Wireless communication system, wireless communication method, wireless communication device, and wireless communication program

Abstract

The present disclosure relates to a wireless communication system, a wireless communication method, a wireless communication device, and a wireless communication program. A wireless communication system is configured to execute: a process for subdividing map information received from a database into a plurality of grids; a process for acquiring attribute information, which is an element indicating features of the grids, on the basis of the map information; a process for extracting map information pertaining to an environment in which wireless communication is to be performed; a process for acquiring the degree of similarity between the attribute information included in the extracted map information and the attribute information pertaining to each grid; a process for extracting a grid for which the degree of similarity is highest; a process for simulating propagation in the environment using a setting parameter that is associated with the extracted grid; and a process for optimizing a communication parameter on the basis of the result of simulating propagation in the environment.

Description

Wireless communication system, wireless communication method, wireless communication device, and wireless communication program

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, a wireless communication device, and a wireless communication program.

[0002] In recent years, the introduction of wireless communication systems using new communication standards represented by 5G or local 5G has been progressing. In order to provide these wireless communication systems with high quality, it is important to optimize the communication parameters of the wireless communication system.

[0003] In order to optimize communication parameters, Non-Patent Document 1 discloses a method of estimating radio propagation characteristics using a previously created database.

[0004] Ishizu, Murakami, Aoi, Chan, Harada, "Wireless Network System Operable in TV White Space in Cooperation with Database", IEICE Technical Report, vol.112, no.55, SR2012-4, pp.23-30, May 2012.

[0005] However, the above method has a problem that the amount of calculation and time required to optimize communication parameters becomes enormous.

[0006] An object of the present disclosure is to provide a wireless communication system capable of reducing the amount of calculation and time required to optimize communication parameters in order to solve the above problems.

[0007] A first aspect of the present disclosure is configured to perform a process of subdividing map information received from a database into a plurality of grids, a process of acquiring attribute information which is an element indicating characteristics of a grid based on the map information, a process of extracting map information of an environment to be wirelessly communicated, a process of acquiring a similarity between the attribute information included in the extracted map information and the attribute information of the grid, a process of extracting a grid having the largest similarity, a process of performing a propagation simulation in the environment using setting parameters associated with the extracted grid, and a process of optimizing communication parameters based on the result of the propagation simulation in the environment. It is preferable that it is a wireless communication system.

[0008] Furthermore, a second aspect of this disclosure is preferably a wireless communication device configured to perform the following: subdivide map information received from a database into multiple grids; acquire attribute information, which is an element that indicates the characteristics of the grid, based on the map information; extract map information of the environment to be wirelessly transmitted; acquire the similarity between the attribute information contained in the extracted map information and the attribute information of the grid; extract the grid with the greatest similarity; perform a propagation simulation in the environment using setting parameters associated with the extracted grid; and optimize communication parameters based on the results of the propagation simulation in the environment.

[0009] Furthermore, a third aspect of this disclosure is preferably a wireless communication method comprising: subdividing map information received from a database into multiple grids; obtaining attribute information, which is an element that indicates the characteristics of the grid based on the map information; extracting map information of the environment to be wirelessly transmitted; obtaining the similarity between the attribute information contained in the extracted map information and the attribute information of the grid; extracting the grid with the greatest similarity; performing a propagation simulation in the environment using setting parameters associated with the extracted grid; and optimizing communication parameters based on the results of the propagation simulation in the environment.

[0010] A fourth aspect of this disclosure is a wireless communication program to be implemented by a wireless communication device having a processor and memory, which is stored in memory and is computer-readable, and preferably includes a program to cause the processor to perform the following: subdivide map information received from a database into a plurality of grids; acquire attribute information which is an element that indicates the characteristics of the grid based on the map information; extract map information of the environment to be the target of wireless communication; acquire the similarity between the attribute information contained in the extracted map information and the attribute information of the grids; extract the grid with the greatest similarity; perform propagation simulation in the environment using setting parameters associated with the extracted grids; and optimize communication parameters based on the results of the propagation simulation in the environment.

[0011] According to the aspects of this disclosure, the amount of computation required to optimize communication parameters can be reduced.

[0012] This is an overall diagram of a system equipped with the wireless communication system according to Embodiment 1 of this disclosure. This is a diagram of the wireless communication system according to Embodiment 1 of this disclosure. This is a diagram of the hardware configuration of the wireless communication device according to Embodiment 1 of this disclosure. This is a flowchart of the processing performed by the wireless communication system according to Embodiment 1 of this disclosure.

