Leaky cable-based high-frequency signal transmission method and device, and electronic device

Abstract

The application discloses a leaky cable-based high-frequency signal transmission method and device and electronic equipment, and relates to the technical field of communication. The method comprises the following steps: determining the type of each existing leaky cable and an abnormal joint list based on the physical characteristics, transmission characteristics of each existing leaky cable in a subway system and the transmission requirement of a high-frequency signal; determining the output power of a preset device based on the interval length of a target leaky cable; adding a preset device meeting the output power, connecting the preset device with the starting point of the target leaky cable, optimizing the impedance matching between the preset device and the starting point of the target leaky cable, and obtaining a first link; replacing the abnormal joint in the first link based on the abnormal joint list, integrating a preset filter for the first link, adding a preset load at the end of the target leaky cable in the first link, and obtaining a second link; and transmitting a high-frequency signal through the second link. The application solves the technical problems of high cost and long construction period in the prior art for transforming the existing leaky cable in a subway.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a high-frequency signal transmission method, apparatus, and electronic device based on leaky cable. Background Technology

[0002] 5G network coverage in subway tunnels mainly relies on leaky cables (referred to as leaky cables) to achieve uniform signal radiation. Leaky cable lines are the core carriers of wireless coverage in rail transit scenarios. In the early subway lines, leaky cables were mostly laid during the 2G / 4G era, and the nominal cutoff frequency was usually set at 3GHz. However, the current main frequency band of 5G networks is set at 3.3-3.6GHz, which exceeds the nominal cutoff frequency of existing leaky cables in the subway system.

[0003] The industry generally believes that when the frequency of the transmitted signal exceeds the nominal cutoff frequency of the leaky cable, the signal transmission loss will increase sharply, making it impossible to achieve effective signal coverage in the subway system. Therefore, the existing 5G transformation scheme for subway leaky cable lines adopts a transformation scheme that completely re-lays new leaky cables adapted to the 5G high-frequency band. However, the transformation cost of re-laying is extremely high, and the construction requires a lot of manpower and material resources. The overall construction period of the transformation scheme is long. At the same time, due to the short maintenance window of the subway system, it also leads to derivative problems such as high construction difficulty and high risk of damage to existing facilities.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This application provides a high-frequency signal transmission method, apparatus, and electronic device based on leaky cable, to at least solve the technical problems of high cost and long construction period in the prior art of retrofitting existing leaky cables in subways.

[0006] According to one aspect of this application, a high-frequency signal transmission method based on leaky cable is provided, comprising: determining the type and abnormal connector list of each existing leaky cable in a subway system based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable, wherein the type is an existing type that can be used or a type that needs to be newly built, and the abnormal connectors in the abnormal connector list are leaky cable connectors whose connector performance is less than a preset performance; determining the output power of a preset device based on the interval length of a target leaky cable, wherein the preset device is used to achieve power compensation, and the target leaky cable is an existing leaky cable of an existing type that can be reused; adding a preset device that meets the output power, connecting the preset device to the starting point of the target leaky cable, and optimizing the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link; replacing the abnormal connectors in the first link based on the abnormal connector list, integrating a preset filter into the first link, and adding a preset load at the end of the target leaky cable in the first link to obtain a second link, and then transmitting a high-frequency signal through the second link, wherein the preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0007] Optionally, before determining the type and abnormal connector list of each existing leaky cable based on its physical characteristics, transmission characteristics, and high-frequency signal transmission requirements in the subway system, the high-frequency signal transmission method based on leaky cables further includes: acquiring the high-frequency signal transmission requirements in the subway system, wherein the transmission requirements include at least the average length of the subway tunnel, the transmission frequency band of the high-frequency signal, the signal receiving power threshold, and the signal-to-noise ratio threshold; collecting the physical characteristics of each existing leaky cable, wherein the physical characteristics include at least the cable specifications, slotting method, manufacturer, service life, and physical integrity; and performing a frequency sweep test on each existing leaky cable using a network analyzer to obtain the transmission characteristics of each existing leaky cable, wherein the frequency band of the frequency sweep test includes at least the transmission frequency band of the high-frequency signal, and the transmission characteristics include at least transmission loss, VSWR, and connector performance.

[0008] Optionally, based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, the type and abnormal connector list of each existing leaky cable are determined, including: obtaining the preset power set by the preset equipment under the average value of the subway tunnel length included in the transmission requirements; inputting the physical characteristics, transmission characteristics, and preset power of each existing leaky cable into an end-to-end link budget evaluation model to obtain the predicted signal received power and predicted signal-to-noise ratio of each existing leaky cable; if the predicted signal received power is greater than or equal to the signal received power threshold, and the predicted signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold, the corresponding existing leaky cable is determined to be of the usable old type; if the predicted signal received power is less than the signal received power threshold, and / or the predicted signal-to-noise ratio is less than the signal-to-noise ratio threshold, the corresponding existing leaky cable is determined to be of the type that needs to be newly built; and determining the abnormal connector list based on the connector performance in the transmission characteristics of each existing leaky cable.

[0009] Optionally, determining the output power of the preset device based on the interval length of the target leaky cable includes: when the interval length is less than or equal to a first preset length, using the first preset power as the output power of the preset device in the high-frequency signal transmission band; when the interval length is greater than the first preset length and less than or equal to a second preset length, using the second preset power as the output power of the preset device in the high-frequency signal transmission band, wherein the second preset length is greater than the first preset length and the second preset power is greater than the first preset power; when the interval length is greater than the second preset length and less than or equal to the average length of the subway tunnel, using the third preset power as the output power of the preset device in the high-frequency signal transmission band, wherein the second preset length is less than the average length and the third preset power is greater than the second preset power.

[0010] Optionally, the impedance matching between the preset device and the starting point of the target leaky cable is optimized, including: determining the target matching network based on the preset standard impedance using the Smith chart simulation tool, wherein the target matching network is used to reduce the return loss between the preset device and the starting point of the target leaky cable; and adding the target matching network to the output end of the preset device.

[0011] Optionally, after obtaining the second link, the high-frequency signal transmission method based on the leaky cable further includes: performing static testing on the second link using testing equipment to obtain P static indicators, where P is a positive integer, and the testing equipment includes at least a VSWR tester, an intermodulation tester, and a network analyzer; the P static indicators include at least VSWR, third-order intermodulation rejection, insertion loss, and return loss; performing full-range mobile network testing on the second link in a subway tunnel using drive testing equipment to obtain Q dynamic indicators, where Q is a positive integer, and the Q dynamic indicators include at least reference signal received power, measured signal-to-noise ratio, signal coverage, uplink and downlink rates, latency, and handover success rate; and performing hierarchical optimization of the second link based on the P static indicators and the Q dynamic indicators.

[0012] Optionally, the optimization strategies used in the hierarchical optimization include at least: a first-level parameter optimization strategy, used to update the output power, frequency band matching parameters, and filter configuration of the preset equipment; a second-level engineering optimization strategy, used to replace abnormal connectors and faulty devices in the link; and a third-level supplementary optimization strategy, used to add preset equipment or signal relay units.

