Propagation environment creation device, propagation environment creation method, and propagation environment estimation system

Abstract

The present disclosure relates to a propagation environment fabricating device, a propagation environment fabricating method, and a propagation environment estimation system suitable for utilizing a scale model to estimate an environment of a radio signal. The propagation environment fabricating device of the present disclosure comprises a block group, a computer, and a raising and lowering mechanism. The block group is formed from a plurality of blocks having an arbitrarily defined reflection coefficient with respect to electromagnetic waves. The computer is configured to implement 3D model creation processing for creating a 3D model of a target environment to be reproduced, and setting processing for setting a height of each block on the basis of the 3D model. The raising and lowering mechanism is configured to implement modification processing for modifying the height of each block on the basis of the setting processing.

Description

[Technical Field]

[0001] The present disclosure relates to a propagation environment creation device, a propagation environment creation method, and a propagation environment estimation system, and more particularly to a propagation environment creation device, a propagation environment creation method, and a propagation environment estimation system that are suitable for estimating the environment of a wireless signal using a scale model. [Background technology]

[0002] In recent years, the explosive spread of wireless communication devices has led to an increasing demand for wireless communication. However, the frequency resources available for wireless communication are limited. This has made it necessary to utilize previously unused frequencies in addition to existing frequencies. When using a new frequency band, it is necessary to investigate in advance the propagation characteristics of wireless signals in the service area and the impact of interference that signals in the new frequency band may have on other systems.

[0003] In response to these demands, the International Telecommunication Union (ITU) Radiocommunication Sector (ITU-R) is attempting to measure the propagation characteristics of wireless signals in real areas and develop propagation models based on various measurement results. However, these types of attempts face challenges, such as insufficient measurement results for unexplored frequencies and insufficient development of propagation models.

[0004] Non-Patent Document 1 discloses a method for reproducing propagation loss characteristics in a mobile communication environment using a scale model. Scale models created for such a method may have their surfaces subjected to a reflective treatment. For example, the scale model is subjected to a surface treatment that reflects visible light with a given reflectance. Next, the visible light emitted from a light-emitting element, which is regarded as a transmitter, is regarded as a radio wave. Then, by observing the propagation of the visible light, it is possible to estimate the propagation of the radio wave. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Ryuichiro Iwakuma, Yu Funaki, Toyokazu Mine, Shinichi Ichitsubo, “Delay Profile Using Scale Model Method for Microcells in Urban Areas,” 2010 International Conference on Broadband, Wireless Computing, Communication and Applications, Nov. 2010, pp. 587-591. Summary of the Invention [Problem to be solved by the invention]

[0006] When creating the scale models mentioned above, 3D printers or blocks are used. However, these methods have the problem that it takes a lot of time just to create the shape. In addition, after the scale models are created, the surfaces need to be processed to reflect light. However, urban environments are complex and require detailed processing, which poses technical challenges.

[0007] In order to solve the above-mentioned problems, a first object of the present disclosure is to provide a propagation environment creation device that uses a scale model, which can shorten the creation time and facilitate surface reflection processing.

[0008] A second object of the present disclosure is to provide a method for creating a propagation environment using a scale model, which can shorten the creation time and facilitate surface reflection processing.

[0009] Furthermore, a third object of the present disclosure is to provide a propagation environment estimation system that uses a scale model that can shorten the production time and facilitates surface reflection processing. [Means for solving the problem]

[0010] A first aspect is preferably a propagation environment creation device comprising a group of blocks, a computer, and a lifting mechanism, wherein the group of blocks is formed of a plurality of blocks having arbitrary reflection coefficients for electromagnetic waves, the computer is configured to perform a 3D model creation process to create a 3D model of the target environment to be reproduced, and a setting process to set the height of each block based on the 3D model, and the lifting mechanism is configured to perform a change process to change the height of each block based on the setting process.

[0011] The second aspect is a propagation environment creation method that uses a group of blocks formed of blocks having any reflection coefficient for electromagnetic waves, and preferably includes a 3D model creation step that creates a 3D model of the target environment to be reproduced, a setting step that sets the height of each block based on the 3D model, and a modification step that modifies the height of each block based on the setting step.

