JP2020136807A - Antenna module, mobile communication device, vehicle, switching method, and computer program - Google Patents

Abstract

To provide an antenna module capable of swiftly switching an array antenna.SOLUTION: An antenna module is used in a mobile communication device that wirelessly communicates with a base station device. The antenna module includes: a plurality of array antennas including a first array antenna capable of transmitting and receiving signals to/from the base station device in a direction included in a first range among directions around the mobile communication device, and a second array antenna capable of transmitting and receiving signals to/from the base station device in a direction included in a second range adjacent to the first range among the directions around the mobile communication device; and a switching unit that, when any one antenna of the first array antenna and the second array antenna is being used for wireless communication with the base station device as a target antenna used in wireless communication with the base station device, performs switching processing of switching the selected antenna from the one antenna to the other antenna.SELECTED DRAWING: Figure 3

Description

The present invention relates to antenna modules, mobile communication devices, vehicles, switching methods, and computer programs.

Patent Document 1 and Non-Patent Document 1 disclose that a mobile communication device capable of wireless communication by a fifth generation mobile communication system is mounted on a vehicle.

International Publication No. 2018/088051

3GPP TSG-RAN WG4 Meeting # 87 R4-1808180, [Search on November 21, 2018], Internet <http://www.3gpp.org/DynaReport/TDocExMtg--R4-87--18787.htm>

In the 5th generation mobile communication system, since wireless communication is performed using millimeter waves or quasi-millimeter waves (for example, radio waves having a very high frequency of 6 GHz or more), propagation loss is large. Therefore, in the 5th generation mobile communication system, beamforming is performed in order to compensate for the attenuation of radio waves.
Therefore, in a mobile station compatible with a 5th generation mobile communication system, it is necessary to install an antenna at a position where a horizontal line of sight can be secured for beamforming. For example, in Patent Document 1, an antenna device (antenna module) is installed on the ceiling (roof) of a vehicle.

By the way, in the frequency band of 6 GHz or more, since the attenuation due to propagation is large, it is necessary to obtain a high antenna gain by using a directional antenna, for example, a patch antenna or the like and further forming an array antenna configuration.
Therefore, when the antenna module is mounted on a vehicle to form a beam directed in each direction around the vehicle, it is conceivable to use a plurality of directional array antennas in combination.
In this case, each array antenna shares a beam in a part of each direction around the vehicle. As a result, the antenna module can form a beam directed in each direction around the vehicle.

As described above, when wirelessly communicating with the base station device using an antenna module that combines a plurality of array antennas, the array antenna used for wireless communication with the base station device is selected from the plurality of array antennas. The selected array antenna needs to form a beam towards the base station equipment.

Here, in order to select the array antenna (target antenna) used for wireless communication with the base station device, the array antenna having the highest communication quality in the propagation path with the base station device may be selected.
For example, a method in which a receiver is connected to each of a plurality of array antennas, the signal received by each array antenna is demodulated by each receiver, and the array antenna having the highest communication quality is selected as the target antenna (hereinafter, also referred to as method 1). Can be considered.

However, in the above method 1, it is necessary to prepare as many receivers as the number of array antennas, which is not preferable from the viewpoint of cost and power consumption.
Therefore, by connecting a single receiver to a plurality of array antennas and sequentially switching the array antennas connected to the receivers with a changeover switch or the like, the signals received by each array antenna are sequentially demolished, and the highest communication quality is achieved. A method of selecting a high array antenna as the target antenna (hereinafter, also referred to as method 2) can be considered.

The above method 2 is advantageous over the method 1 in terms of cost and power consumption.
On the other hand, when one of the plurality of array antennas is selected as the target antenna, the receiver is connected only to the array antenna selected as the target antenna, and therefore is not selected as the target antenna. The signal cannot be received by other array antennas and the communication quality cannot be obtained.
For example, as the vehicle moves, the relative positional relationship with the base station device changes, the communication quality of the array antenna selected as the target antenna deteriorates, and the array antenna adjacent to the array antenna is targeted. Consider the case where you have to select as an antenna.

In this case, when the communication quality of the array antenna selected as the target antenna deteriorates and the signal from the base station device cannot be received, the antenna module again sequentially switches the array antennas connected to the receiver to each array. Acquire the communication quality of the antenna. The antenna module selects the array antenna having the highest communication quality as the target antenna based on the result of acquiring the communication quality of each array antenna.

As described above, the antenna module interrupts the wireless communication with the base station apparatus while the target antenna cannot receive the signal from the base station apparatus and the array antenna having the highest communication quality is reselected. Such interruption of wireless communication is not preferable because it leads to a decrease in communication speed and the like.

Therefore, when the relative positional relationship with the base station device changes due to the movement of the vehicle and it becomes necessary to switch the array antenna selected as the target antenna, there is a technology for promptly switching the array antenna. desired.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique capable of promptly switching an array antenna.

The antenna module according to one embodiment is an antenna module used for a mobile communication device that wirelessly communicates with the base station device, and the base station device is included in the first range of the surrounding directions of the mobile communication device. A first array antenna capable of transmitting and receiving signals to and from the base station device, and a direction included in a second range adjacent to the first range among the directions around the mobile communication device. Based on the communication quality of each of the plurality of array antennas including the second array antenna and the received signals by the plurality of array antennas, the target antenna used for wireless communication with the base station apparatus is selected from among the plurality of array antennas. When the selection unit to be selected and one of the first array antenna and the second array antenna are selected as the target antenna and used for wireless communication with the base station apparatus, the target A switching unit for executing a switching process for switching the antenna from the one antenna to the other antenna is provided.

The mobile communication device according to another embodiment is a mobile communication device including the above-mentioned antenna module.

The vehicle according to another embodiment is a vehicle provided with the above-mentioned mobile communication device.

Another embodiment of the switching method is a method of switching between a first array antenna and a second array antenna included in a plurality of array antennas included in an antenna module used in a mobile communication device that wirelessly communicates with a base station device. The first array antenna can transmit and receive signals to and from the base station device in the direction included in the first range among the directions around the mobile communication device, and the second array antenna is the mobile communication device. It is possible to send and receive signals to and from the base station device in a direction included in the second range adjacent to the first range among the surrounding directions, and based on the communication quality of each received signal by the plurality of array antennas, the said A step of selecting a target antenna to be used for wireless communication with the base station device from a plurality of array antennas, and one of the first array antenna and the second array antenna is selected as the target antenna. A step of executing a switching process of switching the target antenna from the one antenna to the other antenna when the target antenna is used for wireless communication with the base station apparatus is included.

In the computer program of another embodiment, the computer executes a switching process of the first array antenna and the second array antenna included in the plurality of array antennas included in the antenna module used in the mobile communication device that wirelessly communicates with the base station device. The first array antenna is capable of transmitting and receiving signals to and from the base station device in a direction included in the first range of the directions around the mobile communication device. The array antenna can transmit and receive signals to and from the base station device in the direction included in the second range adjacent to the first range among the directions around the mobile communication device, and the computer is operated by the plurality of array antennas. A step of selecting a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas based on the communication quality of each received signal, and either the first array antenna or the second array antenna. When one of the antennas is selected as the target antenna and used for wireless communication with the base station device, a step of performing a switching process of switching the target antenna from the one antenna to the other antenna is performed. , Is a computer program that executes.

