JP6386947B2 - Base station apparatus, pointing direction control method, and computer program - Google Patents

Description

  The present invention relates to a base station apparatus, a directivity control method, and a computer program.

  Conventionally, a technique is known in which a base station apparatus changes its antenna tilt angle to bring its own coverage closer to a target coverage (see, for example, Patent Document 1).

International Publication No. 2011/114372

3GPP (3rd Generation Partnership Project), TS36.331, “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification”, V12.1.0 (2014-03) 3GPP (3rd Generation Partnership Project), TS36.211, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation”, V12.1.0 (2014-03) 3GPP (3rd Generation Partnership Project), TS36.213, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures”, V12.3.0 (2014-09)

  However, in the above-described prior art, since the mobile station measures the position of the mobile station and reports the position information of the measurement result to the base station, the power resource and the communication resource for reporting the position information are obtained. Is consumed each time.

The present invention has been made in view of such circumstances, and can set an antenna directivity direction suitable for each base station apparatus and can save communication resources and power supply resources of terminal apparatuses, and a base station apparatus and directivity direction It is an object to provide a control method and a computer program.

(1) One aspect of the present invention is a base station device that transmits and receives radio signals to and from a terminal device via an antenna device, and a “downlink radio frame transmitted by the base station device to the terminal device in the past A delay time information acquisition unit for acquiring delay time information based on the "uplink radio frame transmission timing correction value for", and based on the acquired delay time information, the antenna pointing direction in the vertical plane of the antenna device A directivity direction determination unit for determining, and a directivity direction control unit that performs control to change to the antenna directivity direction as a result of the determination , the delay time information acquisition unit, based on the transmission timing correction value, A round trip delay time distribution for the terminal device within the coverage of the base station device is calculated, and a representative round trip delay time is determined based on the calculated round trip delay time distribution. Then, when the base station device is in the area where the terminal device is located locally, the delay time information acquisition is performed using the determined representative round trip delay time as the delay time information. The unit determines the maximum number of round trip delay times in the round trip delay time distribution as the representative round trip delay time, and the pointing direction determination unit determines the terminal position direction corresponding to the round trip delay time of the maximum distribution number as the This is a base station apparatus that determines the antenna pointing direction .
(2) According to one aspect of the present invention, in the base station apparatus according to (1), the delay time information acquisition unit is a random access channel signal received from the terminal apparatus by the base station apparatus. The base station apparatus acquires the delay time information based on the transmission timing correction value transmitted to the terminal apparatus with respect to the access channel signal.
( 3 ) One aspect of the present invention is the base station apparatus according to any one of (1) and (2) , wherein the directivity direction control unit determines the antenna directivity direction according to a change amount of the delay time information. It is a base station apparatus that determines whether or not to update.
( 4 ) According to one aspect of the present invention, in the base station device according to any one of (1) to ( 3 ), the update process of the antenna directivity direction is performed when a state of the base station device satisfies a predetermined condition. A base station apparatus to be executed.

( 5 ) One aspect of the present invention is a directivity direction control method for a base station apparatus that transmits and receives a radio signal to and from a terminal apparatus via an antenna apparatus, and the base station apparatus has the terminal apparatus in the past. A delay time information acquisition step for acquiring delay time information based on the “transmission timing correction value of the uplink radio frame for the downlink radio frame” transmitted to the base station apparatus, based on the acquired delay time information A directivity direction determining step for determining an antenna directivity direction in a vertical plane of the antenna device, and a directivity direction control step for performing control to change the antenna directivity direction as a result of the determination by the base station device. seen including, the delay time information obtaining step, on the basis of the transmission timing correction value, with the terminal device located within the coverage of the base station apparatus The round-trip delay time distribution is calculated, a representative round-trip delay time is determined based on the calculated round-trip delay time distribution, and the determined representative round-trip delay time is used as the delay time information. When the base station apparatus is located in an area where the terminal apparatus is located locally, the delay time information acquisition step determines the maximum number of round-trip delay times in the round-trip delay time distribution as the representative round-trip delay time. The pointing direction determining step is a pointing direction control method in which a terminal position direction corresponding to the maximum number of round-trip delay times is determined as the antenna pointing direction .

