Beamforming control method

Abstract

To provide a beamforming control method for increasing a white space by minimizing the influence on users of each communication carrier.SOLUTION: A beamforming control method for communication radio waves emitted from a base station 10 includes: dividing an area 12 supported by the base station 10 according to a predetermined range on a plane to form a plurality of divided areas; detecting, for each divided area, the number of mobile communication devices 14 corresponding to the communication radio waves emitted from the base station 10; and in order to make a divided area where the number of detected mobile communication devices 14 is equal to or less than a preset threshold a white space 16, controlling beamforming so as not to emit the communication radio waves to the divided area.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for controlling beamforming, which directs the radiation range of radio waves in a specific direction in wireless communication. [Background technology]

[0002] Currently, calls and data communications are carried out using mobile communication devices such as mobile phones and smartphones through wireless communication services provided by multiple communication carriers. Each communication carrier installs a plurality of base stations on steel towers, on the roofs of buildings, in the mountains, etc., and transmits and receives radio waves to and from each mobile communication device present within the cell of the base station.

[0003] On the other hand, with the rapid increase in the popularity of smartphones, there has been a surge in requests to enter the telecommunications carrier market, but the frequency resources that can be allocated to multiple telecommunications carriers are limited, resulting in a frequency resource depletion problem. This problem of frequency resource depletion can be solved by allowing multiple communication carriers to share frequencies, but in order for multiple communication carriers to share frequencies, it is necessary to effectively utilize white space, which is an empty space area. For this reason, attempts are being made to create a database of white spaces based on the usage patterns of users of each telecommunications carrier and geographical conditions, and to actually measure the radio wave environment and map white spaces.

[0004] For example, Patent Document 1 discloses that when mapping white spaces, information on observed values ​​of radio waves received by multiple sensors is acquired, a first estimate of the observed value at each spatial coordinate is calculated based on the estimated position coordinates of the radio wave emission source and the observed values ​​acquired from each sensor, the difference between the observed value and the first estimate is calculated as a residual for each sensor position, interpolated data for each spatial coordinate of the calculated residual is calculated, and the first estimate and the value of the interpolated data are added for each spatial coordinate to calculate a second estimate of the observed value of the radio waves at each spatial coordinate, thereby accurately estimating the radio wave environment throughout the entire observation area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-92099 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology in Patent Document 1 attempts to map white spaces by estimating the current radio wave environment, but does not increase or expand the white spaces. In other words, it is conceivable that white spaces will eventually decrease, and therefore the conventional technology has the problem of not being able to completely solve the problem of frequency depletion.

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a beamforming control method for increasing white space while minimizing the impact on users of each communication carrier. [Means for solving the problem]

[0008] According to the beamforming control method of the present invention, there is provided a beamforming control method for radio waves for communication radiated from a base station, which comprises dividing an area supported by the base station into a plurality of divided areas on a plane at predetermined ranges, and determining the number of mobile communication devices corresponding to the radio waves for communication radiated from the base station for each divided area. The detection is performed at predetermined time intervals, and the data is compiled into a database for each day. In order to define a sectional area having a time period in which the number of mobile communication devices detected from the past database is below a preset threshold as a white space, only the relevant time period is recorded. The feature of this method is that beamforming is controlled so that radio waves for communication are not emitted into the divided area. This method allows white space to be secured in divided areas with a small number of mobile communication devices, making it possible to share frequencies between different communication carriers while minimizing the number of mobile communication devices that are out of range. Furthermore, based on data of past mobile communication devices, white space is secured only for divided areas where the number of mobile communication devices is small depending on the time period, so that the number of mobile communication devices that are out of range can be further reduced.

[0010] Another feature may be that beamforming is controlled so that radio waves for communication are not emitted only during a time period in a divided area where the number of mobile communication devices detected from the database on the previous day is below a predetermined threshold. According to this method, based on the data of mobile communication devices from the most recent day, white space is secured only during certain time periods in divided areas where the number of mobile communication devices is low, thereby further reducing the number of mobile communication devices that are out of range.

[0011] Another feature may be that beamforming is controlled so that radio waves for communication are not emitted only during a time period in a divided area having a time period in which the number of mobile communication devices detected from the database from one week ago is below a preset threshold. According to this method, white space is secured only during certain time periods in divided areas where the number of mobile communication devices is low, based on data from mobile communication devices from one week ago on the same day of the week, thereby further reducing the number of mobile communication devices that are out of range.