According to the present invention, the array antenna can be switched quickly.

FIG. 1 is a diagram showing a vehicle equipped with an in-vehicle communication device. FIG. 2A is a perspective view of the antenna module. FIG. 2B is a partial cross-sectional view of the antenna module. FIG. 3 is a block diagram showing an example of the configuration of the antenna module. FIG. 4 is a block diagram showing an example of the configuration of the control device. FIG. 5 is a diagram for explaining a transmission / reception range of each array antenna. FIG. 6 is a flowchart showing an example of the selection process executed by the selection unit of the antenna module. FIG. 7 is a diagram for explaining the direction of the base station device in the vehicle (vehicle-mounted communication device) traveling on the road. FIG. 8 is a flowchart showing an example of a switching determination for determining whether or not to execute the switching process. FIG. 9 is a diagram showing an example of a mode in which the target antenna is switched from the array antenna arranged toward the front of the vehicle 2 to the array antenna arranged toward the left side of the vehicle. It is a figure which shows the antenna module which concerns on the modification.

First, the contents of the embodiments will be listed and described.
[Outline of Embodiment]
(1) The antenna module according to the embodiment is an antenna module used for a mobile communication device that wirelessly communicates with a base station device, and is the direction included in the first range among the directions around the mobile communication device. A first array antenna capable of transmitting and receiving signals to and from the base station device, and transmitting and receiving signals to and from the base station device in directions included in a second range adjacent to the first range among the directions around the mobile communication device. Used for wireless communication with the base station apparatus from among the plurality of array antennas based on the communication quality of each of the plurality of array antennas including the second array antenna capable of the above and the received signals by the plurality of array antennas. When the selection unit for selecting the target antenna and one of the first array antenna and the second array antenna are selected as the target antenna and used for wireless communication with the base station apparatus. A switching unit that executes a switching process for switching the target antenna from the one antenna to the other antenna is provided.

According to the antenna module having the above configuration, since the switching process is executed when one of the antennas of the first array antenna and the second array antenna is used for wireless communication with the base station device, for example, it is moved. When the direction of the base station device in the communication device changes and it becomes necessary to switch the array antenna selected as the target antenna, the selection unit switches to the other antenna without performing the process of selecting the target antenna. Can be done. As a result, the array antenna can be switched quickly.

(2) In the antenna module, a first directivity control unit that controls the directivity direction of the first beam formed by the first array antenna within the first range, and a second beam formed by the second array antenna. The first directivity control unit further includes a second directivity control unit that controls the directivity direction of the above within the second range, and the first directivity control unit is the first beam according to the direction of arrival of a signal from the base station apparatus. The second directivity control unit controls the directivity direction of the second beam according to the direction of arrival of the signal from the base station device, and the switching unit controls the directivity of the first directivity. It is preferable to determine whether or not to execute the switching process based on the directivity direction of the beam formed by the control unit or the one antenna controlled by the second directivity control unit.
In this case, the direction of the base station device in the mobile communication device can be grasped as the directivity direction of the beam formed by both array antennas, and it can be determined whether or not to execute the switching process.

(3) In the antenna module, when the first range and the second range include overlapping ranges that overlap each other and the directing direction of the beam formed by one of the antennas is within the overlapping range, the switching is performed. It is preferable to carry out the process.
In this case, since the first range and the second range have overlapping ranges that overlap each other, hysteresis can be provided when the direction of the beam moves back and forth between the first range and the second range, and the direction of the beam can be provided. It is possible to suppress the occurrence of hunting in which the direction frequently moves back and forth between the first range and the second range.

(4) Further, in the antenna module, the first range and the second range include overlapping ranges that overlap each other, and in the switching unit, the directing direction of the beam formed by the one antenna is the overlapping range. If it is inside, it is determined whether or not the most recent directing direction of the beam formed by the one antenna is outside the overlapping range, and if the determination result is negative, the switching process is not executed. Is preferable.
In this case, it is possible to suppress the execution of the switching process when the mobile communication device is not moving and the directing direction of the beam formed by one of the antennas may not be changed.

(5) In the antenna module, the switching unit determines whether or not the directivity direction of the beam formed by the one antenna is controlled to approach the overlapping range side outside the overlapping range, and the determination is made. If the result is positive, the directing direction of the beam formed by the other antenna may be controlled to be directed in the direction corresponding to the overlapping range.
In this case, the directivity of the beam formed by one antenna can be adjusted in advance just before reaching the overlapping range and before the switching process is executed, so that the directivity of the other antenna can be adjusted more quickly. The array antenna can be switched.

(6) In the antenna module, the switching unit may determine whether or not to execute the switching process based on the direction information indicating the direction of the base station device in the mobile communication device.
In this case, the direction of the base station device among the directions around the mobile communication device can be grasped based on the direction information.

(7) In the antenna module, the first range and the second range include overlapping ranges that overlap each other, and the switching unit has the direction of the base station device indicated by the direction information within the overlapping range. If there is, it is preferable to execute the switching process.
In this case, since the first range and the second range have overlapping ranges that overlap each other, hysteresis can be provided when the direction of the base station apparatus moves back and forth between the first range and the second range, and the base station can be provided with hysteresis. It is possible to suppress the occurrence of hunting in which the direction of the device frequently moves back and forth between the first range and the second range.

(8) In the antenna module, whether the switching unit executes the switching process in consideration of at least one of the speed and the acceleration of the moving body on which the mobile communication device is mounted in addition to the direction information. It is preferable to determine whether or not.
In this case, the change in the direction of the base station device can be grasped more accurately.

(9) Further, the mobile communication device according to another embodiment is a mobile communication device provided with the antenna module according to any one of (1) to (8) above.

(10) The vehicle according to another embodiment is a vehicle provided with the mobile communication device according to (9) above.

(11) The switching method according to another embodiment is a switching method of a first array antenna and a second array antenna included in a plurality of array antennas included in an antenna module used in a mobile communication device that wirelessly communicates with a base station device. Therefore, the first array antenna can transmit and receive signals to and from the base station device in the direction included in the first range among the directions around the mobile communication device, and the second array antenna is said to move. It is possible to send and receive signals to and from the base station device in the direction included in the second range adjacent to the first range among the directions around the communication device, and based on the communication quality of each received signal by the plurality of array antennas. The step of selecting a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas and the antenna of either the first array antenna or the second array antenna are the targets. It includes a step of executing a switching process of switching the target antenna from the one antenna to the other antenna when the target antenna is selected as an antenna and used for wireless communication with the base station apparatus.

