In-vehicle communication device, in-vehicle system, communication method, and program

Abstract

Provided are an in-vehicle communication device, an in-vehicle system, a communication method, and a program that are capable of continuing communication as much as possible while suppressing interference. The in-vehicle communication device comprises: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition unit that acquires position information of a vehicle; a roadside unit position acquisition unit that acquires position information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming unit that performs beamforming so as to form a null in the direction of the roadside unit by means of the plurality of antennas, on the basis of the acquired position information of the vehicle and the acquired position information of the roadside unit.

Description

In-vehicle communication device, in-vehicle system, communication method and program

[0001] The present disclosure relates to an in-vehicle communication device, an in-vehicle system, a communication method and a program.

[0002] In recent years, in-vehicle devices, which are in-vehicle communication devices mounted on vehicles, have become widespread, and their use in various types of communication is expected. For example, V2X (Vehicle-to-everything) communication enables communication between vehicles and various objects.

[0003] The allocation of the 5.9 GHz band for V2X communication is progressing globally, and discussions are also ongoing in Japan. On the other hand, the DSRC (Dedicated Short Range Communications) communication method used in ETC (Electronic Toll Collection System) and other systems uses the 5.8 GHz band adjacent to the 5.9 GHz band. Therefore, frequency sharing between the 5.9 GHz band for V2X communication and the 5.8 GHz band for ETC communication has become an issue.

[0004] As related technology, for example, Patent Document 1 is known. In Patent Document 1, in order to suppress interference between the frequency band for V2X communication and the frequency band for ETC communication, radio signals in either frequency band are attenuated.

[0005] Japanese Patent Application Laid-Open No. 2020-5185

[0006] In order to suppress interference between adjacent frequency bands, there is a method of attenuating radio signals as described in Patent Document 1, and frequency switching, stopping wave transmission, and other methods are also conceivable. However, these related technologies make it difficult to continue communication via the frequency band that has been attenuated or otherwise processed.

[0007] In view of such problems, one object of the present disclosure is to provide an in-vehicle communication device, an in-vehicle system, a communication method and a program that can continue communication as much as possible while suppressing interference.

[0008] An in-vehicle communication device according to one aspect of the present disclosure is an in-vehicle communication device mounted on a vehicle, comprising: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring location information of the vehicle; a roadside unit position acquisition means for acquiring location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means that performs beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information.

[0009] An in-vehicle system according to one aspect of the present disclosure includes a first in-vehicle communication device mounted on a vehicle, the first in-vehicle communication device comprising: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring location information of the vehicle; a roadside unit position acquisition means for acquiring location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means that performs beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information.

[0010] A communication method according to one aspect of the present disclosure is a communication method for an in-vehicle communication device mounted on a vehicle, comprising: performing wireless communication in a first frequency band using a plurality of antennas to acquire location information of the vehicle; acquiring location information of a roadside unit performing wireless communication in a second frequency band adjacent to the first frequency band; and performing beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit.

[0011] A program according to one aspect of this disclosure is a program for causing a computer to execute a communication method in an in-vehicle communication device mounted on a vehicle, wherein the program performs wireless communication in a first frequency band using multiple antennas, acquires location information of the vehicle, acquires location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band, and performs beamforming using the multiple antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit.

[0012] According to this disclosure, it is possible to continue communication as much as possible while minimizing interference.

[0013] This is a configuration diagram showing an example of the configuration of an in-vehicle communication device according to several embodiments. This is a configuration diagram showing an example of the configuration of an in-vehicle system according to several embodiments. This is a flowchart showing an example of a communication method according to several embodiments. This is a configuration diagram showing an example of the configuration of a vehicle according to several embodiments. This is a configuration diagram showing an example of the configuration of a V2X in-vehicle device according to several embodiments. This is a diagram showing a specific example of a coordinate database for interference avoidance according to several embodiments. This is a diagram showing an example of specifying the interference range according to several embodiments. This is a diagram showing an example of beam pattern control according to several embodiments. This is a flowchart showing an example of the operation of a V2X in-vehicle device according to several embodiments. This is a diagram for explaining the overview and effects of several embodiments. This is a configuration diagram showing an example of the configuration of computer hardware according to several embodiments.

[0014] The embodiments will be described below with reference to the drawings. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations will be omitted where necessary.

