Near-field test method and system

Abstract

The invention discloses a near-field test method, which is characterized in that sampling points are arranged on a near-field plane, plane near-far field conversion is carried out according to field values of the sampling points, the sampling points are non-uniformly distributed, the distance between the sampling points is in positive correlation with the test distance of the sampling points, and the test distance is the distance between the positions of the sampling points and the original point of an area to be tested. The invention further discloses a near-field test system which uses the method and comprises a data processing system, a control system and a darkroom. The number of sampling points is reduced, and the problem that an existing testing method is high in cost is solved.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic field testing technology, and in particular to a method, device and system for near-field antenna testing. Background Art

[0002] Antenna measurement technology is an indispensable key technology in the field of modern communications and electronic engineering. Antenna measurement plays an important role in radar, satellite communications, and the Internet of Things. Especially in complex and changing electromagnetic environments, the accuracy and efficiency of antenna measurement directly affect the overall performance of the system.

[0003] Common antenna measurement systems currently include far-field measurement, compact field measurement, and near-field measurement. Among these measurement systems, near-field measurement has attracted much attention due to its advantages such as low space requirements and insensitivity to external interference. According to the shape of the scanning surface, near-field measurement systems are divided into planar, cylindrical, and spherical measurements. In particular, near-field measurement systems are widely used in the measurement of directional antennas due to their simple implementation.

[0004] The traditional near-field measurement system mainly consists of three parts: absorbing materials, near-field scanning frame, and turntable. The absorbing materials are installed on the wall of the darkroom or other locations that may interfere with the test results, providing a test environment close to free space; the near-field scanning frame is installed with a probe, which controls the probe to scan the entire sampling plane to obtain the required near-field data; during the entire test process, the antenna to be tested is placed on the turntable.

[0005] During the test, the antenna to be tested is placed on a turntable and connected to a base station simulator. The base station simulator is used to control the antenna to be tested to operate at maximum power during the entire test period. Then the probe on the near-field scanning frame measures the electric field in the two polarization directions of the corresponding position in turn until the probe scans the entire sampling plane and obtains all uniformly distributed sampling points; finally, the sampling data is used to calculate the far-field radiation pattern of the antenna to be tested.

[0006] In traditional near-field measurements, Fourier transform is usually used to reconstruct the far-field information of the antenna to be tested. According to the Nyquist sampling theorem, in order to obtain the near-field data of the complete sampling plane, the sampling interval must be less than or equal to half a wavelength. However, for scenarios such as when the antenna aperture is too large, this method will result in a long sampling time. Therefore, there is an urgent need for a near-field measurement method that can reduce the number of sampling points while retaining key near-field information. Finally, because near-field test systems have been widely used in various fields, the improved method provided will have a huge market. Summary of the invention

[0007] The present application proposes a near-field test method and device to solve the problem of high cost of existing test methods. The present invention reduces the number of sampling points, reduces test costs, and improves test efficiency while ensuring test accuracy.

[0008] On the one hand, the present application proposes a near field test method, where sampling points are set on a near field plane, and a near field to far field conversion is performed on the plane according to the field value of the sampling points. The sampling points are non-uniformly distributed, and the spacing between the sampling points is positively correlated with the test distance of the sampling points, and the test distance is the distance between the sampling point position and the origin of the area to be tested. Preferably, the intersection of the line between the position of the sampling point and the origin of the area to be measured on the spherical surface with the origin as the center satisfies the Igloo spherical sampling position.

[0009] Preferably, the distribution of the Igloo spherical sampling positions on the spherical coordinates is as follows: the polar angle interval is the same, and the azimuthal angle interval increases as the polar angle decreases; and the near-field plane normal is the direction of 90 degrees at the polar angle.

[0010] Preferably, obtaining the far field value using a planar near-far field conversion algorithm according to the field value of the sampling point further comprises the following steps: Setting uniformly distributed sampling points on a sampling plane, wherein the field values ​​of the uniformly distributed sampling points are obtained by interpolating the field values ​​of the non-uniformly distributed sampling points; The far field value is obtained by using a near-far field conversion algorithm according to the field value of the interpolation point.

