features, and the degree of interference coupling between different wavelength channels can be evaluated by using statistical correlation analysis, power spectrum superposition analysis, or a pre-labeled nonlinear interference model. For example, within a certain observation window, the correlation between the signal quality fluctuation of channel i and the transmission power variation, power optical noise indicator variation of adjacent or specific channel j is analyzed. When the correlation is high and meets the preset conditions, it can be considered that j has a significant interference contribution to i, and the corresponding interference intensity value is calculated according to the correlation strength, spectral interval, and power configuration.

[0044] The matrix elements in the wavelength interference matrix are used to represent the normalized interference intensity between any two wavelength channels, that is, by normalizing the interference intensity, the overall interference relationship is presented in a dimensionless form, which is convenient for comparison with data of different link configurations and different time periods. By constructing the wavelength interference matrix, the signal quality and noise observation data originally scattered in each channel can be organized into a whole interference relationship, and it can be clearly depicted which wavelengths constitute the main interference sources for which wavelengths.

[0045] In step S130, the interference intensity of each wavelength channel is analyzed based on the wavelength interference matrix, the interference degree index of each wavelength channel is calculated, and at least one interference cluster composed of wavelength channels with interference intensity higher than the interference threshold is identified according to the preset interference threshold.

[0046] In some embodiments, the wavelength interference matrix can be regarded as a weighted graph structure with wavelength channels as nodes and normalized interference intensity as edge weight. Node metric analysis is performed on the graph, for example, the sum of interference intensities with other channels, the maximum interference intensity, or the weighted degree of each wavelength channel is calculated as the interference degree index of the channel. For channels with large interference degree index, it means that they are in a high-coupling and high-sensitivity position in the interference topology, which can be either the main victim of interference or an important contributor to interference.

[0047] After obtaining the interference degree index, the elements in the wavelength interference matrix can be truncated according to the preset interference threshold, and the channel pairs with interference intensity higher than the threshold are regarded as having a "strong interference connection". Then, connected subgraphs or clusters are identified under the strong connection relationship, and they are defined as interference clusters, each of which contains a group of wavelength channels highly coupled in the interference relationship. By topological analysis starting from the global interference relationship, the interference coupling region is divided in the spectral domain, and a small part of "problem channel set" that has a significant impact on link performance is effectively extracted. Thus, the wavelength channel set that needs to be isolated and optimized is clearly labeled in the global perspective.

[0048] In step S140, based on the wavelength interference matrix and the at least one interference cluster, target wavelength configuration parameters are adaptively determined according to the interference strength between the wavelength channels, so that in the target wavelength configuration parameters, the wavelength interval and / or guard band width corresponding to the wavelength channels belonging to the interference cluster are greater than the wavelength interval and / or guard band width of the wavelength channels not belonging to the interference cluster.

[0049] The target wavelength configuration parameters include: the center wavelength of each wavelength channel, the wavelength interval between adjacent wavelength channels, the guard band width on both sides of each wavelength channel, and the optical filter bandwidth used for filtering each wavelength channel.

[0050] In an example of an embodiment of the present application, the wavelength interference matrix and the interference cluster information can be mapped into an optical spectrum planning problem under the constraints of a preset available optical spectrum range and device tunable capability, and a heuristic search or optimization solving manner is used to preferentially allocate a larger spectrum interval or a wider guard band to the channels in the interference cluster, while setting a more appropriate passband width and roll-off characteristic for the corresponding optical filter, so as to reduce the effective bandwidth of the spectrum overlap and nonlinear coupling between the channels. In addition, for the wavelength channels not belonging to the interference cluster, a relatively compact spectrum layout and a smaller guard band width can be maintained, so that more service channels or expansion space can be accommodated under the condition of limited overall spectrum resources.

[0051] In another example of an embodiment of the present application, an optimization model can be constructed with the "interference strength" as the objective function and the spectrum resources and device tuning range as the constraint condition, and by adjusting the center wavelength of each wavelength channel, the wavelength interval between adjacent wavelength channels, and the guard band width on both sides, an iterative search is performed to find a parameter combination that reduces the comprehensive interference degree of the key channels and the channels in the interference cluster. For the channels in the interference cluster, a larger minimum wavelength interval requirement can be set, or a wider guard band can be reserved near the power optical wavelength, so as to reduce the injection of nonlinear products and power optical noise in these channels; for the channels not belonging to the interference cluster, a relatively compact interval and a narrower guard band can be used to improve the spectrum utilization. On the basis of the determination of the wavelength interval and the guard band width, a relatively narrower filter bandwidth is configured for the channels in the interference cluster to suppress the four-wave mixing products and power optical noise sidebands falling on the channel edges; a slightly wider filter bandwidth is used for the channels with weak interference to ensure the signal waveform integrity and dispersion tolerance.

[0052] By performing differentiated configuration for channels with different interference levels, the target wavelength configuration parameters overall implement the strategy of "key channel isolation and general channel compact arrangement", so as to effectively weaken the influence of strong interference on the link performance without blindly sacrificing the spectrum efficiency, and improve the comprehensive transmission quality and spectrum utilization in the multi-channel radio frequency optical and power optical co-fiber transmission scenario.

[0053] In step S150, the tunable optical source and the tunable optical filter in the front-haul network are controlled according to the target wavelength configuration parameters, and the center wavelength and the optical filter bandwidth of each wavelength channel are adjusted so that the adjusted wavelength channels work under the target wavelength configuration parameters.

[0054] In some embodiments, a wavelength configuration issuing module can be arranged in a centralized controller of the front-haul network, the target wavelength configuration parameters are converted into working wavelength setting values of each tunable laser and center wavelength, passband width and edge attenuation characteristic parameters of each tunable optical filter, and are issued to corresponding devices through a standardized control interface or a network management protocol to drive the laser to perform micro-step tuning and drive the tunable filter to adjust the center wavelength and the bandwidth.

[0055] After the above adjustment is completed, the actual working wavelength, the inter-channel spacing and the guardband width of each wavelength channel are consistent with the target configuration, the physical spectrum layout of the optical layer is reshaped according to the interference environment, so that the crosstalk path of the channel in the interference cluster is significantly weakened, and the non-interference cluster channel maintains a higher spectral compactness.

[0056] Through the embodiments of the present application, the interference transmission matrix is modeled based on interference monitoring, the target configuration parameters are optimized and calculated, and the tunable devices are controlled to execute, so that the wavelength configuration is no longer a fixed initial design, but can dynamically evolve with the interference environment and the service state. Therefore, under the premise that the existing optical fiber infrastructure remains unchanged, the anti-interference ability and the spectral utilization efficiency of the ARoF+PoF composite front-haul link are continuously optimized through the cooperative control of the tunable optical source and the tunable optical filter, and the link stability and the service carrying capacity are guaranteed when the multiple radio frequency optical signals and the power optical signals are transmitted in the same fiber.

