Surface wave wireless channel modeling and optimization method based on transmitting end coupling distance

Abstract

The application discloses a surface wave wireless channel modeling optimization method based on a sending end coupling distance, which comprises the following steps: setting a sending end, a receiving end and metal pipes with different diameters; a transceiving antenna is coupled to the metal pipes with different diameters in a wireless mode; the height of the receiving end is fixed, the height of the sending end and the distance between the sending end and the receiving end are changed, the measurement data of the wireless channel of the receiving end at different sending end heights are collected, path loss values are extracted, and a path loss model with the influence of the sending end coupling distance is constructed; the path loss model is subjected to parameter fitting by using a least square method, the path loss index is modeled, the correction values of the parameters in the path loss model are obtained, and a final path loss model is obtained after correction; and the distance between the sending end and the receiving end and the sending end coupling distance are inputted, so that the channel path loss value of the transceiving end can be obtained. The application can effectively optimize the performance of a wireless communication system in an indoor environment of an industrial internet of things.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and specifically to a surface wave wireless channel modeling and optimization method, device, and storage medium based on the coupling distance of the transmitting end. Background Technology

[0002] The Industrial Internet of Things (IIoT) is based on traditional industrial systems and integrates advanced information technologies such as sensing technology, embedded systems, communication networks, big data analytics, and artificial intelligence to achieve comprehensive interconnection and intelligent collaboration among industrial equipment, production processes, personnel, and systems. It is widely used in key industries such as manufacturing, power, petrochemicals, transportation, and mining. Under the IIoT architecture, physical entities are virtualized and digitized, and centralized management and optimized scheduling are achieved through cloud computing platforms.

[0003] Compared to traditional indoor environments, IIoT scenarios have unique physical characteristics, resulting in more complex fading characteristics in their wireless channels. Industrial environments are typically large in scale and contain a large number of bulky and densely distributed metal devices, such as machine tools, pipes, and robotic arms. These metal surfaces can cause strong multipath effects and signal reflections. In addition, the diverse types of materials in industrial scenarios (such as metals, concrete, and plastics), combined with electromagnetic interference, mechanical vibrations, and dynamic obstacles, make the channel characteristics highly dynamic and exhibit non-line-of-sight propagation features.

[0004] Furthermore, the complex channel environment places higher demands on communication reliability, latency, and energy efficiency, necessitating in-depth research on channel modeling and optimization techniques for IIoT scenarios.

[0005] Currently, most studies on channel characteristic analysis and modeling in traditional IIoT scenarios treat the numerous metal objects or machines present in the industrial environment as scatterers that interfere with signal transmission to explore the wireless channel propagation characteristics of the IIoT environment. However, they do not consider the impact of transforming metal objects or machines into transmission media, or the reduction of the number of scatterers on the wireless channel propagation characteristics in the IIoT channel model.

[0006] Therefore, domestic and international research has further explored transforming these metallic or mechanical devices in IIoT scenarios into transmission media. For example, patent publication number CN116846499A proposes a method for modeling path loss in indoor wireless channels based on surface wave excitation, which presents a wireless channel modeling method based on surface wave transmission excited by metal wires. Another example is patent publication number CN118713779A, which explores the impact of the vertical coupling distance at the receiver on the surface wave transmission effect and proposes a surface wave wireless channel modeling method with the influence of the vertical coupling distance at the receiver. Furthermore, patent publication number CN119094060A proposes a surface wave wireless channel modeling method with the influence of the horizontal coupling distance at the receiver. However, these existing methods assume a fixed coupling distance at the transmitter and focus on the impact of changes in the coupling distance at the receiver on the surface wave excitation effect. However, they do not address the impact of changes in the coupling distance at the transmitter in loosely coupled scenarios, nor do they consider the impact of dynamic adjustments to the coupling distance at the transmitter on channel characteristics.

[0007] Furthermore, the conventional methods for modeling and optimizing surface wave wireless channels in existing technologies still have the following problems:

[0008] (1) Analysis of the impact of path loss and the target: The impact of the change in the coupling distance at the transmitting end on the path loss is significantly greater than that at the receiving end and is different from that at the receiving end. The adjustment at the receiving end is mainly aimed at comparing the receiving effect, while the change in the coupling distance at the transmitting end is aimed at the change in the surface wave excitation efficiency. However, the existing technology does not model and optimize the coupling distance at the transmitting end.