(12) A computer program according to another embodiment performs switching processing of a first array antenna and a second array antenna included in a plurality of array antennas included in an antenna module used in a mobile communication device that wirelessly communicates with a base station device. A computer program for a computer to execute, the first array antenna can send and receive signals to and from the base station device in a direction included in the first range among the directions around the mobile communication device. The second array antenna can transmit and receive signals to and from the base station device in a direction included in a second range adjacent to the first range among the directions around the mobile communication device, and the computer can transmit and receive the plurality of signals. A step of selecting a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas based on the communication quality of each signal received by the array antenna, and the first array antenna and the second array. When one of the antennas is selected as the target antenna and used for wireless communication with the base station device, a switching process for switching the target antenna from the one antenna to the other antenna is executed. It is a computer program that executes the steps to be performed.

[Details of Embodiment]
Hereinafter, preferred embodiments will be described with reference to the drawings.
In addition, at least a part of each embodiment described below may be arbitrarily combined.

[Configuration of in-vehicle communication device]
FIG. 1 is a diagram showing a vehicle equipped with an in-vehicle communication device.
In FIG. 1, the vehicle-mounted communication device 1 is mounted on the vehicle 2. The in-vehicle communication device (mobile communication device) 1 is a mobile station that wirelessly communicates with the base station device 4 of the mobile communication system. The vehicle 2 includes not only ordinary passenger cars but also buses, railroad cars, and the like.
The base station device 4 is installed at a relatively high place such as the roof of a building, and wirelessly communicates with the on-vehicle communication device 1 on the ground.

The wireless communication performed between the in-vehicle communication device 1 and the base station device 4 is, for example, wireless communication based on the 5th generation mobile communication system.
In the 5th generation mobile communication system, for example, since a radio wave having a very high frequency of 6 GHz or more is used, the attenuation at the time of propagation is large. Therefore, the in-vehicle communication device 1 and the base station device 4 perform beamforming in order to compensate for the attenuation of radio waves. The in-vehicle communication device 1 can improve the gain by directing the directivity of the beam in a specific direction by beamforming. Beamforming is performed by both the in-vehicle communication device 1 and the base station device 4.

The in-vehicle communication device 1 is connected to the wireless LAN wireless unit 6. The wireless LAN wireless unit 6 is a wireless LAN access point and provides a wireless LAN service to the mobile terminal 8 in the vehicle. The mobile terminal 8 in the vehicle is, for example, a mobile phone, a smartphone, a tablet, a laptop computer, or the like owned by a passenger in the vehicle 2. The mobile terminal 8 can communicate with a mobile communication system via wireless LAN communication.
That is, the in-vehicle communication device 1 has a function of relaying communication between the mobile terminal 8 and the base station device 4.

The in-vehicle communication device 1 includes an antenna module 10 and a communication processing unit 12.
The communication processing unit 12 has a function of performing processing related to the baseband signal. The communication processing unit 12 gives a baseband signal to the antenna module 10. Further, the communication processing unit 12 receives the baseband signal given from the antenna module 10.
The antenna module 10 includes a plurality of antenna elements 24. The plurality of antenna elements 24 form an array antenna. As a result, the antenna module 10 has a function of transmitting and receiving radio waves to and from the base station device 4 while performing beamforming.

[Antenna module configuration]
FIG. 2A is a perspective view of the antenna module 10, and FIG. 2B is a partial cross-sectional view of the antenna module 10.
As shown in FIG. 2B, the antenna module 10 is provided on the roof (ceiling) 2a of the vehicle 2.
The antenna module 10 includes four array antennas 20 and a rectangular plate-shaped base plate 22 to which these array antennas 20 are fixed.

Each of the four array antennas 20 includes a substrate 21 and a plurality of antenna elements 24 mounted on the antenna surface 21a of the substrate 21. The antenna element 24 is, for example, a planar antenna such as a patch antenna.
Each substrate 21 is erected along the edge of the base plate 22. Each antenna surface 21a faces diagonally upward from the front, back, left, and right of the vehicle 2. Therefore, the antenna module 10 has a box shape of a quadrangular pyramid.

As will be described later, each array antenna 20 can perform beamforming by adjusting the phase of signals transmitted and received by a plurality of antenna elements 24.
Each array antenna 20 can direct the beam in a range of about 100 degrees in the azimuth direction. Further, each array antenna 20 can direct the directing direction of the beam within a range of about 90 degrees in the elevation angle direction.
Therefore, by combining the four array antennas 20, the antenna module 10 can form a beam toward each direction around the antenna module 10 (vehicle-mounted communication device 1).

In FIG. 2A, the Y direction is the front-rear direction of the vehicle 2, the X direction is the left-right direction of the vehicle 2, and the Z direction is the up-down direction of the vehicle 2.
Further, in the following description, the Z direction indicates the vertical direction, and the XY plane is described as a horizontal plane orthogonal to the vertical direction.
That is, in the following description, the case where the entire vehicle 2 is tilted due to the vehicle 2 being located on the slope and the case where the entire vehicle 2 is tilted due to the change in the posture of the vehicle 2 due to the movement are not considered, and the vehicle 2 The roof 2a will be described as being always parallel to the horizontal plane.
Therefore, the antenna module 10 will be described as being always installed parallel to the horizontal plane.

As shown in FIG. 2B, the circuit board 28 is housed inside the antenna module 10. The circuit board 28 is fixed to the upper surface of the base plate 22. On the circuit board 28, a circuit for controlling the beam directivity formed by the array antenna 20 and a circuit required as an antenna module 10 such as a transmitter / receiver are mounted.
In addition, in FIG. 2A and FIG. 2B, the antenna module 10 is exposed to the outside, but is protected from the outside by being covered with, for example, a radome.

FIG. 3 is a block diagram showing an example of the configuration of the antenna module 10.
In FIG. 3, the antenna module 10 includes four array antennas 20, a changeover switch 32, a transmitter / receiver 34, and a control device 36.
Each array antenna 20 is connected to the transmitter / receiver 34 via a changeover switch 32.

The transmitter / receiver 34 performs processing such as modulation and amplification on the baseband signal given from the communication processing unit 12 (FIG. 1) to generate a radio frequency signal (RF signal). The generated RF signal is given to the array antenna 20 via the changeover switch 32.
Further, the transmitter / receiver 34 performs processing such as amplification and demodulation on the RF signal received by the array antenna 20 to generate a baseband signal. The generated baseband signal is given to the communication processing unit 12.

The changeover switch 32 has a function of switching the connection destination of the transmitter / receiver 34 to any one of the four array antennas 20.
Therefore, wireless communication with the base station apparatus 4 is performed using any one of the four array antennas 20.

That is, of the four array antennas 20, the array antenna 20 connected to the transmitter / receiver 34 is the array antenna used for wireless communication with the base station device 4.
The switching by the changeover switch 32 is controlled by the control device 36.

The array antenna 20 feeds the received radio wave from the base station device 4 to the transmitter / receiver 34 as an RF signal. Further, the array antenna 20 radiates the RF signal given from the transmitter / receiver 34 into space as a radio wave.
The array antenna 20 further includes a phase adjuster 40 and a composite distributor 42 in addition to the plurality of antenna elements 24 described above.