[0013] According to another aspect of this application, a high-frequency signal transmission device based on leaky cable is also provided, comprising: a first determining unit, configured to determine the type and abnormal connector list of each existing leaky cable based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in a subway system, wherein the type is an existing type that can be used or a type that needs to be newly built, and the abnormal connectors in the abnormal connector list are leaky cable connectors whose connector performance is less than a preset performance; a second determining unit, configured to determine the output power of a preset device based on the interval length of a target leaky cable, wherein the preset device is used to achieve power compensation, and the target leaky cable is an existing leaky cable of an existing type that can be reused; a first link setting unit, configured to add a preset device that meets the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link; a second link setting unit, configured to replace the abnormal connectors in the first link based on the abnormal connector list, integrate a preset filter for the first link, and add a preset load to the end of the target leaky cable in the first link to obtain a second link, and then transmit high-frequency signals through the second link, wherein the preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0014] According to another aspect of this application, a computer program product is also provided, which stores a computer program, wherein, when the computer program is running, it controls the computer program product to execute any of the above-mentioned leaky cable-based high-frequency signal transmission methods.

[0015] According to another aspect of this application, an electronic device is also provided, wherein the electronic device includes one or more processors and a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the leaky cable-based high-frequency signal transmission method described above.

[0016] In this application, firstly, based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, the type and abnormal connector list of each existing leaky cable are determined. The type is either a usable old type or a newly created type, and the abnormal connectors in the abnormal connector list are leaky cable connectors with performance lower than a preset performance. Then, based on the interval length of the target leaky cable, the output power of a preset device is determined. This preset device is used for power compensation, and the target leaky cable is an existing leaky cable of a usable old type to be reused. Next, a preset device matching the output power is added, connecting the preset device to the starting point of the target leaky cable, and optimizing the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link. Then, abnormal connectors in the first link are replaced based on the abnormal connector list, a preset filter is integrated into the first link, and a preset load is added to the end of the target leaky cable in the first link to obtain a second link. High-frequency signals are then transmitted through the second link, where the preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0017] As described above, this application adopts a classification and evaluation method for existing leaky cables in the ground system. By detecting whether the leaky cable can be reused based on its physical and transmission characteristics, the type of leaky cable is obtained. Based on the length of the leaky cable section, power compensation equipment (i.e., preset equipment) is dynamically configured, impedance matching is optimized, abnormal leaky cable joints are replaced, filters are integrated, and end loads are added. This achieves the goal of stable transmission of high-frequency signals without replacing all existing leaky cables. Thus, the technical effect of using existing leaky cables in the subway to carry high-frequency signals is realized. This application avoids the high cost and long construction period of rebuilding the entire leaky cable line in traditional technology. By optimizing and modifying some existing cables, the transmission of high-frequency signals can be realized, reducing the consumption of modification resources and construction risks. This solves the technical problems of high cost and long construction period of modifying existing leaky cables in the subway in the prior art. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1This is a flowchart of an optional high-frequency signal transmission method based on a leaky cable according to an embodiment of this application;

[0020] Figure 2 This is a flowchart of an optional method for evaluating the high-frequency signal transmission characteristics of an existing leaky cable according to an embodiment of this application;

[0021] Figure 3 This is a flowchart of an optional method for building and deploying a super-cutoff frequency transmission system according to an embodiment of this application;

[0022] Figure 4 This is a schematic diagram of an optional high-frequency signal transmission device based on a leaky cable according to an embodiment of this application;

[0023] Figure 5 This is a structural block diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] It should also be noted that all information and data (including but not limited to information used for display and analysis) involved in this application are authorized by the user or fully authorized by all parties. For example, if there is an interface between this system and the relevant user or organization, before obtaining the relevant information, it is necessary to send a request to the aforementioned user or organization through the interface, and obtain the relevant information only after receiving consent from the aforementioned user or organization.

[0027] Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of relevant information and data involved in this application all comply with the relevant laws, regulations, and standards of the relevant regions, and necessary security measures have been taken. They do not violate public order and good morals. In addition, this application provides corresponding operation entry points for users to choose to agree to authorization or refuse authorization. If the user chooses to refuse authorization, the corresponding expert decision-making process will be initiated.

[0028] In one optional embodiment, a renovation scheme for a complete overhaul of existing leaky cable systems in a subway is provided, namely, constructing a new leaky cable distribution system and re-laying 2... The new 5 / 4" leaky cable is adapted to the 3.3-3.6GHz 5G high-frequency band transmission. For the newly laid leaky cable, the nominal cutoff frequency is used as the upper limit of transmission. The transmission of signals within the cutoff frequency is optimized, that is, blind power is made up by adding antennas and small repeater equipment. However, this transformation plan still cannot solve the technical problem of high-frequency transmission of leaky cable in long-distance tunnels.

[0029] In response to the technical bottlenecks of the above embodiments, such as extremely high renovation costs, long construction periods, severe limitations imposed by subway maintenance windows, and inability to quickly achieve full coverage of the subway system, this invention solves the technical problems of high cost, long construction period, high construction difficulty, and high risk of damage to existing facilities in the full-scale replacement scheme by enabling the reuse of existing leaky cables.

[0030] To address the misconception in the above embodiments that "the nominal cutoff frequency of the leaky cable is the actual transmission limit," this invention conducts in-depth research and engineering verification on the signal transmission characteristics beyond the cutoff frequency, breaks through this misconception, and verifies and realizes stable transmission of 5G high-frequency signals beyond the cutoff frequency.

[0031] To address the lack of a system-level solution for transmission over cutoff frequencies in existing leaky cables as described in the above embodiments, this invention provides a technical system that includes leaky cable assessment, signal debugging, system construction, and performance optimization. This enables engineering-based and replicable practical applications, solving the technical bottlenecks of high signal transmission loss, deteriorated VSWR, and substandard signal coverage at cutoff frequencies. As a result, high-quality, long-distance transmission of 5G high-frequency signals in existing leaky cables is achieved.

[0032] The present invention will now be described in detail with reference to various embodiments.

[0033] Example 1

[0034] According to an embodiment of this application, an embodiment of a high-frequency signal transmission method based on a leaky cable is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0035] This application provides a leaky cable-based high-frequency signal transmission system (hereinafter referred to as the transmission system) for executing the leaky cable-based high-frequency signal transmission method of this application. Figure 1 This is a flowchart of an optional high-frequency signal transmission method based on a leaky cable according to an embodiment of this application, such as... Figure 1 As shown, the method includes the following steps:

[0036] Step S101: Based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, determine the type and abnormal connector list of each existing leaky cable. The type is either an existing type that can be used or a new type that needs to be created. The abnormal connectors in the abnormal connector list are leaky cable connectors whose performance is lower than the preset performance.

[0037] Optionally, before determining the type and abnormal connector list of each existing leaky cable, the transmission system obtains the transmission requirements of 5G high-frequency signals in the subway system. Then, the transmission system collects the cable specifications, slotting method, manufacturer, service life and physical integrity of each existing leaky cable to obtain the physical characteristics of each existing leaky cable. Then, the transmission system performs frequency sweep test on each existing leaky cable through a network analyzer to obtain the transmission loss, VSWR and connector performance of high-frequency signals in each existing leaky cable.

[0038] Optionally, after obtaining the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of the existing leaky cables, the transmission system inputs the collected information into an end-to-end link budget assessment model. The model predicts the predicted signal received power and predicted signal-to-noise ratio of each existing leaky cable, thereby assessing the feasibility of using the existing leaky cables to transmit 5G high-frequency signals based on the prediction results. Based on the feasibility assessment results, the existing leaky cables are classified into usable old types or new types that need to be built. At the same time, a list of abnormal connectors corresponding to the subway system is output.

