Estimation device, estimation system, estimation method, and program

Abstract

Provided is an estimation device for estimating wireless communication quality in target space, wherein the target space is divided into a plurality of regions having different characteristics, and the estimation device comprises an estimation processing unit that estimates the wireless communication quality using a different estimation formula for each region.

Description

Estimation device, estimation system, estimation method, and program

[0001] The present invention relates to a technique for estimating wireless communication quality.

[0002] It is common to estimate radio wave propagation loss for use in area design of wireless communication systems, and a propagation loss estimation model is used for this purpose. As a conventional technique, a model for IMT-2020 (5G) disclosed in Non-Patent Document 1 and the like is widely used.

[0003] Its indoor (InH: Indoor Hotspot) model is available for a wide frequency range from 0.5-100GHz, and estimates are calculated so that they add up over frequency.

[0004] ITU-R Report ITU-R M.2412-0(10 / 2017)

[0005] However, in conventional technology, frequency characteristics are expressed only by the constant 20log(f). This is equivalent to the frequency characteristics of free space loss and does not take into account the influence of the environment (including surrounding obstacles, etc.) on frequency characteristics, so estimation accuracy is likely to deteriorate when applied to a wide frequency range. Note that this issue arises when estimating wireless communication quality, not limited to propagation loss.

[0006] The present invention has been made in view of the above points, and has an object to provide a technique for estimating wireless communication quality while taking into consideration the influence of the environment on frequency characteristics.

[0007] According to the disclosed technology, there is provided an estimation device for estimating wireless communication quality in a target space, the target space being divided into a plurality of regions with different characteristics, and including an estimation processing unit for estimating the wireless communication quality using a different estimation formula for each region.

[0008] The disclosed technology provides a technology for estimating wireless communication quality while taking into account the influence of the environment on frequency characteristics.

[0009] 4 is a diagram illustrating a waveguide effect; FIG. 5 is a diagram illustrating first Fresnel zone shielding; FIG. 6 is a diagram illustrating an example in which a target space is divided into four regions; FIG. 7 is a diagram illustrating an image of an estimation result corresponding to the region division in FIG. 3; FIG. 8 is a diagram illustrating an example of the configuration of an estimation device 100; FIG. 9 is a flowchart illustrating a processing procedure of the estimation device 100; FIG. 10 is a diagram illustrating region division in an embodiment; FIG. 11 is a diagram illustrating an estimation formula in an embodiment; FIG. 12 is a diagram illustrating an estimation result in an embodiment; FIG. 13 is a diagram illustrating an example of the hardware configuration of the device.

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] In the following, first, the problems with the conventional propagation loss estimation model will be described in more detail, and then the technology according to this embodiment will be described.

[0012] (Regarding Issues) As mentioned above, the propagation loss estimation model of the prior art does not take into account the influence of the environment (including surrounding obstacles, etc.) on frequency characteristics, and there is a possibility that the estimation accuracy will deteriorate when applied to a wide frequency range.

[0013] For example, in an indoor environment, there is a waveguide effect that reduces propagation loss by reflecting and combining multiple paths on the ceiling or floor, as shown in Figure 1. In particular, at high frequencies, the radio wave confinement effect is strong, reducing propagation loss.

[0014] Furthermore, as shown in Figure 2, it is possible that propagation loss increases when the first Fresnel zone is blocked by the ceiling or floor, etc. In particular, at low frequencies, radio waves are blocked by the ceiling, floor, and furniture, increasing loss.

[0015] It is believed that the manner in which the influence of the waveguide effect or the shielding of the first Fresnel zone appears varies depending on the frequency and the environment, but the conventional technology disclosed in Non-Patent Document 1 and the like was unable to estimate propagation loss taking the environment into consideration. Note that this issue is not limited to the estimation of propagation loss, but arises in the estimation of wireless communication quality in general.

[0016] A technique for realizing estimation of wireless communication quality taking into consideration the influence of the environment on frequency characteristics will be described below.

[0017] (Overview of Technology According to the Present Embodiment) In the present embodiment, an estimation device 100 estimates wireless communication quality. First, an overview (basic concept) of the estimation process performed by the estimation device 100 will be described. Note that in the present embodiment, a specific example will be described using propagation loss (propagation characteristics) as an example of wireless communication quality, but the technology according to the present embodiment can also be applied to wireless communication qualities other than propagation loss.

[0018] In this embodiment, in estimating propagation loss, the target space to be estimated is divided into multiple regions with different characteristics (specifically, radio wave propagation characteristics). Note that "division" may also be expressed as "classification." The estimation device 100 estimates radio wave loss using a different estimation formula for each divided region.