The phase adjuster 40 adjusts the phases of a plurality of signals transmitted and received by the plurality of antenna elements 24. The phase adjuster 40 includes a number of phase adjusters 40a corresponding to each of the plurality of antenna elements 24. The phase adjuster 40 can adjust the phases of a plurality of signals by adjusting each phase adjuster 40a, and can change the directivity direction of the beam formed by the array antenna 20.

The composite distributor 42 synthesizes the RF signals received by the plurality of antenna elements 24 and gives them to the transmitter / receiver 34, and distributes the RF signals from the transmitter / receiver 34 given via the changeover switch 32 to the plurality of antenna elements 24. To do.

A directivity control circuit 44 is connected to each array antenna 20. The directivity control circuit 44 has a function of controlling the directivity direction of the beam formed by the array antenna 20.
The directivity control circuit 44 controls the phase adjuster 40 by giving a control command to the phase adjuster 40, and controls the directivity direction of the beam formed by the array antenna 20.

The directivity control circuit 44 has a function of controlling the directivity direction of the beam of the array antenna 20 so as to direct the signal from the base station device 4 in the direction of arrival.
The directivity control circuit 44 controls the directivity direction of the beam of the array antenna 20 within the transmission / reception range described later.
The directivity control circuit 44 may control the directivity direction of the beam in response to an instruction from the base station device 4, or the directivity control circuit 44 itself searches for the direction of arrival of the signal from the base station device 4 and obtains the directivity control circuit 44. The directivity of the beam may be controlled based on the result.

The control device 36 has a function of controlling the changeover switch 32 as described above.
The control device 36 is composed of a computer including a CPU (Central Processing Unit) and a storage device such as a memory. A computer program or the like for execution by the CPU is stored in the storage device of the control device 36, and each function described later is realized by the CPU reading and executing the computer program.

FIG. 4 is a block diagram showing an example of the configuration of the control device 36. As shown in FIG. 4, the control device 36 functionally has a selection unit 36a and a switching unit 36b.
The selection unit 36a and the switching unit 36b have a function of executing processing including switching control of the changeover switch 32. The functions of the selection unit 36a and the switching unit 36b will be described later.

[Transmission / reception range of array antenna]
FIG. 5 is a diagram for explaining a transmission / reception range of each array antenna 20.
FIG. 5 is a top view of the antenna module 10, in which the upper side of the paper is the front of the vehicle 2 and the lower side of the paper is the rear of the vehicle 2.

The antenna module 10 directs the beam in the direction of the base station device 4 and performs wireless communication with the base station device 4.
Therefore, the transmission / reception range in which each array antenna 20 can transmit / receive to / from the base station device 4 is determined by the range in which the directivity of the beam formed by each array antenna 20 can be changed.

The array antenna 20 of the present embodiment is set so that the direction of the beam can be changed within a range of about 100 degrees in the azimuth direction. Further, the array antenna 20 of the present embodiment is set so that the directing direction of the beam can be changed within a range of about 90 degrees in the elevation angle direction.

The azimuth is an angle for specifying the direction in the horizontal plane, and here, it is a central angle for specifying the direction of the beam in the horizontal plane with respect to the array antenna 20 (antenna module 10). is there.
The azimuth direction is a rotation direction around an axis parallel to the vertical direction.
The elevation angle is an angle for specifying the direction with respect to the horizontal plane, and here, it is the center angle of the beam with respect to the horizontal plane.
Further, the elevation angle direction is a rotation direction around a central axis when expressing an elevation angle.

The antenna module 10 is a combination of four array antennas 20 capable of directing the beam within a range of about 100 degrees in the azimuth direction. Therefore, the antenna module 10 can direct the direction of the beam in all directions in the azimuth direction. Further, even in the elevation angle direction, the direction of the beam can be directed in each direction above the horizontal plane. The antenna module 10 can form a beam in each direction around the antenna module 10 (vehicle-mounted communication device 1).

Therefore, the antenna module 10 can transmit and receive signals to and from the base station device 4 located in each direction around the antenna module 10 (vehicle-mounted communication device 1).

In FIG. 5, the transmission / reception range R1 of the array antenna 20A arranged toward the front of the vehicle 2 is a range in which the array antenna 20A can change the directivity direction of the beam. The transmission / reception range R1 is set to a range of about 100 degrees in the azimuth direction. The transmission / reception range R1 is symmetrical with respect to the center line C1. The center line C1 is a center line extending in the front-rear direction of the vehicle 2 passing through the center of the antenna module 10.

Further, the transmission / reception range R2 of the array antenna 20B arranged toward the left side of the vehicle 2 is a range in which the array antenna 20B can change the directivity direction of the beam. Therefore, the transmission / reception range R2 is also set to a range of about 100 degrees in the azimuth direction. The transmission / reception range R2 is symmetrical with respect to the center line C2. The center line C2 is a center line extending in the left-right direction of the vehicle 2 passing through the center of the antenna module 10.

Similarly, the transmission / reception range R3 of the array antenna 20C arranged toward the rear of the vehicle 2 is a range in the azimuth direction in which the array antenna 20C can change the directivity direction of the beam.
Further, the transmission / reception range R4 of the array antenna 20D arranged toward the right side of the vehicle 2 is a range in the azimuth direction in which the array antenna 20D can change the directivity direction of the beam.

Among the transmission / reception ranges R1, R2, R3, and R4, the transmission / reception ranges adjacent to each other include overlapping ranges that overlap each other.
The transmission / reception range R1 is adjacent to the transmission / reception range R2. Therefore, the transmission / reception range R1 and the transmission / reception range R2 include an overlapping range R12 that overlaps with each other. Further, the transmission / reception range R1 is also adjacent to the transmission / reception range R4. Therefore, the transmission / reception range R1 and the transmission / reception range R4 include an overlapping range R14 that overlaps with each other.
Similarly, the transmission / reception range R2 and the transmission / reception range R3 include an overlapping range R23 that overlaps with each other. Further, the transmission / reception range R3 and the transmission / reception range R4 include an overlapping range R34 that overlaps with each other.

The overlapping range R12, R23, R34, and R14 is a range in which both of the array antennas 20 adjacent to each other can direct the direction of the beam. Therefore, in the overlapping ranges R12, R23, R34, and R14, both of the array antennas 20 adjacent to each other can transmit and receive signals to and from the base station device 4.

[About selection process]
The antenna module 10 forms a beam whose direction is directed toward the base station device 4 in order to perform wireless communication with the base station device 4.
Therefore, the antenna module 10 needs to select the array antenna 20 for forming the beam. Therefore, the selection unit 36a of the antenna module 10 executes a selection process of selecting the array antenna (target antenna) to be used for wireless communication with the base station device 4 from the four array antennas 20.

FIG. 6 is a flowchart showing an example of a determination process for determining whether or not to execute the selection process.
First, the selection unit 36a transmits the received power based on the signal from the base station device 4 received by the array antenna 20 currently connected to the transmitter / receiver 34 as the target antenna used for wireless communication with the base station device 4. It is acquired, and it is determined whether or not the acquired received power is lower than a predetermined threshold value (step S1).

