Wavelength Division Isolation Anti-interference Method and System for Front-Backhaul Signals in Radio Frequency Optical Networks

Abstract

This application discloses a wavelength division multiplexing (WDM) isolation anti-interference method and system for front-back signals in radio frequency (RF) optical networks. The method includes: introducing an interference monitoring system that simultaneously characterizes RF signal quality and power optical noise, and constructing a wavelength interference matrix based on this matrix to represent the normalized interference intensity between arbitrary wavelength channel pairs; performing topology analysis based on this matrix to calculate the interference degree and automatically classify high-interference channel interference clusters, achieving global perception and quantitative characterization of interference relationships in co-fiber links; using the interference matrix and interference cluster results, adaptively determining the target wavelength configuration parameters for the center wavelength, wavelength spacing, guard band width, and optical filter bandwidth of each channel, and implementing differentiated widening and frequency shifting of channels within the interference clusters; finally, by controlling tunable light sources and tunable optical filters, the WDM configuration is dynamically reconstructed according to the interference environment. Therefore, in ARoF+PoF co-fiber transmission scenarios, both RF signal anti-interference capability and fiber optic spectrum utilization can be balanced.

Description

Technical Field

[0001] This application relates to the field of radio frequency optical communication control technology, and in particular to wavelength division isolation anti-interference method for fronthaul and backhaul signals in radio frequency optical networks, fronthaul and backhaul networks and systems. Background Technology

[0002] As 5G mobile communication networks evolve towards high bandwidth, low latency, and massive MIMO, radio frequency (RF) optical transmission (especially analog radio-over-fiber, ARoF) is gradually becoming an important implementation method for fronthaul and backhaul links. Transmitting millimeter-wave and higher frequency RF signals in optical fibers can significantly simplify the structure of remote RF units, improve the flexibility of site deployment, and match the cloud-based, centralized wireless access network architecture. In practical engineering deployments, multiple RF carriers are typically transmitted co-located in the same optical fiber using wavelength division multiplexing (WDM) to meet the capacity requirements of multiple sectors, multiple standards, and multiple frequency bands.

[0003] On the other hand, to reduce the power supply cost and cabling complexity of remote active devices, the Power-over-Fiber (PoF) solution has been introduced into fronthaul and backhaul systems. This involves using high-power continuous wave light to power remote RF modules within a single fiber, thus creating a composite link structure that integrates multiple RF signals with high-power power supply light transmission over the same fiber. While this structure improves system integration and deployment flexibility, it also significantly exacerbates fiber nonlinearity and the coupling of power optical noise to RF data signals.

[0004] In current designs, engineering practices typically employ measures such as increasing channel spacing, reserving fixed guard bands, configuring static optical filters, and using dispersion compensation to suppress nonlinear crosstalk such as four-wave mixing (FWM) and cross-phase modulation (XPM), and to minimize the impact of power supply light on data signals. However, these suppression strategies are usually based on conservative assumptions about the most unfavorable interference scenarios and involve static margin configurations. On the one hand, this requires sacrificing a significant amount of available spectral resources, resulting in low fiber optic spectrum utilization. On the other hand, 5G service loads and topologies are highly dynamic, with the number of channels, service types, and transmit power changing over time, making it difficult for static guard bands and fixed filter configurations to continuously match the real-time interference environment. Summary of the Invention

[0005] This application provides a wavelength division multiplexing (WDM) isolation anti-interference method for fronthaul signals in radio frequency optical networks, a fronthaul network, a system, a storage medium, a computer program product, and an electronic device, to at least solve the problem in current related technologies that it is difficult to simultaneously achieve nonlinear interference suppression and efficient utilization of fiber optic spectrum in PoF and multi-channel radio frequency optical co-fiber transmission scenarios.

[0006] In a first aspect, embodiments of this application provide a wavelength division multiplexing (WDM) isolation anti-interference method for front-backhaul signals in radio frequency (RF) optical networks. This method is applied to RF optical signals and power optical signals transmitted in fiber optic links via WDM multiplexing. The method includes: acquiring interference monitoring data for each wavelength channel in the fiber optic link, wherein the interference monitoring data includes at least a signal quality index characterizing the quality of each RF optical signal and a power optical noise index characterizing the power optical noise; determining the interference intensity between each wavelength channel based on the interference monitoring data, and constructing a wavelength interference matrix characterizing the interference relationship between each wavelength channel; the matrix elements in the wavelength interference matrix characterizing the normalized interference intensity between any two wavelength channels; performing topological analysis on the interference intensity of each wavelength channel based on the wavelength interference matrix, calculating the interference degree index of each wavelength channel, and identifying interference channels with higher interference intensity than a preset interference threshold. The system comprises at least one interference cluster consisting of wavelength channels with the aforementioned interference threshold; based on the wavelength interference matrix and the at least one interference cluster, a target wavelength configuration parameter is adaptively determined according to the interference intensity between each wavelength channel, such 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 includes: 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; the system controls the tunable light source and tunable optical filter in the fronthaul network according to the target wavelength configuration parameter to adjust the center wavelength and optical filter bandwidth of each wavelength channel so that the adjusted wavelength channels operate under the target wavelength configuration parameter.

[0007] Secondly, embodiments of this application provide a wavelength division multiplexing (WDM) isolation anti-interference system for front-back signals in a radio frequency optical network. The system includes: an interference monitoring data acquisition unit, used to acquire interference monitoring data for each wavelength channel in an optical fiber link, wherein the interference monitoring data includes at least a signal quality index characterizing the quality of each radio frequency optical signal and a power optical noise index characterizing power optical noise; a wavelength interference matrix construction unit, used to determine the interference intensity between each wavelength channel based on the interference monitoring data, and construct a wavelength interference matrix characterizing the interference relationship between each wavelength channel; the matrix elements in the wavelength interference matrix characterize the normalized interference intensity between any two wavelength channels; and an interference topology analysis unit, used to perform topology analysis on the interference intensity of each wavelength channel based on the wavelength interference matrix, calculate the interference degree index of each wavelength channel, and identify wavelength channels with interference intensity higher than the preset interference threshold according to a preset interference threshold. The system comprises: at least one interference cluster; a target wavelength configuration determination unit, configured to adaptively determine target wavelength configuration parameters based on the wavelength interference matrix and the at least one interference cluster, according to the interference intensity between each wavelength channel, such that, in the target wavelength configuration parameters, 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 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; and a wavelength and filter control unit, configured to control the tunable light source and tunable optical filter in the front-backhaul network according to the target wavelength configuration parameters, to adjust the center wavelength and optical filter bandwidth of each wavelength channel, so that the adjusted wavelength channels operate under the target wavelength configuration parameters.