[0057] Regarding the implementation details of step S110, in some examples of the embodiments of the present application, an optical splitter is introduced in the optical fiber link where each wavelength channel is located, and a portion of the optical power is sent into a high-speed photodetector. Specifically, an optical splitter is connected in series in the optical fiber link where each wavelength channel is located, a small portion of the optical power (for example, 1%~5%) in the main path is split and sent into a high-speed photodetector, which is used for online monitoring of the radio frequency optical signal of the wavelength channel.

[0058] Correlation analysis is performed between the output of the high-speed photodetector and the local reference RF signal to calculate the signal power and noise power of each wavelength channel. Based on this, the signal quality indicators for each wavelength channel are determined and incorporated into the interference monitoring data. The signal quality indicators include at least one of the following: signal-to-noise ratio (SNR), error vector amplitude, and bit error rate (BER). Specifically, the electrical signal output of the high-speed photodetector is correlated with or demodulated against the local reference RF signal to estimate the useful signal power and noise power of each wavelength channel in the intermediate frequency (IF) or baseband domain, and based on this, various signal quality indicators are calculated.

[0059] Simultaneously, the power spectral density of the output power fluctuation and longitudinal mode beat frequency noise of the power light source is collected. Based on the output power fluctuation range and noise power spectral density of the power light source, a power light noise index is determined to characterize the power light noise, and this index is written into the interference monitoring data. Specifically, an optical splitter and a high-speed photodetector are also configured at the output end of the power light source to collect the time-domain power fluctuation of the power light output. The power spectral density of components such as longitudinal mode beat frequency noise is obtained through Fourier transform. Based on this, combined with parameters such as the output power fluctuation range and the integral value of the noise power spectral density, a power light noise index is constructed to quantify the intensity of the power light noise, and this index is also written into the interference monitoring data.

[0060] Regarding the implementation details of step S120, in some examples of embodiments of this application, for any two wavelength channels and By performing frequency domain correlation analysis on the output of the high-speed photodetector, the wavelength channel can be obtained. Leakage to wavelength channel Crosstalk power spectral density In the wavelength channel Occupied frequency band Integrate the crosstalk power spectral density and use wavelength channels signal power Normalization is performed to determine the matrix elements in the wavelength interference matrix. .

[0061] Specifically, wavelength channels can be separated first in the frequency domain. Occupied frequency band Then estimate the channel within this frequency band. Power spectral density curve of the induced interference component Subsequently, in the wavelength channel Occupied frequency band Integrate the crosstalk power spectral density and use the useful signal power of the channel. Normalization is performed to determine the matrix elements in the wavelength interference matrix. The calculation relationship can be expressed as:

[0062] , formula (1)

[0063] wherein, is the frequency, represents the signal power of the wavelength channel ; aggregate all the between channels to form a two-dimensional wavelength interference matrix, represents the relative interference intensity of the channel to the channel .

[0064] By calculating the obtained by all channel pairs , a two-dimensional wavelength interference matrix is formed by aggregation, which describes the interference coupling relationship between any two wavelength channels in the form of dimensionless relative interference intensity, so as to compress the complex frequency domain crosstalk distribution into a matrix form which is easy for subsequent topology analysis and interference cluster identification processing, and realize the quantitative characterization and computable modeling of the interference between channels in the common fiber transmission.

[0065] In some examples of the embodiments of the present application, the wavelength division isolation anti-interference method is repeatedly executed in multiple control periods in an adaptive closed-loop control mode. Specifically, after completing interference monitoring data collection, wavelength interference matrix construction, interference cluster identification, and target wavelength configuration parameter distribution in each control period, the controller caches the configuration results and monitoring data state of the current period together for comparison and decision-making in the subsequent period. The optical layer wavelength layout can be continuously iterated and updated according to the link running state, so that the wavelength interval, guard band width and optical filter bandwidth always remain matched with the current interference pattern, thereby realizing continuous suppression of nonlinear interference and power optical noise in the long-term running process.

[0066] Figure 2 An operation flowchart of an example of the wavelength division isolation anti-interference method with a periodic iterative closed-loop regulation mechanism according to the embodiments of the present application is shown.

[0067] As shown in Figure 2 , in step S210, at the end of each control period, the wavelength interference matrix is reconstructed based on the updated interference monitoring data, the updated interference degree index is calculated, at least one interference cluster is re-identified, and the target wavelength configuration parameter is updated.

[0068] On this basis, the controller dynamically sets the length of the next control period according to the signal quality indicators and the power optical noise indicators of the respective wavelength channels. For example, when the signal quality indicator of any wavelength channel is lower than a preset quality threshold and / or the power optical noise indicator is higher than a preset noise threshold, it is determined that the current link is at a higher risk of interference or in a noise deterioration state, and the control period is shortened to increase the response frequency of the closed-loop regulation. When the signal quality indicators of all wavelength channels are higher than the preset quality threshold and the power optical noise indicators are lower than the preset noise threshold, it is determined that the link is stable, and the control period is appropriately lengthened to reduce the overhead and wavelength switching disturbance caused by frequent reconfiguration. In this way, through adaptive adjustment of the length of the period, fine control of the wavelength resource reconfiguration frequency is achieved while taking into account the timeliness of regulation and system stability.

[0069] In step S220, between two adjacent control periods, when the change amplitude of the signal quality indicator, the interference degree indicator and / or the power optical noise indicator of any wavelength channel is detected to exceed a preset disturbance threshold, the target wavelength configuration parameter is recalculated in advance, and the adjustment operation on the adjustable optical source and the adjustable optical filter in the front-haul network is performed.

[0070] In some embodiments, the controller continuously monitors the short-term change trend of the signal quality indicator, the interference degree indicator and the power optical noise indicator of each wavelength channel between two adjacent control periods, and performs difference or relative change rate calculation on the corresponding indicators at the last time or the last period. When the change amplitude of any indicator exceeds the preset disturbance threshold (for example, sudden decrease in signal quality, significant increase in interference degree or sharp increase in power optical noise indicator), it is considered that the current link is subjected to sudden traffic load change, device abnormality or fiber physical environment disturbance, and the wavelength interference matrix update, interference cluster re-identification and target wavelength configuration parameter recalculation are triggered to be performed in advance, and the adjustment instruction is simultaneously issued to the adjustable optical source and the adjustable optical filter without waiting for the original control period to end. In this way, by adding an early triggering mechanism based on disturbance detection in addition to the periodic closed-loop regulation, the overall control rhythm can be ensured to be smooth while responding quickly to sudden interference events, further improving the anti-interference ability and transmission performance stability of the front-haul network in dynamic complex scenarios.