( 6 ) According to one aspect of the present invention, a “downlink radio” transmitted from the base station apparatus to the terminal apparatus in the past is transmitted to a computer of the base station apparatus that transmits and receives radio signals to and from the terminal apparatus via the antenna apparatus. A delay time information acquisition step for acquiring delay time information based on "transmission timing correction value of uplink radio frame with respect to a frame", and an antenna pointing direction in a vertical plane of the antenna device based on the acquired delay time information And a directivity direction control step for performing control to change to the antenna directivity direction as a result of the determination , wherein the delay time information acquisition step includes the transmission Based on the timing correction value, a round trip delay for the terminal device within the coverage of the base station device The computer program, calculating a distribution of intervals, determining a representative round trip delay time based on the calculated round trip delay time distribution, and using the determined representative round trip delay time as the delay time information. When the base station apparatus is present in a locally located area, the delay time information acquisition step determines the maximum number of round-trip delay times in the round-trip delay time distribution as the representative round-trip delay time, and the pointing direction The determination step is a computer program that determines a terminal position direction corresponding to the maximum number of round-trip delay times as the antenna directivity direction .

  According to the present invention, it is possible to set an antenna directivity direction suitable for each base station apparatus and to save communication resources and power supply resources of terminal apparatuses.

It is a block diagram which shows the base station apparatus 1 which concerns on one Embodiment of this invention. It is a figure which shows the structural example of the hardware which implement | achieves the base station apparatus 1 shown in FIG. It is a figure explaining an antenna directivity direction. It is a flowchart which shows the example of the pointing direction control method which concerns on one Embodiment of this invention. It is a schematic sequence chart concerning a RACH signal. It is explanatory drawing of "TA command." It is a flowchart which shows the other example of the pointing direction control method which concerns on one Embodiment of this invention. It is explanatory drawing which shows the example of the coverage adjustment method which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a radio communication system (LTE system) called LTE (Long Term Evolution) will be described as an example of a radio communication system. The LTE system is described in Non-Patent Documents 1, 2, and 3, for example.

  FIG. 1 is a configuration diagram illustrating a base station apparatus 1 according to an embodiment of the present invention. FIG. 1 shows a configuration related to an antenna directivity direction control function among the configurations of the base station apparatus of the LTE system. In FIG. 1, the base station apparatus 1 includes a delay time information acquisition unit 11, a directivity direction determination unit 12, and a directivity direction control unit 13. The delay time information acquisition unit 11 acquires delay time information about a delay time in communication between the base station apparatus 1 and a terminal apparatus that wirelessly communicates with its own base station apparatus 1.

  The directivity direction determination unit 12 determines the antenna directivity direction based on the delay time information acquired by the delay time information acquisition unit 11. The antenna pointing direction determined by the pointing direction determination unit 12 is a direction in the vertical plane. The directivity direction control unit 13 performs control to change to the antenna directivity direction that is the determination result of the directivity direction determination unit 12.

  FIG. 2 is a diagram illustrating a configuration example of hardware that realizes the base station apparatus 1 illustrated in FIG. 1. In FIG. 2, the base station apparatus 1 includes a wireless communication unit 21, a communication unit 22, a CPU 23, and a storage unit 24. These units are configured to exchange data. The wireless communication unit 21 is connected to the antenna device ANT. The wireless communication unit 21 transmits and receives a wireless signal A to and from the terminal device via the antenna device ANT. The radio communication unit 21 outputs a directivity direction control signal B to the antenna device ANT. The antenna device ANT changes the antenna directivity direction according to the directivity direction control signal B.

  The communication unit 22 communicates with other devices via the backbone network. The CPU 23 controls the base station device 1. This control function is realized by the CPU 23 executing a computer program. The storage unit 24 stores a computer program executed by the CPU 23 and various data. The storage unit 24 stores a directivity direction control program 31. The functions of the respective units of the base station apparatus 1 shown in FIG. 1 are realized by the CPU 23 shown in FIG. 2 executing the pointing direction control program 31 stored in the storage unit 24.