The received power is obtained based on a signal whose transmission power is known in advance, such as a pilot signal, among the signals received by the array antenna 20 which is the target antenna from the base station device 4.
The value of the received power of the pilot signal is obtained from the transmitter / receiver 34 that demodulates the RF signal received by the target antenna.
The selection unit 36a obtains the value of the received power of the pilot signal from the transmitter / receiver 34.

If it is determined in step S1 that the acquired received power is not lower than a predetermined threshold value, the selection unit 36a repeats step S1 again. The predetermined threshold value is set to a value at which it can be determined that wireless communication is possible between the in-vehicle communication device 1 and the base station device 4 without any problem.
Therefore, when maintaining the received power to the extent that wireless communication is possible between the in-vehicle communication device 1 and the base station device 4 without any problem, the selection unit 36a repeatedly executes step S1.

On the other hand, if it is determined in step S1 that the acquired received power is lower than a predetermined threshold value, the selection unit 36a proceeds to step S2 and sequentially obtains the received power of each array antenna 20 (step S2).
Here, the selection unit 36a sequentially switches the array antenna 20 to which the transmitter / receiver 34 is connected by controlling the changeover switch 32.
When the selection unit 36a obtains the received power of the array antenna 20 connected to the transmitter / receiver 34, the selection unit 36a switches the connection destination of the transmitter / receiver 34 to another array antenna 20 and obtains the received power of the other array antenna 20. By repeating this, the received power of the four array antennas 20 is obtained.

When the selection unit 36a obtains the received power of the array antenna 20 in step S2, the selection unit 36a changes the directivity direction of the beam within a range in which the directivity direction of the beam can be changed by the array antenna 20, and the reception power becomes the highest. Let the value be the received power of the array antenna 20.

When the received power of each of the four array antennas 20 is obtained in step S2, the selection unit 36a proceeds to step S3 and compares the received power of each of the four array antennas 20. As a result of comparing the received powers, the selection unit 36a selects the array antenna 20 having the highest received power among the four array antennas 20 as the target antenna (step S3), and returns to step S1.

The above steps S2 and S3 are selection processes. The selection unit 36a determines whether or not to execute the selection process based on the received power.

Of the four array antennas 20, the array antenna 20 having the highest received power can be determined to have the route with the highest communication quality with the base station apparatus 4. That is, it can be determined that the array antenna 20 can form a beam directed to the base station device 4.

Therefore, the selection unit 36a connects the array antenna 20 having the highest received power among the four array antennas 20 and the transmitter / receiver 34 by controlling the changeover switch 32. As a result, the array antenna 20 having the highest received power becomes the target antenna.
In this way, the selection unit 36a causes the vehicle-mounted communication device 1 to perform wireless communication with the base station device 4 by using the selected array antenna 20.

The selection unit 36a has shown a case where the reception power is acquired as the communication quality of the signals received by the four array antennas 20 and the target antenna is selected based on the comparison result of the reception power. In addition to the received power, SIR (Signal to Antenna Radio), SINR (Signal to Antenna and Noise Radio), and the like can be used.

[About switching process]
When one of the four array antennas 20 is selected as the target antenna and used for wireless communication with the base station device 4, the switching unit 36b of the antenna module 10 of the present embodiment uses the target antenna as another. The switching process for switching to the array antenna 20 is executed.

FIG. 7 is a diagram for explaining the direction of the base station device 4 in the vehicle 2 (antenna module 10) traveling on the road.
FIG. 7 shows a case where the vehicle 2 at the position H is traveling on the road 50 toward the upper side of the paper.
The vehicle 2 at the position H is traveling with the front surface facing the base station device 4. The antenna module 10 (vehicle-mounted communication device 1) mounted on the vehicle 2 performs wireless communication with the base station device 4 in front of the vehicle 2 at the position H.
At this time, the antenna module 10 selects the array antenna 20A arranged toward the front of the vehicle 2 as the target antenna, forms a beam by the array antenna 20A, and performs wireless communication with the base station device 4.

In FIG. 7, vehicle 2 at position I is about to turn right on the side road 52. Further, the vehicle 2 at the position J passes right beside the base station device 4.
The left side of the vehicle 2 at position I and position J faces the base station device 4 side.
Therefore, as shown in FIG. 7, the antenna module 10 selects the array antenna 20B arranged toward the left side of the vehicle 2 as the target antenna at the position I and the position J, and forms a beam by the array antenna 20B. ..

Here, consider a case where the vehicle 2 moves from the position H to the position I and turns right from the road 50 to the side road 52.
The vehicle 2 travels toward the front of the base station device 4 until it turns right. After that, when the vehicle 2 reaches the position I and starts turning right, the direction of the base station device 4 in the vehicle 2 changes, and the surface of the vehicle 2 facing the base station device 4 side passes from the front surface to the left side surface. Transition to the rear surface.
Further, the same applies when the vehicle 2 goes straight from the position H to the position J, and the surface of the vehicle 2 facing the base station device 4 side transitions from the front surface to the rear surface via the left side surface.

When the direction of the base station device 4 in the vehicle 2 changes and the surface of the vehicle 2 facing the base station device 4 side changes from the front surface to the left side surface, the antenna module 10 shifts the target antenna from the array antenna 20A to the array antenna 20B. Need to switch to.

If the antenna module 10 performs selection processing and attempts to switch, the antenna module 10 performs selection processing after determining that the reception power of the array antenna 20A selected as the target antenna has decreased, and the reception power is reduced. The array antenna 20B that appears high is selected as the target antenna (FIG. 6).

However, until the reception power of the array antenna 20A decreases and the array antenna 20B is selected, the antenna module 10 performs wireless communication with the base station device 4 in order to select the array antenna 20 having the highest reception power. It will be interrupted.
The same applies to the case where the surface of the vehicle 2 facing the base station device 4 side transitions from the left side surface to the rear surface, and the antenna module 10 needs to switch the target antenna from the array antenna 20B to the array antenna 20C. The antenna module 10 interrupts wireless communication with the base station device 4 in order to select the array antenna 20 having the highest received power until the reception power of the array antenna 20B decreases and the array antenna 20C is selected. It will be.
Such interruption of wireless communication is not preferable because it leads to deterioration of communication quality such as communication speed.

Therefore, the antenna module 10 of the present embodiment switches the target antenna to another array antenna 20 without going through selection by the selection process when wireless communication is performed by the array antenna 20 selected as the target antenna. Has a function to execute.
As a result, even if it becomes necessary to switch the target antenna due to the movement of the vehicle 2 and the change in the direction of the base station device 4 in the vehicle 2, the target antenna is quickly switched without performing selection by the selection process. be able to.

FIG. 8 is a flowchart showing an example of a switching determination for determining whether or not to execute the switching process.
First, the switching unit 36b of the antenna module 10 determines whether or not the selection process is being executed by the selection unit 36a (step S11).

When the selection unit 36a is executing the selection process, the switching unit 36b returns to step S11 again and repeats step S11 until it is determined that the selection process is not being executed.