[0071] Figure 3 An operation flowchart of an example of dividing at least one interference cluster based on a wavelength interference matrix according to an embodiment of the present application is shown.

[0072] As shown in Figure 3 In step S310, for each wavelength channel, the total interference degree and the maximum peer interference degree are calculated based on the matrix elements in the wavelength interference matrix, and the total interference degree and the maximum peer interference degree are written into the interference degree indicator.

[0073] , formula (2)

[0074] In the formula, and respectively represent the wavelength channel corresponding to the total interference degree and the maximum peer interference degree.

[0075] Specifically, represent the wavelength channel suffered from the sum of the normalized interference intensities from all other channels, used to characterize the "total interference degree" of the channel in the overall interference topology; represent the corresponding maximum single peer interference intensity in all channels that have an interference relationship with the wavelength channel , used to characterize the coupling strength of the channel with its "strongest interference neighbor". In this way, the importance and sensitivity of each wavelength channel in the interference network are described from both global and local dimensions.

[0076] In step S320, the total interference degrees of the respective wavelength channels are sorted from large to small, and the wavelength channels with total interference degrees greater than a preset total interference degree threshold are marked as high interference channels to obtain a high interference channel set.

[0077] Here, the preset total interference degree threshold can be set in various ways, for example, predefined according to requirements, or can be set based on the interference tolerance allowed by the system, historical operation statistics or offline simulation results, for example, selecting channels in the upper percentile of the statistical distribution as high interference candidates. Through the screening based on the total interference degree, only a part of the channels that are most seriously affected by the cumulative interference in the overall interference network are retained, which can reduce the computational complexity of subsequent graph structure analysis, and focus the resource reconfiguration and spectral isolation strategy on the channel set that has the greatest impact on link performance, thereby improving the pertinence and efficiency of subsequent wavelength adjustment.

[0078] In step S330, for any two wavelength channels and , when the matrix element is not less than the product of the relative interference coefficient threshold and the smaller one of the maximum peer interference degrees and , the wavelength channel and the wavelength channel are determined as a strong interference link.

[0079] Specifically, when the matrix element is not less than the product of the relative interference coefficient threshold and the smaller one of the maximum peer interference degrees and the product of the smaller one, i.e. satisfying the following formula:

[0080] , formula (3)

[0081] wherein, is a preset relative interference coefficient threshold, usually taking a value between 0 and 1, for controlling the strictness of determining strong interference links. embodies taking the "weaker interference side" in the two channels as the benchmark, only when at least a certain proportion of the smaller maximum mutual interference degree is reached, the mutual interference between the two is considered to be significant for both sides.

[0082] Through the constraint of formula (3), it can be avoided that the two channels are mistakenly marked as a strong interference pair due to only one-way weak crosstalk, and it is ensured that the channel pairs identified as strong interference links have relatively prominent interference relationship in the local topology, thereby improving the reliability and physical interpretability of interference cluster division.

[0083] In step S340, the set of high interference channels is taken as the node set of the graph structure, and the set of all wavelength channel pairs satisfying the strong interference link condition is taken as the edge set of the graph structure, connectivity analysis is performed on the graph structure, and the wavelength channels connected to each other through the strong interference links are divided into the same interference cluster, so that each interference cluster is composed of the combination of wavelength channels satisfying the strong interference link condition in the wavelength interference matrix.

[0084] In some embodiments, the controller takes the set of high interference channels as the node set of the graph structure, and takes all wavelength channel pairs satisfying the strong interference link condition of formula (3) as the edge set of the graph structure, to construct an undirected weighted graph or an undirected unweighted graph; then connectivity analysis is performed on the graph structure, for example, through connectivity component identification algorithms such as depth-first search, breadth-first search or union-find set, to find all node subsets that are reachable to each other through the strong interference links, and each connected subset is divided into an interference cluster. In this way, each interference cluster obtained is composed of the combination of wavelength channels having strong mutual interference relationship in the wavelength interference matrix, and any two channels in the cluster can be connected to each other through one or more strong interference link paths. Therefore, through the above cluster division processing based on graph connectivity, the highly coupled channel group in the interference network between complex channels can be automatically extracted.

[0085] Figure 4 An operation flowchart of an example of adaptively determining target wavelength configuration parameters based on a wavelength interference matrix and at least one interference cluster according to an embodiment of the present application is shown.

[0086] In step S410, for each wavelength channel based on the matrix elements in the wavelength interference matrix and the signal power of each wavelength channel calculating the wavelength offset so that the offset direction of the adjacent wavelength channels determined as strong interference links in the at least one interference cluster is opposite in the wavelength arrangement, and the interval between the adjusted center wavelengths of the corresponding adjacent wavelength channels is increased, and the adjusted center wavelengths are determined according to the wavelength offset .

[0087] Specifically, the following relationship can be used:

[0088] , formula (4)

[0089] In the formula, is a learning rate coefficient, used to control the step size of wavelength adjustment in each control period, to avoid excessive offset leading to link instability at one time; is the center wavelength of the wavelength channel before adjustment, is the signal power of the wavelength channel . is a sign function, used to indicate the relative direction of the wavelength channel to the wavelength channel in the wavelength arrangement, taking a positive value when , and taking a negative value when , used to indicate the relative direction of the channel to the channel in the wavelength arrangement; represents the interval of the two channels in the wavelength index, used to attenuate the interference contribution of the faraway channel, and reflects that the closer neighbor channel has a greater impact on the offset.

[0090] As can be seen from formula (4), when the channel has a large interference intensity to the channel and a high signal power , it will have a more obvious "push away" effect on in the relative direction between the two channels, so that the offset direction of the adjacent wavelength channels determined as strong interference links in the at least one interference cluster is opposite in the wavelength axis, and the interval between the adjusted center wavelengths is increased. Through the vector type wavelength offset update based on the interference intensity and power weighting, the distance between the high interference adjacent channels can be adaptively "pulled apart" while maintaining the continuity of the overall wavelength layout, and the spectral decoupling of the strong interference links can be realized.

[0091] In step S420, for each wavelength channel Based on the wavelength interference matrix and the corresponding maximum peer interference degree Calculate the width of the protective belt and the corresponding optical filter bandwidth Set as channel baseband bandwidth The sum of the widths of the side guardrails.