[0008] Thirdly, embodiments of this application provide a fronthaul / backhaul network, comprising: integrated photonic chips deployed in various remote radio frequency units, and a central controller communicatively connected to each of the integrated photonic chips; each of the integrated photonic chips integrates a tunable laser, a microring resonator array, and a photodetector; the tunable laser is used to emit an optical carrier 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 microring resonator array is used to filter the optical signals entering each wavelength channel according to the optical filter bandwidth and guard band width of each wavelength channel in the target wavelength configuration parameters. The optical signal of the wavelength channel undergoes bandpass filtering to form tunable wavelength channel filtering characteristics; the photodetector is used to receive a portion of the split optical power in the optical fiber link where each wavelength channel is located via an optical splitter and perform photoelectric conversion to generate interference monitoring data containing signal quality indicators and power optical noise indicators; the central controller is configured to execute the method as described in any of the preceding claims of this application to determine the target wavelength configuration parameters based on the interference monitoring data during operation, and to make the front-backhaul network operate under the target wavelength configuration parameters by controlling the tunable laser and the micro-ring resonator array.

[0009] Fourthly, an electronic device is provided, comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being 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 radio frequency optical network front-back signals according to any embodiment of the present application.

[0010] Fifthly, embodiments of this application provide a storage medium storing a computer program thereon, characterized in that, when the program is executed by a processor, it implements the steps of the wavelength division isolation anti-interference method for radio frequency optical network front-back signals according to any embodiment of this application.

[0011] Sixthly, embodiments of this application provide a computer program product, including a computer program / instructions, which, when executed by a processor, implements the steps of the wavelength division isolation anti-interference method for radio frequency optical network front-back signals according to any embodiment of this application.

[0012] The wavelength division isolation anti-interference method and system for front-backhaul signals in radio frequency optical networks provided in this application can achieve at least the following technical effects:

[0013] (1) By jointly monitoring the radio frequency signal quality index and power optical noise index of each wavelength channel in the optical fiber link, a wavelength interference matrix is ​​constructed to characterize the normalized interference intensity between any two wavelength channels. Based on this, topology analysis is performed to obtain the interference index of each channel and identify interference clusters. Thus, a unified quantitative description and global characterization of the nonlinear crosstalk relationship and power optical noise coupling relationship between radio frequency optical channels are realized. This not only accurately identifies the set of channels with high interference intensity from the overall perspective of the link, but also distinguishes channels with significantly weaker interference relationships, ensuring the targetedness 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 each wavelength channel. By controlling the tunable light source and tunable optical filter, the center wavelength, adjacent spacing, guard band width, and optical filter bandwidth of each channel are coordinated and adjusted. Among them, the wavelength channels belonging to the interference cluster adopt a relatively larger wavelength spacing and / or guard band width, and can be matched with a more stringent filter bandwidth configuration, while the channels not belonging to the interference cluster maintain a relatively compact spacing and bandwidth configuration. Through this differentiated configuration method based on interference clusters, on the one hand, the injection of nonlinear products and power optical noise between high interference channels into the RF signal is significantly reduced, improving the RF transmission quality and link margin of key channels; on the other hand, the guard band and filter bandwidth of weaker interference channels are not excessively extended, fully releasing their available spectral resources, so that the overall link can achieve high spectral utilization efficiency while ensuring anti-interference performance, and can be adaptively adjusted according to changes in service load and power optical operating status.

[0015] This technical solution, in the context of ARoF and PoF co-fiber transmission, models interference relationships and identifies interference clusters using a wavelength interference matrix and interference clusters as the central framework. Through adaptive parameter configuration, adjustable devices are adjusted, ensuring that key wavelength division isolation parameters such as wavelength spacing, guard band width, and filter bandwidth are no longer statically reserved but dynamically optimized according to the actual interference environment. Thus, without altering the existing physical structure of the fiber optic link, it achieves precise suppression of interference from multiple RF optical signals and power optical signals transmitted co-fiber, as well as efficient scheduling of spectral resources, improving the stability and scalability of the fronthaul / backhaul network under high bandwidth and high power supply conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart is shown as an example of a wavelength division isolation anti-interference method for radio frequency optical network front-back signals according to an embodiment of this application;

[0018] Figure 2 A flowchart illustrating an example of a wavelength division isolation anti-interference method with a periodic iterative closed-loop control mechanism according to an embodiment of this application is shown.

[0019] Figure 3 A flowchart illustrating an example of dividing at least one interference cluster based on a wavelength interference matrix according to an embodiment of this application is shown.

[0020] Figure 4 A flowchart illustrating 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 this application is shown.

[0021] Figure 5 A flowchart illustrating an example of adjusting the output power of a power light source according to an embodiment of this application is shown.

[0022] Figure 6 A structural block diagram of an example front-backhaul network according to an embodiment of this application is shown;

[0023] Figure 7 A flowchart illustrating the operation mechanism of an example of a wavelength division isolation anti-interference method for radio frequency optical network front-back signals according to an embodiment of this application is shown.

[0024] Figure 8 A schematic diagram illustrating an example of the comparison results of the total crosstalk power of different methods as a function of the number of iterations is output.

[0025] Figure 9 The comparison results of the normalized crosstalk matrix of an 8-channel RF optical fronthaul system are shown.

[0026] Figure 10 A structural block diagram of an example wavelength division isolation anti-interference system for a radio frequency optical network front-back signal is shown according to an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] It should be noted that current technologies for addressing fiber nonlinear interference in fronthaul scenarios largely focus on local optimization of specific physical mechanisms. For example, some studies, starting from third-order nonlinear effects such as four-wave mixing, propose reducing crosstalk between different wavelength radio frequency optical carriers by increasing channel spacing, improving dispersion coefficients, or reducing transmit power. Other solutions attempt to suppress mixing sidelobes using rectangular optical filters and external modulation structures. However, most of these measures are based on fixed wavelength grids and preset worst-case scenarios, with parameters determined only once during link planning, making it difficult to reflect changes in service load and power distribution in a timely manner. Furthermore, to ensure that performance targets are met even in extreme scenarios, some available spectral resources must be sacrificed, significantly limiting fiber optic spectrum utilization.