[0012] A third aspect is a propagation environment estimation system comprising a scale model unit, a calculation unit, an elevating mechanism unit, an element mounter unit, a control unit, and a memory unit, wherein the scale model unit comprises a block group formed of a plurality of blocks having arbitrary reflection coefficients for electromagnetic waves, the calculation unit is configured to perform a 3D model creation process of creating a 3D model based on a target environment and a setting process of setting the height of each block based on the 3D model, the elevating mechanism unit is configured to perform a modification process of changing the height of each block based on the setting process, the element mounter unit is configured to perform an installation process of installing electromagnetic wave transmitters, which resemble radio wave transmitting stations, and electromagnetic wave receivers, which resemble receivers, in the block group, and the control unit is configured to perform an irradiation process of irradiating a measurement range set in the block group with the electromagnetic wave transmitter, a measurement process of measuring electromagnetic wave intensity with the electromagnetic wave receiver, and a calibration process of converting data of electromagnetic wave intensity obtained by the measurement into a radio wave reception level. [Effects of the Invention]

[0013] According to the first to third aspects, the time required to create a scale model used for propagation environment estimation can be reduced, and surface reflection processing can be easily performed. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a scale model used in a conventional propagation environment estimation method. [Figure 2] 1 is a flowchart showing an estimation procedure in a conventional propagation environment estimation method. [Figure 3] 1A to 1C are diagrams illustrating a scale model before and after deformation according to the first embodiment of the present disclosure. [Figure 4] 3 is a flowchart showing an estimation procedure in a propagation environment estimation method according to the first embodiment of the present disclosure. [Figure 5] 1 is a diagram illustrating an entire first lifting mechanism according to a first embodiment of the present disclosure. [Figure 6] FIG. 2 is a diagram illustrating a portion of a first lifting mechanism according to the first embodiment of the present disclosure. [Figure 7] 5 is a flowchart showing a transformation procedure for the first scale model in accordance with the first embodiment of the present disclosure. [Figure 8] FIG. 2 is a first diagram showing a second scale model in accordance with the first embodiment of the present disclosure. [Figure 9] FIG. 10 is a second diagram showing the second scale model in accordance with the first embodiment of the present disclosure. [Figure 10] 10 is a flowchart showing a transformation procedure of the second scale model in accordance with the first embodiment of the present disclosure. [Figure 11] FIG. 10 is a first diagram illustrating a modified example of a block according to the first embodiment of the present disclosure. [Figure 12] FIG. 10 is a second diagram illustrating a modified example of a block according to the first embodiment of the present disclosure. [Figure 13] 3 is a flowchart showing the entire procedure of the propagation environment estimation method according to the first embodiment. [Figure 14]FIG. 14 is a block diagram for explaining the configuration of a propagation environment estimation system that can continuously and fully automatically carry out the series of processes shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiment 1 [Outline of conventional propagation environment estimation methods] Fig. 1 is a perspective view of a scale model used in a conventional propagation environment estimation method. Fig. 2 is a flowchart showing the estimation procedure in the conventional propagation environment estimation method. As shown in Fig. 2, in the propagation environment estimation method of this embodiment, estimation of the propagation environment proceeds in the following steps.

[0016] 1. Create a model of the target area. Hereinafter, this model will be referred to as a "scale model." A scale model is a reproduction of an actual urban space, for example, at a scale of about 1 / 100. Figure 2 shows an example in which an outdoor space is used as the target area, but the interior of a specific building may also be used as the target area.

[0017] 2. A light source is installed to act as a radio wave transmission source. For example, a light-emitting diode or an incandescent lamp can be used as the light source.

[0018] 3. Install a light-receiving element that acts as a radio wave receiver. For example, a photoresistor, photodiode, or phototransistor can be used as the light-receiving element.

[0019] 4. The light source is turned on and the light receiving element measures the light receiving level. In the area simulating the ground of the scale model in Figure 2, the white parts are the illuminated areas and the black parts are the non-illuminated areas. Also, the higher the brightness, the higher the light receiving level.

[0020] 5. The light reception level data obtained in the previous step is calibrated to match the actual communication environment and the distance characteristics of the simulation results, and the light reception level is converted into radio wave reception level.