[0015] (Embodiment 1) First, Embodiment 1 will be described. In this embodiment, the outlines of several embodiments will be described.

[0016] Figure 1 shows some configuration examples of an in-vehicle communication device 10 according to several embodiments. The in-vehicle communication device 10 is a wireless communication device mounted on a vehicle that performs wireless communication. For example, the in-vehicle communication device 10 may be an in-vehicle device for V2X communication, or an in-vehicle device for other types of communication.

[0017] In the example shown in Figure 1, the in-vehicle communication device 10 includes multiple antennas 11, a vehicle position acquisition unit 12, a roadside unit position acquisition unit 13, and a beamforming unit 14.

[0018] The multiple antennas 11 are antennas that perform wireless communication in a first frequency band. For example, the first frequency band may be the 5.9 GHz frequency band for V2X communication (first communication method), or it may be any other frequency band. The first frequency band may also be any other frequency band for any other communication method. The multiple antennas 11 may be phase-adjustable phased array antennas. Multiple phase shifters may be provided to adjust the phase of each of the multiple antennas 11.

[0019] The vehicle position acquisition unit 12 acquires location information of the vehicle equipped with the in-vehicle communication device 10. For example, the vehicle position acquisition unit 12 may acquire the vehicle's location information using GNSS (Global Navigation Satellite System), or it may acquire the vehicle's location information by other methods.

[0020] The roadside unit position acquisition unit 13 acquires position information of roadside units that perform wireless communication in a second frequency band adjacent to the first frequency band. For example, the second frequency band may be the 5.8 GHz frequency band used for ETC communication (second communication method). The second frequency band may be any other frequency band that interferes with the first frequency band, and the communication method is not limited. Roadside units using the second frequency band are examples of devices to be avoided due to interference, and may include ETC gates and ITS (Intelligence Transport System) spots. ETC gates are wireless communication devices that communicate wirelessly with vehicles for the automatic toll payment system on expressways and toll roads, and are installed in lanes at the entrances to expressways and toll roads. ITS spots are distribution devices that distribute road traffic information to vehicles, and are installed on the side of the road.

[0021] The beamforming unit 14 performs beamforming to form a null in the direction of the roadside unit using multiple antennas 11, based on the vehicle position information acquired by the vehicle position acquisition unit 12 and the roadside unit position information acquired by the roadside unit position acquisition unit 13. A null is the point in the antenna beam pattern where the signal strength is minimum between adjacent lobes (main lobe or side lobe). The beamforming unit 14 may also perform beamforming by controlling the phase of multiple phase shifters connected to the multiple antennas 11. The beamforming unit 14 may calculate the distance between the vehicle and the roadside unit based on the vehicle position information and the roadside unit position information. The beamforming unit 14 may also perform beamforming to form a null in the direction of the roadside unit using multiple antennas 11 when the distance between the vehicle and the roadside unit falls below a predetermined value.

[0022] For example, the in-vehicle communication device 10 may include a database that stores the location information of roadside units in advance. In this case, the roadside unit position acquisition unit 13 may acquire the location information of roadside units from the database. The database may store the location information of roadside units and the interference distance. In this case, the beamforming unit 14 may perform beamforming so as to form a null in the direction of the roadside unit using multiple antennas 11 when the distance between the vehicle and the roadside unit becomes less than or equal to the interference distance.

[0023] For example, the in-vehicle communication device 10 may include a navigation unit that navigates the vehicle's travel path. The beamforming unit 14 may identify the edge of the interference range based on the interference distance in the database and the travel path to be navigated, and perform beamforming so as to form a null in the direction of the roadside unit using multiple antennas 11 when the vehicle's position is closer to the roadside unit than the edge of the interference range.

[0024] Each part of the in-vehicle communication device 10 may be included in one device or more devices, or in an in-vehicle system comprising one device or more devices. Figure 2 shows an example configuration of an in-vehicle system 20 according to several embodiments. In the example of Figure 2, the in-vehicle system 20 includes a plurality of antennas 11, a vehicle position acquisition unit 12, a roadside unit position acquisition unit 13, and a beamforming unit 14, as shown in Figure 1. For example, the plurality of antennas 11, the vehicle position acquisition unit 12, the roadside unit position acquisition unit 13, and the beamforming unit 14 may be distributed among multiple devices. Furthermore, the in-vehicle system 20 may include the in-vehicle communication device 10 (first in-vehicle communication device) shown in Figure 1 and other in-vehicle communication devices (second in-vehicle communication device). For example, the other in-vehicle communication device may include an in-vehicle unit for ETC communication that performs wireless communication in a second frequency band.