[0029] To address nonlinear interference such as cross-phase modulation that varies with both power and dispersion, some studies have attempted to reduce phase crosstalk by selecting specific dispersion maps, adding dispersion compensation modules in each span, or optimizing fiber type. Other research has discussed using multimode or ultra-low-loss fibers in the fronthaul link at the system architecture level to improve overall transmission performance. However, these methods often require the introduction of additional components and complex link designs, increasing construction and maintenance costs. Furthermore, they primarily focus on the nonlinear interactions between signal beams, lacking systematic treatment of coupling issues such as beat noise and mode splitting noise generated when power beams and RF data signals are transmitted together on the same fiber.

[0030] Regarding power fiber optic power supply, some studies have shown that longitudinal mode beat frequency noise and mode splitting noise of high-power continuous wave power supply light are transferred to the radio frequency data signal via dispersion and nonlinear effects during co-fiber transmission. This leads to a deterioration in indicators such as bit error rate and error vector amplitude as the power supply light power increases. Existing solutions mostly improve PoF power supply performance from the perspectives of increasing photoelectric conversion efficiency and optimizing power budget, but pay less attention to the quantitative modeling and suppression mechanism of the coupling channel between "power light noise and wavelength division multiplexing (WDM) radio frequency signal". Usually, only coarse-grained isolation is achieved by reducing the power supply light power or adding a fixed sheath, which is difficult to balance power supply efficiency and interference suppression.

[0031] Furthermore, in the design of wavelength spacing and guard band width, some WDM systems adopt fixed spacing, fixed guard band, or simple "unequal spacing" rules to reduce the impact of specific nonlinear effects. In RF optical fronthaul and backhaul scenarios, fronthaul and backhaul, multi-standard and multi-band services are often configured in pairs, and symmetrical wavelength arrangements and static optical filter parameters are commonly used in engineering. As time changes, the number of channels carrying RF optical signals, service types, and the transmit power of each channel will fluctuate significantly. The above static configuration cannot accurately reflect the current interference relationship between channels, and can only reserve a large protection bandwidth and filtering margin, which wastes spectrum and makes it difficult to deal with interference degradation caused by power optical noise and multi-channel crosstalk in a timely manner.

[0032] Overall, current technologies typically handle wavelength division multiplexing interference between radio frequency (RF) beams and noise coupling of power beams to RF data signals separately: the former is optimized offline using fixed wavelength planning and linear / nonlinear compensation models, while the latter is isolated using simple power limiting or static guard band configuration. There is a lack of a dynamic anti-interference mechanism that unifies quantization of both, monitors in real-time, and drives the coordinated adjustment of multi-dimensional parameters such as light source wavelength, guard band width, filter bandwidth, and power beam output within the same framework. This deficiency makes it difficult for RF optical fronthaul systems to simultaneously meet the comprehensive requirements of high bandwidth, high spectral efficiency, and low interference in complex, time-varying interference environments.

[0033] It should be understood that the above description of the relevant technologies is intended only to help the public better understand the inventive spirit and motivation of this application, and is not intended to limit this application. Furthermore, the technical solutions described in the above-mentioned relevant technologies are not prior art, and may also be undisclosed technical solutions, such as those under research or in the laboratory stage.

[0034] The technical solutions in this application, including the collection, storage, use, processing, transmission, provision, and disclosure of users' personal information, comply with relevant laws and regulations and do not violate public order and good morals.

[0035] Figure 1 A flowchart illustrating an example of a wavelength division isolation anti-interference method for front-back signals in a radio frequency optical network according to an embodiment of this application is shown.

[0036] Regarding the execution subject of the method in the embodiments of this application, it can be any controller or processor with computing or processing capabilities. It can be a front-backhaul network that transmits radio frequency optical signals and power optical signals in an optical fiber link via wavelength division multiplexing, such as a centralized wavelength division resource management controller in the front-backhaul network. By executing program instructions stored in its storage medium, it obtains interference monitoring data of each wavelength channel in the optical fiber link, constructs a wavelength interference matrix and identifies interference clusters, and then sends target wavelength configuration parameters to the tunable light source and tunable optical filter. This enables the front-backhaul network to adaptively adjust the center wavelength, wavelength spacing and guard band width of each wavelength channel during the co-fiber transmission of multiple radio frequency optical signals and power optical signals, thereby enhancing the anti-interference capability of the link and improving the utilization efficiency of optical fiber spectrum resources.

[0037] In some examples, it may be integrated into an electronic device or terminal through software, hardware, or a combination of both, and the type of terminal or electronic device may be diverse.

[0038] like Figure 1As shown, in step S110, interference monitoring data of each wavelength channel in the optical fiber link is acquired. The interference monitoring data includes at least signal quality indicators used to characterize the quality of each radio frequency optical signal and power optical noise indicators used to characterize power optical noise.

[0039] In some implementations, interference monitoring modules can be installed at the centralized side equipment or aggregation node of the fronthaul / backhaul fiber optic link. Online monitoring is performed by extracting a small portion of the optical power from the optical path of each wavelength channel (e.g., using 1:99 or 2:98 optical splitters). For each wavelength channel carrying radio frequency optical signals, signal quality indicators characterizing the link transmission quality, such as bit error rate (BER), block error rate (BLER), error vector amplitude (EVM), carrier-to-noise ratio (CNR), and distortion indicators (e.g., third-order intermodulation product power), can be obtained after photoelectric conversion. These indicators can also be comprehensively evaluated in conjunction with parameters such as receiver RSSI and level margin. For wavelength channels carrying power light, high-speed photodetectors and power sampling circuits can be used to measure power light noise indicators such as relative intensity noise (RIN), low-frequency amplitude fluctuations, and spurious modulation components superimposed on the power light. Statistics are then performed within a time window to balance instantaneous fluctuations with long-term trends, forming noise characteristic quantities that can be used for subsequent analysis.

[0040] It should be understood that the term "wavelength channel" used in the context description of the embodiments of this application, if not explicitly distinguishing the type of signal carried, can be either a wavelength channel carrying radio frequency optical signals or a wavelength channel carrying power light, and should not be restricted by type.