  FIG. 3 is a diagram for explaining an example of antenna direction control. FIG. 3 shows a case where the tilt angle of the antenna device ANT is controlled as an example of controlling the antenna directivity direction. The antenna device ANT is installed at a high place such as a steel tower or a building. The antenna device ANT is connected to an RRH (Remote Radio Head). The RRH has a function of a wireless part of the wireless communication unit 21. The RRH is connected to a BBU (Base Band Unit). The BBU has a function of a baseband portion in the wireless communication unit 21. The RRH transmits and receives a radio signal A to and from the antenna device ANT. The RRH outputs a directivity direction control signal B to the antenna device ANT. The antenna device ANT changes the tilt angle θ_tilt according to the directivity direction control signal B. The tilt angle θ_tilt of the antenna device ANT is an angle of the maximum directivity direction DirBM of the vertical plane (plane including the z axis) directivity with reference to the horizontal plane (xy plane). Generally, the directivity direction of the main lobe BM of the vertical radiation pattern of the antenna device ANT is the maximum directivity direction DirBM. When the tilt angle θ_tilt increases (when the tilt is down), the maximum directivity direction DirBM is more directed toward the ground. For this reason, the coverage of the base station apparatus 1 is reduced. On the other hand, when the tilt angle θ_tilt is small (up-tilt), the maximum directivity direction DirBM is directed to the sky opposite to the ground. For this reason, the coverage of the base station apparatus 1 is expanded.

[Example of directivity control method]
FIG. 4 is a flowchart illustrating an example of the directivity control method according to the present embodiment. With reference to FIG. 4, the example of operation | movement of the base station apparatus 1 shown in FIG. 1 is demonstrated.

(Step S <b> 101) The delay time information acquisition unit 11 acquires delay time information about a delay time in communication between a terminal device that wirelessly communicates with its own base station device 1 and the base station device 1. Here, a method for acquiring the delay time information will be described.

  In the present embodiment, the delay time information acquisition unit 11 acquires delay time information based on a history of uplink (Uplink: UL) timing correction values (TA command (Timing Advance command)). The uplink is a link in a direction from the terminal device to the base station device 1. In the LTE system, a RACH (Random Access CHannel) signal is used when communication is started between a terminal device (User Equipment: UE) and a base station device (eNodeB: eNB). The RACH signal is used to synchronize the UL signal between the terminal device and the base station device. The base station apparatus transmits “TA command” to the terminal apparatus according to the RACH signal received from the terminal apparatus.

  FIG. 5 is a schematic sequence chart relating to the RACH signal. With reference to FIG. 5, a signal transmission procedure related to the RACH signal will be described.

(Step S1) A base station apparatus (eNB) alert | reports a RACH related parameter with a broadcast signal with respect to the terminal device (UE) which exists in coverage Cov.

(Step S2) The terminal apparatus (UE) transmits a RACH signal using the broadcasted RACH related parameters.

(Step S3) The base station apparatus (eNB) transmits “TA command” to the terminal apparatus (UE) that has transmitted the RACH signal.

(Step S4) The terminal apparatus (UE) transmits a UL data signal using the “TA command” received from the base station apparatus (eNB).

FIG. 6 is an explanatory diagram of “TA command”. In FIG. 6, the UL timing correction value “N _TA × T _S [second]” by “TA command” is a downlink (DL) when the terminal apparatus transmits a UL radio frame (UL Radio Frame). It is a transmission timing correction value of a UL radio frame with respect to a radio frame (DL Radio Frame). The downlink is a link in a direction from the base station device 1 to the terminal device. T _S is "1/30720000" seconds. As N _TA , for example, “N _TA = TA × 16, where TA is any integer from 0 to 1282” is used. With this UL timing correction value (TA command), timing correction from 0 to 670 [microseconds] is possible. This is because the UL signal can be synchronized with respect to the terminal device in the range of about 0 to 100 [km] as the radius of the coverage size converted into the round-trip delay time between the base station device and the terminal device. It corresponds to.