[0025] Figure 3 shows examples of communication methods according to several embodiments. For example, communication methods according to some embodiments are performed by the in-vehicle communication device 10 in Figure 1 and the in-vehicle system 20 in Figure 2.

[0026] In the example shown in Figure 3, the vehicle position acquisition unit 12 acquires the position information of the vehicle equipped with the in-vehicle communication device 10 (S11). For example, the vehicle position acquisition unit 12 may acquire the vehicle's position information using GNSS or the like.

[0027] Next, the roadside unit position acquisition unit 13 acquires the position information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band (S12). For example, the roadside unit position acquisition unit 13 may acquire the position information of a roadside unit from a database that stores information on roadside units.

[0028] Next, the beamforming unit 14 performs beamforming to form a null in the direction of the roadside unit using multiple antennas 11, based on the acquired vehicle position information and the acquired roadside unit position information (S13). For example, the beamforming unit 14 may perform beamforming to form a null in the direction of the roadside unit using multiple antennas 11 when the distance between the vehicle and the roadside unit falls below a predetermined value.

[0029] As described above, in this embodiment, beamforming is performed using multiple antennas to form a null in the direction of the roadside unit, based on the vehicle's position information and the roadside unit's position information. For example, when the distance between the vehicle and the roadside unit falls below a predetermined value, beamforming is performed using multiple antennas to form a null in the direction of the roadside unit. This makes it possible to continue communication using the first frequency band as much as possible while suppressing interference with the second frequency band used by the roadside unit.

[0030] (Embodiment 2) Next, Embodiment 2 will be described. In this embodiment, a specific example of Embodiment 1 will be described.

[0031] Figure 4 shows an example configuration of vehicle 1 according to several embodiments. In the example in Figure 4, vehicle 1 (in-vehicle system) is equipped with a V2X in-vehicle unit 100 and an ETC in-vehicle unit 200.

[0032] The V2X in-vehicle unit 100 is an in-vehicle communication device that performs V2X communication. V2X communication uses the 5.9 GHz band for wireless communication. V2X includes V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure), etc. For example, the V2X in-vehicle unit 100 performs wireless communication (vehicle-to-vehicle communication) with other vehicles (in-vehicle units) that are capable of V2X communication, and also performs wireless communication (vehicle-to-infrastructure communication) with roadside units such as ITS spots that are capable of V2X communication. For example, in V2X communication, information related to vehicle driving assistance and cooperative autonomous driving is transmitted and received. As vehicle-related information, information such as the vehicle's position, speed, direction, accelerator operation status, and the distance between vehicles required for lane changes is transmitted and received. As infrastructure (traffic)-related information, information such as road congestion and construction, priority / non-priority lane information, and intersection and traffic light information is transmitted and received. To send and receive this information, V2X communication involves the transmission and reception of wireless signals (radio waves) between vehicles and between vehicles and roadside units, etc. In other words, the V2X onboard unit 100 transmits 5.9 GHz band radio waves to the surroundings as needed while driving, and also receives 5.9 GHz band radio waves from the surroundings.

[0033] The ETC onboard unit 200 is an onboard communication device that performs ETC communication. ETC communication uses the 5.8 GHz band for wireless communication. The DSRC communication method is used for ETC communication. For example, the ETC onboard unit 200 performs wireless communication (vehicle-to-infrastructure communication) with roadside units such as ETC gates and ITS spots that are capable of ETC communication. For example, an ETC gate transmits information related to highway tolls and payment. An ITS spot transmits information related to infrastructure in the same way as above. In order to send and receive this information, ETC communication transmits wireless signals (radio waves) from ETC gates and ITS spots to vehicles. In other words, the ETC onboard unit 200 is near ETC gates and ITS spots and receives radio waves in the 5.8 GHz band from ETC gates and ITS spots.

[0034] Furthermore, Vehicle 1 is equipped with a V2X antenna 101 for V2X communication. It can also be said that the V2X onboard unit 100 is equipped with the V2X antenna 101. The V2X antenna 101 is a phased array antenna that transmits and receives radio signals (radio waves) for V2X. For example, in order to perform V2X communication in all 360 degrees from Vehicle 1, multiple V2X antennas 101 are arranged on the roof of Vehicle 1. In this example, the V2X antennas 101 are arranged in a ring shape at half-wavelength (approximately 25 mm) intervals of the wavelength (approximately 50 mm) of the operating frequency (5.9 GHz).