[0021] To create the scale models mentioned above, 3D printers or blocks are used. However, these methods have the problem of requiring a lot of time just to create the shape. For example, it takes several tens of hours to create a city that spreads over an area of ​​100m x 100m at a scale of about 1 / 20.

[0022] Furthermore, after the scale model is created, it is necessary to perform a surface reflection treatment. However, urban environments are complex and require detailed processing, which poses technical challenges. The present disclosure solves these challenges.

[0023] [Overview of First Embodiment of the Present Disclosure] 3 is a diagram illustrating a scale model before and after deformation according to the first embodiment of the present disclosure. The diagram on the left in FIG. 3 shows the scale model before deformation. The diagram on the right in FIG. 3 shows the scale model before deformation. Numbers enclosed in boxes in FIG. 3 correspond to numbers shown in the flowchart in FIG. 4, which will be described later.

[0024] The scale model 10 is a block group that includes a plurality of blocks 2. Here, the blocks 2 are rectangular parallelepiped blocks. The blocks 2 have their surfaces subjected to a reflective treatment. Examples of reflective treatment include plating, polishing, or applying a mirror film.

[0025] The reflection process is expected to be performed with different reflectance depending on the frequency band of the object to be measured. The higher the frequency of the radio wave, the lower the power of the reflected wave from the wall surface. Therefore, the higher the target frequency, the reflection process is performed to lower the light reflectance.

[0026] In the propagation environment estimation of the present disclosure, a target environment is reproduced using a scale model 10. That is, the target environment is reproduced by changing the relative height of each of a plurality of blocks 2. A specific estimation procedure will be described later.

[0027] 4 is a flowchart showing an estimation procedure in the propagation environment estimation method according to Embodiment 1 of the present disclosure. As shown in FIG. 4, in the propagation environment estimation method of this embodiment, estimation of the propagation environment proceeds in the following steps.

[0028] First, in step 100, a group of blocks is created. Specifically, a plurality of blocks 2 are created and laid out to create the group of blocks that make up the scale model 10. Here, the blocks 2 are assumed to be rectangular parallelepipeds.

[0029] Furthermore, the block 2 has a given reflection coefficient for visible light, and therefore the surface of the block 2 is subjected to a reflection treatment, such as plating, polishing, or applying a mirror film.

[0030] Next, in step 102, a 3D model of the target environment to be reproduced is created. This 3D model is created, for example, by a computer.

[0031] Next, the height of each block is calculated in step 104. First, the 3D model created in step 102 is mapped onto the scale model 10 created in step 100. Then, the height of each block 2 is set based on the mapping results.

[0032] Next, in step 106, the lifting mechanism is used to push up each block, thereby changing the height of each block 2 to the height set in step 104.

[0033] Next, in step 108, the propagation environment is measured using visible light. Next, in step 110, it is confirmed whether there are any other differences in the target environment that need to be measured. Differences in the target environment are assumed to be, for example, the construction of a new building or cars parked on the road. If there are other differences that need to be measured, the process returns to step 102 and repeats the process for the relevant target environment. If there are no other differences that need to be measured, the process proceeds to step 112.

[0034] Next, in step 112, all blocks are returned to their initial height, thereby resetting the scale model 10 to its initial state.

[0035] As described above, the scale model of the present disclosure is formed by creating and combining multiple blocks of the same shape, and then changing the height of each block. This means that the time required to create the entire scale model can be significantly reduced compared to conventional methods. Furthermore, the scale model of the present disclosure is created by combining blocks that have been subjected to a reflective surface treatment. This means that the reflective surface treatment is easier than conventional methods.

[0036] [Modification of the first embodiment of the present disclosure] 5 is a diagram illustrating an entire first lifting mechanism according to the first embodiment of the present disclosure. The scale model 10a is a block group including a plurality of blocks 2a. A lifting mechanism 9 is installed below the scale model 10a. The lifting mechanism 9 is connected to the computer 4. Then, in steps 106 and 112, the computer 4 controls the height of each block 2a.