[0011] Further preferably, the spacing between the uniformly distributed sampling points is less than or equal to half the wavelength.

[0012] Further preferably, the field value of each uniformly distributed sampling point is obtained by interpolating the field values ​​of four surrounding non-uniform sampling points.

[0013] In any embodiment of the present application, preferably, the planar near-field to far-field conversion uses plane wave spectroscopy.

[0014] In a second aspect, the present application further proposes a near-field testing system, using any method described in the first aspect of the present application, the system comprising a data processing system, a control system and a darkroom.

[0015] A mechanical system is arranged in the darkroom, and the mechanical system comprises a near-field scanning frame and a turntable; the near-field scanning frame comprises a vertical frame movable on a horizontal base, and a movable probe is arranged on the vertical frame.

[0016] The control system has a built-in computer program for determining the sampling point position and controls the position of the probe according to the sampling point position.

[0017] The data processing system has a built-in planar near-field to far-field conversion algorithm, and preferably, has a built-in interpolation algorithm.

[0018] In a third aspect, an embodiment of the present application further proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the first aspect of the present application.

[0019] In a fourth aspect, an embodiment of the present application further proposes an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described in any embodiment of the first aspect of the present application is implemented.

[0020] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects: The simple and efficient near-field testing method described in the present invention improves the drawbacks caused by redundant sampling in the classic half-wavelength uniform sampling method through electromagnetic information theory, and adopts a non-uniform sampling method with fewer sampling points. Under the condition of consistent test accuracy, the method described in the present invention requires fewer sampling points, thereby reducing test costs and improving test efficiency. At the same time, the simple and efficient near-field testing method described in the present invention has a wide range of test scenarios and is more flexible than other non-redundant sampling methods. When the method described in the present invention is used to build a near-field testing system, the planning can be more flexibly selected based on multiple aspects such as system cost and test requirements; the simple and efficient near-field testing method described in the present invention adopts program control, the test process is simple and efficient, and the linear characteristics of the test probe scanning trajectory are retained. No manual intervention is required, which greatly improves the efficiency of near-field testing.

[0021] Furthermore, in the data processing system, the positions of the classical half-wavelength uniform sampling points are calculated, interpolation is performed based on the sampled point data, and the interpolation results of the uniformly sampled missing positions are recorded as the corresponding sampling values. The simple and efficient near-field test method described in the present invention does not perform linear interpolation on a simple electric field vector; Processing can be performed to better utilize the existing test information and further improve the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 Schematic diagram of a near-field test chamber used in an embodiment of the present invention, wherein 1 is a probe with known characteristics, 2 is a Y-axis steel frame, 3 is an X-axis base, 4 is a near-field scanning frame, and 5 is an absorbing material; Figure 2The results of the simple and efficient near-field test method used in the embodiment of the present invention and the test results of the E-plane far-field pattern using the existing method are compared; Figure 3 The results of the H-plane far-field pattern test using the simple and efficient near-field test method adopted in the embodiment of the present invention are compared with those of the prior art method; Figure 4 It shows the E-plane far-field patterns reconstructed by two methods; Figure 5 Shown are the H-plane far-field patterns reconstructed by two methods. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0024] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, the present invention discloses a near-field test system, using the method described in any embodiment of the present application, the system includes a data processing system, a control system and a darkroom. The inner wall of the darkroom is coated with a wave absorbing material layer. A mechanical system is provided in the darkroom, and the mechanical system includes a near-field scanning frame and a turntable; the near-field scanning frame includes a vertical frame movable on a horizontal base, and a movable probe is provided on the vertical frame. For example, in the coordinate system of the embodiment of the present application, the near-field scanning frame includes a Y-axis steel frame movable on an X-axis base; the antenna to be tested is placed above the turntable; a movable probe is provided on the Y-axis steel frame of the near-field scanning frame, and the characteristics of the probe are known.

[0026] The control system has a built-in computer program to determine the sampling point location and control the position of the probe according to the sampling point location. The control system has a built-in non-uniform sampling method and can accurately control the probe position. The data processing system has a built-in planar near-field to far-field conversion algorithm, and preferably, has a built-in interpolation algorithm.