[0019] The above-mentioned division refers to a division other than the division between line-of-sight (LoS) regions and non-line-of-sight (NLoS) regions, which is also used in conventional technology. However, the division in this embodiment may also include the division between line-of-sight (LoS) regions and non-line-of-sight (NLoS) regions.

[0020] Specifically, the classification into a plurality of regions with different characteristics is performed according to the frequency characteristics in the target space, such as whether or not the first Fresnel zone is blocked, the number of times it is blocked, the distance between the transmitting and receiving stations, etc. Since the size of the first Fresnel zone depends on the frequency, the division of the regions may be set for each frequency expected to be used.

[0021] Fig. 3 shows an example in which a target space (here, an indoor space) is divided into four regions. The estimation device 100 specifies the propagation loss in the target space using a different estimation formula for each region. Fig. 4 shows an image of the estimation results.

[0022] 3 and 4 show examples in which regions are divided based on the horizontal distance between the transmitting station and the receiving station (reception point), but the division of regions is not limited to being based on horizontal distance. For example, regions may be divided based on the distance in three-dimensional space between the transmitting station and the receiving station (reception point), or may be divided based on criteria other than distance. Furthermore, the shape of each region is not limited to a rectangular shape (a rectangular parallelepiped / cube in space) as shown in FIG. 3, and regions may have any shape.

[0023] (Configuration Example of Estimation Apparatus 100) Fig. 5 shows a configuration example of the estimation apparatus 100 according to this embodiment. As shown in Fig. 5, the estimation apparatus 100 includes an estimation processing unit 110, an input unit 120, and an output unit 130. Note that the output unit 130 may not be included.

[0024] Parameters necessary for the estimation process are input from the input unit 120. The estimation processing unit 110 estimates the wireless communication quality using the parameters input from the input unit 120. The output unit 130 outputs the estimation result obtained by the estimation processing unit 110. A specific example of the estimation process will be described later.

[0025] The estimation device 100 may be configured as a single device (computer) or multiple devices. In either case, the estimation device may be called an "estimation system." The estimation device 100 may be a virtual machine on the cloud.

[0026] Furthermore, for example, when the estimation processing unit 110 is configured as a device (such as a server), the estimation processing unit 110 may be referred to as an estimation processing device. Furthermore, for example, the above-mentioned estimation processing device may be provided on a cloud, and the input unit 120 and the output unit 130 may be realized by a terminal such as a smartphone. As described above, a configuration consisting of an estimation processing device on a cloud and a terminal (the input unit 120 and the output unit 130) is an example of an estimation system.

[0027] (Processing Procedure) Next, an example of a processing procedure executed by the estimation device 100 will be described with reference to the flowchart shown in FIG.

[0028] <S101: Input> In S101, parameters are input by the input unit 120. The parameters are information necessary for dividing the target space into multiple regions, such as the frequency of radio waves used for wireless communication in the target space, the possible distance between a transmitting station and a moving receiving station, environmental information, etc. For example, if the target space is an indoor space, the environmental information is the location of the transmitting station, the height of the ceiling (height from the floor), and information on the placement of furniture.

[0029] <S102: Estimation Region Division> In S102, the estimation processing unit 110 divides the target space into a plurality of regions based on the parameters input in S101. The estimation processing unit 110 also identifies an estimation formula to be used for each divided region.

[0030] The method of dividing the image into multiple regions is not limited to a specific method. For example, data on multiple regions previously divided manually may be stored in a storage device such as a memory in the estimation device 100 together with the parameters used at that time, and the current parameters may be compared with the past parameters, and division data that is closest to the past parameters may be used for the current division. Furthermore, estimation formulas created in the past may also be used for the estimation formulas for each region.

[0031] Note that the estimation device 100 may not necessarily divide the target space into multiple regions. That is, the division of the target space into multiple regions may be performed outside the estimation device 100, and parameters corresponding to the division results into multiple regions may be input in S101. In this case, the estimation formula for each region may also be input as a parameter in S101.

[0032] <S103: Estimation Process> In S103, the estimation processing unit 110 estimates the wireless communication quality in the target space by using a different estimation formula for each region. The estimation may be to estimate the wireless communication quality at a certain position in the target space, to estimate a graph showing the wireless communication quality at the reception point according to the distance from the transmitting station to the reception point, or to estimate information other than these.

[0033] <S104: Output> In S104, the output unit 130 outputs the estimation result estimated by the estimation processing unit 110.

[0034] Next, a specific example of the estimation process performed by the estimation device 100 will be described as an example. In this example, the target space is an indoor space, and the distance (here, the horizontal distance) from the transmitting station to the position where the first Fresnel zone is shielded is used to divide the target space into multiple regions.

[0035] Specifically, as shown in Figure 7, the distance from the transmitting station (Tx) to the position where the first Fresnel zone is shielded by the ceiling (position A) is 10 m, and this area is designated as area 1; the distance from the transmitting station to the position where the first Fresnel zone is shielded by indoor furniture (position B) is 30 m, and the area from position A to position B is designated as area 2; and the area from position B away from the transmitting station is designated as area 3.