[0037] 6 is a diagram illustrating a portion of a first lifting mechanism according to the first embodiment of the present disclosure. Block 2a is connected to gears 6 and motors 8, and a bundle of gears 6 and motors 8 constitutes lifting mechanism 9. Gear 6 is, for example, a rack gear. Calculator 4 operates the corresponding gears 6 and motors 8 to lift and lower the corresponding block 2a.

[0038] 7 is a flowchart showing a procedure for deforming the first scale model according to the first embodiment of the present disclosure. First, in step 114, blocks with reflective surfaces are laid out. Here, the blocks 2a are rectangular parallelepipeds.

[0039] The block 2a has a given reflection coefficient for visible light, and therefore the surface of the block 2a is subjected to a reflection treatment, such as plating, polishing, or applying a mirror film.

[0040] Next, in step 116, lifting mechanisms are attached to all the blocks. That is, by attaching gears 6 and motors 8, all the blocks 2a can be lifted and lowered.

[0041] Next, in step 118, the number of rotations of the motors attached to each block is determined by a computer, and a scale model is formed. First, the height of each block 2a is determined according to the 3D model of the scale model to be formed. Next, the number of rotations of the motors required to change the height of each block 2a is calculated by a computer. Then, based on the calculation results, each motor is rotated to form the scale model.

[0042] Depending on the size and complexity of the target environment, the above-described transformation procedure can produce a scale model in just a few minutes. In contrast, conventional 3D printers require tens of hours to produce a scale model. In other words, by using the above-described transformation procedure, the desired scale model can be produced very quickly.

[0043] FIG. 8 is a first diagram showing a second scale model according to the first embodiment of the present disclosure. The scale model 10b is a block group including a plurality of blocks 2b. The scale model 10b is deformed by a block push-up device 12. The block push-up device 12 is installed directly below the block 2 to be pushed up by an XY table 14. That is, in step 106, the block push-up device 12 controls the height of the block 2.

[0044] 9 is a second diagram showing a second scale model according to the first embodiment of the present disclosure. The diagram on the left of FIG. 9 is a diagram showing an operation for returning the formed scale model to its initial state. The diagram on the right of FIG. 9 is a diagram showing the scale model returned to its initial state.

[0045] The scale model 10b has a top plate 16 on top. The top plate 16 uniformly presses down on the scale model 10b, returning the scale model 10b to its initial state. Note that the top plate used here is not limited to a top plate, and any plate that can uniformly press down the height of all of the blocks that make up the scale model 10b will suffice.

[0046] FIG. 10 is a flowchart showing a procedure for transforming a second scale model according to the first embodiment of the present disclosure. First, in step 120, blocks with reflective surfaces are laid out. Here, the blocks 2b are rectangular parallelepipeds with an arbitrary reflectance coefficient for visible light. Therefore, the blocks 2b have been subjected to a reflective treatment on their surfaces. Examples of reflective treatments include plating, polishing, and applying a mirror film.

[0047] Next, in step 122, a block lifting device is installed under the blocks, and in step 124, each block is lifted up by the block lifting device to form the desired scale model.

[0048] Next, in step 126, a top plate or the like is used to push down all of the blocks to make them all the same height. In other words, the scale model 10b is returned to its initial state. As mentioned above, the object used here is not limited to a top plate, and any object that can uniformly push down the height of all of the blocks that make up the scale model 10b will suffice.

[0049] Unlike the first scale model, the above-described transformation procedure does not require the use of gears 6 and motors 8. This means that the size of the entire device can be reduced. This allows the second scale model to be a high-resolution scale model at a lower cost than the first scale model.

[0050] 11 is a first diagram illustrating a modified example of a block according to the first embodiment of the present disclosure. Block 2c is a triangular prism block whose base is a right-angled isosceles triangle. Block 2c has an arbitrary reflection coefficient for visible light.

[0051] 12 is a second diagram illustrating a modified example of a block according to the first embodiment of the present disclosure. Block 2d is a hexagonal prism block with a regular hexagonal base. Block 2d has an arbitrary reflection coefficient for visible light.

[0052] As described above, the blocks according to this embodiment are not limited to rectangular parallelepipeds. That is, the bottom surface of the blocks is not limited to a specific shape as long as the blocks have an arbitrary reflection coefficient for visible light.