[0027] The present application proposes a near-field test method, in which sampling points are set on a near-field plane, and a near-field to far-field conversion is performed on the plane according to the field value of the sampling points. The sampling points are non-uniformly distributed, and the spacing between the sampling points is positively correlated with the test distance of the sampling points. The test distance is the distance between the sampling point position and the origin of the area to be tested. In other words, the farther the distance between the sampling point and the origin of the area to be tested, the larger the spacing between the sampling points, or in other words, the smaller the density of the sampling points.

[0028] Preferably, the lines connecting these non-uniformly distributed sampling points and the origin of the area to be measured form a set of intersections with at least one spherical surface (the spherical surface refers to a sphere with the origin of the area to be measured as the center). The distance between any two adjacent intersections in the set of intersections is less than or equal to half a wavelength. The radius of the at least one spherical surface is not less than the minimum spherical radius that can surround the antenna to be measured. The adjacent intersections are azimuths. Adjacent intersection points in direction or polar angle Adjacent intersection points in direction.

[0029] The near-field test system described in the present invention adopts a simple and efficient near-field test method. Compared with the classic half-wavelength uniform sampling method, it reduces the number of sampling points, reduces the test cost, and improves the test efficiency while ensuring the test accuracy.

[0030] Preferably, the intersection of the line between the position of the sampling point and the origin of the area to be measured on the sphere with the origin as the center satisfies the Igloo spherical sampling position. The radius of the Igloo sphere can be the minimum sphere radius surrounding the antenna to be measured. The non-uniform sampling method determines the position and number of the plane non-uniform sampling points by mapping the spherical sampling to the plane sampling. The specific mapping process is: , ; in, Represents the polar coordinates of the Igloo spherical sampling point in the spherical coordinate system, Represents the azimuth coordinates of the Igloo spherical sampling point in the spherical coordinate system, represents the horizontal coordinate of the non-uniform sampling point on the sampling plane in the rectangular coordinate system, represents the ordinate of the non-uniform sampling point on the sampling plane in the rectangular coordinate system, Represents the distance between the antenna aperture plane to be tested and the near-field sampling plane. Map the Igloo spherical sampling points to the near-field sampling plane to determine the final position and number of non-uniform sampling points on the sampling plane.

[0031] Figure 2The specific process of mapping the Igloo spherical sampling points to the sampling plane is shown. Preferably, the sphere is between the test origin and the sampling plane. The test origin refers to the center point of the measured area. Figure 2 The corresponding relationship between the position coordinates of the spherical sampling points and the plane sampling points is shown. Since the corresponding relationship between the position coordinates of the spherical sampling points and the plane sampling points is a nonlinear tangent function, the spherical sampling points are non-uniformly distributed on the sampling plane after mapping. The spherical sampling points have the same vertical coordinates after being mapped to the plane sampling points ; Similarly, for the same polar coordinates The spherical sampling points have the same vertical coordinates after being mapped to the plane sampling points The propagation from the Igloo spherical sampling points to the plane sampling points can be approximated as a local plane wave. The near-field information carried by the spherical sampling points that can reconstruct the far-field pattern of the antenna to be tested is mapped to the non-uniform sampling points on the near-field sampling plane through the mapping process.

[0032] Preferably, the distribution of the Igloo spherical sampling positions on the spherical coordinates is: the polar angle interval is the same, and the azimuthal angle interval increases as the polar angle decreases; the near-field plane normal is in the direction of 90 degrees at the polar angle. The method of the present application determines the position and number of non-uniform sampling points by mapping spherical sampling to plane sampling. Among them, the spherical sampling method selects Igloo spherical sampling. The Igloo spherical sampling method is a sparse sampling method that can cover the entire sampling sphere with fewer sampling points. The relationship satisfied by the Igloo spherical sampling method is: , ; in, is the polar angle interval, which is fixed and satisfies the spherical Nyquist sampling theorem; is the azimuth interval, which varies with the polar angle variable; , represents the wave number in vacuum, represents the minimum radius surrounding the antenna under test; therefore, the Igloo spherical sampling method overcomes the drawback of oversampling at the poles of the classic equiangular spherical sampling method. Finally, the Igloo spherical sampling method obtains the necessary information to reconstruct the far-field radiation pattern of the antenna under test.