[0009] (2) Misjudgment of the influence of metal tube diameter: When the diameter of the metal tube increases from 0.1 m to 0.8 m, the impact of adjusting the coupling distance at the transmitting end on path loss is much smaller than that at the receiving end. However, the existing model does not distinguish between the two, which leads to the distortion of the optimization suggestions for the metal tube structure.

[0010] (3) Simplification deviation of signal propagation path: The receiver adjustment relies on surface wave transmission through the metal tube, and only a small portion and a fixed amount of wave are transmitted from free space; while when the coupling distance of the transmitter is adjusted, the signal can propagate through both free space and metal tube paths, and as the coupling distance of the transmitter increases, the receiver will receive more "waves" transmitted from the transmitter from free space. However, the existing technology does not consider the effect of free space propagation on the randomness of the channel.

[0011] To address these technical problems, this application proposes a surface wave wireless channel modeling and optimization method based on the coupling distance at the transmitting end. Summary of the Invention

[0012] The main objective of this invention is to provide a surface wave wireless channel modeling and optimization method based on the coupling distance of the transmitting end, so as to solve the technical problems mentioned in the background art.

[0013] The present invention solves the above-mentioned technical problems by adopting the following technical solutions:

[0014] A surface wave wireless channel modeling and optimization method based on transmitter coupling distance includes the following specific steps:

[0015] S1. Configure the sending end Receiver And several sets of metal pipes of different diameters, wherein the distance between the transmitting end and the receiving end is... It can be changed;

[0016] S2. Use a calibrator to calibrate the transmitting end. Transmitting antenna and receiving end The receiving antenna is calibrated;

[0017] S3. Place a set of metal tubes directly above the transmitting and receiving ends, and adjust the coupling distance between the transmitting and receiving antennas and the metal tubes to ensure that the surface wave mode can be fully excited.

[0018] S4. Measure the horizontal distance between the transmitter and receiver. With the receiver height fixed, the transmitter height is varied. A vector network analyzer (VNA) is used to collect measurement data of the wireless channel at that height, and the path loss value is calculated and extracted from this measurement data. The vertical distance between the transmitter and the metal tube is the coupling distance. ;

[0019] S5. Change the horizontal distance between the transmitter and receiver. And repeat step S4 above;

[0020] S6. Replace with another metal tube of a different diameter and repeat steps S3 to S5 above;

[0021] S7. Based on the multiple path loss values ​​extracted in the above steps, construct a path loss model that incorporates the influence of the receiver coupling distance. ;

[0022] S8. The path loss model constructed in step S7 above The path loss model is obtained by fitting the parameters using the least squares method. The path loss exponent is modeled using the corrected values ​​of each parameter, and finally, the path loss model is obtained using the corrected values ​​of each parameter. ;

[0023] S9. The distance between the sending and receiving ends Transmitter coupling distance Input final path loss model This allows us to obtain the path loss value of the transceiver channel under the corresponding conditions.

[0024] Preferably, in step S1, the transmitting antenna of the transmitting end and the receiving antenna of the receiving end are both connected to the vector network analyzer (VNA) via cables, and both the transmitting and receiving ends are equipped with surface wave exciters; the initial height of the transmitting end and the receiving end are both adjusted to 1.3m, and two height-adjustable brackets are placed on the left side of the transmitting end and the right side of the receiving end, respectively.

[0025] Preferably, in step S3, the metal tube has a diameter of 2.5 cm, a length of 3 m, and a horizontal distance of 0.5 m between the transmitting and receiving ends. Initially, both the transmitting and receiving ends are 2 cm away from the metal tube. At this time, the coupling distance is no greater than 1 / 4 wavelength (85.7 mm) corresponding to the center working frequency, which is used to fully excite the surface wave mode.

[0026] Preferably, in the specific operation process of step S4: during the initial measurement, the transmitting end performs a measurement every time it moves down 0.1m, and the corresponding path loss value is extracted and calculated for each measurement, and the path loss value under free space propagation conditions is compared.

[0027] The cutoff value for the coupling distance at the transmitting end is set to 0.5m. After 0.5m, a smaller measurement range is selected to more accurately depict the functional relationship between the coupling distance at the transmitting end and the path loss, especially the subtle changes near the cutoff value. 0.05m is selected as the new measurement range to avoid errors in the experimental operation due to the coupling distance at the transmitting end being too short if the range is too small.