[0012] Further, the present invention may be characterized in that deep learning is performed on the number of mobile communication devices at a predetermined time interval for each divided area that is databased for each day, a predicted number of mobile communication devices at a predetermined time interval for each divided area is calculated, and beamforming is controlled so that communication radio waves are not emitted only during a time period in a divided area where the predicted number is below a predetermined threshold. According to this method, based on predicted data, white space is secured only during certain time periods in divided areas where the number of mobile communication devices is small, thereby further reducing the number of mobile communication devices that are out of range. [Effects of the Invention]

[0013] According to the present invention, it is possible to increase white space while minimizing the impact on users of each communication carrier. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram illustrating base stations owned by a communications carrier and their support areas. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of a base station. [Figure 3] FIG. 2 is a schematic explanatory diagram of a support area in which a white space is formed from the state of FIG. 1. [Figure 4] 1 is a flowchart of a first embodiment of a method for forming a white space by reducing the number of mobile communication devices that are out of range. [Figure 5] FIG. 10 is an explanatory diagram showing a support area on a plane centered on a base station, divided at a predetermined angle to form a plurality of divided areas. [Figure 6] FIG. 10 is an explanatory diagram showing an example in which the locations of mobile communication devices are plotted for each divided area obtained by dividing a support area at a predetermined angle around a base station on an actual map. [Figure 7] This is a graph showing the number of mobile communication devices per 30-minute period for each database-based area. [Figure 8] 10 is a flowchart of a second embodiment of a method for forming a white space by reducing the number of mobile communication devices that are out of range. [Figure 9] 10 is a flowchart of a third embodiment of a method for forming a white space by reducing the number of mobile communication devices that are out of range. [Figure 10] 1 is an explanatory diagram of an embodiment in which the area is divided into Area 1 and Area 2, with 0° north as the center of the base station and 30° to 120° clockwise (eastward) as the center of the base station. [Figure 11] 11 is a graph showing the number of mobile communication devices for one day every 30 minutes in area 1 in FIG. 10. [Figure 12] 12 is an explanatory diagram in which the positions of mobile communication devices in a predetermined time period on the day following the graph in FIG. 11 are plotted on a map, with the ranges of Area 1 and Area 2 superimposed. DETAILED DESCRIPTION OF THE INVENTION

[0015] The beamforming control method according to this embodiment will be described below with reference to the drawings. Figure 1 is a schematic diagram of a base station owned by a given communications carrier and its support area. Note that Figure 1 shows radio waves being emitted in a plane centered on the base station. The base station 10 emits radio waves for communication in a predetermined frequency band, and transmits and receives radio waves to and from mobile communication devices 14 (such as mobile phones and smartphones) present within the support area 12.

[0016] Here, the schematic configuration of the base station will be explained with reference to FIG. The base station 10 has an array antenna 20, a control unit 22 that can control the direction of radio wave radiation from the array antenna 20, and a storage device 24 such as a hard disk drive or SSD. The control unit 22 is composed of a CPU, ROM, RAM, etc., and operates according to a predetermined program. The storage device 24 also stores a database of the number of mobile communication devices 14 for each designated time period for each divided area for each day, as will be described later. The control unit 22 and the storage device 24 may be implemented as one or more computers.

[0017] FIG. 3 shows an example of creating white space from the state shown in FIG. In FIG. 3, the base station 10 emits radio waves only in the direction in which the mobile communication device 14 exists, and the area in which the radio waves are not emitted becomes a white space 16, which is an empty space area. The white space 16 is an empty space where there is no radio wave in a specific frequency band from the base station 10, and therefore can be used by other communication carriers in the same frequency band.

[0018] 3, it is necessary to reduce the number of out-of-service mobile communication devices 14. Hereinafter, a method for reducing the number of out-of-service mobile communication devices 14 will be described.

[0019] (First embodiment) FIG. 4 shows a flowchart of a first embodiment of a method for forming a white space by minimizing the number of out-of-service mobile communication devices. First, as shown in step S100, the control unit 22 divides the support area 12 of the base station 10 into a plurality of divided areas.

[0020] 5 shows an example in which a support area 12 on a plane is divided at a predetermined angle around the base station to form a plurality of sectional areas. In FIG. 5, the area is divided every 30° around the base station 10 to form 12 sectional areas. For example, the sectional area extending 30° north counterclockwise from due east around the base station 10 is sectional area 1, the sectional area extending 30° north counterclockwise from sectional area 1 is sectional area 2, and the sectional area extending 30° north counterclockwise from sectional area 2 is sectional area 3.