[0039] Optionally, the transmission system, through the above steps, abandons the limitation of the nominal cutoff frequency of existing cables and replaces traditional experience-based judgment with the actual leaky cable characteristics (i.e., physical characteristics and transmission characteristics) obtained through quantitative measurement. This achieves accurate classification of existing leaky cables, thereby avoiding the waste caused by replacing all leaky cables in a "one-size-fits-all" manner and helping to reduce subsequent construction costs. At the same time, the establishment of an abnormal connector list provides a data foundation for the implementation of the transformation plan. The transmission system can replace abnormal connectors in the available old types of leaky cables based on the abnormal connector list, providing a stable hardware environment for subsequent power transmission.

[0040] Step S102: Determine the output power of the preset device based on the interval length of the target leaky cable, wherein the preset device is used to achieve power compensation, and the target leaky cable is an existing leaky cable of a usable old type to be reused.

[0041] Optionally, the output power refers to the radio frequency power value output by the preset device in a specified frequency band, which is used to compensate for the increased transmission loss due to frequency over-cutoff.

[0042] Optionally, the transmission system integrates a 5G high-frequency power amplification and gain adjustment module into a special-type POI (Point of Interface, combiner) device (i.e., the pre-installed device), and formulates a graded power compensation strategy based on the length of the target leaky cable interval. The strategy is as follows:

[0043] (1) Interval length ≤ 100m: The output power of the special POI device in the 5G band is set to 43dBm;

[0044] (2) 100m < interval length ≤ 200m: output power increased to 46dBm;

[0045] (3) 200m < interval length ≤ 300m: output power increased to 49dBm.

[0046] Optionally, the transmission system implements power compensation according to interval length through the above steps, which can avoid device overload, increased intermodulation interference or adjacent channel interference caused by uniform high power, and helps to ensure signal purity and system stability. In addition, the output power setting of the compensation is related to the actual transmission loss, which helps to improve the energy efficiency ratio, thereby reducing the power consumption and heat dissipation pressure of the preset equipment.

[0047] Step S103: Add a preset device that matches the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain the first link.

[0048] Optionally, at the starting point of the target leaky cable, the transmission system installs a special POI device with a corresponding power level and designs a 50Ω standard impedance matching network. It is specifically optimized for the 3.3-3.6GHz frequency band, that is, the matching network is designed using Smith chart simulation and the component parameters of the matching circuit are optimized, such as adjusting the capacitance and inductance values ​​in the matching network to make the port return loss ≤-20dB.

[0049] Optionally, the transmission system performs power compensation for the leaky cable transmitting high-frequency signals by using preset equipment, which can offset the additional transmission loss caused by the over-cutoff frequency and ensure that the signal power at the end of the leaky cable meets the coverage requirements of the high-frequency signal. At the same time, the transmission system can avoid device saturation and intermodulation degradation by controlling the upper limit of the output power of the preset equipment.

[0050] Step S104: Replace the abnormal connectors in the first link based on the abnormal connector list, integrate a preset filter for the first link, and add a preset load to the end of the target leaky cable in the first link to obtain the second link. Then, transmit high-frequency signals through the second link. The preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0051] Optionally, the transmission system replaces the faulty connectors of existing leaky cables by replacing the old faulty connectors with high-performance, low-loss, waterproof connectors. At the same time, the connector crimping process is optimized to reduce impedance mismatch and signal reflection at the connectors, ensuring that the VSWR of the entire link is ≤1.3. Furthermore, in order to achieve out-of-band interference and spurious suppression, the transmission system integrates a dedicated narrowband cavity filter (i.e., a preset filter) in the signal transmission debugging link (i.e., the first link after replacing the faulty connector) to suppress spurious signals and harmonic signals outside the 3.3-3.6GHz frequency band, with out-of-band suppression ≥60dB. Meanwhile, the transmission system can also optimize the filtering isolation between the first link and the subway PIS (Passenger Information System) private network frequency band, thereby avoiding mutual interference between public network and private network signals and ensuring the transmission quality of 5G high-frequency signals.

[0052] Optionally, through the above steps, the transmission system constructs a mechanism to ensure the transmission quality of the entire signal link. By replacing abnormal connectors, the quality of the modified leaky cable line is improved, providing a stable hardware environment for the transmission of 5G high-frequency signals. The transmission system, by integrating a preset filter, helps to isolate the subway PIS private network from the public network 5G high-frequency signals, solving the problem of mutual interference in shared cable transmission. The transmission system, by setting a preset load at the end of the leaky cable, eliminates reflected standing waves, avoiding the formation of standing wave peaks and valleys by the transmitted high-frequency 5G signals reflecting back and forth in the leaky cable, thus ensuring the uniformity of signal coverage.

[0053] As described above, this application adopts a classification and evaluation method for existing leaky cables in the ground system. By detecting whether the leaky cable can be reused based on its physical and transmission characteristics, the type of leaky cable is obtained. Based on the length of the leaky cable section, power compensation equipment (i.e., preset equipment) is dynamically configured, impedance matching is optimized, abnormal leaky cable joints are replaced, filters are integrated, and end loads are added. This achieves the goal of stable transmission of high-frequency signals without replacing all existing leaky cables. Thus, the technical effect of using existing leaky cables in the subway to carry high-frequency signals is realized. This application avoids the high cost and long construction period of rebuilding the entire leaky cable line in traditional technology. By optimizing and modifying some existing cables, the transmission of high-frequency signals can be realized, reducing the consumption of modification resources and construction risks. This solves the technical problems of high cost and long construction period of modifying existing leaky cables in the subway in the prior art.

[0054] In one optional embodiment, before determining the type and abnormal connector list of each existing leaky cable based on its physical characteristics, transmission characteristics, and high-frequency signal transmission requirements in the subway system, the transmission system first acquires the high-frequency signal transmission requirements in the subway system. These requirements include at least the average length of the subway tunnel, the transmission frequency band of the high-frequency signal, the signal receiving power threshold, and the signal-to-noise ratio threshold. Then, the physical characteristics of each existing leaky cable are collected, including at least the cable specifications, slotting method, manufacturer, usage time, and physical integrity. Subsequently, a network analyzer is used to perform a frequency sweep test on each existing leaky cable to obtain its transmission characteristics. The frequency band used in the frequency sweep test includes at least the high-frequency signal transmission frequency band, and the transmission characteristics include at least transmission loss, VSWR, and connector performance.

[0055] Optionally, the transmission system establishes a multi-dimensional evaluation system for the high-frequency transmission capability of existing leaky cables to clarify the feasibility boundaries of transmission beyond the cutoff frequency. The multi-dimensional evaluation indicators are set as follows:

[0056] (1) Physical characteristic assessment of existing leaky cables: Verify the physical parameters of existing leaky cables, including cable specifications (e.g., 2...). The following factors should be considered: 13 / 8”), slotting method (such as straight slot / U-shaped slot / figure-eight slot), manufacturer, service life (i.e., usage time), and physical integrity. It should be noted that the high-frequency signal transmission characteristics of straight slot / U-shaped slot leaky cables are significantly better than those of figure-eight slots. The slotting structure and opening direction of straight slot / U-shaped slots can reduce the impact of high-order waves on 3.3-3.6GHz signals, which is the core physical basis for realizing ultra-cutoff frequency transmission.