[0035] Vehicle 1 is also equipped with an ETC antenna (not shown) for ETC communication. For example, the ETC antenna is placed on the windshield or dashboard of Vehicle 1 to communicate with ETC gates, etc., facing forward.

[0036] Figure 5 shows an example configuration of a V2X in-vehicle unit 100 according to several embodiments. In the example in Figure 5, the V2X in-vehicle unit 100 includes a plurality of V2X antennas 101, a plurality of phase shifters 110, a V2X transceiver 120, a GNSS antenna 131, a GNSS receiver 130, a database of coordinates to be avoided for interference 140, a navigation system for coordinates to be avoided for interference 150, and an antenna control unit 160. Note that the configuration of the V2X in-vehicle unit 100 in Figure 5 is just one example, and other configurations are also possible. For example, the database of coordinates to be avoided for interference 140 may be an external storage device. The navigation system for coordinates to be avoided for interference 150 may be an external navigation device or information processing device.

[0037] The phase shifter 110 is a variable phase shifter that changes the phase of the V2X antenna 101 in response to control from the antenna control unit 160. By changing the phase of multiple antennas V2X 101 using multiple phase shifters 110, a beam with a desired beam pattern can be formed (beamforming).

[0038] The V2X transceiver 120 performs V2X communication via the phase shifter 110 and the V2X antenna 101. The V2X transceiver 120 transmits and receives V2X messages, including vehicle-related information, to and from other vehicles and roadside units, etc., via the phase shifter 110 and the V2X antenna 101.

[0039] The GNSS receiver 130 is a vehicle position acquisition unit that acquires the position (self-position) coordinates of the vehicle 1 using GNSS. The GNSS receiver 130 acquires the position coordinates (latitude and longitude) of the vehicle 1 based on signals received from GNSS satellites via the GNSS antenna 131. The GNSS receiver 130 may also acquire position coordinates based on signals received from GPS (Global Positioning System) or other positioning systems.

[0040] The Interference Avoidance Target Coordinate Database 140 is a database that stores the position coordinates of the objects to be avoided. In this example, the objects to be avoided are ETC gates and ITS spots that perform ETC communication. The Interference Avoidance Target Coordinate Database 140 also functions as an Interference Avoidance Target (Roadside Unit) Position Acquisition Unit that acquires the position coordinates of the objects to be avoided.

[0041] FIG. 6 shows a specific example of the interference-affecting avoidance target coordinate database 140. In the example of FIG. 6, the interference-affecting avoidance target coordinate database 140 stores position coordinates (latitude and longitude) and an interference-affecting distance for each ETC gate that is an interference-affecting avoidance target. The interference-affecting distance indicates the distance (range) that interferes with V2X communication from the position coordinates of the ETC gate.

[0042] For example, before passing through an ETC gate, the position coordinates and interference-affecting distance of the ETC gate may be downloaded from an external server via the Internet or the like, and stored in the interference-affecting avoidance target coordinate database 140. The position coordinates and interference-affecting distance of the ETC gate may be downloaded and updated periodically. Note that the communication means for downloading is not limited. V2X communication may be used, or mobile phone communication, wireless LAN communication, or the like may be used. The interference-affecting avoidance target coordinate navigation 150 may acquire information on ETC gates together with map information. A user may input information on ETC gates.

[0043] The interference-affecting distance may be a predetermined distance, or may be a distance calculated from the position of the ETC gate. In this case, only the position coordinates of the ETC gate may be downloaded. Since the interference-affecting distance varies depending on the surrounding environment (such as walls or structures on the side of the road), a margin that takes into account fluctuations due to the environment may be included. For example, information on the surrounding environment may be acquired, and the interference-affecting distance may be calculated based on the surrounding environment.

[0044] The interference-affecting avoidance target coordinate navigation 150 is navigation for navigating a travel route of the vehicle 1. The interference-affecting avoidance target coordinate navigation 150 navigates a road scheduled to be traveled to specify the travel route of the vehicle 1. Further, the interference-affecting avoidance target coordinate navigation 150 specifies an interference-affecting range based on the navigated travel route.