[0092] Specifically, the following relationship can be used:

[0093] Equation (5)

[0094] Equation (6)

[0095] In the formula, The preset minimum guard band width is used to ensure a basic spectral spacing margin even when interference is low; This is the system's nonlinear sensitivity scaling factor, used to reflect the impact of link nonlinear crosstalk on the maximum peer interference. The degree of sensitivity, The larger the size, the larger the additional protective straps. This refers to the baseband bandwidth of the radio frequency signal carried by this wavelength channel. This is the total passband width of the optical filter, which is composed of the baseband bandwidth and the widths of the symmetrical sheaths on both sides. The sum of them constitutes the whole.

[0096] By using equations (5) and (6), and adopting the same... The proportional bandgap and filter bandwidth adaptive expansion mechanism ensures that the channel with higher interference level within the interference cluster has a wider bandgap and filter passband, thus reserving a larger safety interval in the spectral dimension. This helps suppress crosstalk caused by spectral overlap and nonlinear effects of adjacent channels. At the same time, the bandgap width of different channels is adaptively adjusted according to their respective interference levels. In the ARoF+PoF co-fiber transmission scenario, this avoids the waste of spectrum resources caused by uniformly widening the bandgap for all channels.

[0097] In step S430, for each wavelength channel that does not belong to any interference cluster, the guard band width of the wavelength channel is uniformly set to the minimum guard band width. And set the optical filter bandwidth to the base bandwidth configuration. This results in the wavelength channels within the interference cluster having a larger sheath width than the wavelength channels outside the interference cluster in the target wavelength configuration parameters.

[0098] Specifically, these channels exhibit low levels of both total interference and maximum peer interference in the wavelength interference matrix, thus meeting the crosstalk suppression requirements without additional guard bands. By configuring the channels outside the interference cluster with the minimum guard band and configuring the channels inside the interference cluster with a larger guard band according to equation (5), a differentiated spectral layout of "key protection of interference-sensitive channels and compact arrangement of ordinary channels" is naturally formed in the target wavelength configuration parameters. Thus, on the one hand, the wavelength channels inside the interference cluster obtain stronger isolation in the guard band and filter passband dimensions, which is conducive to improving the transmission quality of these bottleneck channels; on the other hand, a large number of channels outside the interference cluster maintain a small guard band, which improves the utilization efficiency of the fiber spectrum and the number of channels that can be carried as a whole.

[0099] As a further preferred embodiment of the present application, in the case where the power optical noise indicator is detected to exceed the preset noise threshold, the system nonlinear sensitivity proportionality coefficient is increased , and the guard band width of each wavelength channel inside the interference cluster is recalculated based on the adjusted and the corresponding optical filter bandwidth to adaptively widen the guard band width of the wavelength channels inside the interference cluster, thereby improving the wavelength division isolation between the power optical and radio frequency optical signals.

[0100] Specifically, the may be increased from the base value to an amplified value matching the current noise level according to a preset mapping relationship, and the guard band width of each wavelength channel inside the interference cluster is recalculated and the corresponding optical filter bandwidth based on the adjusted without changing the calculation forms of equation (5) and equation (6). Since the increase of amplifies the contribution of the maximum peer interference to the guard band width, the guard band width of the high-interference channels, especially the channels close to the power optical wavelength, is further widened relative to the normal state, thereby adaptively widening the spectral isolation band of the wavelength channels inside the interference cluster when the power optical noise deteriorates.

[0101] Through this adaptive widening mechanism, the effective spectral isolation between the power optical wavelength and the adjacent radio frequency optical wavelength can be increased in time when the power optical noise is high, thereby strengthening the suppression of the power optical noise and related nonlinear products, while does not need to be improved when the power optical noise is at a normal level, thereby avoiding long-term occupation of excessive guard band resources, and balancing the spectral utilization efficiency of the PoF power supply wavelength and the multiple ARoF services while ensuring the transmission quality of the radio frequency optical.

[0102] Figure 5A flowchart illustrating an example of adjusting the output power of a power light source according to an embodiment of this application is shown.

[0103] like Figure 5 As shown, in step S510, based on the power optical noise index used to characterize power optical noise in the interference monitoring data, the power noise intensity parameter of the corresponding power light source is determined. And determine the target wavelength channel index carrying the power light in the wavelength interference matrix. and the indexes of each wavelength channel carrying the radio frequency optical signal. .

[0104] In some implementations, the controller first reads power light noise indicators characterizing power light noise from the interference monitoring data, such as the relative intensity noise of power light, low-frequency power fluctuations, or longitudinal mode beat frequency noise power spectral density, and then converts these noise indicators into scalar power noise intensity parameters by normalization or weighted integration. This parameter can be understood as a strength coefficient of the current power light source noise level relative to the nominal noise level. Simultaneously, the controller determines the target wavelength channel index carrying the power light based on the current wavelength division multiplexing configuration and the index relationship of the wavelength interference matrix. and the set of indexes for each wavelength channel carrying radio frequency optical signals. .

[0105] Therefore, the actual monitored power optical noise characteristics are mapped into intensity parameters that can be used in calculations. And lock the correspondence between the power optical channel and all radio frequency optical channels in the wavelength interference matrix.

[0106] In step S520, for each wavelength channel carrying the radio frequency optical signal... Read the target wavelength channel from the wavelength interference matrix. Pointing to wavelength channel matrix elements And based on power noise intensity parameters With each matrix element Calculate the combined contribution of power optical noise to crosstalk in each wavelength channel. .

[0107] Here, matrix elements This indicates the power optical channel versus the radio frequency channel under the current wavelength configuration. The normalized interference intensity. Then, based on the power noise intensity parameter. With each matrix element Calculate the combined contribution of power optical noise to crosstalk across all RF optical channels. :

[0108] , formula (7)

[0109] In the formula, is the number of wavelength channels carrying radio frequency optical signals.

[0110] In formula (7), can be understood as the equivalent relative interference amount of the power optical noise on the channel , and the sum of all radio frequency channels reflects the overall coupling strength of the current power optical noise to the entire set of ARoF service channels. Thus, the multiplication of the physical power optical noise intensity and the coupling relationship on the spectrum into a single quantitative index directly reflects the overall interference level of the current power optical noise on the entire set of radio frequency service wavelengths, providing a quantitative criterion for closed-loop adjustment of the power optical output power.

[0111] In step S530, when the integrated contribution degree exceeds the preset noise coupling threshold , the output power of the power light source is adjusted.