[0013] Each embodiment will be described with reference to the drawings. The same or corresponding components will be denoted by the same reference numerals, and repetition of the description may be omitted.

[0014] Embodiment 1 Figure 1 is an overall diagram of a system equipped with a wireless communication system according to Embodiment 1 of the present disclosure. System 1000 is a system that can optimize the communication parameters used in the wireless communication system in real time by utilizing a large-scale database prepared in advance. Here, only an overview of System 1000 is shown, and the details of the wireless communication system according to the present disclosure will be described later.

[0015] First, input information 10 and 10a are input to the wireless communication device 500 of the system 1000. Input information 10 is information relating to the outdoors. Information relating to the outdoors includes, for example, spatial information such as map information, pedestrian flow information, traffic information, or material information for the past, present, or future. Input information 10a is information relating to the indoors. Information relating to the indoors includes, for example, floor plan information, building information, activity information of people or things, or material information for the past, present, or future.

[0016] Input information 10 and 10a are received by the propagation simulation unit 20, the pedestrian flow simulation unit 20a, and the traffic simulation unit 20b. The information processed by the pedestrian flow simulation unit 20a and the traffic simulation unit 20b is aggregated in the propagation simulation unit 20.

[0017] The propagation simulation unit 20 processes the aggregated information and transmits it to the data processing unit 30. The data processing unit 30 processes the received information and transmits it to the database 40. The database 40 stores the received information.

[0018] The information stored in database 40 is retrieved by data analysis unit 50. The data analysis unit 50 processes the retrieved information and stores it in database 40.

[0019] Similarly, the information stored in the database 40 is acquired by the measurement data unit 60. The measurement data unit 60 stores the data measured based on the acquired information in the database 40.

[0020] Furthermore, the information stored in the database 40 is acquired by the optimization unit 70. The optimization unit 70 optimizes the communication parameters based on the acquired information.

[0021] The optimization unit 70 transmits the optimized communication parameters to the wireless base station 80. The wireless base station 80 uses the received communication parameters to perform wireless communication with the wireless terminal station 90. Although this example shows a configuration with multiple wireless terminal stations 90, it is not limited to this configuration; for example, a configuration with only one wireless terminal station 90 is also possible.

[0022] Figure 2 shows a wireless communication system according to Embodiment 1 of the present disclosure. Here, we will extract and explain the wireless communication system 100, which is a characteristic part of the present disclosure, from the system 1000. It is assumed that the settings of each device have been configured in advance.

[0023] First, input information 10 is input to the map extraction unit 15 of the wireless communication device 500. The input information 10 is, for example, information about the outdoors. Information about the outdoors includes spatial information such as map information, pedestrian flow information, traffic information, or material information for the past, present, or future. The map extraction unit 15 extracts map information of the environment targeted for wireless communication by creating 3D map information based on the input information 10.

[0024] The map extraction unit 15 transmits the extracted information to the propagation simulation unit 20. Based on the received information, the propagation simulation unit 20 performs a propagation simulation in the environment targeted for wireless communication. The propagation simulation performed here may include, for example, the network topology, propagation characteristics, or traffic volume. Propagation characteristics may include, for example, received power, throughput, delay profile, or fading. As a result, the propagation simulation unit 20 obtains the simulation results.

[0025] The propagation simulation described above is performed based on the setting parameters 25 included in the analysis information stored in the database 40, which will be described later. The setting parameters include, for example, the frequency used, the bandwidth used, the number of reflections and diffractions in wireless communication, the transmittance, the dielectric constant of the building, the antenna pattern determined at the transmitting and receiving points, and the transmitted power. The setting parameters may also be a channel model that represents the relationship between distance and received power. Details of this propagation simulation will be described later.

[0026] The propagation simulation unit 20 transmits the simulation results to the data processing unit 30. The data processing unit 30 integrates external information 35 with the received simulation results.

[0027] External information 35 is information related to the simulation results, such as time information, location information, or measured sensor information. By integrating external information 35 with the simulation results, it becomes possible to perform data analysis based on the integrated information.

[0028] The data processing unit 30 inputs the integrated information into the database 40. The database 40 then databases the input information. Therefore, if the 3D map information obtained based on the input information 10 is 3D map information scattered throughout Japan, the database 40 can database the simulation results for each environment throughout Japan.

[0029] The database 40 transmits the stored information to the data analysis unit 50. Based on the received information, the data analysis unit 50 extracts one or more setting parameters in order of highest estimation accuracy. The data analysis unit 50 also creates analysis information that links the extracted setting parameters to the corresponding 3D map information and the attribute information contained in that 3D map information. Furthermore, the data analysis unit 50 transmits the analysis information to the database 40. The detailed method for creating the analysis information will be described later.