[0045] Figure 7 shows an example of identifying the interference range. For example, the interference avoidance target coordinate navigation 150 identifies the location (latitude and longitude) of the edge of the interference range on the vehicle 1's travel path from the position coordinates and interference distance of the ETC gate (interference avoidance target) stored in the interference avoidance target coordinate database 140. For example, the edge of the interference range may be a predetermined position where the interference avoidance operation is to be started.

[0046] The antenna control unit 160 controls the phases of multiple phase shifters 110 and controls the beam patterns of multiple V2X antennas 101. The antenna control unit 160 is a beamforming unit that forms a beam pattern using multiple V2X antennas 101. The antenna control unit 160 performs interference avoidance operations by controlling the beam pattern formed by beamforming.

[0047] The antenna control unit 160 obtains the position coordinates of the vehicle 1 from the GNSS receiver 130 and the position coordinates and interference distance of the interference avoidance target from the interference avoidance target coordinate database 140, and controls the beam pattern of the V2X antenna 101. Figure 8 shows an example of beam pattern control. For example, as shown in Figure 8, when the vehicle 1 is within a certain distance from the interference avoidance target, the antenna control unit 160 controls multiple phase shifters 110 to direct the null in the direction of the interference avoidance target (ETC gate) in the 5.9 GHz band beam pattern, and performs beamforming. This suppresses interference to the 5.8 GHz band of ETC communication in the direction of the ETC gate, while maintaining V2X communication in other directions. For example, when the vehicle 1 approaches the ETC gate and the ETC gate is in front of the vehicle 1, beamforming is performed to direct the null forward, and V2X communication is maintained in directions other than forward. When vehicle 1 passes through an ETC gate and the ETC gate is behind vehicle 1, beamforming is performed with the null pointing towards the rear, and V2X communication is maintained in directions other than the rear.

[0048] FIG. 9 shows an operation example of the V2X on-board device 100 according to some embodiments. In the example of FIG. 9, first, the V2X on-board device 100 acquires its own position (S101). A GNSS receiver 130 acquires the position coordinates of a vehicle 1 by GNSS, and outputs the acquired position coordinates to an antenna control unit 160.

[0049] Subsequently, the V2X on-board device 100 calculates the distance and azimuth to an interference avoidance target (S102). The antenna control unit 160 acquires the position coordinates and interference distance of an interference avoidance target such as an ETC gate from an interference avoidance target coordinate database 140. The antenna control unit 160 calculates the distance and azimuth to the interference avoidance target from the self-position coordinates acquired from the GNSS receiver 130 and the position coordinates of the interference avoidance target acquired from the interference avoidance target coordinate database 140.

[0050] Subsequently, the V2X on-board device 100 determines whether the distance to the interference avoidance target is within a predetermined range (S103), and if the distance is within the predetermined range, performs beamforming to direct a null to the interference avoidance target (S104). The antenna control unit 160 determines whether the calculated distance to the interference avoidance target is within the predetermined range. The predetermined distance may be the interference distance of the interference avoidance target acquired from the interference avoidance target coordinate database 140. When the distance to the interference avoidance target falls within the predetermined range, the antenna control unit 160 controls the phases of a plurality of phase shifters 110 so as to direct a null in the calculated direction of the interference avoidance target. It may also be determined whether the vehicle has approached the end position of the interference range specified by interference avoidance target coordinate navigation 150. When the position of the vehicle enters the interference range from the end position of the interference range, the phases of the plurality of phase shifters 110 may be controlled to direct a null in the direction of the interference avoidance target.

[0051] For example, the beam pattern may be changed according to the distance to the interference avoidance target. A plurality of beam patterns having different null directions and levels for different distances to the interference avoidance target may be prepared in advance, and the beam pattern may be changed stepwise according to the distance to the interference avoidance target. For example, the null level may be decreased as the vehicle approaches the interference avoidance target, and increased as the vehicle moves away from the interference avoidance target.

[0052] Figure 10 shows an overview and effects of several embodiments. In this embodiment, by utilizing a fade array antenna and performing beamforming to form a null in the direction of the object to be avoided, such as an ETC gate, it is possible to achieve both interference avoidance and communication. That is, in order to avoid interference from the 5.9 GHz band for V2X communication to the 5.8 GHz band for ETC communication, a null is formed in the direction of the ETC gate when the distance to the ETC gate is within a predetermined range. This makes it possible to maintain V2X communication as much as possible while avoiding interference with ETC communication. For example, as shown in Figure 10, if the ETC gate is ahead, by forming a null in front, automatic information distribution to following vehicles using V2X communication can be continued.