If it is determined that the selection process is not being executed, the switching unit 36b obtains antenna information indicating the current array antenna 20 which is the target antenna and directivity information indicating the directivity direction of the beam formed by the array antenna 20 which is the target antenna. Acquire (step S12).
The antenna information can be acquired from, for example, the selection unit 36a, or can be acquired from the changeover switch 32.
The directivity direction information is acquired from the directivity control circuit 44 that controls the directivity direction of the array antenna 20 which is the target antenna.

The array antenna 20 of the present embodiment is configured to change the beam discretely. Each beam formed within the transmission / reception range is given a beam ID (identifier) for identifying each beam, and each beam can be identified by the beam ID, and the direction of the beam can be grasped. ..

The switching unit 36b stores the beam ID of each beam formed by each array antenna 20 in association with the information regarding the direction of direction. The information regarding the direction of direction includes information indicating the direction of direction of the beam. Further, the information regarding the directional direction may include information indicating a range (transmission / reception range or overlapping range) to which the directional direction of the beam belongs.
Therefore, the switching unit 36b can grasp the direction of the beam, the range to which the direction of the beam belongs, and the like from the beam ID.
The switching unit 36b acquires the beam ID as the directivity direction information from the directivity control circuit 44.

When the information regarding the target antenna is acquired, the switching unit 36b determines in step S13 whether or not the antenna information acquired this time and the antenna information acquired most recently in the past indicate the same array antenna 20 (step S13). ..
The antenna information acquired most recently in the past means the latest antenna information acquired before the determination in step S13.

In step S13, when the array antenna 20 indicated by the antenna information acquired this time and the array antenna 20 indicated by the antenna information acquired most recently in the past are different, either the selection of the target antenna in the selection process immediately before or the switching process is performed. It may have been done. Therefore, in this case, the switching unit 36b returns to step S11 and acquires information about the target antenna again (step S12).

In step S13, when the antenna information acquired this time and the antenna information acquired most recently indicate the same array antenna 20, the switching unit 36b proceeds to step S14, and the directing direction of the beam formed by the current target antenna is changed. It is determined whether or not it is in the overlapping range (step S14).
The switching unit 36b determines whether or not the directing direction of the beam formed by the current target antenna is within the overlapping range based on the beam ID acquired in step S12.

In step S14, when it is determined that the directing direction of the beam formed by the current target antenna is within the overlapping range, the switching unit 36b determines whether or not the directing direction of the beam acquired most recently in the past is outside the overlapping range. (Step S15).

In step S15, when it is determined that the directing direction of the beam acquired most recently in the past is out of the overlapping range, the switching unit 36b proceeds to step S16 and executes the switching process (step S16).
The switching unit 36b executes the switching process in step S16 and returns to step S11.

In step S16, the switching unit 36b switches the target antenna from the array antenna 20 currently selected as the target antenna to another array antenna 20 having a transmission / reception range including overlapping ranges that overlap each other.
That is, when the array antenna 20 of any one of the pair of array antennas 20 arranged adjacent to each other is the target antenna, the switching unit 36b has a directing direction of the beam formed by one of the array antennas 20. When the transmission / reception ranges of each other are controlled within the overlapping range, the process of switching the target antenna from the one array antenna 20 to the other array antenna 20 (switching process) is executed (step S16).

More specifically, the switching unit 36b controls the changeover switch 32 to switch the connection destination of the transmitter / receiver 34 from one array antenna 20 to the other array antenna 20.
The switching unit 36b connects the other array antenna 20 and the transmitter / receiver 34. As a result, the other array antenna 20 becomes the target antenna.

In step S15, when it is determined that the direction direction of the beam of the beam ID acquired most recently is not outside the overlapping range (when it is determined that the direction direction of the beam of the beam ID acquired most recently in the past is within the overlapping range), switching is performed. Part 36b returns to step S11.

In this case, since the direction of the beam directed by the current target antenna maintains the overlapping range, there is a possibility that the switching process is executed in the loop most recent in the past, and then the vehicle 2 is stopped without moving. is there.
As described above, the switching unit 36b suppresses the execution of the switching process when the vehicle 2 is not moving and there is a possibility that the directing direction of the beam by the current target antenna has not changed.

If it is determined in step S14 that the directing direction of the beam formed by the current target antenna is not in the overlapping range, the switching unit 36b does not execute the switching process, and the directing direction of the beam formed by the current target antenna is immediately before the overlapping range. It is determined whether or not it is (step S17).

In step S17, when it is determined that the directing direction of the beam formed by the current target antenna is immediately before the overlapping range, the switching unit 36b determines that the beam to be formed by the other array antenna 20 having a transmission / reception range including the overlapping range. The directivity direction is controlled in advance (step S18), and the process returns to step S11.

In step S17, the switching unit 36b determines whether or not the direction of the beam of the target antenna is immediately before the overlap range so that the direction of the beam of the target antenna approaches the overlap range side outside the overlap range. Determine if it is controlled.

When the directing direction of the beam of the target antenna is immediately before the overlapping range, it can be determined that the directing direction of the beam of the target antenna is controlled so as to approach the overlapping range side from a position other than immediately before the overlapping range.
Therefore, when the switching unit 36b determines in step S17 that the directivity direction of the beam of the target antenna is immediately before the overlapping range, the switching unit 36b controls so that the directivity direction of the beam to be formed by the other array antenna 20 is in the overlapping range. ..

As a result, the directivity direction of the beam by the current target antenna is set in advance to the direction direction of the other array antenna 20 selected as the target antenna next immediately before reaching the overlapping range and before the switching process is executed. Since it can be adjusted, the array antenna 20 can be switched more quickly to form the required beam.

If it is determined in step S17 that the directing direction of the beam formed by the current target antenna is not immediately before the overlapping range, the switching unit 36b returns to step S11.
In this case, the directivity direction of the beam of the target antenna is maintained outside the overlapping range and is not immediately before the overlapping range, so that the switching process is not performed and the directivity control of the other adjacent array antennas 20 is not executed. Return to step S11.

As described above, the antenna module 10 of the present embodiment can execute the switching process of switching the target antenna to another array antenna 20 without going through the selection process when wirelessly communicating with the target antenna. ..
As a result, even if it becomes necessary to switch the target antenna due to the movement of the vehicle 2 and the change in the direction of the base station device 4 in the vehicle 2, the target antenna is quickly switched without performing selection by the selection process. be able to.

Further, the switching unit 36b determines whether or not to execute the switching process based on the directing direction of the beam by the current target antenna.
As a result, the direction of the base station device 4 in the in-vehicle communication device 1 can be grasped as the direction of the beam directed by the target antenna, and it can be determined whether or not to execute the switching process.
That is, in the present embodiment, the direction of the beam is used as the direction information indicating the direction of the base station device 4 in the vehicle-mounted communication device 1.

FIG. 9 is a diagram showing an example of a mode in which the target antenna is switched from the array antenna 20A arranged toward the front of the vehicle 2 to the array antenna 20B arranged toward the left side of the vehicle 2.
Note that FIG. 9 shows a beam formed on a horizontal plane.