[0030] The database 40 stores the received analysis information. The database 40 also transmits the stored analysis information to the propagation simulation unit 20. Based on the received analysis information, the propagation simulation unit 20 performs a propagation simulation in the environment targeted for wireless communication.

[0031] Specifically, the propagation simulation unit 20 obtains the similarity between the attribute information included in the 3D map information of the environment targeted for wireless communication and the attribute information of the grid described later. The similarity is, for example, the correlation between the attribute information included in the 3D map information of the environment targeted for wireless communication and the attribute information of the grid described later. Alternatively, the similarity may be cosine similarity, which is an index that takes the direction of the vector into consideration, or similarity based on the distance between data.

[0032] Next, the propagation simulation unit 20 extracts the grid with the greatest similarity. Furthermore, the propagation simulation unit 20 uses the setting parameters associated with the extracted grid to perform a propagation simulation in the environment targeted for wireless communication. As a result, the propagation simulation unit 20 obtains the simulation results for the environment targeted for wireless communication.

[0033] The database 40 also inputs the simulation results, which integrate the external information 35, into the optimization unit 70. The optimization unit 70 then optimizes the communication parameters.

[0034] Specifically, the optimization unit 70 outputs communication parameters that optimize wireless communication based on the input simulation results. These communication parameters include, for example, the optimal frequency, optimal bandwidth, beam to be used, communication method, directivity, antenna pattern determined at the transmission and reception points, and transmission power.

[0035] The optimization unit 70 transmits the outputted communication parameters to the wireless base station 80. The wireless base station 80 uses the received communication parameters 85 to perform wireless communication with the wireless terminal station 90.

[0036] In other words, the wireless base station 80 is a wireless base station of the target wireless communication system 100 and is controlled according to the communication parameters 85 output by the optimization unit 70. The wireless terminal station 90 is a terminal that performs wireless communication in the target wireless communication system 100. If the wireless terminal station 90 is a mobile terminal, the wireless terminal station 90 is connected to the wireless base station 80 via a wireless network.

[0037] Figure 3 shows the hardware configuration of a wireless communication device according to Embodiment 1 of the present disclosure. Each function of the wireless communication device 500 may be partially or entirely configured by hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array), or it may be configured as a program executed by a processor such as a CPU.

[0038] For example, the wireless communication device 500 can be realized by using a computer and a program, and the program can be recorded on a storage medium or provided through a network.

[0039] As shown in FIG. 3, the wireless communication device 500 includes an input unit 508, an output unit 501, a communication unit 502, a CPU 503, a memory 504, and an HDD 505 connected via a bus 506, and has functions as a computer. Further, the wireless communication device 500 is capable of inputting and outputting data to and from a computer-readable storage medium 507.

[0040] The input unit 508 is, for example, a keyboard and a mouse. The output unit 501 is, for example, a display device such as a display.

[0041] The communication unit 502 is, for example, a communication interface for communicating with a wireless device to be controlled.

[0042] The CPU 503 controls each part constituting the wireless communication device 500 and performs predetermined processing and the like. The memory 504 and the HDD 505 store data and the like.

[0043] The storage medium 507 is capable of storing a program and the like for causing the wireless communication device 500 to execute functions. Note that the architecture constituting the wireless communication device 500 is not limited to the example shown in FIG. 3.

[0044] FIG. 4 is a flowchart showing the processing performed by the wireless communication system according to Embodiment 1 of the present disclosure.

[0045] First, in step 100, the data analysis unit 50 creates analysis information. Specifically, the following five processes are performed.

[0046] First, the data analysis unit 50 subdivides the map information received from the database 40 into a plurality of grids. This subdivision may be, for example, in a mode of subdividing into grids of Xm × Xm, or in a mode of subdividing into grids with a radius of Xm centered on the transmission antenna. Note that X is an arbitrary value.

[0047] Second, the data analysis unit 50 acquires the attribute information of each grid based on the map information. The attribute information is an element indicating the characteristics of each grid. The attribute information is, for example, the position information of the antenna, the shielding information, and the line-of-sight information.

[0048] The position information of the antenna is, for example, the height of the transmitting antenna, the height of the receiving antenna, the distance and direction between the transmitting antenna and the receiving antenna. The shielding information is, for example, the distance between the transmitting antenna and the shielding object, the distance between the receiving antenna and the shielding object, the shielding object density for the grid, the road density for the grid, and the road width. The shielding object is, for example, a building. The line-of-sight information is, for example, the line-of-sight rate between the transmitting antenna and the receiving antenna, the presence or absence of major reflectors, and the ratio of windows in the building.