[0057] (2) Evaluation of the transmission characteristics of the existing leaky cable: The existing leaky cable was subjected to a full-band sweep test of 800MHz-4GHz using a vector network analyzer. The transmission indicators of the 3.3-3.6GHz band were measured, including: transmission loss. If the measured transmission loss of the full band is 8-10dB / 100m, it is determined that the existing leaky cable is within the acceptable threshold range of ≤12dB / 100m, and has the feasibility of long-distance high-frequency signal transmission; standing wave ratio. If the measured standing wave ratio of the full band is ≤1.3, it indicates that there is no serious signal reflection problem and meets the communication transmission requirements of high-frequency signals; joint performance. That is, the joints and transitions along the leaky cable were tested to identify fault points and additional loss points, providing a basis for the subsequent generation of an abnormal joint list.

[0058] Optionally, by collecting the physical characteristics of existing leaky cables, the transmission system can accurately identify which existing leaky cables possess the basic physical conditions for high-frequency transmission, avoiding blind judgment in the classification of existing leaky cables. By conducting frequency sweep tests in the target frequency band, multi-dimensional dynamic electrical performance data is obtained, thereby accurately evaluating the transmission capability of the leaky cable at the actual operating frequency. Even if a leaky cable is in good physical condition, if the loss reaches 15dB / 100m in the 3.5GHz band, or the VSWR exceeds the standard, the leaky cable is still not reusable. This avoids the incorrect reuse of unqualified existing leaky cables, which would lead to the failure of high-frequency signal coverage in the subway system. At the same time, it avoids the waste of resources caused by the incorrect removal of qualified existing leaky cables.

[0059] In one optional embodiment, the step of the transmission system determining the list of abnormal connectors and each existing leaky cable type includes: first, obtaining the preset power set by a preset device under the average value of the subway tunnel length included in the transmission requirements; then, inputting the physical characteristics, transmission characteristics, and preset power of each existing leaky cable into an end-to-end link budget evaluation model to obtain the predicted signal received power and predicted signal-to-noise ratio of each existing leaky cable; subsequently, if the predicted signal received power is greater than or equal to a signal received power threshold and the predicted signal-to-noise ratio is greater than or equal to a signal-to-noise ratio threshold, determining the corresponding existing leaky cable as a usable old type; if the predicted signal received power is less than a signal received power threshold and / or the predicted signal-to-noise ratio is less than a signal-to-noise ratio threshold, determining the corresponding existing leaky cable as a type that needs to be newly built; and finally, determining the list of abnormal connectors based on the connector performance in the transmission characteristics of each existing leaky cable.

[0060] Optionally, an end-to-end link budget assessment model is used to quantitatively assess the high-frequency signal coverage capability of high-frequency signals in existing cables; the predicted signal received power refers to the 5G signal power value expected to be received at the end of the leaky cable (the farthest end of the tunnel) calculated by the link budget assessment model; the predicted signal-to-noise ratio refers to the ratio of expected signal to interference plus noise at the end of the leaky cable calculated by the link budget assessment model, and the signal-to-noise ratio can reflect signal quality.

[0061] Optionally, the transmission system first creates an end-to-end link budget assessment model based on the transmission requirements of high-frequency signals. Then, by combining the link budget assessment model with the preset power, physical characteristics of the leaky cable, transmission characteristics, connector power loss, antenna port power requirements, and high-frequency signal transmission requirements of 5G coverage reception sensitivity under the average length of the subway tunnel (e.g., 300m) of the special POI device, the end-to-end link budget is completed. This allows the system to detect whether the 5G signal reception power at the end of the leaky cable can meet the signal coverage requirements of ≥-105dBm (i.e., signal reception power threshold) and the 5G network coverage standard of SINR (Signal-to-Interference-plus-Noise Ratio) ≥3dB (i.e., signal-to-noise ratio threshold) within a typical 300m section length of a subway tunnel. Afterward, based on the feasibility assessment results, the existing leaky cables are divided into reusable types (used to characterize slotted / U-shaped slots, transmission loss meets the standard, and link budget meets signal coverage requirements) and new types.

[0062] Optionally, the transmission system determines the type of each existing leaky cable through an end-to-end link budget evaluation model, realizing the scientific quantification and automated judgment of whether existing leaky cables can be reused. By setting signal received power thresholds and signal-to-noise ratio thresholds, it ensures that only existing leaky cables that truly meet the network coverage requirements of high-frequency signals are retained, while the rest are marked as needing to be newly built, thus preventing resource waste. While determining the type of leaky cable, the transmission system simultaneously generates a list of abnormal connectors, enabling subsequent construction personnel to save time in locating abnormal connectors during on-site construction, thereby improving the efficiency of upgrading existing links.

[0063] In one optional embodiment, the step of determining the output power of a preset device based on the interval length of the target leaky cable includes: when the interval length is less than or equal to a first preset length, using the first preset power as the output power of the preset device in the transmission frequency band of a high-frequency signal; when the interval length is greater than the first preset length and less than or equal to a second preset length, using the second preset power as the output power of the preset device in the transmission frequency band of a high-frequency signal, wherein the second preset length is greater than the first preset length and the second preset power is greater than the first preset power; when the interval length is greater than the second preset length and less than or equal to the average length of the subway tunnel, using the third preset power as the output power of the preset device in the transmission frequency band of a high-frequency signal, wherein the second preset length is less than the average length and the third preset power is greater than the second preset power.

[0064] Optionally, the transmission system integrates a 5G high-frequency band power amplifier and gain adjustment module into a special-type POI device (i.e., a pre-set device), and formulates a graded power compensation strategy based on the interval length of the target leaky cable, as follows:

[0065] (1) The interval length is ≤100m (i.e., the first preset length): the output power of the special POI device in the 5G band is set to 43dBm (i.e., the first preset power).

[0066] (2) 100m < interval length ≤ 200m (i.e., the second preset length): the output power is increased to 46dBm (i.e., the second preset power).

[0067] (3) 200m < interval length ≤ 300m (i.e., the average length of the subway tunnel): the output power is increased to 49dBm (i.e., the third preset power).

[0068] Optionally, the transmission system implements a power compensation mechanism based on interval length through the above embodiments, which can avoid device overload, increased intermodulation interference, or adjacent channel interference caused by uniform high power, thus helping to ensure signal purity and system stability. Furthermore, the output power setting of the compensation is related to the actual transmission loss, which helps to improve the energy efficiency ratio, thereby reducing the power consumption and heat dissipation pressure of the preset equipment.

[0069] In one alternative embodiment, the step of optimizing the impedance matching between the preset device and the starting point of the target leaky cable includes: determining a target matching network based on a preset standard impedance using a Smith chart simulation tool, wherein the target matching network is used to reduce the return loss between the preset device and the starting point of the target leaky cable, and then adding the target matching network to the output of the preset device.