[0041] In step S120, the interference intensity between each wavelength channel is determined based on the interference monitoring data, and a wavelength interference matrix is ​​constructed to characterize the interference relationship between each wavelength channel.

[0042] In some implementations, a channel interference assessment module is established in the network management and control unit. For a target RF wavelength channel, the changes in its signal quality indicators are compared as other channels are sequentially turned on / off or have their power changed. This allows for an estimation of the additional degradation caused by different channel combinations to the target channel. Alternatively, based on long-term monitoring data, the correlation or regression coefficients between quality fluctuations and power optical noise between different channels can be calculated to obtain an interference metric reflecting the coupling relationship between channels. For power optical channels, the impact of their noise indicators on the quality indicators of adjacent and specific frequency offset RF channels can be assessed, incorporating this type of coupling into the interference intensity evaluation.

[0043] Specifically, the signal quality index and power optical noise index of each wavelength channel can be used as input features. Statistical correlation analysis, power spectrum superposition analysis, or a pre-calibrated nonlinear interference model can be used to evaluate the degree of interference coupling between different wavelength channels. For example, within an observation window, for the signal quality fluctuation of channel i, the correlation between its transmission power change and power optical noise index change with adjacent or specific channel j can be analyzed. When the correlation is high and the preset conditions are met, j can be considered to have a significant interference contribution to i, and the corresponding interference intensity value can be calculated based on the correlation strength, spectral spacing, and power configuration.

[0044] The matrix elements in the wavelength interference matrix are used to characterize 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, facilitating comparison with data from different link configurations and time periods. By constructing this wavelength interference matrix, signal quality and noise observation data originally scattered across various channels can be organized into a holistic interference relationship picture, clearly depicting which wavelengths constitute the main sources of interference to which wavelengths.

[0045] In step S130, a topological analysis is performed on the interference intensity of each wavelength channel based on the wavelength interference matrix, the interference 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 implementations, the wavelength interference matrix can be viewed as a weighted graph structure with wavelength channels as nodes and normalized interference intensity as edge weights. Node metric analysis is then performed on this graph, such as calculating the sum of interference intensities of each wavelength channel with other channels, the maximum interference intensity, or the weighting degree, as an interference index for that channel. Channels with larger interference indices indicate that they are in a highly coupled and sensitive position in the interference topology, potentially representing both a primary victim and a significant perpetrator of interference.

[0047] After obtaining the interference index, the elements in the wavelength interference matrix can be truncated according to a preset interference threshold. Channel pairs with interference intensity exceeding the threshold are considered to have "strong interference connections." Then, connected subgraphs or clusters under these strong connections are identified and defined as interference clusters. Each interference cluster contains a set of wavelength channels highly coupled in terms of interference relationships. Starting from the global interference relationships through topology analysis, interference coupling regions are delineated in the spectral domain, effectively extracting a small set of "problem channels" that have a concentrated and significant impact on link performance. This results in a set of wavelength channels that require focused isolation and optimization from a global perspective.

[0048] In step S140, based on the wavelength interference matrix and at least one interference cluster, the target wavelength configuration parameters are adaptively determined according to the interference intensity between each wavelength channel, such that in the target wavelength configuration parameters, 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.

[0049] The target wavelength configuration parameters include: the center wavelength of each wavelength channel, the wavelength spacing between adjacent wavelength channels, the sheath width on both sides of each wavelength channel, and the bandwidth of the optical filter used to filter each wavelength channel.

[0050] In one example of this application's embodiments, under the constraints of a preset available spectral range and device tunability, the wavelength interference matrix and interference cluster information can be mapped to a spectral planning problem. Through heuristic search or optimization solutions, channels within interference clusters are preferentially allocated larger spectral spacing or wider guard bands. Simultaneously, more suitable passband widths and roll-off characteristics are set for the corresponding optical filters to reduce the effective bandwidth of spectral overlap and nonlinear coupling between channels. Furthermore, for wavelength channels not belonging to interference clusters, a relatively compact spectral layout and smaller guard band width can be maintained to accommodate more service channels or leave room for expansion even with limited overall spectral resources.

[0051] In another example of this application's embodiments, an optimization model can be constructed with "interference intensity" as the cost function and spectral resources and device tuning range as constraints. By adjusting the center wavelength of each wavelength channel, the wavelength spacing between adjacent wavelength channels, and the width of the side guard bands, an iterative search is performed to find parameter combinations that reduce the overall interference level of key channels and channels within interference clusters. Specifically, for channels within interference clusters, a larger minimum wavelength spacing requirement can be set, or a wider guard band can be reserved near the power light wavelength to reduce the injection of nonlinear products and power light noise into these channels. For channels not belonging to interference clusters, a relatively compact spacing and a narrower guard band can be used to improve spectral utilization. Based on the determined wavelength spacing and guard band width, a relatively narrower filter bandwidth is configured for channels within interference clusters to suppress four-wave mixing products and power light noise sidebands falling at the channel edges; a slightly wider filter bandwidth is used for channels with weaker interference to ensure signal waveform integrity and dispersion tolerance.

[0052] By implementing differentiated configurations for channels with different interference levels, the target wavelength configuration parameters achieve an overall strategy of "key channels being isolated and general channels being arranged compactly." This effectively reduces the impact of strong interference on link performance without blindly sacrificing spectral efficiency, and improves the overall transmission quality and spectral utilization in multi-channel RF optical and power optical co-fiber transmission scenarios.

[0053] In step S150, the adjustable light source and adjustable optical filter in the forward backhaul network are controlled according to the target wavelength configuration parameters to adjust the center wavelength and optical filter bandwidth of each wavelength channel so that each wavelength channel operates under the target wavelength configuration parameters after adjustment.

[0054] In some implementations, a wavelength configuration distribution module can be set in the centralized controller of the fronthaul network to convert the target wavelength configuration parameters into the operating wavelength setting values ​​of each tunable laser and the center wavelength, passband width, and edge attenuation characteristic parameters of each tunable optical filter. This module is then distributed to the corresponding devices through a standardized control interface or network management protocol to drive the lasers to perform micro-step tuning and drive the tunable filters to adjust their center wavelength and bandwidth.

[0055] After the above adjustments are completed, the actual operating wavelength, channel spacing and guard band width of each wavelength channel are consistent with the target configuration. The physical spectrum layout of the optical layer is reshaped with the interference environment, which significantly weakens the crosstalk path of the channel within the interference cluster, while the channel of the non-interference cluster maintains a high spectral compactness.