In FIG. 9, the array antenna 20A can form the beams B11, B12, B13, and B14. Further, the array antenna 20B can form the beams B21, B22, B23, and B24.
The beam shown in FIG. 9 shows a part of the beams that can be formed by the array antenna 20A and the array antenna 20B.

Of the beams B11 to B14, the directing directions of the beams B11, B12, and B13 are within the transmission / reception range R1 and outside the overlap range R12. The direction of the beam B13 is the direction immediately before the overlapping range R12.
The directing direction of the beam B14 formed by the array antenna 20A is within the transmission / reception range R1 and within the overlap range R12.

Further, among the beams B21 to B24 formed by the array antenna 20B, the directing directions of the beams B22, B23, and B24 are within the transmission / reception range R2 and outside the overlap range R12. Further, the directing direction of the beam B22 is immediately before the overlapping range R12.
The directing direction of the beam B21 formed by the array antenna 20B is within the transmission / reception range R2 and within the overlap range R12.

Hereinafter, as described with reference to FIG. 7, as the vehicle 2 moves and the direction of the base station device 4 in the vehicle 2 changes, the surface of the vehicle 2 facing the base station device 4 side shifts from the front surface to the left side surface. Then, the case where the antenna module 10 switches the target antenna from the array antenna 20A to the array antenna 20B will be described.

While the front surface of the vehicle 2 faces the base station device 4 side and the array antenna 20A is selected as the target antenna (position H in FIG. 7), the antenna module 10 forms a beam by the array antenna 20A.
When the vehicle 2 advances from the position H in FIG. 7, the direction of the base station device 4 in the vehicle 2 gradually changes from the front to the left as the vehicle 2 moves.

As described above, the directivity direction of the beam of the array antenna 20A is controlled so as to be directed in the direction of arrival of the signal from the base station device 4 received by the array antenna 20A.
Therefore, the beam of the array antenna 20A is sequentially switched to the beams B11, B12, B13, and B14 in FIG. 9, and the beam directed to the left of the vehicle 2.
As a result, the directivity direction of the beam by the array antenna 20 changes discretely so as to be directed toward the arrival direction of the signal from the base station device 4.

While the beam of the array antenna 20A is sequentially switched to the beams B11, B12, B13, and B14, the switching unit 36b executes the switching determination at any time.
Here, the switching determination performed by the switching unit 36b immediately after the beam of the array antenna 20A is switched from the beam B12 to the beam B13 will be described.
In this case, the directing direction of the beam B13 is within the transmission / reception range R1 and immediately before the overlapping range R12.
Therefore, the switching unit 36b controls the beam formed by the array antenna 20B to be the beam B21 within the overlapping range R12 (step S17 in FIG. 8).
As a result, the directivity direction of the array antenna 20B selected as the target antenna can be set in advance so as to be the beam B21 within the overlapping range R12, so that the array antenna 20 can be switched more quickly.

Further, the switching determination performed by the switching unit 36b immediately after the beam of the array antenna 20A is switched from the beam B13 to the beam B14 will be described.
In this case, the directing direction of the beam B14 is within the transmission / reception range R1 and within the overlapping range R12 (step S14 in FIG. 8).
Further, the directing direction of the beam B13 most recently in the past is a direction within the transmission / reception range R1 and outside the overlapping range R12 (step S15 in FIG. 8).

Therefore, the switching unit 36b executes the switching process. The switching unit 36b switches the target antenna from the array antenna 20A to the array antenna 20B by executing the switching process.
The switching unit 36b controls the changeover switch 32 to switch the connection destination of the transmitter / receiver 34 from the array antenna 20A to the array antenna 20B. As a result, the array antenna 20B becomes the target antenna.
The switching unit 36b uses the array antenna 20B to cause the vehicle-mounted communication device 1 to perform wireless communication with the base station device 4.

The array antenna 20B, which has become the target antenna by the switching process, forms the beam B21 within the overlapping range R12 according to the setting made in advance.
The beam B14 of the array antenna 20A and the beam B21 of the array antenna 20B both overlap within the overlap range R12.
Therefore, even if the switching unit 36b executes the switching process to switch the target antenna from the array antenna 20A to the array antenna 20B, the switching can be smoothly performed without affecting the wireless communication.

Further, when the array antenna 20B is switched to the array antenna 20A by the switching process, when the beam of the array antenna 20B is switched from the beam B22 outside the overlapping range R12 to the beam 21 within the overlapping range R12, the switching unit 36b performs the switching process. Is executed, and the target antenna is switched from the array antenna 20B to the array antenna 20A.
That is, the determination criteria for executing the switching process differs between the case of switching from the array antenna 20A to the array antenna 20B and the case of switching from the array antenna 20B to the array antenna 20A.

As described above, in the present embodiment, since the transmission / reception range R1 and the transmission / reception range R2 that are adjacent to each other have the overlapping range R12 that overlaps with each other, hysteresis is performed when the direction of the beam moves back and forth between the transmission / reception range R1 and the transmission / reception range R2. It is possible to suppress the occurrence of hunting in which the direction of the beam frequently moves back and forth between the transmission / reception range R1 and the transmission / reception range R2.

As a result, for example, even if the direction of the base station device 4 in the antenna module 10 is located near the boundary between the transmission / reception range R1 and the transmission / reception range R2 by temporarily stopping when the vehicle 2 turns left or right on the road. It is possible to suppress the occurrence of the above hunting.

Similar to the array antenna 20A, the directivity direction of the beam of the array antenna 20B is also controlled so as to be directed in the direction of arrival of the signal from the base station device 4 received by the array antenna 20B.
Therefore, the beam of the array antenna 20B is sequentially switched to the beams B21, B22, B23, and B24 in FIG.

Therefore, as the vehicle 2 moves further and the direction of the base station device 4 in the vehicle 2 changes, the surface of the vehicle 2 facing the base station device 4 side shifts from the left side surface to the rear surface, and the antenna module 10 is targeted. The same process is executed when the antenna is switched from the array antenna 20B to the array antenna 20C.

[Other]
It should be noted that the embodiments disclosed this time are examples in all respects and are not restrictive.
In the above embodiment, the case where the directivity direction of the beam formed by the array antenna 20 is used as the direction information indicating the direction of the base station device 4 in the vehicle-mounted communication device 1 is exemplified in determining whether or not to execute the switching process. However, as the direction information, for example, relative position information indicating the relative positional relationship between the vehicle-mounted communication device 1 and the base station device 4 may be used.

By using such direction information, the direction of the base station device 4 among the directions around the in-vehicle communication device 1 can be grasped.
The relative position information may be acquired from, for example, a car navigation system mounted on the vehicle 2, or the relative position information may be obtained by receiving the position information of the base station device 4 from the base station device 4. You may ask.

Further, in the above embodiment, the case where it is determined whether or not to execute the switching process using only the direction of the beam is illustrated, but the relative position information may be used together, and the vehicle-mounted communication device 1 is mounted. It is also possible to determine whether or not to execute the switching process by taking at least one of the speed and the acceleration of the vehicle 2 to be performed into consideration.
In this case, the change in the direction of the base station device 4 in the in-vehicle communication device 1 can be grasped over time, and the change in the direction of the base station device 4 can be grasped more accurately.