[0070] Optionally, the Smith chart simulation tool refers to an engineering graphical tool for RF impedance matching design. This tool visually analyzes the impedance matching state between the transmission line and the load by plotting complex impedances or complex reflection coefficients on a chart. In this embodiment, it is used to assist in the design of matching circuits for the 3.3–3.6 GHz frequency band, ensuring that the matching network parameters are accurately adapted to the input impedance characteristics of the leaky cable.

[0071] Optionally, the preset standard impedance refers to a 50Ω standard impedance, which is the theoretical benchmark for achieving "reflection-free" transmission between the output port of the POI device and the input port of the leaky cable. In this embodiment, all impedance matching designs are carried out around making the overall transmission system close to 50Ω.

[0072] Optionally, the target matching network refers to a circuit network composed of components such as capacitors, inductors, or transmission lines. Its function is to convert the impedance of the output terminal of the specific POI device into a value that matches the starting impedance of the target leaky cable, thereby reducing signal reflection. In this embodiment, the network is designed specifically for the 3.3–3.6 GHz frequency band to solve the impedance mismatch problem caused by leaky cable aging or connector mismatch at the over-cutoff frequency.

[0073] Optionally, the transmission system is specifically optimized for the 3.3-3.6GHz frequency band using a pre-designed 50Ω standard impedance (i.e., preset standard impedance). This involves optimizing the impedance matching of the connection port between the specific POI device and the target leaky cable. Through Smith chart simulation and actual testing, the component parameters of the matching circuit are optimized to ensure that the port return loss is ≤-20dB, thereby achieving the following technical effects:

[0074] (1) Reduce signal reflection: At the connection between POI and the leaky cable, the matching network actively compensates for the input impedance shift caused by the aging, material or slot structure difference of the leaky cable, thereby reducing the reflection loss of high frequency band signals.

[0075] (2) Improve signal injection efficiency: Due to the reduction of reflection, the 5G high-frequency power output by POI enters the leaky cable more effectively, avoiding power waste caused by impedance mismatch and ensuring the starting power level required for subsequent long-distance transmission.

[0076] (3) Enhance system robustness: The matching network, as a front-end fixed compensation unit, does not rely on on-site debugging, reduces the dependence on personnel experience during construction, and improves the adaptability and consistency of the system under different existing leaky cable models and different service life conditions.

[0077] In one optional embodiment, after obtaining the second link, the transmission system also needs to perform testing on the second link and perform hierarchical optimization based on the test results. Specific steps include: First, performing static testing on the second link using testing equipment to obtain P static indicators, where P is a positive integer. The testing equipment includes at least a VSWR tester, an intermodulation tester, and a network analyzer. The P static indicators include at least VSWR, third-order intermodulation rejection, insertion loss, and return loss. Then, performing full-range mobile network testing on the second link in a subway tunnel using drive testing equipment to obtain Q dynamic indicators, where Q is a positive integer. The Q dynamic indicators include at least reference signal received power, measured signal-to-noise ratio, signal coverage, uplink and downlink rates, latency, and handover success rate. Based on the P static indicators and the Q dynamic indicators, the second link is then hierarchically optimized.

[0078] Optionally, the optimization strategies used in the hierarchical optimization include at least: a first-level parameter optimization strategy, used to update the output power, frequency band matching parameters, and filter configuration of the preset equipment; a second-level engineering optimization strategy, used to replace abnormal connectors and faulty devices in the link; and a third-level supplementary optimization strategy, used to add preset equipment or signal relay units.

[0079] Optionally, the transmission system establishes a system-level performance detection and closed-loop optimization mechanism, which helps to improve the coverage and operational stability of the over-cutoff frequency transmission system. The specific implementation steps of this mechanism are as follows:

[0080] (1) Link static index detection: After the construction is completed, the core electrical indexes of the entire link are tested using a standing wave ratio tester, intermodulation tester, and network analyzer, including standing wave ratio, third-order intermodulation suppression, insertion loss, return loss, etc., to identify fault points, high loss points, and reflection points in the link and ensure that the static indexes meet the design requirements.

[0081] (2) Air interface performance network test: Simulate the subway train running state, use professional 5G road test equipment to complete the mobility network test of the entire tunnel section, and focus on collecting key indicators of 5G network such as RSRP (Reference Signal Received Power), SINR, comprehensive coverage, uplink and downlink rates, latency, and handover success rate to verify the actual coverage effect.

[0082] (3) Hierarchical closed-loop optimization strategy: For the problems of non-compliance of indicators found in the detection and testing, a three-level optimization strategy is adopted, including: Level 1 parameter optimization strategy: Prioritize adjusting the output power of POI equipment, frequency band matching parameters, and filter configuration to solve the problems of insufficient signal power and large in-band fluctuations; Level 2 parameter optimization strategy: For the problems of abnormal local VSWR and large connector loss, reprocess the connectors, replace faulty devices, and optimize the fixed cable and radiation angle; Level 3 parameter optimization strategy: For the local weak coverage areas in long distances, supplement the signal power by adding supplementary POI equipment and miniaturized repeater equipment to achieve full coverage of high frequency signals.

[0083] Optionally, the transmission system combines static electrical measurements with dynamic network drive tests to form a complete and quantifiable link performance verification and feedback mechanism, achieving the following technical effects:

[0084] (1) Confirm whether the electrical performance of the transmission link meets the design requirements. Through static index testing, promptly identify and locate engineering hazards such as poor connectors, impedance mismatch, and device damage to ensure the underlying stability of the system when there is no signal transmission.

[0085] (2) Verify the coverage capability of 5G high-frequency signals in the subway system under actual application environment. Through a simulated train movement test, dynamic indicators are obtained by actual measurement, thereby detecting whether the high-frequency signal can meet the communication service requirements in the dynamic scenario of subway operation.

[0086] (3) Establish a progressive problem-solving mechanism: Through three optimization strategies with different priorities, the general power or filtering problems are solved first by adjusting the software parameters to avoid unnecessary hardware modifications; then, engineering repairs are carried out for local anomalies to reduce maintenance costs; finally, blind spots that are difficult to cover are precisely filled to ensure full coverage without omissions. This three-level optimization mechanism realizes the rapid response to signal transmission problems in the subway system and the efficient use of resources, which helps to improve the delivery quality and long-term operational reliability of the subway system.

[0087] In one alternative embodiment, Figure 2 This is a flowchart of an optional evaluation method for the high-frequency signal transmission characteristics of an existing leaky cable according to an embodiment of this application, such as... Figure 2 As shown, the method includes the following steps:

[0088] Step S201: Evaluate the physical characteristics of the existing leaky cable.

[0089] Optionally, verify the core physical parameters of existing leaky cables, including cable specifications (e.g., 2). 13 / 8”), slotting method (straight slot / U-shaped slot / figure-eight slot), manufacturer, service life, physical integrity. It should be noted that the high-frequency signal transmission characteristics of straight slot / U-shaped slot leaky cables are significantly better than those of figure-eight slots. The slotting structure and opening direction of straight slot / U-shaped slots can reduce the impact of high-order waves on 3.3-3.6GHz signals, which is the core physical basis for realizing ultra-cutoff frequency transmission.

[0090] Step S202: Evaluate the transmission characteristics of the existing leaky cable.