The delay time information acquisition unit 11 is based on the “TA command” transmitted from the base station apparatus 1 to the terminal apparatus with respect to the RACH signal at the time of initial access among the RACH signals received from the terminal apparatus in the past. A round-trip delay time distribution (round-trip delay time distribution) is calculated for the terminal devices within the coverage of the base station apparatus 1. The delay time information acquisition unit 11 determines a representative round trip delay time based on the round trip delay time distribution. The representative round trip delay time is an example of delay time information. The following examples are given as representative round trip delay times.
(Example of representative round trip delay time) 95% tile value in round trip delay time distribution.
(Example 2 of representative round trip delay time) The longest round trip delay time in the round trip delay time distribution.
(Example 3 of representative round trip delay time) The maximum number of round trip delay times in the round trip delay time distribution.
(Example 4 of representative round trip delay time) Average value of round trip delay time in round trip delay time distribution.

  Note that the “TA command” is also transmitted to the terminal device for the RACH signal at the time of loss of synchronization. However, “TA command” at the time of loss of synchronization is a difference value from the previous “TA command”. When processing is performed in consideration of the difference value, the “TA command” at the time of loss of synchronization may be used for calculation of the round-trip delay time distribution.

Returning to FIG.
(Step S102) The directivity direction determination unit 12 determines the antenna directivity direction based on the delay time information acquired by the delay time information acquisition unit 11. The delay time information can be used as information indicating the position of the terminal device within the coverage of the base station device 1. From this, the direction in the vertical plane of the direction from the antenna device ANT to the terminal position based on the delay time information is determined as the antenna pointing direction. Generally, the distribution of the position of the terminal device within the coverage of each base station device is different. For this reason, it is preferable that the antenna directivity direction which affects the coverage of the base station apparatus is a direction suitable for each base station apparatus. In the present embodiment, the directivity direction determination unit 12 determines the antenna directivity direction of its own base station apparatus 1 based on the delay time information acquired by the delay time information acquisition unit 11.

  The pointing direction determination unit 12 determines the terminal position direction corresponding to the representative round trip delay time that is the delay time information acquired by the delay time information acquisition unit 11 as the antenna pointing direction. The terminal position direction is a direction in a vertical plane from the antenna device ANT. The correspondence relationship between the representative round trip delay time and the terminal position direction is set in the pointing direction determination unit 12 in advance. For example, a correspondence table showing a correspondence relationship between the representative round trip delay time and the terminal position direction is held in the pointing direction determination unit 12 in advance.

(Step S <b> 103) The directivity direction control unit 13 performs control to change to the antenna directivity direction that is the determination result of the directivity direction determination unit 12. Thereby, the directivity direction control signal B indicating the antenna directivity direction, which is the determination result of the directivity direction determination unit 12, is output from the wireless communication unit 21 to the antenna device ANT. The antenna device ANT changes the antenna directivity direction according to the directivity direction control signal B. As a result, the antenna directivity direction of the antenna device ANT is changed to the antenna directivity direction that is the determination result of the directivity direction determination unit 12.

  Note that the antenna directivity direction indicated by the directivity direction control signal B may be the tilt angle θ_tilt of the antenna device ANT.

  According to the embodiment described above, the antenna apparatus ANT of the base station apparatus 1 according to the delay time information based on the “UL timing correction value (TA command)” transmitted from the base station apparatus 1 to the terminal apparatus in the past. The antenna directivity direction can be set. Thereby, the effect that the antenna directivity direction suitable for each base station apparatus 1 can be set is acquired. In addition, since the terminal device does not need to acquire and report its own location information to the base station device 1, it is possible to save power resources for acquiring the location information and communication resources for the reporting.