[0053] [Details of the procedure in the first embodiment] Fig. 13 is a flowchart showing all steps of the propagation environment estimation method according to Embodiment 1. The steps shown in Fig. 13 start when information collection is completed for the actual target environment, such as the dimensions and locations of buildings and roads, the radio wave reflectivity at key points, and the frequency of the radio waves to be used.

[0054] First, in step 128, the target environment of the scale model to be created is set. Next, in step 130, a 3D model of the target environment is created. Here, the 3D model is created based on information about the dimensions and locations of various structures and other objects present in the target environment. This 3D model is created, for example, by a computer.

[0055] Next, in step 132, a scale model is formed. Here, a scale model is created by laying out blocks of the same shape, and the height of each block is changed to form the desired scale model. The details of the formation method are as described above.

[0056] Next, in step 134, a light source representing a radio wave transmitting station and a light receiving element representing a receiver are installed. The light source is installed at a candidate installation location for the transmitting station on the scale model, and the light receiving element is installed at a candidate installation location for the receiver on the scale model. The installation of the light source and the light receiving element may be done manually or by a fully automated element mounter.

[0057] Once the above preparations are complete, the light source begins illuminating the scale model in step 136. If the light source is a light-emitting diode or an incandescent lamp, the light source is turned on in this step.

[0058] When irradiation by the light source begins, the light reception level in the measurement range is measured in step 138. When measurement of the measurement range is completed, a calibration process is performed. The values ​​for each reception point determined by the calibration process are stored as information representing the radio wave reception level in a planar manner.

[0059] [Propagation environment estimation system according to the first embodiment] Fig. 14 is a block diagram for explaining the configuration of a propagation environment estimation system that can continuously and fully automatically carry out the series of processes shown in Fig. 13. The system shown in Fig. 14 includes a control device 20 and a storage device 22. The control device 20 includes an arithmetic processing unit. The storage device 22 stores a program to be executed by the arithmetic processing unit. The control device 20 controls each part of the system shown in Fig. 14 by the arithmetic processing unit carrying out processing in accordance with the program.

[0060] In addition to the above programs, the storage device 22 stores various information related to the target environment. This information includes the dimensions, locations, and radio wave reflectivity of buildings, roads, etc. The storage device 22 also stores dimensional data for various elements that can be used in the scale model. Furthermore, the storage device 22 also stores the results of measurements performed using the scale model, i.e., the area-wide reception level information obtained in the processing of step 138 above.

[0061] The system shown in Fig. 14 includes a computer 24. The control device 20 reads various information from the storage device 22 and performs the process of step 128 above, that is, the process of setting the target environment. The computer 24 reads information about the target environment from the storage device 22 and creates a 3D model. Then, based on the created 3D model, the computer 24 calculates the height of each block and transmits it to the control device 20. The control device 20 changes the height of each block so that it matches the received height.

[0062] The system shown in Fig. 14 includes a scale model 26. The scale model 26 is formed from blocks that provide a reflection coefficient according to the frequency band for the light source used in the measurement. If a scale model for a different frequency band is required, the scale model included in the system is replaced with a block group that includes the corresponding block.

[0063] 14 also includes a lifting mechanism 27 that raises and lowers each block. The lifting mechanism 27 changes the height of each block based on a command from the control device 20.

[0064] 14 includes an element mounter 28. The element mounter 28 has the function of installing elements to be used in the scale model at any position on the scale model. In this embodiment, an element that functions as a light source and an element that functions as a receiver are installed by the element mounter 28 in accordance with commands from the control device 20.

[0065] The element functioning as a receiver installed as described above receives light emitted from the element functioning as a light source. The received light data is stored in the memory device 22. The control device 20 performs a calibration process on the received light data stored in the memory device 22, thereby making it possible to estimate the overall reception level of radio waves generated within the measurement range. The estimated reception level is stored in the memory device 22 as described above.

[0066] As described above, the propagation environment estimation method of this embodiment makes it possible to shorten the time required to create a scale model and to easily process the reflection of the surface. Furthermore, the estimation method of this embodiment also makes it possible to significantly reduce the cost required for propagation estimation of the target environment.