[0028] Afterwards, the transmitter moves downwards by 0.05m and performs a measurement every time it moves down, until it reaches 0.8m. At this distance, the path loss value of the surface wave environment under all conditions reaches the path loss value of the free space environment. That is, there are 6 measurement points from 0m to 0.5m, 6 measurement points from 0.55m to 0.8m, and a total of 12 measurement points. The coupling distance of the transmitter is adjusted and 9 measurements are performed at each point to obtain the corresponding path loss value. Then, the average value of all path loss values ​​is calculated as the final path loss value corresponding to each measurement.

[0029] Preferably, the specific operation process of step S5 includes: changing the horizontal distance between the transmitting end and the receiving end. Adjust to 1.0m, 1.5m, 2.0m and 2.5m, and repeat step S4.

[0030] Preferably, in step S6, the 2.5cm diameter metal tube is replaced with metal tubes with diameters of 4.0cm and 10.0cm, and steps S3 to S5 are repeated. By replacing the metal tubes with different diameters, the rigor of the experiment can be ensured, common influences can be sought, and the influence of the transmitting end coupling distance on the surface wave excitation and transmission characteristics can be investigated.

[0031] Preferably, in step S7, the obtained path loss value is subjected to parameter fitting, different function models are selected for fitting, and the root mean square error (RMSE) values ​​corresponding to different function models are compared. Combined with R-squared (coefficient of determination), it is found that when using the composite exponential function model... The path loss model with the smallest root mean square error (RMSE) value is therefore the constructed path loss model. The final expression is:

[0032]

[0033] in, The distance between the transmitting end and the metal tube is the coupling distance, and a, b, c, and d are the parameters of the expression.

[0034] Preferably, in step S8, the horizontal distance between the transceiver ends is... The path loss exponent at 1m was calculated and modeled. Different function models were selected for fitting, and the root mean square error (RMSE) values ​​corresponding to different function models were compared. Combined with R-squared (coefficient of determination), it was found that when using the cubic function model... The root mean square error (RMSE) value is the smallest, therefore the constructed path loss exponential model has the lowest RMSE value. The final expression is:

[0035]

[0036] in, The coupling distance between the transmitting end and the metal tube. , , , The parameter is used for the expression.

[0037] The final path loss model The final expression is:

[0038]

[0039] in, The selected reference distance, To be at the reference distance The path loss value at point d, where d is the distance between the transmitting and receiving antennas. This is the path loss index. To conform to a mean of 0 and a standard deviation of A Gaussian distributed random variable.

[0040] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0041] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0042] As can be seen from the above technical solution, the present invention provides a surface wave wireless channel modeling and optimization method based on the coupling distance at the transmitting end. Compared with the prior art, the present invention has the following advantages:

[0043] 1. This invention establishes a nonlinear relationship model between the coupling distance at the transmitting end and the path loss exponent, which can demonstrate the significant increase in the path loss exponent when the coupling distance at the transmitting end exceeds 0.5 m, and proves that the influence of the metal tube diameter on path loss weakens as the transmitting end is adjusted. Thus, the established model can better reduce path loss and improve the reliability and security of signal transmission.

[0044] It should be understood that the descriptions in this section are not intended to identify key or essential features of embodiments of the invention, nor are they intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Of course, implementing any product of the invention does not necessarily require achieving all of the advantages described above simultaneously. Attached Figure Description

[0045] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0046] Figure 1 This is a schematic diagram of the modeling process framework of the present invention;

[0047] Figure 2 This is a schematic diagram of the measurement scenario of the present invention;

[0048] Figure 3 This is a schematic diagram of the vertical coupling distance design of the transmitting end of the present invention;

[0049] Figure 4 The horizontal distance between the transceiver ends of this invention is A schematic diagram comparing the path loss of the transmitting end coupling distance of metal tubes with different diameters at a distance of 1m with the path loss under free space conditions.

[0050] Figure 5 This is a schematic diagram comparing the path loss model fitting curves of the transmitting end coupling distance under different horizontal distances between the transmitting and receiving ends in the case of a 2.5cm diameter metal tube according to the present invention.

[0051] Figure 6 This is a schematic diagram comparing the path loss model fitting curves of the transmitting end coupling distance under different horizontal distances between the transmitting and receiving ends in the case of a metal tube with a diameter of 4.0cm.