[0021] In the next step S102, the control unit 22 counts the number of mobile communication devices 14 in each divided area at predetermined time intervals. FIG. 6 shows an example in which the support area 12 is divided at a predetermined angle on an actual map around a base station to form divided areas, and the location of a mobile communication device is plotted for each divided area. Between the base station 10 and the mobile communication device 14, the mobile communication device 14 transmits location registration information such as the identification number of the mobile communication device 14 and the date and time of reception to the base station 10 within the support area 12 at a predetermined interval. Therefore, the base station 10 can identify the location of the mobile communication device 14 that is present within the support area 12 based on the location registration information. Note that the location of the mobile communication device 14 may be identified based on latitude and longitude information of the mobile communication device 14 obtained by a GPS built into the mobile communication device 14, rather than based on location identification information from the mobile communication device 14.

[0022] The diagram shown in FIG. 6 shows the position of each mobile communication device 14 plotted on map data by the control unit 22 based on the location registration information obtained by the base station 10 or the latitude and longitude information obtained by GPS.

[0023] In the next step S104, the control unit 22 creates a database of the measured number of mobile communication devices 14. Figure 7 is a graph showing the number of mobile communication devices for each 30-minute period for each databased area. In Figure 7, the horizontal axis shows the time of day, and the vertical axis shows the number of mobile communication devices. The start time is midnight.

[0024] Then, in the next step S106, the control unit 22 detects from the previous day's database the time periods in which the number of mobile communication devices is below a preset threshold for each divided area, and controls the divided areas having time periods in which the number of mobile communication devices is below the threshold so that radio waves are not emitted during those time periods.

[0025] For example, if the threshold for the number of mobile communication devices 14 is set to 75, in Figure 7, in the divided area 11 (300° to 330°), the number of mobile communication devices 14 is below the threshold between midnight and 7:30, between 10:30 and 12:00, between 14:00 and 15:00, between 16:00 and 16:30, between 18:00 and 18:30, and between 19:30 and midnight. In addition, in the section area 10 (270° to 300°), the number of mobile communication devices 14 is below the threshold between midnight and 8:00 and between 19:00 and midnight. In addition, in the section area 12 (330° to 360°), the number of mobile communication devices 14 is below the threshold between midnight and 6:30 and between 22:00 and midnight.

[0026] In addition, in the divided area 11, the number of mobile communication devices 14 is slightly below the threshold between 10:30 and 12:00, between 14:00 and 15:00, between 16:00 and 16:30, and between 18:00 and 18:30, and the time during which the number is below the threshold is also short, so radio waves are emitted in the divided area 11 between 10:30 and 12:00, between 14:00 and 15:00, between 16:00 and 16:30, and between 18:00 and 18:30.

[0027] Therefore, in the example of FIG. 7, the control unit 22 controls the sectional area 11 so that radio waves are not emitted between midnight and 7:30 and between 19:30 and midnight. Furthermore, the control unit 22 controls the sectional area 10 so that radio waves are not emitted between midnight and 8:00 and between 19:00 and midnight. Furthermore, the control unit 22 controls the sectioned area 12 so that radio waves are not emitted between midnight and 6:30 and between 22:00 and midnight.

[0028] According to the first embodiment described above, it is possible to ensure white space only in a time period for a divided area where the number of mobile communication devices is small depending on the time period, based on the database of the previous day.

[0029] (Second embodiment) FIG. 8 shows a flowchart of a second embodiment of a method for forming a white space by minimizing the number of out-of-service mobile communication devices.

[0030] The second embodiment is the same as the first embodiment in steps S100, in which the support area 12 of the base station 10 is divided into a plurality of divided areas, S102, in which the number of mobile communication devices 14 in each divided area is measured at predetermined time intervals, and S104, in which the measured number of mobile communication devices 14 is compiled into a database, and therefore the explanation thereof will be omitted here.

[0031] In the second embodiment, in step S206, which is the next step after step S104, the control unit 22 detects, from the database from one week ago, time periods for each divided area in which the number of mobile communication devices is below a preset threshold, and controls the divided area having time periods in which the number of mobile communication devices is below the threshold so that radio waves are not emitted during the time periods in which the number of mobile communication devices is below the threshold.

[0032] According to the second embodiment, white space is secured only during certain time periods in divided areas where the number of mobile communication devices is low depending on the time period, based on the database from one week ago on the same day of the week, so that white space can be secured by accurately reflecting the presence status of mobile communication devices 14, which differs depending on the day of the week.

[0033] (Third embodiment) FIG. 9 shows a flowchart of a third embodiment of a method for forming a white space by minimizing the number of out-of-service mobile communication devices.