[0091] Optionally, a vector network analyzer can be used to perform a full-band sweep test of the existing leaky cable from 800MHz to 4GHz, with a focus on measuring the transmission indicators in the 3.3-3.6GHz band, including: transmission loss (if the measured full-band transmission loss is 8-10dB / 100m, the existing leaky cable is determined to be within the acceptable threshold range of ≤12dB / 100m, indicating feasibility for long-distance high-frequency signal transmission); standing wave ratio (VSWR) (if the measured full-band VSWR is ≤1.3, it indicates no serious signal reflection problems and meets the communication transmission requirements of high-frequency signals); and connector performance (testing the connectors and transitions along the leaky cable to identify fault points and additional loss points, providing a basis for generating a list of abnormal connectors later).

[0092] Step S203: Based on the physical and transmission characteristics of the existing leaky cable, perform an end-to-end link budget assessment.

[0093] Optionally, by combining the preset power set by the special POI device under the average length of the subway tunnel (e.g., 300m) of the transmission requirements, the physical characteristics of the leaky cable, the transmission characteristics, the connector power loss, the antenna port power requirements, and the high-frequency signal transmission requirements of 5G coverage reception sensitivity, an end-to-end link budget is completed. This allows the detection of whether the 5G signal reception power at the end of the leaky cable can meet the signal coverage requirements of ≥-105dBm (i.e., the signal reception power threshold) and the 5G network coverage standard of SINR≥3dB (i.e., the signal-to-noise ratio threshold) within a typical 300m section length of a subway tunnel.

[0094] Step S204: Based on the link budget assessment results, determine the feasibility of existing leaky cables to obtain the leaky cable type.

[0095] Optionally, based on the feasibility assessment results, existing leaky cables can be divided into reusable types (characterized by straight / U-shaped slots, compliant transmission loss, and link budget meeting signal coverage requirements) and new types that need to be built.

[0096] In one alternative embodiment, Figure 3 This is a flowchart of an optional method for building and deploying a super-cutoff frequency transmission system according to an embodiment of this application, such as... Figure 3As shown, this method constructs a complete transmission system consisting of a special-type POI signal injection end, a reused leaky cable transmission link, and an end-matching load, achieving stable transmission of public and private network signals on the same cable. The scheme includes the following steps:

[0097] Step S301: A system topology design using dual leaky cable split transmission is adopted.

[0098] Alternatively, the two existing 13 / 8” leaky cables in the subway can be used to reduce signal coupling interference between the two cables, while also being compatible with the operation requirements of the original PIS system.

[0099] Step S302: Perform link rectification and optimization on the existing leaky cable.

[0100] Optionally, faulty joints and damaged parts along the leaky cable can be replaced and repaired; the fixing clamps of the leaky cable can be inspected and reinforced to prevent cable displacement and performance degradation caused by train vibration; and a high-performance, low-reflection load can be matched at the end of the leaky cable to reduce signal reflection at the end and optimize the standing wave ratio of the entire link.

[0101] Step S303: For leaky cables with excessively long intervals, a repeater replacement scheme is adopted.

[0102] Optionally, for leaky cables in ultra-long tunnels with a section length exceeding 300m, a mid-section replacement plan can be developed, which involves adding miniaturized special-type POIs or signal relay units at the mid-section to achieve signal relay amplification, avoid excessive signal attenuation caused by long-distance transmission, and ensure that the coverage index of the entire section meets the standards.

[0103] In summary, the technical solution of this application can achieve the following technical effects:

[0104] (1) It breaks through the inherent technical understanding in the industry that "the nominal cutoff frequency of the leaky cable is the actual transmission limit". For the first time, through theoretical analysis, laboratory testing and engineering verification, it has realized the stable and long-distance transmission of 3.3-3.6GHz 5G high-frequency signals on the existing leaky cable with a nominal cutoff frequency of 3GHz, filling the technical gap in the industry and subverting the traditional technical route of 5G transformation of the existing subway lines.

[0105] (2) It reduced the cost and construction period of 5G transformation of existing subway lines, reduced the investment cost of single-line transformation, shortened the construction period, avoided a series of problems such as large-scale construction, material handling, and finished product protection caused by the construction of new leaky cables, greatly reduced the safety risks of subway construction, and solved the technical bottleneck that restricts the transformation of existing subway lines to 5G.

[0106] (3) A complete engineering technology system has been built, from leaky cable assessment, signal debugging, system construction to closed-loop optimization. A standardized implementation plan that can be replicated and promoted has been formed. It is not only applicable to subway scenarios, but can also be promoted to 5G upgrade and transformation of leaky cable coverage scenarios such as high-speed rail, intercity railway, and highway tunnels.

[0107] (4) It realizes the compatible transmission of public network 5G signals and subway PIS private network signals on the same cable without interference. While making use of the old leaky cable to achieve 5G coverage, it ensures the stable operation of the original subway private network system and takes into account the dual needs of operators and subway companies.

[0108] Example 2

[0109] This application embodiment can also provide a high-frequency signal transmission device based on a leaky cable. It should be noted that the high-frequency signal transmission device based on a leaky cable in this application embodiment can be used to execute the high-frequency signal transmission method based on a leaky cable provided in this application embodiment. The high-frequency signal transmission device based on a leaky cable provided in this application embodiment will be described below.

[0110] According to an embodiment of this application, an apparatus for implementing the above-described high-frequency signal transmission method based on leaky cable is also provided. Figure 4 This is a schematic diagram of an optional high-frequency signal transmission device based on a leaky cable according to an embodiment of this application, such as... Figure 4 As shown, the device includes: a first determining unit 401, a second determining unit 402, a first link setting unit 403, and a second link setting unit 404.

[0111] Optionally, the first determining unit 401 is used to determine the type and abnormal connector list of each existing leaky cable based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, wherein the type is an existing type that can be used or a type that needs to be newly built, and the abnormal connectors in the abnormal connector list are leaky cable connectors whose connector performance is less than the preset performance; the second determining unit 402 is used to determine the output power of the preset device based on the interval length of the target leaky cable, wherein the preset device is used to achieve power compensation, and the target leaky cable is an existing leaky cable of an existing type that can be reused; the first link setting unit 403 is used to add a preset device that meets the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link; the second link setting unit 404 is used to replace the abnormal connectors in the first link based on the abnormal connector list, integrate a preset filter for the first link, and add a preset load to the end of the target leaky cable in the first link to obtain a second link, and then transmit high-frequency signals through the second link, wherein the preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0112] As described above, this device classifies and evaluates existing leaky cables in the ground system. By detecting whether a leaky cable can be reused based on its physical and transmission characteristics, the device identifies the type of leaky cable. It then dynamically configures power compensation equipment (i.e., preset equipment) based on the length of the leaky cable section, optimizes impedance matching, replaces abnormal leaky cable joints, integrates filters, and adds end loads. This achieves stable transmission of high-frequency signals without replacing all existing leaky cables, thus realizing the technical effect of using existing subway leaky cables to carry high-frequency signals. This device avoids the high cost and long construction period of rebuilding the entire leaky cable line in traditional technologies. By optimizing and modifying some existing cables, high-frequency signal transmission can be achieved, reducing resource consumption and construction risks. This solves the technical problems of high cost and long construction period in existing subway leaky cable modifications.

[0113] In one optional embodiment, the high-frequency signal transmission device based on leaky cable further includes: a demand acquisition unit, a characteristic acquisition unit, and a characteristic testing unit.