[0033] In this mapping process, the finite sampling sphere is mapped to an infinite sampling plane. However, in actual near-field measurement, it is impossible to scan an infinite sampling plane. With azimuth The sampling range expression is: , , , ; in, represents the horizontal coordinate length of the near-field sampling plane in the rectangular coordinate system, It represents the ordinate length of the near-field sampling plane in the rectangular coordinate system; To restore the near field distribution of the sampling plane, two-dimensional linear interpolation is performed on the non-uniformly distributed sampling data. Preferably, the far field value is obtained by using a plane near-far field conversion algorithm according to the field value of the sampling point, further comprising the following steps: Setting uniformly distributed sampling points on a sampling plane, wherein the field values ​​of the uniformly distributed sampling points are obtained by interpolating the field values ​​of the non-uniformly distributed sampling points; The far field value is obtained by using a near-far field conversion algorithm according to the field value of the interpolation point.

[0034] Further preferably, the spacing between the uniformly distributed sampling points is less than or equal to half the wavelength.

[0035] Further preferably, the field value of each uniformly distributed sampling point can be obtained by interpolating the field values ​​of four non-uniformly distributed sampling points around it.

[0036] Figure 3 The specific linear interpolation process is shown. The electric field amplitude distribution on the sampling plane changes slowly and can be fitted by a slow-varying function. Compared with the electric field amplitude distribution on the sampling plane, the electric field phase distribution on the sampling plane The electric field phase changes rapidly, and the interpolated electric field phase result has a large error, making it difficult to restore the true near-field distribution. In order to reduce the problem of large phase interpolation error, a new electric field vector is constructed in the simple and efficient near-field test method described in the present invention. , the specific expression is:

[0037] in, represents the magnitude distribution of the electric field vector, represents the phase distribution of the electric field vector. , the amplitude distribution and phase distribution on the sampling plane can be fitted by a slowly varying function. Linear interpolation is performed, and the error of the interpolated result is much smaller than that of direct interpolation of the electric field vector. Figure 3 As shown, the sampling plane coordinates after interpolation The electric field vector The expression is: , , , , , , It can be found that the linear interpolation point The interpolation result of and the four nearest non-uniform sampling points around it , , , Vector Regarding, interpolation weights It is related to the distance between the linear interpolation point and the non-uniform sampling point. Finally, the plane wave spectrum method is used to calculate the far-field radiation pattern of the antenna under test on the interpolated half-wavelength uniform grid.

[0038] In any embodiment of the present application, preferably, the planar near-field to far-field conversion uses plane wave spectroscopy.

[0039] The test frequency band of the embodiment of the present invention is 10 GHz, and a pyramid horn antenna is used as the antenna to be tested. The aperture size of the antenna to be tested is ; The size of the near-field sampling plane is ; The distance between the antenna aperture plane and the sampling plane is In order to verify the effectiveness of the simple and efficient near-field test method, the embodiment of the present invention uses the existing standard method and the improved method supporting the present invention to perform near-field tests on the antenna to be tested: A simple and efficient near-field testing method based on the near-field testing system comprises the following steps: Step 1: Place the antenna to be tested on a turntable in a darkroom so that the antenna to be tested is at the center of the sampling plane, connect the antenna to be tested to a base station simulator, and control the antenna to be tested to transmit signals at maximum power during the entire test process; Step 2: The control system sets the position of the non-uniform sampling point on the sampling plane, and controls the probe on the near-field scanning frame to sequentially collect the electric field in two polarization directions at the position, and stores it in the data processing system; In the data processor, the energy flow density is calculated according to the energy flow density calculation formula. Polarization direction and Energy flux density in polarization direction; Step 3: Repeat step 2 until the probe scans the entire sampling plane; Step 4: In the data processing system, calculate the classical half-wavelength uniform sampling point positions, interpolate the positions of the missing probe sampling according to the sampled point data, record the interpolation results as the corresponding sampling values, and obtain all the required uniformly distributed sampling points on the sampling plane; Step 5: Input all sampled data into the data processing system and calculate the far-field pattern of the antenna to be tested.