[0034] In the third embodiment, the steps up to step S100 of dividing the support area 12 of the base station 10 into a plurality of divided areas, step S102 of measuring the number of mobile communication devices 14 in each divided area at predetermined time intervals, and step S104 of creating a database of the measured number of mobile communication devices 14 are the same as those in the first and second embodiments, and therefore will not be described here.

[0035] In the third embodiment, in step S306 following step S104, deep learning is performed on the number of mobile communication devices at predetermined time intervals for each divided area that has been made into a database. Deep learning is processing using a neural network that has multiple intermediate layers between an input layer and an output layer. In this embodiment, this can be achieved by connecting an AI (not shown) having a deep learning algorithm to the control unit 22, or the control unit 22 itself may be an AI having a deep learning algorithm. As an example of deep learning, a linear regression model can be adopted. The correlation between time and number of mobile communication devices for each divided area and day of the week can be analyzed using the linear regression model, and the number of mobile communication devices for each divided area, day of the week, and time of day can be predicted.

[0036] In the next step S308, the control unit 22 controls the divided area having the time period in which the number of mobile communication devices predicted by deep learning is below the threshold so as not to emit radio waves during the time period in which the number is below the threshold. According to the third embodiment, white space is secured based on the number of mobile communication devices predicted by deep learning, so that white space can be secured while accurately reflecting the presence status of mobile communication devices 14.

[0037] (Example) The results of actually performing beamforming control to form a white space will be described below. FIG. 10 shows the divided areas, with the north being 0° from the center of base station 10, and the range of 30° to 120° clockwise (toward the east) as Area 1, and the range of 60° to 150° as Area 2. In this example, the areas overlap in the range of 60° to 120°.

[0038] Figure 11 shows the number of mobile communication devices detected every 30 minutes in Area 1 and Area 2 on a certain day, plotted as a graph. 11, the threshold is set to 200. When the threshold is set to 200, there is no time period in area 1 in which the number of mobile communication devices 14 is below the threshold, and in area 2, the number of mobile communication devices 14 is below the threshold between 2:30 and 5:30 in the middle of the night.

[0039] FIG. 12 shows an image in which the positions of mobile communication devices from 3:00 to 3:30 on the day after the number of mobile communication devices was detected in FIG. 11 are plotted on a map, with the ranges of Area 1 and Area 2 superimposed. According to FIG. 12, it can be seen that the number of mobile communication devices is small in the area defined between the southern boundary line of Area 1 and the southern boundary line of Area 2. At this point, the number of mobile communication devices capable of communication in area 1 is 121, and the number of mobile communication devices capable of communication in area 2 is 104.

[0040] Therefore, if radio waves are radiated to Area 1 and not radiated to Area 2 based on the number of mobile communication devices on the previous day, radio waves will not be radiated to the area separated by the southern boundary of Area 1 and the southern boundary of Area 2, and white space can be secured in areas with a small number of mobile communication devices.

[0041] In each of the above-described embodiments, mobile communication devices exist in areas where white spaces are formed, and such mobile communication devices are out of range, but it is preferable to support such mobile communication devices with other frequency bands. [Explanation of symbols]

[0042] 10 base station 12 Support Area 14 Mobile communication devices 16 White Space 20 Array Antenna 22 Control Unit 24 Storage device

Claims

1. A beamforming control method for communication radio waves emitted from a base station, comprising: an area supported by the base station is divided into a plurality of divided areas on a plane by predetermined ranges; For each of the divided areas, the number of mobile communication devices that respond to radio waves for communication radiated from the base station is detected at predetermined time intervals, and the number is stored in a database on a daily basis; A beamforming control method characterized by controlling beamforming so as not to emit communication radio waves to a divided area during a time period in which the number of mobile communication devices detected from a past database is below a predetermined threshold, in order to make the divided area a white space.

2. The beamforming control method according to claim 1, characterized in that beamforming is controlled so as not to emit radio waves for communication in a divided area having a time period in which the number of mobile communication devices detected from the database of the previous day is below a predetermined threshold value only during that time period.

3. The beamforming control method according to claim 1, characterized in that beamforming is controlled so as not to emit radio waves for communication only in a divided area having a time period in which the number of mobile communication devices detected from a database from one week ago is below a predetermined threshold.

4. deep learning is performed on the number of mobile communication devices at predetermined time intervals for each sectional area that has been databased for each day, and a predicted number of mobile communication devices at predetermined time intervals for each sectional area is calculated; The beamforming control method according to claim 1, characterized in that beamforming is controlled so that radio waves for communication are not emitted only in a divided area having a time period in which the predicted number is below a predetermined threshold value.

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