[0052] Figure 7 This is a schematic diagram comparing the path loss model fitting curves of the transmitting end coupling distance under different horizontal distances between the transmitting and receiving ends in the case of a metal tube with a diameter of 10.0cm.

[0053] Figure 8 The present invention relates to the horizontal distance between the transmitting and receiving ends. Path loss index of different metal tubes as the coupling distance at the transmitting end changes at a distance of 1m A diagram illustrating the comparison of fitted curves;

[0054] Figure 9 This is a schematic diagram illustrating the wave transmission with changes in the transmitting and receiving ends of the present invention, wherein (a) is a schematic diagram of wave transmission with changes in the vertical coupling distance of the transmitting end, and (b) is a schematic diagram of wave transmission with changes in the vertical coupling distance of the receiving end. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] For details in the embodiments, please refer to Figures 1 to 9 .

[0057] like Figure 1 and Figure 3 As shown. The surface wave wireless channel modeling and optimization method based on the transmitting end coupling distance proposed in this embodiment of the invention is generally used in industrial IoT scenarios. The following steps are performed using experimental equipment:

[0058] S1. Construct an indoor surface wave transmission measurement scenario, with a transmitter within the scenario. Receiver And metal pipes, in which the distance between the transmitting end and the receiving end It can be changed;

[0059] Both the transmitting antenna at the transmitting end and the receiving antenna at the receiving end are connected to the Vector Network Analyzer (VNA) via cables, and both the transmitting and receiving ends are equipped with surface wave exciters.

[0060] The initial height of both the transmitter and receiver was adjusted to 1.3m, and two adjustable-height brackets were placed on the left side of the transmitter and the right side of the receiver, respectively. The brackets were 2cm higher than the transmitter and receiver and were used to hold the metal tubes.

[0061] Specifically, this scenario can be referenced. Figure 2 The measurement scheme shown in the experiment included a channel measurement instrument and two coaxial cables with identical losses. The surface wave exciter at the transmitting and receiving ends was fixed on two adjustable tripods, serving as the transmitting and receiving ends, respectively. The channel measurement instrument was connected to both the transmitting and receiving ends via coaxial cables, and a metal tube was fixed directly above it on a tripod to simulate the surface wave transmission scenario. The experimental setup included instruments, tables, chairs, and other facilities to simulate propagation characteristics under complex conditions.

[0062] S2. Use a calibrator to calibrate the transmitting end. Transmitting antenna and receiving end The receiving antenna is calibrated, and then the path loss value under free space propagation conditions is measured. If the error is no greater than 1dB compared with the calculated value, the calibration is completed, reducing the influence of other uncertainties in the experiment.

[0063] S3. Place a metal tube directly above the transmitting and receiving ends. The metal tube has a diameter of 2.5 cm and a length of 3 m. The horizontal distance between the transmitting and receiving ends is... Initially, both the transmitting and receiving ends are 2cm away from the metal tube. At this time, the coupling distance is no greater than 1 / 4 wavelength (85.7mm) corresponding to the center working frequency, which is used to fully excite the surface wave mode.

[0064] S4. First, determine the horizontal distance between the transmitting and receiving ends. With the receiver at a fixed height, measurements were initially taken every 0.1m downwards from the transmitter. The path loss value was extracted and calculated for each measurement, and compared with the path loss under free-space propagation conditions. The boundary value of the transmitter's coupling distance was found to be 0.5m. After determining this boundary value, 0.05m was selected as the new measurement range. Measurements were then taken every 0.05m downwards from the transmitter until 0.8m. At this distance, the path loss value for the surface wave environment under all conditions reached the path loss value for the free-space environment. That is, there were 6 measurement points from 0m to 0.5m, and 6 measurement points from 0.55m to 0.8m, for a total of 12 measurement points. The transmitter's coupling distance was adjusted, and measurements were taken 9 times at each point. A Vector Network Analyzer (VNA) was used to collect wireless channel measurement data at the vertical coupling distance of the transmitter at each measurement point, and the path loss value was extracted and calculated from the measurement data.

[0065] S5. Change the horizontal distance between the transmitter and receiver. Adjust to 1.0m, 1.5m, 2.0m and 2.5m, and repeat step S4.

[0066] Step 6. Replace the 2.5cm diameter metal tube with 4.0cm and 10.0cm diameter metal tubes, and repeat steps S3, S4 and S5.