  In addition, as the delay time information, any one of the above-described representative round trip delay times 1 to 4 may be acquired. For example, when the 95% tile value in the round trip delay time distribution of Example 1 of the representative round trip delay time is acquired as the delay time information, a peculiar round trip delay time that is too large is excluded and is within the coverage of the base station apparatus 1. Many terminal devices can be covered. In addition, the above-described representative round trip time examples 1 to 4 may be selectively used according to the radio frequency band used by the base station apparatus 1 or the location of the base station apparatus 1. For example, for the base station device 1 located in an area where the terminal device is located locally, the maximum number of round-trip delay times in the round-trip delay time distribution of Example 3 of the representative round-trip delay time may be used. Can be mentioned.

[Other examples of directivity control methods]
Next, another example of the operation of the base station apparatus 1 shown in FIG. 1 will be described with reference to FIG. FIG. 7 is a flowchart showing another example of the pointing direction control method according to the present embodiment.

(Step S <b> 201) The base station device 1 determines execution of the pointing direction update process. An example of a method for determining execution of the pointing direction update process is given below.

(Example 1 of determination method of execution of directivity direction update process)
It is determined whether it is a predetermined timing for executing the pointing direction update process. For example, the directivity direction update process may be executed at a constant cycle.

(Example 2 of determination method of execution of directivity direction update process)
It is determined whether or not the status of the base station apparatus 1 of the base station apparatus 1 satisfies the condition for executing the pointing direction update process. For example, the statistical value of the communication quality of the terminal device existing within the coverage of the base station device 1 is calculated at a constant period, and the pointing direction update process is executed when the change amount of the statistical value is equal to or greater than a predetermined threshold value Can be mentioned. The terminal device for which the communication quality statistical value is to be calculated may be limited to a terminal device located in the coverage boundary part of the base station device 1. Alternatively, a statistical value of the traffic load of the base station apparatus 1 is calculated at a fixed period, and the pointing direction update process is executed when the change amount of the statistical value is equal to or greater than a predetermined threshold. As the traffic load, for example, the number of terminal devices connected can be mentioned. Alternatively, a statistical value of the resource usage amount of the base station apparatus 1 is calculated at a fixed period, and the pointing direction update process is executed when the change amount of the statistical value is equal to or greater than a predetermined threshold.

(Step S202) As a result of the determination in step S201, when the pointing direction update process is executed, the process proceeds to step S203, and when the pointing direction update process is not executed, the process returns to step S201.

(Step S <b> 203) The delay time information acquisition unit 11 acquires delay time information about a delay time in communication between the base station apparatus 1 and a terminal apparatus that wirelessly communicates with its own base station apparatus 1. The method for acquiring the delay time information is the same as step S101 in FIG. 4 described above.

(Step S204) The directivity direction determination unit 12 determines the antenna directivity direction based on the delay time information acquired by the delay time information acquisition unit 11. The method for determining the antenna directivity direction is the same as that in step S102 in FIG. 4 described above.

(Step S205) The directivity direction control unit 13 determines update of the antenna directivity direction. In this determination of the update of the antenna directivity direction, the antenna directivity direction that is the determination result of step S204 is compared with the already set antenna directivity direction, and if they are different, it is determined that the antenna directivity direction is updated. To do. Alternatively, the representative round trip delay time that is the delay time information acquired in step S203 of the current orientation direction update process and the representative round trip delay time that is the delay time information acquired in step S203 of the previous orientation direction update process. In comparison, when the difference between the two is equal to or greater than a predetermined threshold, it may be determined to update the antenna pointing direction.

  As a result of the determination in step S205, if the antenna directivity direction is updated, the process proceeds to step S206. If the antenna directivity direction is not updated, the process returns to step S201.

(Step S206) The directivity direction control unit 13 performs control to change to the antenna directivity direction that is the determination result of the directivity direction determination unit 12. Thereby, the directivity direction control signal B indicating the antenna directivity direction, which is the determination result of the directivity direction determination unit 12, is output from the wireless communication unit 21 to the antenna device ANT. The antenna device ANT changes the antenna directivity direction according to the directivity direction control signal B. As a result, the antenna directivity direction of the antenna device ANT is changed to the antenna directivity direction that is the determination result of the directivity direction determination unit 12.