[0067] Furthermore, according to the propagation environment estimation system described with reference to Fig. 14, the propagation environment estimation method of this embodiment can be performed as a fully automatic procedure in a single operation. Therefore, this system can significantly improve the efficiency of work related to propagation estimation of a target environment.

[0068] In the above-described embodiment, the configuration shown in Fig. 14 is described as a system consisting of multiple devices, but the present disclosure is not limited to this. That is, the configuration shown in Fig. 14 may be a single device in which the illustrated elements are housed in a single housing.

[0069] Furthermore, in the above-described embodiment, the block group of the present disclosure is described as reflecting visible light, but the present disclosure is not limited to this. That is, the block group may reflect any electromagnetic wave that can be used to estimate the radio wave propagation environment. In this case, the light source corresponds to an electromagnetic wave transmitter, the light receiving element corresponds to an electromagnetic wave receiver, and the received light level corresponds to the electromagnetic wave intensity. [Explanation of symbols]

[0070] Blocks 2, 2a, 2b, 2c, and 2d 4 calculator 6 gears 8 motors 9 Lifting mechanism 10, 10a, 10b scale models 12 Equipment 24 Calculator 26 scale model 27 Lifting mechanism 28 Element mounter

Claims

1. The device includes a group of blocks, a computer, and an elevator mechanism; the block group is formed of a plurality of blocks having a given reflection coefficient for electromagnetic waves, The computer a 3D model creation process for creating a 3D model of the target environment to be reproduced; a setting process for setting the height of each of the blocks based on the 3D model; configured to perform The lifting mechanism is configured to perform a change process for changing the height of each of the blocks based on the setting process. Propagation environment creation device.

2. 2. The propagation environment creating device according to claim 1, wherein the block has a surface that is subjected to a reflective treatment so that the block has a reflectance according to a frequency band to be measured.

3. 3. The propagation environment creating device according to claim 2, wherein the reflection treatment is at least one of plating, polishing, and attaching a mirror film.

4. 2. The propagation environment creating device according to claim 1, wherein the lifting mechanism is a gear and a motor attached to the bottom of each of the blocks.

5. 2. The propagation environment creating device according to claim 1, wherein the lifting mechanism is a block push-up device having an XY table.

6. A propagation environment creation method using a block group formed of blocks having an arbitrary reflection coefficient for electromagnetic waves, comprising: a 3D model creation step of creating a 3D model of the target environment to be reproduced; a setting step of setting a height of each of the blocks based on the 3D model; a changing step of changing the height of each of the blocks based on the setting step; A propagation environment creating method comprising:

7. A propagation environment estimation system comprising a scale model unit, a calculation unit, an elevation mechanism unit, an element mounter unit, a control unit, and a storage unit, the scale model portion includes a block group formed of a plurality of blocks having a given reflection coefficient for electromagnetic waves, The calculation unit: a 3D model creation step of creating a 3D model based on the target environment; a setting step of setting a height of each of the blocks based on the 3D model; configured to perform the lifting mechanism is configured to perform a changing step of changing the height of each of the blocks based on the setting step, the element mounter unit is configured to perform an installation step of installing an electromagnetic wave transmitter, which is likened to a radio wave transmitting station, and an electromagnetic wave receiver, which is likened to a receiver, on the block group; The control unit an irradiation step of irradiating a measurement range set in the block group with the electromagnetic wave transmitter; a measuring step of measuring the electromagnetic wave intensity with the electromagnetic wave receiver; The apparatus is configured to carry out a calibration process of converting the data of the electromagnetic wave intensity obtained by the measurement into a radio wave reception level. Propagation environment estimation system.

8. a step of setting a target environment to be reproduced in the 3D model creation step; a step of installing an electromagnetic wave transmitter, which is likened to a radio wave transmitting station, and an electromagnetic wave receiver, which is likened to a receiver, in the group of blocks; a step of irradiating a measurement range set in the block group with the electromagnetic wave transmitter; measuring the electromagnetic wave intensity with the electromagnetic wave receiver; The propagation environment creating method according to claim 6, further comprising a calibration step of converting data on the electromagnetic wave intensity obtained by the measurement into a radio wave reception level.

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