[0053] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its spirit.

[0054] Each configuration in the above-described embodiment may consist of hardware, software, or both, and may consist of one piece of hardware or software, or multiple pieces of hardware or software. Each device and each function (process) such as an in-vehicle communication device (in-vehicle unit) may be realized by a computer 30 having a processor 31 such as a CPU (Central Processing Unit) and a memory 32 which is a storage device, as shown in Figure 11. For example, a program for performing the method (communication method) in the embodiment may be stored in the memory 32, and each function may be realized by executing the program stored in the memory 32 with the processor 31.

[0055] These programs, when loaded into a computer, include a set of instructions (or software code) for causing the computer to perform one or more of the functions described in the embodiments. The programs may be stored on non-temporary computer-readable media or tangible storage media. Examples, but not limited to, include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drives (SSDs), or other memory technologies, CD-ROMs, digital versatile discs (DVDs), Blu-ray® discs, or other optical disc storage, magnetic cassettes, magnetic tapes, magnetic disk storage, or other magnetic storage devices. The programs may be transmitted over temporary computer-readable media or communication media. Examples, but not limited to, include electrical, optical, acoustic, or other forms of propagating signals.

[0056] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0057] Each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated with one or more other embodiments, rather than being associated with only one specific embodiment. As those skilled in the art will understand, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings, for example, to create embodiments not explicitly shown or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps described in any of the drawings may be changed as appropriate.

[0058] Some or all of the above embodiments may also be described as follows, but are not limited to the following:

[0059] (Note 1) An in-vehicle communication device mounted on a vehicle, comprising: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring the location information of the vehicle; a roadside unit position acquisition means for acquiring the location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means that performs beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information. (Note 2) The in-vehicle communication device according to Note 1, wherein the beamforming means performs beamforming to form a null in the direction of the roadside unit when the distance between the vehicle and the roadside unit becomes less than or equal to a predetermined value, based on the vehicle position information and the roadside unit position information. (Note 3) The in-vehicle communication device according to Note 1 or 2, comprising a database for storing the location information of the roadside unit, wherein the roadside unit position acquisition means acquires the location information of the roadside unit from the database. (Note 4) The in-vehicle communication device according to Note 3, wherein the database stores the position information and interference distance of the roadside unit, and the beamforming means performs beamforming to form a null in the direction of the roadside unit when the distance between the vehicle and the roadside unit becomes less than or equal to the interference distance. (Note 5) The in-vehicle communication device according to Note 4, comprising navigation means for navigating the vehicle's travel path, wherein the beamforming means identifies the edge position of the interference range based on the interference distance and the travel path, and performs beamforming to form a null in the direction of the roadside unit when the vehicle's position approaches the roadside unit from the edge position of the interference range. (Note 6) The in-vehicle communication device according to Note 1 or 2, comprising a plurality of phase shifters for adjusting the phases of the plurality of antennas, wherein the beamforming means performs beamforming to form a null in the direction of the roadside unit by controlling the phases of the plurality of phase shifters. (Note 7) The in-vehicle communication device as described in Note 6, wherein the plurality of antennas are phase-adjustable phased array antennas.(Note 8) The in-vehicle communication device according to Note 7, wherein the multiple antennas are arranged in a ring shape at intervals of half the wavelength of the first frequency band. (Note 9) The in-vehicle communication device according to Note 1 or 2, wherein the first frequency band is a 5.9 GHz frequency band for V2X communication, and the second frequency band is a 5.8 GHz frequency band for ETC communication. (Note 10) The in-vehicle communication device according to Note 9, wherein the roadside unit is an ETC gate or an ITS spot. (Note 11) An in-vehicle system comprising: a first in-vehicle communication device mounted on a vehicle, wherein the first in-vehicle communication device comprises: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring the location information of the vehicle; a roadside unit position acquisition means for acquiring the location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means for performing beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information. (Note 12) The in-vehicle system according to Note 11, further comprising: a second in-vehicle communication device that performs wireless communication with the roadside unit in the second frequency band. (Note 13) A communication method for an in-vehicle communication device mounted on a vehicle, comprising: performing wireless communication in a first frequency band using a plurality of antennas; acquiring location information of the vehicle; acquiring location information of a roadside unit performing wireless communication in a second frequency band adjacent to the first frequency band; and performing beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit. (Note 14) A program for causing a computer to execute a communication method for an in-vehicle communication device mounted on a vehicle, comprising: performing wireless communication in a first frequency band using a plurality of antennas; acquiring location information of the vehicle; acquiring location information of a roadside unit performing wireless communication in a second frequency band adjacent to the first frequency band; and performing beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit.