(Step S207) The base station apparatus 1 determines the end of the pointing direction control process of FIG. As a result of the determination, if the process is to be ended, the directivity direction control process of FIG. 7 is ended. If not, the process returns to step S201.

  According to the other example of the directivity direction control method of FIG. 7 described above, the update of the antenna directivity direction can be appropriately executed. For example, if a base station device is added to meet an increase in demand for communication speed, radio wave interference may occur between the base station devices. On the other hand, by monitoring the communication quality at the coverage boundary part and executing the pointing direction update process when it is determined that radio wave interference has occurred based on the monitoring result, the coverage is automatically changed to Interference can be eliminated.

  Note that an antenna pointing direction corresponding to a large coverage within an allowable range may be set for the base station apparatus 1 as an initial value of the antenna pointing direction.

  In the other example of the directivity direction control method of FIG. 7 described above, the base station device 1 determines execution of the directivity direction update process in step S201, but another device different from the base station device 1 is a base station device. It may be determined to execute one directivity direction update process and instruct the base station apparatus 1 to execute the directivity direction update process. For example, a center station that manages a plurality of base station apparatuses 1 determines execution of the directivity direction update process of the base station apparatus 1 under its management and instructs the base station apparatus 1 to execute the directivity direction update process. Can be mentioned.

  FIG. 8 is an explanatory diagram illustrating an example of the coverage adjustment method according to the present embodiment. First, the coverage Cov_fa_1 of the radio frequency fa is formed by the antenna directivity direction DirBM_1 of the radio frequency fa. The coverage Cov_fb of the radio frequency fb overlaps with the coverage Cov_fa_1. At this time, terminal apparatuses (UEs) that are wirelessly communicating with the coverage Cov_fa_1 are concentrated in the central portion of the coverage Cov_fa_1. Therefore, the coverage of the radio frequency fa is reduced from Cov_fa_1 to Cov_fa_2 by changing the antenna directivity direction of the radio frequency fa from DirBM_1 to the direction DirBM_2 of the concentration area of the terminal device (UE). The direction of the concentration area of the terminal device (UE) is obtained as the terminal position direction corresponding to the maximum number of round-trip delay times in the round-trip delay time distribution of Example 3 of the representative round-trip delay time described above, for example.

  Thereby, since the antenna directivity direction of the radio frequency fa is directed to the area where the terminal apparatus (UE) using the radio frequency fa is concentrated, the radio wave environment of the area where the terminal apparatus (UE) is concentrated is reduced. Can be improved. On the other hand, when the coverage of the radio frequency fa is reduced from Cov_fa_1 to Cov_fa_2, the terminal apparatus (UE) that has been outside the coverage of the radio frequency fa has a radio frequency fb due to the coverage Cov_fb overlapping with the coverage Cov_fa_1. Wireless communication is possible. This example of the coverage adjustment method can be applied to, for example, a countermeasure when the communication capacity of the radio frequency fa of the base station apparatus 1 is tight.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  For example, the delay time information acquisition unit 11 may limit the “TA command” used for calculating the round-trip delay time distribution under a predetermined condition. For example, the time zone in which “TA command” is transmitted to the terminal device may be limited. Or you may limit the area where the terminal device which transmitted "TA command" exists. Those limitations may be determined according to the usage status (the usage time zone change status, the usage zone change status, etc.) regarding the coverage of the base station apparatus 1.

  In the above-described embodiment, the control of the tilt angle of the antenna device is given as an example of the control of the antenna directivity direction. You may go.

  Moreover, although LTE system was mentioned as an example of a radio | wireless communications system in embodiment mentioned above, it is applicable similarly to other radio | wireless communications systems other than an LTE system.