[0056] Through the embodiments of this application, an interference transmission matrix based on interference monitoring and modeling is formed. Target configuration parameters are optimized and controlled by tunable devices, enabling wavelength configuration to evolve dynamically with the interference environment and service status, rather than being a fixed initial design. Therefore, without altering the existing fiber optic infrastructure, continuous optimization of the anti-interference capability and spectral utilization efficiency of the ARoF+PoF composite fronthaul / backhaul link is achieved through the coordinated control of tunable light sources and tunable optical filters, ensuring link stability and service carrying capacity when multiple RF optical signals and power optical signals are transmitted on the same fiber.

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

[0063] in, For frequency, Indicates wavelength channel Signal power; aggregation of all channels This constitutes a two-dimensional wavelength interference matrix. Indicates channel For the channel The relative interference intensity.

[0064] By examining all channel pairs Calculated The interference is aggregated to form a two-dimensional wavelength interference matrix. This matrix describes the interference coupling relationship between any two wavelength channels with dimensionless relative interference intensity, thereby compressing the complex frequency domain crosstalk distribution into a matrix form that is easy to process for subsequent topology analysis and interference cluster identification. This enables quantitative characterization and computable modeling of inter-channel interference in co-fiber transmission.

[0065] In some examples of embodiments of this application, the wavelength division multiplexing (WDM) isolation anti-interference method is repeatedly executed in multiple control cycles using an adaptive closed-loop control approach. Specifically, after completing interference monitoring data acquisition, wavelength interference matrix construction, interference cluster identification, and target wavelength configuration parameter distribution in each control cycle, the controller caches the configuration results of the current cycle along with the monitoring data status for comparison and decision-making in subsequent cycles. The optical layer wavelength layout can be continuously iteratively updated according to the link operating status, ensuring that the wavelength spacing, guard band width, and optical filter bandwidth always match the current interference pattern, thereby achieving continuous suppression of nonlinear interference and power optical noise during long-term operation.

[0066] Figure 2 A flowchart illustrating an example of a wavelength division multiplexing (WDM) isolation anti-interference method with a periodic iterative closed-loop control mechanism according to an embodiment of this application is shown.

[0067] like Figure 2 As shown, in step S210, at the end of each control cycle, 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 parameters are updated.

[0068] Based on this, the controller dynamically sets the cycle length of the next control cycle according to the signal quality and power-optical noise indices of each wavelength channel. For example, when the signal quality index of any wavelength channel is lower than a preset quality threshold and / or the power-optical noise index is higher than a preset noise threshold, the current link is determined to be in a state of high interference risk or noise degradation, and the control cycle is shortened to improve the response frequency of closed-loop regulation. When the signal quality index of all wavelength channels is higher than the preset quality threshold and the power-optical noise index is lower than the preset noise threshold, the link is determined to be operating stably, and the control cycle is appropriately extended to reduce the overhead and wavelength switching disturbances caused by frequent reconfiguration. Thus, through adaptive adjustment of the cycle length, fine control of the reconfiguration frequency of wavelength division multiplexing (WDM) resources is achieved while taking into account both the timeliness of regulation and system stability.

[0069] In step S220, between two adjacent control cycles, when the change in the signal quality index, interference index, and / or power optical noise index of any wavelength channel exceeds the preset disturbance threshold, the target wavelength configuration parameters are recalculated in advance, and the adjustment operations of the tunable light source and tunable optical filter in the forward backhaul network are performed.

[0070] In some implementations, the controller continuously monitors the short-term trends of signal quality, interference, and power optical noise indicators for each wavelength channel between two adjacent control cycles, and calculates the differential or relative rate of change with the corresponding indicators from the previous moment or cycle. When the change in any indicator exceeds a preset disturbance threshold (e.g., a sudden drop in signal quality, a significant increase in interference, or a sharp increase in power optical noise), it is considered that the current link has suffered a sudden change in service load, equipment malfunction, or fiber optic physical environment disturbance. This triggers the early execution of wavelength interference matrix updates, interference cluster re-identification, and recalculation of target wavelength configuration parameters, and simultaneously issues adjustment commands to the tunable light source and tunable optical filter without waiting for the original control cycle to end. Thus, by adding an early triggering mechanism based on disturbance detection in addition to periodic closed-loop adjustment, it is possible to maintain a stable overall control rhythm while responding quickly to sudden interference events, further improving the anti-interference capability and transmission performance stability of the fronthaul / backhaul network in dynamic and complex scenarios.

[0071] Figure 3 A flowchart illustrating an example of dividing at least one interference cluster based on a wavelength interference matrix according to an embodiment of this application is shown.

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

[0073] Equation (2)

[0074] In the formula, and These represent wavelength channels. The corresponding total interference and maximum peer interference.

[0075] Specifically, Indicates wavelength channel The sum of the normalized interference intensities from all other channels is used to characterize the “total interference level” of that channel in the overall interference topology. Indicates all wavelength channels The maximum single peer interference intensity in channels with interfering relationships is used to characterize the channel. The coupling strength with its "strongest interfering neighbor" is used to characterize the importance and sensitivity of each wavelength channel in the interference network from both global and local dimensions.

[0076] In step S320, based on the total interference of each wavelength channel Sort from largest to smallest, and calculate the total interference. Wavelength channels with a total interference level greater than a preset threshold are marked as high interference channels to obtain a set of high interference channels.

[0077] Here, the setting of the preset total interference threshold can be varied. For example, it can be predefined according to requirements, or it can be set based on the system's allowed interference tolerance, historical operating statistics, or offline simulation results. For instance, channels in the percentile of the statistical distribution can be selected as high-interference candidates. By filtering based on total interference, only a subset of channels in the overall interference network that suffer the most severe cumulative interference can be retained. This reduces the computational complexity of subsequent graph structure analysis and allows resource reconfiguration and spectral isolation strategies to focus on the set of channels that have the greatest impact on link performance, thereby improving the targeting and efficiency of subsequent wavelength adjustments.

[0078] In step S330, for any two wavelength channels and When matrix elements Not less than the relative interference coefficient threshold With maximum peer interference and When multiplying the smaller of the two, the wavelength channel is... With wavelength channel The combination was determined to be a strong interference link.