[0112] Specifically, the controller continuously compares the integrated contribution degree with the preset noise coupling threshold , and when is detected, it is determined that the overall interference of the current power optical noise on the radio frequency optical channels through nonlinear coupling and co-fiber transmission has exceeded the system allowed range, triggering automatic adjustment of the output power of the power light source. Specifically, the new power optical output power can be calculated according to the following proportional relationship:

[0113] , formula (8)

[0114] wherein, and represent the power optical output power before and after adjustment, respectively, to reduce the overall contribution of the power optical noise to the interference intensity in the wavelength interference matrix.

[0115] In formula (8), when , the proportional factor , so as to achieve proportional reduction of the power optical output power according to the degree of interference exceeding the limit. Through the above closed-loop control mechanism, the overall interference contribution of the power optical noise in the wavelength interference matrix can be automatically suppressed while ensuring that the PoF still has sufficient power supply capability, so that the crosstalk of the PoF noise to each radio frequency optical channel is maintained within the preset tolerance, thereby improving the anti-interference performance and long-term operation stability of the multi-channel radio frequency optical and power optical co-fiber transmission link.

[0116] As a further preferred implementation of the embodiments of the present application, when the overall contribution of the power light noise to the overall interference strength is further reduced by adjusting the polarization state of the power light source to a polarization state approximately orthogonal to the characteristic polarization states of the individual radio frequency light signals via the polarization controller to suppress the coupling of the mode splitting noise and the longitudinal mode beating noise of the power light to the individual radio frequency light signals corresponding to the wavelength channels via the polarization extinction ratio.

[0117] Specifically, the characteristic polarization states of the individual wavelength channels carrying the radio frequency light signals can be obtained by performing polarization analysis or pre-calibration on the output light of the individual wavelength channels, and then the target polarization direction approximately orthogonal to the set of characteristic polarization states is calculated by the controller and the polarization controller is driven to adjust the polarization state of the power light to the target polarization direction. Since the power light is approximately orthogonal to the radio frequency light signals in the polarization space, the mode splitting noise and the longitudinal mode beating noise of the power light will be significantly suppressed when coupled to the radio frequency light signals corresponding to the individual wavelength channels via the polarization extinction ratio, thereby equivalently reducing the interference strength matrix elements in the wavelength interference matrix from the power light channel to the individual radio frequency channels, further reducing the contribution of the power light noise to the overall interference strength, and improving the anti-interference margin and stability of the PoF and the multi-channel radio frequency light co-fiber transmission link.

[0118] Figure 6 A structural block diagram of an example of a front-haul network according to an embodiment of the present application is shown.

[0119] As Figure 6 shown, the front-haul network 600 includes integrated photon chips 610, 620…6N0 deployed at individual remote radio units, and a central controller 620 in communication connection with the individual integrated photon chips.

[0120] The adjustable laser 611, the micro-ring resonator array 612 and the photodetector 613 are integrated on each integrated photon chip 610.

[0121] The adjustable laser 611 is configured to emit optical carriers carrying the radio frequency light signals and / or the power light on the corresponding wavelength channels according to the center wavelengths of the individual wavelength channels in the target wavelength configuration parameters.

[0122] The micro-ring resonator array 612 is configured to perform band-pass filtering on the optical signals entering the individual wavelength channels according to the optical filter bandwidth and the guard bandwidth of the individual wavelength channels in the target wavelength configuration parameters to form adjustable wavelength channel filtering characteristics.

[0123] The photoelectric detector 613 is configured to receive the branched part of the optical power in the optical fiber link where the wavelength channels are located through the optical splitter and perform photoelectric conversion to generate interference monitoring data containing signal quality indicators and power optical noise indicators.

[0124] The central controller 620 is configured to execute the wavelength division isolation anti-interference method of the radio frequency optical network front-haul signal as described in any of the above embodiments to determine the target wavelength configuration parameters based on the interference monitoring data during operation, and control the tunable laser and the micro-ring resonator array to make the front-haul network work under the target wavelength configuration parameters.

[0125] Through the above structural configuration, the tunable laser, the reconfigurable optical filter unit, and the interference monitoring detection unit are integrated into the photonic chip of the remote radio unit, and the wavelength interference modeling and target wavelength configuration parameter calculation are uniformly executed by the central controller, realizing a closed-loop regulation and control link of local real-time sensing, central collaborative decision-making, and optical layer rapid execution. Thus, on the one hand, the integrated photonic chip provides on-site wavelength tunable and bandwidth tunable transmission and filtering capabilities, so that the configuration parameters such as the center wavelength, the guard bandwidth, and the optical filter bandwidth calculated by the central controller can be precisely landed on each wavelength channel, thereby implementing enhanced isolation on the key channels in the interference cluster; on the other hand, the interference monitoring data fed back by the photoelectric detector can continuously reflect the actual coupling condition of the radio frequency optical signal and the power optical noise in the co-fiber transmission, so that the network automatically converges to a wavelength division configuration state matching the current interference environment in long-term operation, thereby improving the anti-interference capability and spectrum resource utilization efficiency of the front-haul system in the PoF and multi-path radio frequency optical co-fiber scene.

[0126] Figure 7 An operation mechanism flowchart of an example of the wavelength division isolation anti-interference method of the radio frequency optical network front-haul signal according to an embodiment of the present application is shown.

[0127] As shown in Figure 7 The wavelength division isolation anti-interference method of the radio frequency optical network front-haul signal takes the photonic sensor data as input, first processes the interference monitoring data of each wavelength channel through a wavelength interference matrix calculation module (Wavelength Interference Matrix, WIM) to generate a wavelength interference matrix representing the normalized interference intensity relationship between channels; then, a spectral interference topology analysis module (Spectral Interference Topology Analysis, SITA) calculates the interference degree index of each channel and identifies the interference cluster based on the WIM, and sends the interference topology result to the dynamic control logic for adaptively setting the control period, the interference threshold, and the control parameters related to the power optical and guard band configuration.

[0128] Further, an adaptive wavelength allocation and filtering module (AWAF) reconfigures the center wavelengths and filter bandwidths of each wavelength channel according to the target wavelength configuration parameters output by the dynamic control logic, and inserts an interference-aware guard band, reserving a wider guard band for the key channels within the interference cluster and a compact guard band for the channels outside the interference cluster, thereby forming an interference-aware differentiated spectrum allocation. The above processing obtains an optical channel with minimized interference, which exhibits improved signal quality at the receiving end, and realizes adaptive wavelength division isolation and anti-interference optimization in the power light and multi-channel RF light co-fiber transmission scenario.