[0049] Each numerical value included in the attribute information includes a statistical quantity. The statistical quantity is, for example, the average, variance, moving average, moving variance, peak value, and the difference between the maximum value and the minimum value.

[0050] Also, the attribute information may be saved as a graph or an image. By allowing the user to view the saved graph or image, it becomes easier for the user to understand the attribute information.

[0051] Further, by visualizing the attribute information in a form other than numerical values, the data analysis unit 50 can newly extract potential attribute information other than the attribute information set manually. By using the newly extracted attribute information, the data analysis unit 50 can improve the accuracy and speed of the similarity calculation during data analysis.

[0052] For example, when the data analysis unit 50 images the attribute information, the positional relationship between obstacles or the correlation with the feature amounts of adjacent grids can be newly extracted as the attribute information. Alternatively, when the data analysis unit 50 graphs the attribute information using a data structure representing the relationship between vertices (nodes), the number and weights of the nodes and edges of the structured data can be newly extracted as the attribute information.

[0053] Thirdly, the data analysis unit 50 performs propagation simulations for each grid. This propagation simulation is performed for each changed setting parameter. As a result, the data analysis unit 50 obtains simulation results for each grid that correspond to the combination of changed setting parameters.

[0054] Fourth, the data analysis unit 50 compares the acquired simulation results with the measured values ​​and extracts one or more simulation results in order of the degree of agreement.

[0055] As a result of the first to fourth processes, the data analysis unit 50 can extract one or more setting parameters in order of highest estimation accuracy based on the received information. The setting parameters to be extracted may be just the one with the highest estimation accuracy, or a specific number or a specific proportion of parameters in order of highest estimation accuracy.

[0056] Fifth, the data analysis unit 50 creates analysis information. Specifically, the data analysis unit 50 creates analysis information that links the setting parameters corresponding to the extracted simulation results to the corresponding grid.

[0057] Next, in step 102, the database 40 stores the analysis information. Then, in step 104, the map extraction unit 15 receives the input information 10. This input information 10 includes spatial information as described above.

[0058] Next, in step 106, the map extraction unit 15 extracts map information of the environment to be used for wireless communication. Specifically, the map extraction unit 15 extracts map information of the environment to be used for wireless communication by creating 3D map information based on the input information 10 which includes spatial information.

[0059] Next, in step 108, the propagation simulation unit 20 performs a simulation in the environment targeted for wireless communication. Specifically, the propagation simulation unit 20 first obtains a similarity score based on the extracted map information and analysis information of the environment targeted for wireless communication. That is, the similarity score obtained here is the similarity between the attribute information included in the extracted map information and the grid attribute information included in the analysis information.

[0060] Next, the propagation simulation unit 20 extracts the grid with the highest similarity. Furthermore, the propagation simulation unit 20 uses the setting parameters associated with the extracted grid to perform a propagation simulation in the environment targeted for wireless communication. As a result, the propagation simulation unit 20 obtains the simulation results for the environment targeted for wireless communication.

[0061] Next, in step 110, the data processing unit 30 integrates the external information 35 into the simulation results. Then, in step 112, the database 40 databases the simulation results with the integrated external information 35.

[0062] Next, in step 114, the optimization unit 70 optimizes the communication parameters. Specifically, the optimization unit 70 outputs communication parameters that optimize wireless communication based on the input simulation results.

[0063] Next, in step 116, the optimization unit 70 transmits the communication parameters to the wireless base station 80. The wireless base station 80 can then use the received communication parameters 85 to perform wireless communication with the wireless terminal station 90.

[0064] Next, in step 118, the wireless base station 80 determines whether the optimization of communication parameters is complete. If it is complete, the process ends. If it is not complete, the process returns to step 114 and repeats the process up to step 118.

[0065] Step 118 is provided to test the communication parameters optimized based on the simulation results in the actual environment. Even if the communication parameters optimized in the simulation are not optimal in the actual environment, step 118 allows for readjustment of the communication parameters.

[0066] The effects obtained by the wireless communication system according to this embodiment will be explained. In recent years, the introduction of wireless communication systems using new communication standards such as 5G or local 5G has been progressing. In order to provide these wireless communication systems with high quality, it is important to optimize the communication parameters of the wireless communication system.

[0067] As mentioned above, one known optimization method involves investigating the wireless propagation characteristics in the environment targeted for wireless communication and utilizing the results of that investigation. In this method, sensing-based detection was commonly used to investigate the wireless propagation characteristics.