[0079] Specifically, when matrix elements Not less than the relative interference coefficient threshold With maximum peer interference and When the product of the smaller of the two is used, the following equation is satisfied:

[0080] Equation (3)

[0081] In the formula, This is a preset relative interference coefficient threshold, typically between 0 and 1, used to control the strictness of determining strong interference links. This reflects the principle of using the "weaker interference side" of the two channels as the benchmark, only when... The mutual interference between the two is considered significant only when it reaches at least a certain proportion of the smaller maximum peer interference.

[0082] By constraining Equation (3), we can avoid mistakenly marking two channels as strong interference pairs due to a single weak unidirectional crosstalk, and ensure that the channel pairs identified as strong interference links have relatively prominent interference relationships 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 used as the set of nodes of the graph structure, and all wavelength channel pairs that satisfy the strong interference link condition are used as the set of edges of the graph structure. Connectivity analysis is performed on the graph structure, and wavelength channels that are interconnected through strong interference links are divided into the same interference cluster, so that each interference cluster is composed of wavelength channels that satisfy the strong interference link condition in the wavelength interference matrix.

[0084] In some implementations, the controller uses the set of high-interference channels as the node set of the graph structure and all wavelength channel pairs that satisfy the strong interference link condition of equation (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, by using connectivity component identification algorithms such as depth-first search, breadth-first search, or disjoint-set data structure, to find all node subsets that are reachable from each other through strong interference links, and each connected subset is divided into an interference cluster. Thus, each interference cluster is composed of wavelength channels with strong mutual interference relationships in the wavelength interference matrix, and any two channels within the cluster can be interconnected through one or more strong interference link paths. Therefore, through the above cluster partitioning process based on graph connectivity, highly coupled channel groups can be automatically extracted from complex inter-channel interference networks.

[0085] Figure 4 A flowchart illustrating 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 this 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 Calculate wavelength offset This is done so that adjacent wavelength channels within at least one interference cluster and identified as strong interference links have opposite offset directions in wavelength arrangement, and the spacing between the adjusted center wavelengths of corresponding adjacent wavelength channels is increased, and the adjusted center wavelength is determined based on the wavelength offset. .

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

[0088] Equation (4)

[0089] In the formula, The learning rate coefficient is used to control the step size of wavelength adjustment within each control cycle, so as to avoid excessive one-time offset that could cause link instability. Wavelength channel The center wavelength before adjustment Wavelength channel The signal power. This is a sign function used to indicate the wavelength channel. Relative to wavelength channel The relative orientation in wavelength arrangement, when When the time is positive, The time is negative, used to indicate the channel. Relative to channel Relative orientation in wavelength arrangement; This indicates the interval between the two channels on the wavelength index, used to attenuate the interference contribution of distant channels, reflecting that closer channels have a greater impact on the offset.

[0090] As can be seen from equation (4), when the channel For the channel Interference intensity Larger and signal power At higher levels, it will be in the relative direction between the channel and the channel. This produces a more pronounced "push-away" effect, causing adjacent wavelength channels identified as strong interference links to have opposite offset directions on the wavelength axis within at least one interference cluster, resulting in increased spacing between the center wavelengths after adjustment. By using vector-based wavelength offset updates weighted by interference intensity and power, it is possible to adaptively "distance" adjacent high-interference channels while maintaining the continuity of the overall wavelength layout, thus achieving spectral decoupling of strong interference links.

[0091] In step S420, for each wavelength channel belonging to at least one interference cluster... 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 total interference and maximum peer interference in the wavelength interference matrix, thus meeting crosstalk suppression requirements without the need for additional guard band extension. By configuring the channels outside the interference cluster with the minimum guard band and the channels inside the interference cluster with a larger guard band width according to equation (5), a differentiated spectral layout of "key protection for 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 achieve stronger isolation in the guard band and filter passband dimensions, which is beneficial 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 overall utilization efficiency of the fiber optic spectrum and the number of channels that can be carried.

[0099] As a further preferred embodiment of this application, when the power optical noise index is detected to exceed a preset noise threshold, the proportional coefficient of the system's nonlinear sensitivity is increased. And based on the adjusted Recalculate the bandgap width of each wavelength channel within the interference cluster. and the corresponding optical filter bandwidth This allows for adaptive widening of the guard band width of the wavelength channels within the interference cluster, thereby improving the wavelength division isolation between power light and radio frequency optical signals.

[0100] Specifically, it can be mapped according to a preset mapping relationship. Increase the base value to an amplification value that matches the current noise level, and while keeping the calculation forms of equations (5) and (6) unchanged, based on the adjusted... Recalculate the bandgap width of each wavelength channel within the interference cluster. and the corresponding optical filter bandwidth .because Increasing this will amplify the maximum peer interference. The contribution to the sheath width makes the sheath width of high interference channels, especially those close to the power light wavelength, further widen relative to the normal state, thereby adaptively widening the spectral isolation band of wavelength channels within the interference cluster when the power light noise deteriorates.

[0101] This adaptive relaxation mechanism can promptly increase the effective spectral isolation between the power light wavelength and the adjacent radio frequency light wavelength when the power light noise is high, thereby enhancing the suppression of power light noise and related nonlinear products. Meanwhile, when the power light noise is at a normal level, there is no need to increase the isolation. This avoids occupying too much sheathing resources for a long time, and ensures the quality of radio frequency optical transmission while taking into account the spectrum utilization efficiency of PoF power supply wavelength and multiple ARoF services.

[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] Equation (7)

[0109] In the formula, The number of wavelength channels that carry radio frequency optical signals.

[0110] In equation (7), This can be understood as power optical noise in the channel. The equivalent relative interference is obtained by summing over all RF channels. This reflects the overall coupling strength of the current power optical noise to the entire ARoF service channel set. Therefore, the physical power optical noise intensity is multiplied by the spectral coupling relationship to form a single quantitative indicator. It directly reflects the overall interference level of current power optical noise across the entire set of radio frequency service wavelengths, providing a quantitative criterion for closed-loop adjustment of power optical output power.

[0111] In step S530, after detecting the overall contribution... Exceeding the preset noise coupling threshold In this case, adjust the output power of the power light source.