[0067] Step 7: Fit the obtained path loss values ​​to parameters, select different function models for fitting, and compare the root mean square error (RMSE) values ​​corresponding to different function models. Combined with R-squared (coefficient of determination), it is found that when using the composite exponential function model... The path loss model has the smallest root mean square error (RMSE) and conforms to the data trend, therefore the constructed path loss model... The final expression is:

[0068]

[0069] in, The distance between the transmitting end and the metal tube is the coupling distance, and a, b, c, and d are the parameters of the expression.

[0070] Based on the aforementioned measurement data related to the coupling distance at the transmitting end, different function models were used to construct path loss models related to the coupling distance at the transmitting end. The model with the smallest root mean square error (RMSE) is selected. The RMSE values ​​for fitting different function models are shown in the table below:

[0071]

[0072] The table shows that the RMSE of the fit is minimized when using the proposed function, regardless of how the diameter of the metal tube and the horizontal distance between the transmitting and receiving ends change.

[0073] S8. The path loss model constructed in step S7 above The path loss model is obtained by fitting the parameters using the least squares method. The path loss exponent is modeled by adjusting the values ​​of each parameter, and finally, the path loss model is obtained using the adjusted values ​​of all parameters. ;

[0074] (1) The final path loss model The final expression is:

[0075]

[0076] in, The selected reference distance, To be at the reference distance The path loss value at point d, where d is the distance between the transmitting and receiving antennas. This is the path loss index. To conform to a mean of 0 and a standard deviation of The following table shows the Gaussian distributed random variables. The parameter data for fitting the proposed model are as follows:

[0077]

[0078] (2) Horizontal distance between the transmitting and receiving ends The path loss exponent at 1m was calculated and modeled. Different function models were selected for fitting, and the root mean square error (RMSE) values ​​corresponding to different function models were compared. Combined with R-squared (coefficient of determination), it was found that when using the cubic function model... The root mean square error (RMSE) value is the smallest, therefore the constructed path loss exponential model has the lowest RMSE value. The final expression is:

[0079]

[0080] in, The coupling distance between the transmitting end and the metal tube. , , , The parameter is used for the expression.

[0081] Horizontal distance between transceiver ends When it is 1m, The RMSE and R-square of different function models are shown in the table below:

[0082]

[0083] The table shows that, regardless of the diameter of the metal tube chosen, the proposed function results in the smallest RMSE and the best R-squared performance.

[0084] Therefore, the horizontal distance between the transmitting and receiving ends When the path loss index is 1m, The parameter data for fitting different function models are shown in the table below:

[0085]

[0086] It should be noted that the parameter values ​​in the table above are obtained by fitting actual measurement data and the established model. Different scenarios or other variables may lead to different parameter values, and these parameter values ​​are only applicable to the specific scenarios mentioned above.

[0087] S9. The distance between the sending and receiving ends Transmitter coupling distance Input final path loss model This allows us to obtain the path loss value of the transceiver channel under the corresponding conditions.

[0088] In the specific results, Figure 4 The following data are presented: Surface wave propagation with varying coupling distance at the transmitter for three different diameter metal tubes, with a horizontal distance of 1m between the transmitter and receiver. Figure. As can be seen from the figure, in the case of surface wave propagation excited by a metal tube, The path loss is smaller than that under free-space conditions, and compared to Yang et al.'s (Patent Publication No. XDPCN241424, A Channel Modeling Method, Device, and Storage Medium Based on Surface Wave Transmission), the impact of changes in the metal tube diameter on path loss when the coupling distance at the transmitting end changes is far less than the impact of changes in the metal tube diameter on path loss when the coupling distance at the receiving end changes. As the diameter increases, The value decreases, but the decrease is small. This is because, unlike the change in coupling distance at the receiving end, when the coupling distance at the transmitting end increases, the receiving end will still receive the "wave" transmitted from free space by the transmitting end. Therefore, the change in the diameter of the metal tube has a smaller impact on path loss when the coupling distance at the transmitting end changes.