[0114] Optionally, the requirement acquisition unit is used to acquire the transmission requirements of high-frequency signals in the subway system before determining the type and abnormal joint list of each existing leaky cable based on its physical characteristics, transmission characteristics, and high-frequency signal transmission requirements. The transmission requirements include at least the average length of the subway tunnel, the transmission frequency band of the high-frequency signal, the signal receiving power threshold, and the signal-to-noise ratio threshold. The characteristic acquisition unit is used to acquire the physical characteristics of each existing leaky cable. The physical characteristics include at least the cable specifications, slotting method, manufacturer, service life, and physical integrity. The characteristic testing unit is used to perform a frequency sweep test on each existing leaky cable using a network analyzer to obtain the transmission characteristics of each existing leaky cable. The frequency band of the frequency sweep test includes at least the transmission frequency band of the high-frequency signal, and the transmission characteristics include at least transmission loss, VSWR, and joint performance.

[0115] In one optional embodiment, the first determining unit 401 includes: a first acquiring subunit, an input subunit, a first determining subunit, a second determining subunit, and a third determining subunit.

[0116] Optionally, the first acquisition subunit is used to acquire the preset power set by the preset device under the average value of the subway tunnel length included in the transmission requirements; the input subunit is used to input the physical characteristics, transmission characteristics, and preset power of each existing leaky cable into the end-to-end link budget evaluation model to obtain the predicted signal received power and predicted signal-to-noise ratio of each existing leaky cable; the first determination subunit is used to determine that the corresponding existing leaky cable is a usable old type when the predicted signal received power is greater than or equal to the signal received power threshold and the predicted signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold; the second determination subunit is used to determine that the corresponding existing leaky cable is a type that needs to be newly built when the predicted signal received power is less than the signal received power threshold and / or the predicted signal-to-noise ratio is less than the signal-to-noise ratio threshold; and the third determination subunit is used to determine a list of abnormal connectors based on the connector performance in the transmission characteristics of each existing leaky cable.

[0117] In one optional embodiment, the second determining unit 402 includes a fourth determining subunit, a fifth determining subunit, and a sixth determining subunit.

[0118] Optionally, the fourth determining subunit is used to determine the first preset power as the output power of the preset device in the high-frequency signal transmission band when the interval length is less than or equal to the first preset length; the fifth determining subunit is used to determine the second preset power as the output power of the preset device in the high-frequency signal transmission band when the interval length is greater than the first preset length and the interval length is less than or equal to the second preset length, wherein the second preset length is greater than the first preset length and the second preset power is greater than the first preset power; the sixth determining subunit is used to determine the third preset power as the output power of the preset device in the high-frequency signal transmission band when the interval length is greater than the second preset length and the interval length is less than or equal to the average length of the subway tunnel, wherein the second preset length is less than the average length and the third preset power is greater than the second preset power.

[0119] In an optional embodiment, the first link setting unit 403 includes a seventh determining subunit and an adding subunit.

[0120] Optionally, the seventh determining subunit is used to determine the target matching network based on the preset standard impedance using the Smith chart simulation tool, wherein the target matching network is used to reduce the return loss between the preset device and the starting point of the target leaky cable; the additional subunit is used to add the target matching network to the output end of the preset device.

[0121] In one optional embodiment, the high-frequency signal transmission device based on leaky cable further includes: a static testing unit, a dynamic testing unit, and a hierarchical optimization unit.

[0122] Optionally, the static testing unit is used to perform static testing on the second link after obtaining it, using testing equipment to obtain P static indicators, where P is a positive integer. The testing equipment includes at least a VSWR tester, an intermodulation tester, and a network analyzer. The P static indicators include at least VSWR, third-order intermodulation rejection, insertion loss, and return loss. The dynamic testing unit is used to perform full-range mobile network testing on the second link in a subway tunnel using drive testing equipment to obtain Q dynamic indicators, where Q is a positive integer. The Q dynamic indicators include at least reference signal received power, measured signal-to-noise ratio, signal coverage, uplink and downlink rates, latency, and handover success rate. The hierarchical optimization unit is used to perform hierarchical optimization on the second link based on the P static indicators and the Q dynamic indicators.

[0123] Optionally, the optimization strategies used in the hierarchical optimization include at least: a first-level parameter optimization strategy, used to update the output power, frequency band matching parameters, and filter configuration of the preset equipment; a second-level engineering optimization strategy, used to replace abnormal connectors and faulty devices in the link; and a third-level supplementary optimization strategy, used to add preset equipment or signal relay units.

[0124] It should be noted that the first determining unit 401, the second determining unit 402, the first link setting unit 403, and the second link setting unit 404 mentioned above correspond to steps S101 to S104 in the method embodiment. The instances and application scenarios implemented by the above units and the corresponding steps are the same, but are not limited to the content disclosed in the above embodiment.

[0125] Example 3

[0126] Embodiments of this application can also provide an electronic device. Figure 5 This is a structural block diagram of an electronic device according to an embodiment of this application, such as... Figure 5 As shown, the electronic device includes: one or more ( Figure 5 (Only one is shown) processor 502, memory 504, memory controller, and peripheral interface, wherein the peripheral interface is connected to the radio frequency module, audio module and display.

[0127] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the methods and devices in the embodiments of this application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the above-mentioned high-frequency signal transmission method based on leaky cable.

[0128] The memory may include high-speed random access memory (RAM), and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, which can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks (LANs), mobile communication networks, and combinations thereof.

[0129] The processor can invoke information and application programs stored in the memory through the transmission device to execute the following steps: Based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, determine the type and abnormal connector list of each existing leaky cable. The type is either a usable old type or a newly created type. Abnormal connectors in the abnormal connector list are leaky cable connectors with performance lower than a preset performance. Based on the interval length of the target leaky cable, determine the output power of a preset device. The preset device is used for power compensation, and the target leaky cable is an existing leaky cable of a usable old type to be reused. Add a preset device matching the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link. Replace the abnormal connectors in the first link based on the abnormal connector list, integrate a preset filter into the first link, and add a preset load to the end of the target leaky cable in the first link to obtain a second link. Then, transmit high-frequency signals through the second link. The preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

[0130] This application provides a solution for high-frequency signal transmission based on leaky cables. The solution classifies and evaluates existing leaky cables in the ground system. By assessing the reusability of leaky cables based on their physical and transmission characteristics, the solution identifies the corresponding cable type. It then dynamically configures power compensation equipment (i.e., preset equipment) based on the length of the leaky cable section, optimizes impedance matching, replaces abnormal leaky cable joints, integrates filters, and adds end loads. This achieves stable high-frequency signal transmission without completely replacing existing leaky cables, thus realizing the technical effect of using existing subway leaky cables to carry high-frequency signals. This solution avoids the high cost and long construction period of rebuilding the entire leaky cable network in traditional technologies. By optimizing and modifying a portion of the existing cables, high-frequency signal transmission can be achieved, reducing resource consumption and construction risks. This solves the technical problems of high cost and long construction period in the prior art of modifying existing subway leaky cables.

[0131] Those skilled in the art will understand that Figure 5 The structure shown is for illustrative purposes only. Electronic devices can also be smartphones, tablets, PDAs, mobile internet devices, PADs, and other terminal devices. Figure 5 This does not limit the structure of the aforementioned electronic device. For example, electronic devices may also include components that are more... Figure 5 The more or fewer components shown (such as network interfaces, display devices, etc.), or having the same Figure 5 The different configurations shown.