[0112] Specifically, the controller continuously compares the overall contribution. Coupled with preset noise threshold When detected When the system determines that the overall interference of the current power optical noise on the RF optical channel through nonlinear coupling and co-fiber transmission has exceeded the system's allowable range, it triggers automatic adjustment of the power source output power. Specifically, the new power optical output power can be calculated according to the following proportional relationship:

[0113] Equation (8)

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

[0115] In equation (8), when When, the scaling factor This allows the power output power to be reduced proportionally to the degree of interference exceeding the limit. Through the above closed-loop control mechanism, while ensuring that the PoF still has sufficient power supply capacity, the overall interference contribution of power optical noise in the wavelength interference matrix can be automatically suppressed, so that the crosstalk of PoF noise to each radio frequency optical channel is kept within the preset tolerance, thereby improving the anti-interference performance and long-term operational stability of the multi-channel radio frequency optical and power optical co-fiber transmission link.

[0116] As a further preferred embodiment of the present application, when When reducing the output power of the power light alone is insufficient to bring the overall contribution back below the threshold, the polarization state of the power light source is adjusted by the polarization controller to a polarization state that is approximately orthogonal to the characteristic polarization state of each radio frequency optical signal. This is done by using the polarization extinction ratio to suppress the coupling of the mode splitting noise and longitudinal mode beat frequency noise of the power light to the radio frequency optical signals corresponding to each wavelength channel, thereby further reducing the overall contribution of power light noise to the interference intensity in the wavelength interference matrix.

[0117] Specifically, by performing polarization analysis or pre-calibration on the output light of each wavelength channel carrying the radio frequency optical signal, the characteristic polarization state of each channel can be obtained. Then, the controller calculates the target polarization direction that is approximately orthogonal to this set of characteristic polarization states and drives the polarization controller to adjust the polarization state of the power light to this target polarization direction. Since the power light and the radio frequency optical signal are nearly orthogonal in polarization space, the mode splitting noise and longitudinal mode beat frequency noise of the power light will be significantly suppressed by the polarization extinction ratio when coupled to the corresponding radio frequency optical signals of each wavelength channel through the optical fiber. This effectively reduces the interference intensity matrix elements in the wavelength interference matrix pointing from the power light channel to each radio frequency channel, further reducing the contribution of power light noise to the overall interference intensity and improving the anti-interference margin and stability of the PoF and multi-channel radio frequency optical co-fiber transmission link.

[0118] Figure 6 A structural block diagram of an example of a fronthaul / backhaul network according to an embodiment of this application is shown.

[0119] like Figure 6 As shown, the fronthaul network 600 includes integrated photonic chips 610, 620...6N0 deployed in each remote radio frequency unit, and a central controller 620 that is communicatively connected to each integrated photonic chip.

[0120] Each integrated photonic chip 610 integrates a tunable laser 611, a micro-ring resonator array 612, and a photodetector 613.

[0121] The tunable laser 611 is used to emit an optical carrier 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.

[0122] The micro-ring resonator array 612 is used to perform bandpass filtering on the optical signals entering each wavelength channel according to the optical filter bandwidth and guard band width of each wavelength channel in the target wavelength configuration parameters, so as to form adjustable wavelength channel filtering characteristics.

[0123] The photodetector 613 is used to receive a portion of the optical power split out in the optical fiber link where each wavelength channel is located via an 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 perform the wavelength division isolation anti-interference method for the front-backhaul signal of the radio frequency optical network as described in any of the preceding claims of this application, to determine the target wavelength configuration parameters based on the interference monitoring data during operation, and to enable the front-backhaul network to operate under the target wavelength configuration parameters by controlling the tunable laser and the microring resonator array.

[0125] Through the above structural configuration, the tunable laser, reconfigurable optical filter unit, and interference monitoring and detection unit are integrated into the photonic chip of the remote radio frequency unit. The central controller uniformly executes wavelength interference modeling and target wavelength configuration parameter calculation, realizing a closed-loop control link of local real-time perception, central collaborative decision-making, and rapid execution at the optical layer. Thus, on the one hand, the integrated photonic chip provides local tunable wavelength and bandwidth-tunable transmission and filtering capabilities, allowing the configuration parameters such as center wavelength, guard band width, and optical filter bandwidth calculated by the central controller to be precisely applied to each wavelength channel, thereby enhancing isolation of key channels within interference clusters. On the other hand, the interference monitoring data fed back by the photodetector continuously reflects the actual coupling of radio frequency optical signals and power optical noise in co-fiber transmission, enabling the network to automatically converge to a wavelength division configuration state matching the current interference environment during long-term operation. This improves the anti-interference capability and spectrum resource utilization efficiency of the fronthaul system in PoF and multi-channel radio frequency optical co-fiber scenarios.

[0126] Figure 7 A flowchart illustrating the operating mechanism of an example of a wavelength division isolation anti-interference method for radio frequency optical network front-back signals according to an embodiment of this application is shown.

[0127] like Figure 7 As shown, the wavelength division isolation anti-interference method for front-back signals in radio frequency optical networks takes photonic sensor data as input. First, the interference monitoring data of each wavelength channel is processed by the Wavelength Interference Matrix (WIM) module to generate a wavelength interference matrix characterizing the normalized interference intensity relationship between channels. Then, the Spectral Interference Topology Analysis (SITA) module calculates the interference index of each channel based on the WIM and identifies interference clusters. The interference topology results are sent to the dynamic control logic for adaptively setting the control cycle, interference threshold, and control parameters related to power beam and guard band configuration.

[0128] Furthermore, the Adaptive Wavelength Allocation and Filtering (AWAF) module reconstructs the center wavelength and filtering bandwidth of each wavelength channel based on the target wavelength configuration parameters output by the dynamic control logic. Combined with interference-aware guard band insertion, it reserves wider guard bands for critical channels within interference clusters and adopts a compact guard band layout for channels outside interference clusters, thereby forming a differentiated spectral allocation for interference awareness. The above processing results in an optical channel with minimized interference, which manifests as improved signal quality at the receiver, achieving adaptive wavelength division isolation and anti-interference optimization in scenarios involving power optical and multi-path RF optical co-fiber transmission.