[0089] Figures 5 to 7 A comparative diagram of path loss model fitting curves for the transmitting-end coupling distance of three metal tubes with different diameters is presented, showing the results under different horizontal distances between the transmitting and receiving ends. Figures 5 to 7 As can be seen, regardless of changes in the diameter of the metal tube and the horizontal distance between the transmitting and receiving ends, It increases with the increase of the coupling distance at the transmitting end, but it is not a simple linear relationship. When the coupling distance at the transmitting end is small... The increase is significant; when the coupling distance at the transmitting end exceeds a certain value, The growth rate gradually decreased, although the final growth rate did indeed decrease. The efficiency of surface wave propagation continues to increase, rather than converging to a constant value. Furthermore, from the three figures, we observe that as the vertical coupling distance at the transmitter increases, the efficiency of surface wave propagation decreases. This is because surface wave propagation dominates when the vertical coupling distance is small. However, when the vertical coupling distance exceeds a certain value, the growth trend gradually stabilizes. At this point, although surface waves may still exist, free propagation of the signal becomes dominant, and the propagation mode gradually shifts from surface wave propagation to free space propagation. Therefore, there is a boundary value for the vertical coupling distance at the transmitter. Before this boundary value, surface wave propagation is dominant; after this boundary value, it gradually transitions to free space propagation.

[0090] Numerical analysis Figures 5 to 7 Looking solely at the 2.5cm metal tube, when the horizontal distance between the transmitting and receiving ends is different, as the coupling distance at the transmitting end increases, The maximum coupling distance for path loss values ​​under free-space propagation conditions also varies. When the horizontal distance between the transmitter and receiver is 0.5m, the maximum transmitting-end coupling distance is approximately 0.4m. However, when the horizontal distance between the transmitter and receiver is 1m and 1.5m, the maximum transmitting-end coupling distances are 0.55m, 0.6m, 0.65m, and 0.7m respectively. It can be seen that the larger the horizontal distance between the transmitter and receiver, the greater the path loss value. The larger the path loss value under free-space propagation conditions, the greater the coupling distance at the transmitting end; that is, the larger the boundary value of the transmitting end coupling distance. Furthermore, by comparing the three figures, when at the same horizontal distance between the transmitting and receiving ends, the larger the diameter of the metal tube, the larger the boundary value of the transmitting end coupling distance. For example, when the horizontal distance between the transmitting and receiving ends is 1m, the maximum coupling distance of a 2.5cm metal tube is 0.55m, the maximum coupling distance of a 4.0cm metal tube is 0.65m, and the maximum coupling distance of a 10cm metal tube is approximately 0.75m.

[0091] like Figure 8As shown, the path loss exponent increases with increasing coupling distance at the transmitting end. Initially, the increase is stable, but when the coupling distance exceeds 0.5m, the increase becomes larger, and the smaller the diameter of the metal tube, the larger the path loss exponent. This is because the larger the coupling distance at the transmitting end, the longer the emitted "wave" will travel in free space before reaching the surface of the metal tube for surface wave propagation, and finally being received by the receiving end. Furthermore, the receiving end will also receive the "wave" transmitted from free space by the transmitting end. The larger the coupling distance at the transmitting end, the greater the probability that the receiving end will receive the "wave" transmitted from free space, thus increasing the path loss exponent's growth rate. (The path loss exponent in free space is 2).

[0092] In summary, this method establishes a nonlinear relationship model between the coupling distance at the transmitting end and the path loss exponent. This model can demonstrate the significant increase in the path loss exponent when the coupling distance at the transmitting end exceeds 0.5 m. It also proves that the influence of the metal tube diameter on path loss weakens as the transmitting end is adjusted. Thus, the established model can better reduce path loss and improve the reliability and security of signal transmission.

[0093] Furthermore, it should be emphasized that the transmitter adjustment used in this application is significantly different from the conventional receiver adjustment in the prior art (CN118713779A: A channel modeling method, device and storage medium based on surface wave transmission):

[0094] Firstly, considering the wave transmission path, when the coupling distance at the receiving end changes, because the exciter and the metal tube are tightly coupled, the wave can be fully coupled and excited from the transmitting end and emitted. It then transmits as a surface wave through the metal tube. The receiving end receives the transmitted wave. The wave received at the receiving end includes the wave transmitted from the transmitting end through the metal tube and a fixed but small amount of wave transmitted through free space. When the coupling distance at the receiving end changes, the amount of wave received through the metal tube will change. Changing the coupling distance at the transmitting end also changes the effectiveness of the wave's coupling and excitation at the transmitting end. Generally, the larger the coupling distance at the transmitting end, the worse the effect of the wave's coupling and excitation at the transmitting end. Therefore, the probability of the receiving end receiving the wave transmitted from the metal tube at the transmitting end decreases, while the probability of receiving the wave transmitted from free space increases. Thus, the impact of changes in the transmitting end coupling distance on path loss is greater than, and different from, the impact of changes in the receiving end coupling distance on path loss.