[0068] However, this detection method can only detect information from the nearby area that can be sensed. In other words, the aforementioned method had the problem of not being able to optimize for the communication conditions at a distance.

[0069] To address this issue, Non-Patent Document 1 discloses a method for estimating wireless propagation characteristics using a pre-created database.

[0070] However, the aforementioned method relies on database-based estimation in response to changes in the environment targeted by wireless communication. These changes are caused by a vast number of factors, such as the movement of people or robots, changes in the environment's configuration, changes in indoor layout, and changes in wireless base stations or terminal stations.

[0071] In other words, the aforementioned method requires simulating all possible combinations of factors and creating a large-scale database. As a result, depending on the complexity of the environment targeted by wireless communication and the required estimation accuracy, the amount of computation required for propagation simulation and database creation becomes enormous. In addition, the enormous amount of computation required also leads to an enormous amount of time. In short, there was a problem in that the amount of computation and time required to optimize communication parameters was enormous.

[0072] In this embodiment, the data analysis unit 50 acquires analysis information in advance based on information obtained from the database 40. Subsequently, the propagation simulation unit 20 performs a propagation simulation based on the analysis information. As a result, the amount of computation required for propagation simulation and database creation can be reduced. In other words, the amount of computation and time required to optimize communication parameters can be reduced.

[0073] Embodiment 2 The data analysis unit 50 in this embodiment differs from Embodiment 1 in that it further acquires pedestrian flow information or traffic information as attribute information for each grid.

[0074] In the method disclosed in Non-Patent Document 1, if the environment targeted by wireless communication changes in real time, estimation using the database also needs to be performed in real time. As a result, the number of times estimation using the database is performed increases. In other words, there was a problem in that the amount of computation and time required to optimize communication parameters became even more enormous.

[0075] The data analysis unit 50 according to this embodiment can perform propagation simulations that take into account pedestrian flow information or traffic information. In other words, the data analysis unit 50 can perform propagation simulations that assume the environment targeted by wireless communication changes in real time.

[0076] As a result, in this embodiment, even when the environment targeted by wireless communication changes in real time, the amount of computation and time required to optimize communication parameters can be reduced compared to Embodiment 1, which re-estimates each time the environment changes.

[0077] 40 Database 85 Communication Parameters 100 Wireless Communication System 500 Wireless Communication Device 504 Memory 1000 System

Claims

1. A wireless communication system configured to perform the following steps: subdivide map information received from a database into multiple grids; acquire attribute information, which is an element that indicates the characteristics of the grid, based on the map information; extract map information of the environment to be wirelessly transmitted; acquire the similarity between the attribute information contained in the extracted map information and the attribute information of the grid; extract the grid with the greatest similarity; perform a propagation simulation in the environment using setting parameters associated with the extracted grid; and optimize communication parameters based on the results of the propagation simulation in the environment.

2. A wireless communication device configured to perform the following steps: subdivide map information received from a database into multiple grids; acquire attribute information, which is an element that indicates the characteristics of the grid, based on the map information; extract map information of the environment to be wirelessly transmitted; acquire the similarity between the attribute information contained in the extracted map information and the attribute information of the grid; extract the grid with the greatest similarity; perform a propagation simulation in the environment using setting parameters associated with the extracted grid; and optimize communication parameters based on the results of the propagation simulation in the environment.

3. A wireless communication method comprising: subdividing map information received from a database into multiple grids; obtaining attribute information which is an element that indicates the characteristics of the grid based on the map information; extracting map information of the environment to be wirelessly transmitted; obtaining the similarity between the attribute information contained in the extracted map information and the attribute information of the grid; extracting the grid with the greatest similarity; performing a propagation simulation in the environment using setting parameters associated with the extracted grid; and optimizing communication parameters based on the results of the propagation simulation in the environment.

4. A wireless communication program to be implemented by a wireless communication device having a processor and memory, the program being stored in the memory and computer-readable, and including a program to cause the processor to perform the following: a process of subdividing map information received from a database into a plurality of grids; a process of acquiring attribute information which is an element that indicates the characteristics of the grid based on the map information; a process of extracting map information of an environment to be the target of wireless communication; a process of acquiring the similarity between the attribute information contained in the extracted map information and the attribute information of the grids; a process of extracting the grid with the greatest similarity; a process of performing a propagation simulation in the environment using setting parameters associated with the extracted grids; and a process of optimizing communication parameters based on the results of the propagation simulation in the environment.

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