[0129] To verify the effectiveness of the proposed WIM+AWAF wavelength division isolation and anti-interference method, a simulation environment for an 8-channel RF light front-haul system is constructed. In the simulation, the initial wavelength spacing of each RF light channel is set to 100 GHz, and the power light uses a continuous wave laser source with an output power of 10 W, which is transmitted through the same optical fiber as each RF light channel. According to the system dispersion, nonlinear coefficient, and power configuration, an initial wavelength interference matrix is randomly generated to comprehensively simulate the inter-channel crosstalk caused by FWM, XPM, and power light noise coupling. On this basis, the traditional fixed wavelength and fixed filter baseline scheme is configured, and the proposed method using WIM calculation and AWAF adaptive wavelength / filter reconfiguration is configured. The WIM+AWAF algorithm is iteratively executed during the simulation process, and the total crosstalk power, single-channel error vector magnitude, and changes in the wavelength interference matrix are recorded at each iteration.

[0130] Figure 8 An example of a schematic diagram of the comparison results of the total crosstalk power of different methods with the number of iterations is output.

[0131] As Figure 8 shown, the crosstalk power of the baseline scheme remains unchanged, and the total crosstalk power remains at an initial level of about 18 within 0-10 iterations. The solid square curve represents the simulation results when the proposed WIM+AWAF method is used. With the increase in the number of iterations, the total crosstalk power shows a monotonous decreasing trend, gradually decreasing from the initial value of about 18 to about 7 at the 10th iteration. It can be seen that the total crosstalk power has decreased significantly within the first few iterations, and then gradually converges to a lower level. Compared with the baseline scheme, the final total crosstalk power is reduced by more than 50%, verifying the effectiveness of the proposed WIM+AWAF method in terms of iteration convergence and inter-channel interference suppression capability.

[0132] Figure 9The comparison results of the normalized crosstalk matrix of the 8-channel RF optical feeder link are shown. The horizontal and vertical axes of the figure are both channel indices, and the color depth of the matrix elements represents the normalized crosstalk intensity of the corresponding transmitting channel to the receiving channel. The deeper the color, the stronger the crosstalk. The diagonal elements are zero and not drawn. Figure 9 The left side of the figure is the "baseline crosstalk matrix" corresponding to the initial interference distribution under the traditional fixed wavelength and fixed filter configuration. It can be seen that there is a clear dark band near the main diagonal, indicating that there is strong crosstalk between adjacent and secondary adjacent channels. These high crosstalk areas correspond to the channel combinations in the aforementioned interference clusters.

[0133] Figure 9 The "adapted crosstalk matrix" on the right side of the figure is the crosstalk distribution obtained after applying the WIM calculation and the AWAF algorithm to complete multiple iterations under the same simulation conditions. Compared with the baseline, the overall color of the matrix is significantly lighter, and the maximum normalized crosstalk intensity is reduced from about 0.6 in the left figure to about 0.14 in the right figure. In particular, the matrix elements corresponding to the adjacent channel pairs originally belonging to the interference clusters change from dark blocks to light blocks, indicating that the high crosstalk links have been effectively isolated by expanding the guard band, adjusting the center wavelength, and reconfiguring the filter bandwidth. Thus, it is verified that the proposed WIM+AWAF method not only reduces the total crosstalk power, but also reshapes the interference topology between channels at the matrix level, significantly weakening the interference concentration area, thereby significantly improving the overall signal quality of the system.

[0134] This paper focuses on the interference problem of multi-channel wavelength division multiplexing in the RF optical network feeder link and proposes a wavelength division isolation anti-interference method. This method measures the channel crosstalk and power optical noise in real time, constructs a wavelength interference matrix and identifies interference clusters. It uses adaptive wavelength allocation and filtering algorithms to dynamically calculate the wavelength offset and guard band according to the interference degree. It suppresses the power optical noise coupling through power and polarization optimization. Finally, a closed-loop control mechanism is formed. Compared with existing schemes that rely on fixed intervals, dispersion compensation or single filters, the proposed scheme can significantly reduce the crosstalk caused by FWM, XPM and power optical coupling while ensuring spectral efficiency, improving the reliability and capacity of the feeder link. Simulation results show that the proposed algorithm can reduce the total crosstalk power by about 50% within a few iterations and has good adaptability to changes in power optical noise.

[0135] It should be noted that, for the foregoing method embodiments, for the purpose of simple description, they are all described as a series of actions, but those skilled in the art should know that the present application is not limited to the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application. In the above embodiments, the description of each embodiment is focused on, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0136] Figure 10 A structure block diagram of an example of a wavelength division isolation anti-jamming system of a radio frequency optical network front-haul signal according to an embodiment of the present application is shown, which is deployed in a remote radio node.

[0137] As shown in Figure 10 The wavelength division isolation anti-jamming system 1000 of the radio frequency optical network front-haul signal includes an interference monitoring data acquisition unit 1010, a wavelength interference matrix construction unit 1020, an interference topology analysis unit 1030, a target wavelength configuration determination unit 1040, and a wavelength and filter control unit 1050.

[0138] The interference monitoring data acquisition unit 1010 is configured to acquire interference monitoring data of each wavelength channel in the optical fiber link, wherein the interference monitoring data at least includes a signal quality index for characterizing the quality of each radio frequency optical signal and a power optical noise index for characterizing the power optical noise.

[0139] The wavelength interference matrix construction unit 1020 is configured to determine the interference strength between each wavelength channel based on the interference monitoring data, and construct a wavelength interference matrix for characterizing the interference relationship between each wavelength channel; the matrix element in the wavelength interference matrix is used to characterize the normalized interference strength between any two wavelength channels.

[0140] The interference topology analysis unit 1030 is configured to perform topology analysis on the interference strength of each wavelength channel based on the wavelength interference matrix, calculate an interference degree index of each wavelength channel, and identify at least one interference cluster composed of wavelength channels with interference strength higher than a preset interference threshold according to the preset interference threshold.

[0141] The target wavelength configuration determination unit 1040 is configured to adaptively determine target wavelength configuration parameters according to the interference intensity between wavelength channels based on the wavelength interference matrix and the at least one interference cluster, so that in the target wavelength configuration parameters, the wavelength interval and / or guard band width corresponding to the wavelength channels belonging to the interference cluster are greater than the wavelength interval and / or guard band width of the wavelength channels not belonging to the interference cluster; wherein the target wavelength configuration parameters include: the center wavelength of each wavelength channel, the wavelength interval between adjacent wavelength channels, the guard band width on both sides of each wavelength channel, and the optical filter bandwidth for filtering each wavelength channel.