[0095] In terms of results, changing the coupling distance at the transmitting end has a greater impact than changing the coupling distance at the receiving end. Changing the coupling distance at the transmitting end alters the path loss by 20 to 22 dB, while changing the coupling distance at the receiving end alters the path loss by a maximum of 16 dB. Furthermore, the maximum coupling distance threshold also differs. Finally, analyzing the impact of the metal tube diameter, from 0.1 m to 0.8 m, the change in the metal tube diameter has a far smaller impact on path loss than the change in the metal tube diameter when the coupling distance at the receiving end changes. As the diameter increases, the path loss decreases, but the decrease is relatively small. This is because, unlike the change in the coupling distance at the receiving end, when the coupling distance at the transmitting end increases, the receiving end receives more "waves" transmitted from free space, while only a small amount of "waves" are transmitted from the surface of the metal tube. Therefore, the change in the metal tube diameter has a smaller impact on path loss when the coupling distance at the transmitting end changes.

[0096] Finally, in terms of performance indicators, this application also provides an index of path loss index and a formula model. Initially, the growth is stable, but when the coupling distance at the transmitting end exceeds 0.5m, the growth rate increases. A comparison of different metal tubes was also made. The smaller the diameter of the metal tube, the larger the path loss index. The path loss index in free space is 2, which better illustrates the above situation.

[0097] In summary, due to the different transmission paths and changes, the fitted path loss models and path loss exponential models with the influence of the transmitting end coupling distance are significantly different from the receiving end model.

[0098] In free space regions, such as Figure 9 As shown, by comparing the wave transmission diagrams under two different conditions at the transmitting and receiving ends, the technical advantages of the proposed solution are further illustrated:

[0099] refer to Figure 9 In (a), for example, in this application, by changing the vertical coupling distance of the transmitting end, when the coupling distance is large, the efficiency of the transmitting end to excite surface waves is very poor. At this time, the probability of transmitting surface waves will decrease, and the probability of transmitting free space waves will increase.

[0100] Specifically, the wave first passes through free space and then propagates as a surface wave through the metal tube. At this point, some of the waves that pass through free space are directly transmitted to the receiving end, meaning that the probability of free space transmission is relatively high.

[0101] Therefore, with changes in the vertical coupling distance at the transmitting end, when the coupling distance is large, the excitation effect of the metal tube is also very poor. The receiving end receives more of what the transmitting end directly obtains from free space, and the surface wave transmitted through the metal tube has a lower impact.

[0102] refer to Figure 9In (b), for example, a channel modeling method, device and storage medium based on surface wave transmission in patent publication number CN118713779A, by changing the vertical coupling distance of the receiving end, when only the coupling distance of the receiving end is changed, that is, when the transmitting end is tightly coupled, the efficiency of the transmitting end in exciting surface waves is very good. At this time, the probability of the metal tube transmitting surface waves will be very high. The amount of wave directly transmitted to the outside world (free space) is small and fixed. At this time, the wave first passes through the metal tube and then passes through free space to be transmitted to the receiving end.

[0103] Therefore, with changes in the vertical coupling distance at the receiving end, when the coupling distance is large, the free space distance that the wave travels through after passing through the surface of the metal tube increases, and its path loss elevation increases until it reaches a certain fixed value.

[0104] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0105] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0106] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the surface wave wireless channel modeling and optimization methods based on the transmitting end coupling distance in the above embodiments.

[0107] It is understood that the system provided in the embodiments of the present invention corresponds to the method provided in the embodiments of the present invention, and the explanation, examples and beneficial effects of the relevant content can be referred to the corresponding parts of the above methods.

[0108] This application also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, communication interface, and memory communicate with each other via the communication bus.

[0109] Memory, used to store computer programs;

[0110] When the processor executes the program stored in the memory, it implements the above-mentioned surface wave wireless channel modeling and optimization method based on the coupling distance of the transmitting end.

[0111] The communication bus mentioned in the above-mentioned electronic devices can be a standard bus for interconnecting peripheral components or an extended industrial standard structure bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc.