[0040] The far-field pattern reconstructed by the existing standard method and the far-field pattern reconstructed by the improved method are plotted on the same graph. Figure 4 It shows the E-plane far-field pattern reconstructed by two methods. Figure 5 Shown are the H-plane far-field patterns reconstructed by two methods. Figure 4 , Figure 5 It can be shown that the far-field radiation patterns reconstructed by the existing standard method and the improved method are basically the same, and the difference is almost negligible. However, the number of sampling points required for the antenna to be tested using the existing standard method in the embodiment of the present invention is 2809; while the improved method only requires 261, which reduces the number of sampling points by 90.35%. Finally, the embodiment of the present invention proves that the improved method greatly reduces the number of sampling points, reduces the test cost, and improves the test efficiency while ensuring the same test accuracy as the existing standard method.

[0041] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0042] Therefore, the present application also proposes a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present application is implemented.

[0043] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0044] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0045] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0046] Furthermore, the present application also proposes an electronic device (or computing device), comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present application when executing the computer program.

[0047] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory. Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium. Computer-readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device. According to the definition in this article, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0048] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0049] Those skilled in the art will understand that, unless expressly stated, the singular forms "a", "an", "said" and "the" used may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. In addition, the terms "horizontal" and "vertical" are based on the orientation and positional relationship of the devices or components shown in the accompanying drawings, and are only for the purpose of better describing the present invention, rather than requiring the devices, components or equipment shown to have this specific orientation, and therefore cannot be understood as limiting the present invention. Those skilled in the art will understand that, unless otherwise defined, all terms (including technical, terminological and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the present invention belongs.

[0050] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A near-field test method, wherein sampling points are set on a near-field plane, and a near-field to far-field conversion is performed on the plane according to the field values ​​of the sampling points, characterized in that: The sampling points are non-uniformly distributed, and the spacing between the sampling points is positively correlated with the testing distance of the sampling points. The testing distance is the distance between the sampling point position and the origin of the area to be tested.

2. The near field testing method according to claim 1, characterized in that: The intersection point of the line between the position of the sampling point and the origin of the area to be measured on the spherical surface with the origin as the center satisfies the Igloo spherical surface sampling position.

3. The near field testing method according to claim 1, characterized in that: The distribution of the Igloo spherical sampling positions on the spherical coordinates is as follows: the polar angle interval is the same, and the azimuth angle interval increases as the polar angle decreases; the near-field plane normal is the direction of 90 degrees at the polar angle.

4. The near field testing method according to claim 1, characterized in that: According to the field value of the sampling point, the far field value is obtained by using the plane near-far field conversion algorithm, further comprising the following steps: Setting uniformly distributed sampling points on a sampling plane, wherein the field values ​​of the uniformly distributed sampling points are obtained by interpolating the field values ​​of the non-uniformly distributed sampling points; The far field value is obtained by using a near-far field conversion algorithm according to the field value of the interpolation point.

5. The near field testing method according to claim 4, characterized in that: The spacing between the evenly distributed sampling points is less than or equal to half the wavelength.

6. The near field testing method according to claim 4, characterized in that: The field value of each uniformly distributed sampling point is obtained by interpolating the field values ​​of the four surrounding non-uniform sampling points.

7. The near field testing method according to claim 1, characterized in that: The planar near-field to far-field conversion uses plane wave spectroscopy.

8. A near field test system, using the method according to any one of claims 1 to 7, characterized in that: Including data processing system, control system and darkroom; A mechanical system is arranged in the darkroom, and the mechanical system comprises a near-field scanning frame and a turntable; the near-field scanning frame comprises a vertical frame movable on a horizontal base, and a movable probe is arranged on the vertical frame; The control system has a built-in computer program to determine the sampling point location, and controls the position of the probe according to the sampling point location; The data processing system has a built-in planar near-field and far-field conversion algorithm.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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