[0129] To verify the effectiveness of the proposed WIM+AWAF wavelength division isolation anti-interference method, a simulation environment for an 8-channel RF optical fronthaul / backhaul system was constructed. In the simulation, the initial wavelength spacing of each RF optical channel was set to 100 GHz, and the power light used a 10W continuous wave laser source, transmitted along the same fiber as each RF optical channel. An initial wavelength interference matrix was randomly generated based on system dispersion, nonlinear coefficients, and power configuration to comprehensively simulate inter-channel crosstalk caused by FWM, XPM, and power light noise coupling. Based on this, baseline schemes with traditional fixed wavelengths and fixed filters were configured, as well as the proposed method using WIM calculation and AWAF adaptive wavelength / filter reconfiguration. During the simulation, the WIM+AWAF algorithm was iteratively executed, and the changes in total crosstalk power, single-channel error vector amplitude, and wavelength interference matrix were recorded for each iteration.

[0130] Figure 8 This is a schematic diagram illustrating an example of the comparison results of the total crosstalk power of different methods as a function of the number of iterations.

[0131] like Figure 8 As shown, the crosstalk power of the baseline scheme remains unchanged, and the total crosstalk power is basically maintained at an initial level of about 18 within the range of 0 to 10 iterations. The solid block curve represents the simulation results when using the proposed WIM+AWAF method. With the increase of the number of iterations, the total crosstalk power shows a monotonically decreasing trend, gradually decreasing from the initial value of about 18, and dropping to about 7 by the 10th iteration. It can be seen that the total crosstalk power has decreased significantly in 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%, which verifies the effectiveness of the proposed WIM+AWAF method in terms of iterative convergence and inter-channel interference suppression capability.

[0132] Figure 9The comparison results of the normalized crosstalk matrix of an 8-channel RF optical fronthaul system are shown. The horizontal and vertical axes in the figure are channel indices. The color intensity of the matrix elements represents the normalized crosstalk intensity of the corresponding transmit channel to the receive channel. The darker the color, the stronger the crosstalk. The diagonal elements are set to zero and not plotted. Figure 9 The left side shows the "baseline crosstalk matrix," which corresponds to the initial interference distribution under traditional fixed wavelength and fixed filter configuration. It can be seen that there are obvious dark bands near the main diagonal, indicating that there is strong crosstalk between adjacent and next-nearest channels. These high crosstalk regions correspond to the channel combinations in the aforementioned interference clusters.

[0133] Figure 9 The "Adapted Crosstalk Matrix" on the right shows the crosstalk distribution obtained after multiple iterations using WIM calculation and the AWAF algorithm under the same simulation conditions. Compared to the baseline, the overall color of the matrix is ​​significantly lighter, and the maximum normalized crosstalk intensity decreases from approximately 0.6 in the left figure to approximately 0.14 in the right figure. In particular, the corresponding matrix elements of adjacent channel pairs that originally belonged to the interference clusters have changed from dark blocks to light blocks, indicating that effective isolation of high crosstalk links has been achieved by expanding the guard band, adjusting the center wavelength, and reconfiguring the filter bandwidth. Thus, it is verified that the proposed WIM+AWAF method can not only reduce the total crosstalk power but also reshape the inter-channel interference topology at the matrix level, significantly weakening the interference concentration area and thus significantly improving the overall signal quality of the system.

[0134] This paper addresses the interference problem of multi-channel wavelength division multiplexing (WDM) in the fronthaul / backhaul link of radio frequency optical networks, proposing a wavelength division isolation anti-interference method. This method constructs a wavelength interference matrix and identifies interference clusters by real-time measurement of channel crosstalk and power optical noise; dynamically calculates wavelength offset and guard band based on the interference level using an adaptive wavelength allocation and filtering algorithm; suppresses power optical noise coupling through power and polarization optimization; and finally forms a closed-loop control mechanism. Compared with existing schemes relying on fixed spacing, dispersion compensation, or single filters, the proposed scheme can significantly reduce crosstalk caused by FWM, XPM, and power optical coupling while ensuring spectral efficiency, thus improving the reliability and capacity of the fronthaul / backhaul system. Simulation results show that the proposed algorithm can reduce the total crosstalk power by approximately 50% within several iterations and exhibits good adaptability to changes in power optical noise.

[0135] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of combined actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Secondly, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application. In the above embodiments, the descriptions of each embodiment have their own emphasis; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0136] Figure 10 A structural block diagram of an example wavelength division isolation anti-interference system for radio frequency optical network front-back signals, according to an embodiment of this application, is shown. The system is deployed at a remote wireless node.

[0137] like Figure 10 As shown, the wavelength division isolation anti-interference system 1000 for radio frequency optical network front-back signals 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 used to acquire interference monitoring data for each wavelength channel in the optical fiber link. The interference monitoring data includes at least 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.

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

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

[0141] The target wavelength configuration determination unit 1040 is used to adaptively determine target wavelength configuration parameters based on the wavelength interference matrix and the at least one interference cluster, according to the interference intensity between each wavelength channel, such that in the target wavelength configuration parameters, 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 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 used to control the tunable light source and tunable optical filter in the front-backhaul network according to the target wavelength configuration parameters, and to adjust the center wavelength and optical filter bandwidth of each wavelength channel so that each wavelength channel operates under the target wavelength configuration parameters after adjustment.

[0143] In some embodiments, this application provides a non-volatile computer-readable storage medium storing 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, server, or network device) to perform the steps of the wavelength division isolation anti-interference method for the front-back signal of any of the above claims of this application.

[0144] In some embodiments, this application also provides a computer program product, the computer program product including a computer program stored on a non-volatile computer-readable storage medium, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the steps of any of the above-described wavelength division isolation anti-interference methods for radio frequency optical network front-back signals.

[0145] In some embodiments, this application also provides an electronic device comprising: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the steps of a wavelength division isolation anti-interference method for radio frequency optical network front-back signals.

[0146] The above-described product can perform the methods provided in the embodiments of this application, and has the corresponding functional modules and beneficial effects for performing the methods. Technical details not described in detail in this embodiment can be found in the methods provided in the embodiments of this application.

[0147] The electronic devices in this application can exist in various forms, including but not limited to: mobile communication devices, ultra-mobile personal computer devices, portable entertainment devices, or other airborne electronic devices with data interaction functions.

[0148] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0149] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this 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 a radio frequency optical signal reading from the wavelength interference matrix a matrix element pointing to a wavelength channel and calculating a power optical noise contribution relative to a crosstalk of the respective wavelength channel based on the power noise intensity parameter and the respective matrix element :​ ， 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 and the optical filter bandwidth of each wavelength channel, so that the adjusted each wavelength channel works under the target wavelength configuration parameters.

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