[0112] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0113] The memory may include random access memory or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0114] The processors mentioned above can be general-purpose processors, including central processing units, network processors, etc.; they can also be digital signal processors, application-specific integrated circuits, field-programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0115] It should also be noted that electronic devices include terminal devices, which can also be called terminals, user equipment, mobile stations, mobile terminals, etc. Terminal devices can be mobile phones, smart TVs, wearable devices, tablets, computers with wireless transceiver capabilities, virtual reality terminal devices, augmented reality terminal devices, wireless terminals in industrial control, wireless terminals in autonomous driving, wireless terminals in remote surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, and so on. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

[0116] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0118] Furthermore, it should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present invention, the directional indication is only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0119] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, in the embodiments of this invention, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

Claims

1. A surface wave wireless channel modeling and optimization method based on the coupling distance at the transmitting end, comprising the following specific steps: S1. Setting the sending end , the receiving end and several sets of metal pipes of different diameters, wherein the distance between the sending end and the receiving end can be changed; S2. Use a calibrator to calibrate the transmitting end. Transmitting antenna and receiving end The receiving antenna is calibrated; S3. Place a set of metal tubes directly above the transmitting and receiving ends, and adjust the coupling distance between the transmitting and receiving antennas and the metal tubes to ensure that the surface wave mode can be fully excited. Its features are, Also includes: S4. Measure the horizontal distance between the transmitter and receiver. With the receiver height fixed, the transmitter height is varied. A vector network analyzer (VNA) is used to collect measurement data of the wireless channel at that height, and the path loss value is calculated and extracted from this measurement data. The vertical distance between the transmitter and the metal tube is the coupling distance. ; S5. Change the horizontal distance between the transmitter and receiver. And repeat step S4 above; S6. Replace with another metal tube of a different diameter and repeat steps S3 to S5 above; S7. Based on the multiple path loss values ​​extracted in the above steps, construct a path loss model that incorporates the influence of the receiver coupling distance. ; S8. The path loss model constructed in step S7 above The path loss model is obtained by fitting the parameters using the least squares method. The path loss exponent is modeled using the corrected values ​​of each parameter, and finally, the path loss model is obtained using the corrected values ​​of each parameter. ; S9. The distance between the sending and receiving ends Transmitter coupling distance Input final path loss model This allows us to obtain the path loss value of the transceiver channel under the corresponding conditions; In step S4: during the initial measurement, the transmitting end performs a measurement every time it moves down 0.1m. For each measurement, the corresponding path loss value is extracted and calculated, and the path loss value under free space propagation conditions is compared. The boundary value of the coupling distance at the transmitting end is set to 0.5m. After 0.5m, the transmitting end is measured once every time it moves down 0.05m, until it reaches 0.8m. The coupling distance at the transmitting end is adjusted and 9 measurements are taken at each point to obtain the corresponding path loss value. The average value of all path loss values ​​is then calculated as the final path loss value corresponding to each measurement.

2. The surface wave wireless channel modeling and optimization method based on transmitter coupling distance as described in claim 1, characterized in that, In step S1, both the transmitting antenna at the transmitting end and the receiving antenna at the receiving end are connected to the Vector Network Analyzer (VNA) via cables, and both the transmitting and receiving ends are equipped with surface wave exciters.

3. The surface wave wireless channel modeling and optimization method based on transmitter coupling distance as described in claim 1, characterized in that, In step S7, the obtained path loss values ​​are fitted with parameters, and a composite exponential function model is selected for fitting to construct the path loss model. The final expression is: in, The distance between the transmitter and the metal tube is the coupling distance, and a, b, c, and d are the specified weight parameters in the expression.

4. The surface wave wireless channel modeling and optimization method based on transmitter coupling distance as described in claim 1, characterized in that, In step S8, the horizontal distance between the transceiver ends is... The path loss index at 1m was calculated and modeled, and a cubic function model was selected for fitting, resulting in the constructed path loss index model. The final expression is: in, The coupling distance between the transmitting end and the metal tube. , , , Specify weight parameters for the expression.

5. The surface wave wireless channel modeling and optimization method based on transmitter coupling distance as described in claim 1, characterized in that, The final path loss model in step S8 The expression is represented as: in, The selected reference distance, To be at the reference distance The path loss value at point d, where d is the distance between the sender and receiver. This is the path loss index. To conform to a mean of 0 and a standard deviation of A Gaussian distributed random variable.

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