[0036] In this embodiment, the estimation processing unit 110 estimates the propagation loss using an estimation formula with a different slope for each region. An example of the estimation formula is shown in Fig. 8. Here, the point where the slope changes is called an inflection point.

[0037] The equation in FIG. 8 is based on the environment shown in FIG. 7, and the distance from the transmitting station to the first inflection point is d １ = 10 (m), and the distance from the transmitting station to the second inflection point is d ２ = 30 (m).

[0038] Also, in region 1 (d １ ≧d ３Ｄ The slope in １ = 19, and region 2 (d ２ ≧d ３Ｄ ≧d １ The slope in １ = 36, and region 3 (d ３Ｄ ≧d ２ The slope in １ =56.

[0039] For example, when the receiving station is in region 2, that is, when the receiving station (Rx) shown in FIG. 7 is located at a height shown in FIG. 7, it is located between position A and position B (the horizontal distance from the transmitting station is d３Ｄ ), the propagation loss is given by "PL = s ２ log １０ (d ３Ｄ ) + (s １ -s ２ ) log １０ (d １ ) + L ＦＳＰＬ " can be estimated from

[0040] Fig. 9 shows the results of estimation performed by the estimation device 100 based on the above-described region division and estimation formula. For comparison, the figure also shows actual measurement values. As shown in Fig. 9, it can be seen that estimation was performed with high accuracy.

[0041] Since the size of the first Fresnel zone varies depending on the frequency, the region division and the estimation formula may also be changed if the frequency used is changed. In this way, the technology according to the present embodiment can take into account characteristics that vary depending on the frequency, and can achieve high estimation accuracy over a wide range of frequencies.

[0042] (Hardware Configuration Example) Any of the devices (estimation device, estimation processing device, estimation system, terminal, etc.) described in this embodiment can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on the cloud.

[0043] That is, the device can be realized by executing a program corresponding to the processing performed by the device using hardware resources such as a CPU and memory built into a computer. The program can be recorded on a computer-readable recording medium (such as a portable memory) and stored or distributed. The program can also be provided via a network such as the Internet or email.

[0044] Fig. 10 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 10 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected by a bus BS. The computer may further include a GPU.

[0045] The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0046] The memory device 1003 reads and stores the program from the auxiliary storage device 1002 when an instruction to start the program is received. The CPU 1004 realizes the functions related to the light touch maintenance device 100 in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, etc. The display device 1006 displays a GUI (Graphical User Interface) or the like according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the results of calculations.

[0047] (Summary, Effects, etc. of the Embodiment) As described above, the technology described in the present embodiment makes it possible to estimate wireless communication quality taking into consideration the influence of the environment on frequency characteristics. As a result, highly accurate estimation results can be obtained, and the estimation results can be used for wireless area design, etc.

[0048] The following additional notes are provided regarding the above-described embodiments.

[0049] <Additional Notes> (Additional Item 1) An estimation device for estimating wireless communication quality in a target space, the estimation device comprising: an estimation processing unit that divides the target space into a plurality of regions with different characteristics and estimates the wireless communication quality using a different estimation formula for each region. (Additional Item 2) An estimation system for estimating wireless communication quality in a target space, the estimation system comprising: an estimation processing unit that divides the target space into a plurality of regions with different characteristics and estimates the wireless communication quality using a different estimation formula for each region. (Additional Item 3) An estimation method executed by an estimation device for estimating wireless communication quality in a target space, the estimation method comprising: an estimation processing step that divides the target space into a plurality of regions with different characteristics and estimates the wireless communication quality using a different estimation formula for each region. (Additional Item 4) A non-transitory storage medium that stores a program for causing a computer to function as the estimation processing unit in the estimation device described in Additional Item 1.

[0050] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0051] REFERENCE SIGNS LIST 100 Estimation device 110 Estimation processing unit 120 Input unit 130 Output unit 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. An estimation device for estimating wireless communication quality in a target space, the target space being divided into a plurality of regions with different characteristics, and comprising an estimation processing unit for estimating the wireless communication quality using a different estimation formula for each region.

2. An estimation system for estimating wireless communication quality in a target space, the target space being divided into a plurality of regions with different characteristics, and comprising an estimation processing device for estimating the wireless communication quality using a different estimation formula for each region.

3. An estimation method executed by an estimation device that estimates wireless communication quality in a target space, comprising an estimation processing step in which the target space is divided into a plurality of regions with different characteristics, and the wireless communication quality is estimated using a different estimation formula for each region.

4. A program for causing a computer to function as the estimation processing unit in the estimation device according to claim 1.

Images