Further, a computer program for realizing the functions of the base station apparatus 1 described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Good. Here, the “computer system” may include an OS and hardware such as peripheral devices.
“Computer-readable recording medium” refers to a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), and a built-in computer system. A storage device such as a hard disk.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Base station apparatus, 11 ... Delay time information acquisition part, 12 ... Directional direction determination part, 13 ... Directional direction control part, 21 ... Wireless communication part, 22 ... Communication part, 23 ... CPU, 24 ... Memory | storage part, 31 ... Directional direction control program, ANT ... antenna device

Claims (6)

A base station device that transmits and receives radio signals to and from a terminal device via an antenna device,
A delay time information acquisition unit for acquiring delay time information based on the "transmission timing correction value of an uplink radio frame for a downlink radio frame" transmitted by the base station device to the terminal device in the past;
A directivity direction determination unit that determines an antenna directivity direction in a vertical plane of the antenna device based on the acquired delay time information;
A directivity direction control unit that performs control to change to the antenna directivity direction as a result of the determination ,
The delay time information acquisition unit calculates a round trip delay time distribution for the terminal device within the coverage of the base station device based on the transmission timing correction value, and based on the calculated round trip delay time distribution The base station apparatus determines a representative round trip delay time, and uses the determined representative round trip delay time as the delay time information,
When the base station device is in an area where the terminal device is located locally,
The delay time information acquisition unit determines the maximum number of round trip delay times in the round trip delay time distribution as the representative round trip delay time,
The pointing direction determining unit determines a terminal position direction corresponding to the maximum number of round-trip delay times as the antenna pointing direction;
Base station device. The delay time information acquisition unit is based on the transmission timing correction value transmitted to the terminal device for the random access channel signal at the time of initial access among the random access channel signals received by the base station device from the terminal device. Obtaining the delay time information;
The base station apparatus according to claim 1. The directivity direction control unit determines whether to update the antenna directivity direction according to the amount of change in the delay time information.
The base station apparatus of any one of Claim 1 or 2 . The base station apparatus of any one of Claim 1 to 3 which performs the update process of the said antenna directivity direction, when the condition of the said base station apparatus satisfies predetermined conditions. A base station device directing direction control method for transmitting and receiving radio signals to and from a terminal device via an antenna device,
A delay time information acquisition step in which the base station apparatus acquires delay time information based on a "transmission timing correction value of an uplink radio frame for a downlink radio frame" that the base station apparatus has transmitted to the terminal device in the past;
A directivity direction determining step in which the base station device determines an antenna directivity direction in a vertical plane of the antenna device based on the acquired delay time information;
The base station apparatus, viewed contains a directivity direction control step, the performing control to change the antenna directivity direction is the result of the determination,
The delay time information acquisition step calculates a round trip delay time distribution for the terminal device within the coverage of the base station device based on the transmission timing correction value, and based on the calculated round trip delay time distribution A representative round trip delay time is determined, and the determined representative round trip delay time is used as the delay time information.
When the base station device is in an area where the terminal device is located locally,
The delay time information acquisition step determines the maximum number of round trip delay times in the round trip delay time distribution as the representative round trip delay time,
In the pointing direction determination step, a terminal position direction corresponding to the maximum number of round-trip delay times is determined as the antenna pointing direction.
Directional direction control method. In the computer of the base station device that transmits and receives radio signals to and from the terminal device via the antenna device,
A delay time information acquisition step for acquiring delay time information based on the "transmission timing correction value of an uplink radio frame for a downlink radio frame" transmitted by the base station device to the terminal device in the past;
A directivity direction determining step for determining an antenna directivity direction in a vertical plane of the antenna device based on the acquired delay time information;
A directivity direction control step for performing control to change to the antenna directivity direction as a result of the determination, and a computer program for executing
The delay time information acquisition step calculates a round trip delay time distribution for the terminal device within the coverage of the base station device based on the transmission timing correction value, and based on the calculated round trip delay time distribution The computer program for determining a representative round-trip delay time and using the determined representative round-trip delay time as the delay time information,
When the base station device is in an area where the terminal device is located locally,
The delay time information acquisition step determines the maximum number of round trip delay times in the round trip delay time distribution as the representative round trip delay time,
In the pointing direction determination step, a terminal position direction corresponding to the maximum number of round-trip delay times is determined as the antenna pointing direction.
Computer program.

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