[0132] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0133] Example 4

[0134] Embodiments of this application may also provide a storage medium.

[0135] Optionally, in this embodiment of the application, the storage medium can be used to store the program code executed by the high-frequency signal transmission method based on leaky cable provided in the above method embodiment.

[0136] Optionally, in this embodiment, the storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0137] This application also provides a computer program product that, when executed on a data processing device, is suitable for performing steps of a leaky cable-based high-frequency signal transmission method.

[0138] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0139] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0140] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0141] 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0142] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0143] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0144] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A high-frequency signal transmission method based on leaky cable, characterized in that, include: Based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, the type and abnormal connector list of each existing leaky cable are determined. The type is either an existing type that can be used or a type that needs to be newly built. The abnormal connectors in the abnormal connector list are leaky cable connectors whose connector performance is less than the preset performance. The output power of the preset device is determined based on the interval length of the target leaky cable, wherein the preset device is used to achieve power compensation, and the target leaky cable is an existing leaky cable of a usable old type to be reused. Add a preset device that matches the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain a first link; After replacing the abnormal connectors in the first link based on the abnormal connector list, integrating a preset filter into the first link, and adding a preset load at the end of the target leaky cable in the first link to obtain a second link, the high-frequency signal is transmitted through the second link. The preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

2. The high-frequency signal transmission method based on leaky cable according to claim 1, characterized in that, Before determining the type and abnormal connector list of each existing leaky cable based on its physical characteristics, transmission characteristics, and high-frequency signal transmission requirements in the subway system, the high-frequency signal transmission method based on leaky cables further includes: The transmission requirements of high-frequency signals in the subway system are obtained, wherein the transmission requirements include at least the average length of the subway tunnel, the transmission frequency band of the high-frequency signal, the signal receiving power threshold, and the signal-to-noise ratio threshold. The physical characteristics of each existing leaky cable are collected, including at least the cable specifications, slotting method, manufacturer, service life, and physical integrity. The transmission characteristics of each existing leaky cable are obtained by performing a frequency sweep test on each existing leaky cable using a network analyzer. The frequency band of the frequency sweep test includes at least the transmission frequency band of the high-frequency signal, and the transmission characteristics include at least transmission loss, VSWR, and connector performance.

3. The high-frequency signal transmission method based on leaky cable according to claim 1, characterized in that, Based on the physical characteristics, transmission characteristics, and high-frequency signal transmission requirements of each existing leaky cable in the subway system, the type and abnormal connector list of each existing leaky cable are determined, including: Obtain the preset power set by the preset device under the average value of the subway tunnel length included in the transmission requirements; The physical characteristics, transmission characteristics, and preset power of each existing leaky cable are input into an end-to-end link budget evaluation model to obtain the predicted signal received power and predicted signal-to-noise ratio of each existing leaky cable. If the predicted signal received power is greater than or equal to the signal received power threshold, and the predicted signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold, the corresponding existing leaky cable is determined to be the available old type; If the predicted signal received power is less than the signal received power threshold, and / or the predicted signal-to-noise ratio is less than the signal-to-noise ratio threshold, the corresponding existing leaky cable is determined to be the type that needs to be newly built. The list of abnormal connectors is determined based on the connector performance in the transmission characteristics of each existing leaky cable.

4. The high-frequency signal transmission method based on leaky cable according to claim 1, characterized in that, The output power of the preset device is determined based on the interval length of the target leaky cable, including: When the interval length is less than or equal to the first preset length, the first preset power is used as the output power of the preset device in the transmission frequency band of the high-frequency signal; When the interval length is greater than the first preset length and the interval length is less than or equal to the second preset length, the second preset power is used as the output power of the preset device in the transmission frequency band of the high-frequency signal, wherein the second preset length is greater than the first preset length and the second preset power is greater than the first preset power. When the interval length is greater than the second preset length and the interval length is less than or equal to the average length of the subway tunnel, the third preset power is used as the output power of the preset device in the transmission frequency band of the high-frequency signal, wherein the second preset length is less than the average value and the third preset power is greater than the second preset power.

5. The high-frequency signal transmission method based on leaky cable according to claim 1, characterized in that, Optimizing the impedance matching between the preset device and the starting point of the target leaky cable includes: The target matching network is determined based on a preset standard impedance using the Smith chart simulation tool, wherein the target matching network is used to reduce the return loss between the preset device and the starting point of the target leaky cable; The target matching network is added to the output of the preset device.

6. The high-frequency signal transmission method based on leaky cable according to claim 1, characterized in that, After obtaining the second link, the high-frequency signal transmission method based on leaky cable further includes: The second link is subjected to static testing using testing equipment to obtain P static indicators, where P is a positive integer. The testing equipment includes at least a VSWR tester, an intermodulation tester, and a network analyzer. The P static indicators include at least VSWR, third-order intermodulation rejection, insertion loss, and return loss. The second link was subjected to a full-range mobile network test in a subway tunnel using road testing equipment, and Q dynamic indicators were obtained, where Q is a positive integer. The Q dynamic indicators include at least the reference signal received power, measured signal-to-noise ratio, signal coverage, uplink and downlink rates, latency, and handover success rate. The second link is optimized in a hierarchical manner based on the P static indicators and the Q dynamic indicators.

7. The high-frequency signal transmission method based on leaky cable according to claim 6, characterized in that, The optimization strategies used in the hierarchical optimization include at least the following: A first-level parameter optimization strategy is used to update the output power, frequency band matching parameters, and filter configuration of the preset device and the preset filter. The secondary engineering optimization strategy is used to replace abnormal connectors and faulty devices in the link; The three-level supplementary optimization strategy is used to add the preset device or signal relay unit.

8. A high-frequency signal transmission device based on a leaky cable, characterized in that, include: The first determining unit is used to determine the type and abnormal connector list of each existing leaky cable based on the physical characteristics, transmission characteristics and high-frequency signal transmission requirements of each existing leaky cable in the subway system. The type is either an available old type or a type that needs to be newly built. The abnormal connectors in the abnormal connector list are leaky cable connectors whose connector performance is less than the preset performance. The second determining unit is used to determine the output power of the preset device based on the interval length of the target leaky cable, wherein the preset device is used to realize power compensation, and the target leaky cable is an existing leaky cable of a usable old type to be reused. The first link setting unit is used to add a preset device that meets the output power, connect the preset device to the starting point of the target leaky cable, and optimize the impedance matching between the preset device and the starting point of the target leaky cable to obtain the first link. The second link setting unit is used to replace the abnormal connectors in the first link based on the abnormal connector list, integrate a preset filter for the first link, and add a preset load at the end of the target leaky cable in the first link to obtain the second link. After obtaining the second link, the high-frequency signal is transmitted through the second link. The preset filter is used to suppress spurious signals and harmonic signals, and the preset load is used to reduce signal reflection at the end.

9. A computer program product, characterized in that, The computer program product includes a computer program, wherein, when the computer program is executed, it controls the computer program product to perform the high-frequency signal transmission method based on any one of claims 1 to 7.

10. An electronic device, characterized in that, It includes one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the high-frequency signal transmission method based on leaky cable as described in any one of claims 1 to 7.

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