Further, in the above embodiment, the case where the antenna module 10 includes four array antennas 20 is illustrated, but for example, it may be configured by a number of array antennas 20 less than four, as shown in FIG. In addition, it may be composed of eight array antennas 20 which are more than four.

Further, in the above embodiment, the case where the array antenna 20 is configured to change the beam discretely is illustrated, but the beam may be configured to be continuously changed.

Further, in the above embodiment, in the switching process, if the directing direction of the beam formed by the current target antenna is in the overlapping range, the switching process is executed, and if it is out of the overlapping range, the switching process is not executed. (Step S14 in FIG. 8) was illustrated. That is, the case where the switching process is executed when the directing direction of the beam of the target antenna is within the overlapping range is shown.

On the other hand, the switching process may be executed when the directing direction of the beam of the target antenna is out of the transmission / reception range of the target antenna.
That is, in FIG. 9, when the array antenna 20A is the target antenna, the beam of the array antenna 20A sequentially changes from the beam B11 to reach the beam B14, and the reception power (communication quality) of the beam B14 is lowered, so that the antenna When it is determined that the direction of the base station device 4 in the module 10 is out of the transmission / reception range R1 (overlapping range R12) of the array antenna 20A, the target antenna may be switched from the array antenna 20A to the array antenna 20B. ..
Even in this case, hysteresis can be provided when the beam directing direction moves back and forth between the transmission / reception range R1 and the transmission / reception range R2, and hunting in which the beam directionality frequently moves back and forth between the transmission / reception range R1 and the transmission / reception range R2 It can be suppressed from occurring.

The scope of the present invention is indicated by the scope of claims, not the above-mentioned meaning, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

1 In-vehicle communication device 2 Vehicle 2a Roof 4 Base station device 6 Radio unit 8 Mobile terminal 10 Antenna module 12 Communication processing unit 20 Array antenna 20A Array antenna 20B Array antenna 20C Array antenna 20D Array antenna 21 Board 21a Antenna surface 22 Base plate 24 Antenna Element 28 Circuit board 32 Changeover switch 34 Transmitter / receiver 36 Controller 36a Selection part 36b Switching part 40 Phase adjuster 40a Phaser 42 Composite distributor 44 Directional control circuit 50 Road 52 Side road C1 Center line C2 Center line R1 Transmission / reception range R2 Range R3 Transmission / reception range R4 Transmission / reception range R12 Overlapping range R14 Overlapping range R23 Overlapping range R34 Overlapping range B11 Beam B12 Beam B13 Beam B14 Beam B21 Beam B22 Beam B23 Beam B24 Beam

Claims (12)

An antenna module used in mobile communication devices that wirelessly communicate with base station devices.
A first array antenna capable of transmitting and receiving signals to and from the base station device in a direction included in the first range among the directions around the mobile communication device, and the first range among the directions around the mobile communication device. A plurality of array antennas including a second array antenna capable of transmitting and receiving signals to and from the base station device in a direction included in the second range adjacent to the base station device.
A selection unit that selects a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas based on the communication quality of each signal received by the plurality of array antennas.
When one of the antennas of the first array antenna and the second array antenna is selected as the target antenna and used for wireless communication with the base station apparatus, the target antenna is used as the one antenna. A switching unit that executes switching processing to switch from to the other antenna,
Antenna module with. A first directivity control unit that controls the directivity direction of the first beam formed by the first array antenna within the first range.
A second directivity control unit that controls the directivity direction of the second beam formed by the second array antenna within the second range.
With more
The first directivity control unit controls the directivity direction of the first beam according to the direction of arrival of the signal from the base station apparatus.
The second directivity control unit controls the directivity direction of the second beam according to the direction of arrival of the signal from the base station apparatus.
The switching unit determines whether or not to execute the switching process based on the directivity direction of the beam formed by the one antenna controlled by the first directivity control unit or the second directivity control unit. The antenna module according to claim 1. The first range and the second range include overlapping ranges that overlap each other.
The antenna module according to claim 2, wherein when the directing direction of the beam formed by one of the antennas is within the overlapping range, the switching process is executed. The first range and the second range include overlapping ranges that overlap each other.
When the directing direction of the beam formed by the one antenna is within the overlapping range, the switching unit determines whether or not the most recent directing direction of the beam formed by the one antenna is outside the overlapping range. The antenna module according to claim 2, wherein the switching process is not executed when the determination result is negative. The switching unit determines whether or not the directivity direction of the beam formed by the one antenna is controlled to approach the overlapping range side outside the overlapping range, and if the determination result is positive, the switching unit determines. The antenna module according to claim 3 or 4, wherein the directing direction of the beam formed by the other antenna is controlled so as to be directed in a direction corresponding to the overlapping range. The antenna module according to claim 1, wherein the switching unit determines whether or not to execute the switching process based on the direction information indicating the direction of the base station device in the mobile communication device. The first range and the second range include overlapping ranges that overlap each other.
The antenna module according to claim 6, wherein the switching unit executes the switching process when the direction of the base station device indicated by the direction information is within the overlapping range. 6. The switching unit determines whether or not to execute the switching process by taking at least one of the speed and the acceleration of the moving body on which the mobile communication device is mounted into consideration in addition to the direction information. Alternatively, the antenna module according to claim 7. A mobile communication device including the antenna module according to any one of claims 1 to 8. A vehicle provided with the mobile communication device according to claim 9. A method for switching between a first array antenna and a second array antenna included in a plurality of array antennas included in an antenna module used in a mobile communication device that wirelessly communicates with a base station device.
The first array antenna can transmit and receive signals to and from the base station device in the direction included in the first range among the directions around the mobile communication device.
The second array antenna can transmit and receive signals to and from the base station device in the direction included in the second range adjacent to the first range among the directions around the mobile communication device.
A step of selecting a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas based on the communication quality of each of the received signals by the plurality of array antennas.
When either one of the first array antenna and the second array antenna is selected as the target antenna and used for wireless communication with the base station apparatus, the target antenna is used as the one antenna. A switching method including a step of executing a switching process of switching from one antenna to the other antenna. A computer program for causing a computer to perform switching processing of a first array antenna and a second array antenna included in a plurality of array antennas included in an antenna module used in a mobile communication device that wirelessly communicates with a base station device.
The first array antenna can transmit and receive signals to and from the base station device in the direction included in the first range among the directions around the mobile communication device.
The second array antenna can transmit and receive signals to and from the base station device in the direction included in the second range adjacent to the first range among the directions around the mobile communication device.
A step of selecting a target antenna to be used for wireless communication with the base station apparatus from the plurality of array antennas on the computer based on the communication quality of each signal received by the plurality of array antennas.
When either one of the first array antenna and the second array antenna is selected as the target antenna and used for wireless communication with the base station apparatus, the target antenna is used as the one antenna. A computer program that executes the step of executing the switching process of switching from one antenna to the other antenna.

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