[0142] The wavelength and filter control unit 1050 is configured to control the adjustable optical source and the adjustable optical filter in the front-haul network according to the target wavelength configuration parameters, and adjust the center wavelength and the optical filter bandwidth of each wavelength channel, so that the adjusted each wavelength channel works under the target wavelength configuration parameters.

[0143] In some embodiments, the embodiments of the present application provide a non-volatile computer readable storage medium, the storage medium stores one or more programs including execution instructions, the execution instructions can be read and executed by an electronic device (including but not limited to a computer, a server, or a network device, etc.) to perform the steps of any of the above-mentioned radio frequency optical network front-haul signal wavelength division isolation anti-interference method.

[0144] In some embodiments, the embodiments of the present application also provide a computer program product, the computer program product includes a computer program stored on a non-volatile computer readable storage medium, the computer program includes program instructions, when the program instructions are executed by a computer, the computer executes the steps of any of the above-mentioned radio frequency optical network front-haul signal wavelength division isolation anti-interference method.

[0145] In some embodiments, the embodiments of the present application also provide an electronic device, which includes at least one processor, and a memory connected with the at least one processor in communication, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the radio frequency optical network front-haul signal wavelength division isolation anti-interference method.

[0146] The above-mentioned products can execute the method provided by the embodiments of the present application, have the corresponding function modules and beneficial effects of executing the method. The technical details not described in detail in the embodiments can be referred to the method provided by the embodiments of the present application.

[0147] The electronic device of the embodiments of the present application exists in various forms, including but not limited to: a mobile communication device, an ultra-mobile personal computer device, a portable entertainment device, or other onboard electronic devices with data interaction functions.

[0148] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments.

[0149] Through the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0150] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for wavelength division isolation of interference for radio over fiber front-haul signals, applied to a front-haul network transmitting radio over fiber signals and power optical signals in an optical fiber link by wavelength division multiplexing, characterized in that, The method comprises: obtaining interference monitoring data of each wavelength channel in the optical fiber link, the interference monitoring data at least comprising a signal quality index for characterizing the quality of each radio frequency optical signal and a power optical noise index for characterizing power optical noise; determining the interference strength between each wavelength channel based on the interference monitoring data, and constructing a wavelength interference matrix for characterizing the interference relationship between each wavelength channel; the matrix element in the wavelength interference matrix is used to characterize the normalized interference strength between any two wavelength channels; performing topological analysis on the interference strength of each wavelength channel based on the wavelength interference matrix, calculating an interference degree index of each wavelength channel, and identifying at least one interference cluster composed of wavelength channels with interference strength higher than a preset interference threshold according to the interference threshold; based on the wavelength interference matrix and the at least one interference cluster, adaptively determining a target wavelength configuration parameter according to the interference strength between each wavelength channel, so that in the target wavelength configuration parameter, the wavelength interval and / or guard band width corresponding to the wavelength channel belonging to the interference cluster is greater than the wavelength interval and / or guard band width of the wavelength channel not belonging to the interference cluster; wherein the target wavelength configuration parameter comprises: the center wavelength of each wavelength channel, the wavelength interval between adjacent wavelength channels, the guard band width on both sides of each wavelength channel, and the optical filter bandwidth for filtering each wavelength channel; controlling the adjustable optical source and the adjustable optical filter in the front-haul network according to the target wavelength configuration parameter, adjusting the center wavelength and the optical filter bandwidth of each wavelength channel, so that the adjusted each wavelength channel works under the target wavelength configuration parameter.

2. The method of claim 1, wherein, The method comprises: introducing an optical branching device into the optical fiber link where each wavelength channel is located, and sending part of the optical power branched out into a high-speed photodetector; performing correlation analysis on the output of the high-speed photodetector and a local reference radio frequency signal, respectively calculating the signal power and noise power of each wavelength channel, and determining the signal quality index of each wavelength channel based on the signal power and noise power, and writing the signal quality index into the interference monitoring data; the signal quality index contains at least one of the following: signal-to-noise ratio, error vector amplitude, and bit error rate; acquiring the output power fluctuation of the power optical source and the power spectral density of the longitudinal mode beat noise, and determining the power optical noise index for characterizing the power optical noise based on the output power fluctuation range and the noise power spectral density of the power optical source, and writing the power optical noise index into the interference monitoring data; wherein the method comprises: For any two wavelength channels and By performing frequency domain correlation analysis on the output of the high-speed photodetector, the wavelength channel can be obtained. Leakage to wavelength channel Crosstalk power spectral density In the wavelength channel Occupied frequency band The crosstalk power spectral density is integrated above and expressed as a wavelength channel. signal power Normalization is performed to determine the matrix elements in the wavelength interference matrix. : ， wherein, is the frequency, represents the signal power of the wavelength channel aggregates all inter-channel constitutes a two-dimensional wavelength interference matrix, represents the relative interference strength of the channel to the channel .

3. The method according to claim 1 or 2, characterized in that, The method is repeatedly executed in multiple control cycles in an adaptive closed-loop control manner, specifically comprising: at the end of each control cycle, based on the updated interference monitoring data, the wavelength interference matrix is reconstructed, the updated interference degree index is calculated, the at least one interference cluster is re-identified, and the target wavelength configuration parameter is updated. The period length of the control period is dynamically set according to the signal quality indicators and the power optical noise indicators of the wavelength channels: when the signal quality indicator of any wavelength channel is lower than a preset quality threshold and / or the power optical noise indicator is higher than a preset noise threshold, the control period is shortened; when the signal quality indicators of all the wavelength channels are higher than the preset quality threshold and the power optical noise indicators are lower than the preset noise threshold, the control period is lengthened; Between two adjacent control periods, when the change amplitude of the signal quality indicator, the interference degree indicator and / or the power optical noise indicator of any wavelength channel exceeds a preset disturbance threshold, the target wavelength configuration parameters are recalculated and the adjustment operation on the adjustable optical source and the adjustable optical filter in the front-haul network is performed in advance.

4. The method of claim 2, wherein, The interference strength of each wavelength channel is topologically analyzed based on the wavelength interference matrix, the interference degree indicators of each wavelength channel are calculated, and at least one interference cluster composed of wavelength channels with interference strength higher than a preset interference threshold is identified according to the preset interference threshold, including: For each wavelength channel, the total interference degree and the maximum peer interference degree are calculated based on the matrix elements in the wavelength interference matrix, and the total interference degree and the maximum peer interference degree are written into the interference degree indicators; ， wherein and respectively represent the wavelength channel corresponding to the total interference degree and the maximum peer interference degree; According to the total interference degree of each wavelength channel Sort from large to small, and total interference degree Wavelength channels greater than the preset total interference degree threshold are marked as high interference channels to obtain a high interference channel set; for any two wavelength channels and when the matrix element is not smaller than a relative interference coefficient threshold and the product of the maximum equivalent interference degree and the smaller one, the wavelength channel is determined as a strong interference link in combination with the wavelength channel , i.e. it satisfies: ， In the formula, is a preset relative interference coefficient threshold value; The set of high-interference channels is taken as the node set of the graph structure, and all wavelength channel pairs satisfying the strong interference link condition are taken as the edge set of the graph structure, the connectivity analysis is performed on the graph structure, and the wavelength channels connected to each other through strong interference links are divided into the same interference cluster, so that each interference cluster is composed of wavelength channels satisfying the strong interference link condition in the wavelength interference matrix.

5. The method of claim 4, wherein, The target wavelength configuration parameters are adaptively determined according to the interference strength between each wavelength channel based on the wavelength interference matrix and the at least one interference cluster, including: for each wavelength channel based on the matrix elements in the wavelength interference matrix and the signal power of each wavelength channel calculating a wavelength shift such that the shift direction of the adjacent wavelength channels determined as strong interference links is opposite in the wavelength arrangement within the at least one interference cluster and the spacing between the adjusted center wavelengths of the corresponding adjacent wavelength channels is increased, and determining the adjusted center wavelengths based on the wavelength shift : ， wherein is a learning rate coefficient, is a center wavelength of the wavelength channel before adjustment, is a signal power of the wavelength channel is a sign function for indicating a relative direction of the wavelength channel with respect to the wavelength channel on the wavelength arrangement;​ for each wavelength channel belonging to the at least one interference cluster based on the wavelength interference matrix and the corresponding maximum interference degree calculate guard band widths and set the corresponding optical filter bandwidths to the sum of the channel baseband bandwidths and the two side guard band widths: ， ， In the formula, is a preset minimum guard band width, is a system nonlinear sensitivity proportional coefficient; for each wavelength channel not belonging to any interference cluster, setting a guard band width of the wavelength channel to a minimum guard band width and setting an optical filter bandwidth to such that in the target wavelength configuration parameters, wavelength channels within an interference cluster have a guard band width that is greater than a guard band width of wavelength channels outside the interference cluster.

6. The method of claim 5, wherein, The method further includes: In a case where it is detected that the power optical noise index exceeds a preset noise threshold, a system nonlinear sensitivity proportionality coefficient is increased , and based on the adjusted , the guard band width of each wavelength channel in the interference cluster is recalculated , and the corresponding optical filter bandwidth , so as to adaptively widen the guard band width of the wavelength channel in the interference cluster, thereby improving the wavelength division isolation between the power optical signal and the radio frequency optical signal.

7. The method of claim 2, wherein, The method further includes: determining a power noise intensity parameter of the corresponding power light source based on a power optical noise indicator for characterizing power optical noise in the interference monitoring data and determining in the wavelength interference matrix an index of a target wavelength channel carrying the power light and an index of each wavelength channel carrying the radio frequency optical signal ; For each wavelength channel carrying radio frequency optical signals Read the target wavelength channel from the wavelength interference matrix. Pointing to wavelength channel matrix elements Based on the power noise intensity parameter With each matrix element Calculate the combined contribution of power optical noise to crosstalk in each wavelength channel. : ， In the formula, is the number of wavelength channels carrying radio frequency optical signals; adjusting the output power of the power light source in case the combined contribution degree is detected exceeds a preset noise coupling threshold ​ ， wherein, and respectively represent the pre-adjusted and post-adjusted power optical output power to reduce the overall contribution of the power optical noise to the interference strength in the wavelength interference matrix.

8. A front-haul network, characterized by, including: The integrated photonic chips are deployed in each remote radio frequency unit, and a central controller is in communication connection with each integrated photonic chip; Each integrated photonic chip is integrated with an adjustable laser, a micro-ring resonator array and a photodetector; The adjustable laser is used to emit optical carriers carrying radio frequency optical signals and / or power light on the corresponding wavelength channel according to the center wavelength of each wavelength channel in the target wavelength configuration parameters; The micro-ring resonator array is used to perform band-pass filtering on the optical signals entering each wavelength channel according to the optical filter bandwidth and the guard bandwidth of each wavelength channel in the target wavelength configuration parameters, to form adjustable wavelength channel filtering characteristics; The photodetector is used to receive part of the optical power branched out by an optical splitter in the optical fiber link where each wavelength channel is located and perform photoelectric conversion to generate interference monitoring data containing signal quality indicators and power optical noise indicators; The central controller is configured to perform the method of any one of claims 1-7 to determine the target wavelength configuration parameters based on the interference monitoring data during operation, and to control the tunable laser and the micro-ring resonator array to make the front-haul network work under the target wavelength configuration parameters.

9. A wavelength division isolation anti-jamming system for radio over fiber network front-haul signals, characterized in that, The system comprises: an interference monitoring data acquisition unit configured to acquire interference monitoring data of each wavelength channel in the fiber link, the interference monitoring data comprising at least a signal quality indicator for characterizing the quality of each radio frequency optical signal and a power optical noise indicator for characterizing the power optical noise; a wavelength interference matrix construction unit configured to determine the interference strength between each wavelength channel based on the interference monitoring data, and to construct a wavelength interference matrix for characterizing the interference relationship between each wavelength channel, wherein a matrix element in the wavelength interference matrix is used to characterize the normalized interference strength between any two wavelength channels; an interference topology analysis unit configured to perform topology analysis on the interference strength of each wavelength channel based on the wavelength interference matrix, to calculate an interference degree indicator of each wavelength channel, and to identify at least one interference cluster composed of wavelength channels with interference strength higher than a preset interference threshold according to the preset interference threshold; a target wavelength configuration determination unit configured to adaptively determine target wavelength configuration parameters according to the interference strength between each wavelength channel based on the wavelength interference matrix and the at least one interference cluster, so that in the target wavelength configuration parameters, the wavelength spacing and / or guard band width of the wavelength channels belonging to the interference cluster are greater than those of the wavelength channels not belonging to the interference cluster; wherein the target wavelength configuration parameters comprise the center wavelength of each wavelength channel, the wavelength spacing between adjacent wavelength channels, the guard band width on both sides of each wavelength channel, and the optical filter bandwidth for filtering each wavelength channel; a wavelength and filter control unit configured to control the tunable optical source and the tunable optical filter in the front-haul network according to the target wavelength configuration parameters, to adjust the center wavelength of each wavelength channel and the optical filter bandwidth, so that the adjusted each wavelength channel works under the target wavelength configuration parameters.

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