[0060] Some or all of the elements (e.g., configuration and function) described in Appendices 2 to 10 that are subordinate to Appendice 1 (In-vehicle communication device) may also be subordinate to Appendice 11 (In-vehicle system), Appendice 13 (Communication method), and Appendice 14 (Program) in the same way as Appendices 2 to 10. Some or all of the elements described in any appendice may be applied to various hardware, software, recording means, systems, and methods for recording software.

[0061] 1 Vehicle 10 In-vehicle communication device 11 Antenna 12 Vehicle position acquisition unit 13 Roadside unit position acquisition unit 14 Beamforming unit 20 In-vehicle system 30 Computer 31 Processor 32 Memory 100 V2X in-vehicle unit 101 V2X antenna 110 Phase shifter 120 V2X transceiver 130 GNSS receiver 131 GNSS antenna 140 Interference avoidance target coordinate database 150 Interference avoidance target coordinate navigation 160 Antenna control unit 200 ETC in-vehicle unit

Claims

1. An in-vehicle communication device mounted on a vehicle, comprising: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring the location information of the vehicle; a roadside unit position acquisition means for acquiring the location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means that performs beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information.

2. The in-vehicle communication device according to claim 1, wherein the beamforming means performs beamforming to form a null in the direction of the roadside unit when the distance between the vehicle and the roadside unit becomes less than or equal to a predetermined value, based on the position information of the vehicle and the position information of the roadside unit.

3. The in-vehicle communication device according to claim 1 or 2, comprising a database for storing the location information of the roadside unit, wherein the roadside unit location acquisition means acquires the location information of the roadside unit from the database.

4. The in-vehicle communication device according to claim 3, wherein the database stores the position information and interference distance of the roadside unit, and the beamforming means performs beamforming to form a null in the direction of the roadside unit when the distance between the vehicle and the roadside unit becomes less than or equal to the interference distance.

5. An in-vehicle communication device according to claim 4, comprising navigation means for navigating the vehicle's travel path, wherein the beamforming means identifies the edge position of the interference range based on the interference distance and the travel path, and performs beamforming to form a null in the direction of the roadside unit when the vehicle's position is closer to the roadside unit than the edge position of the interference range.

6. An in-vehicle communication device according to claim 1 or 2, comprising a plurality of phase shifters for adjusting the phases of the plurality of antennas, wherein the beamforming means performs beamforming to form a null in the direction of the roadside unit by controlling the phases of the plurality of phase shifters.

7. The in-vehicle communication device according to claim 6, wherein the plurality of antennas are phase-adjustable phased array antennas.

8. The in-vehicle communication device according to claim 7, wherein the plurality of antennas are arranged in a ring shape at intervals of half the wavelength of the first frequency band.

9. The in-vehicle communication device according to claim 1 or 2, wherein the first frequency band is a 5.9 GHz frequency band for V2X communication, and the second frequency band is a 5.8 GHz frequency band for ETC communication.

10. The in-vehicle communication device according to claim 9, wherein the roadside unit is an ETC gate or an ITS spot.

11. An in-vehicle system comprising: a first in-vehicle communication device mounted on a vehicle, the first in-vehicle communication device comprising: a plurality of antennas that perform wireless communication in a first frequency band; a vehicle position acquisition means for acquiring the location information of the vehicle; a roadside unit position acquisition means for acquiring the location information of a roadside unit that performs wireless communication in a second frequency band adjacent to the first frequency band; and a beamforming means that performs beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired vehicle position information and the acquired roadside unit position information.

12. The in-vehicle system according to claim 11, further comprising a second in-vehicle communication device that performs wireless communication with the roadside unit in the second frequency band.

13. A communication method for an in-vehicle communication device mounted on a vehicle, comprising: performing wireless communication in a first frequency band using a plurality of antennas; acquiring location information of the vehicle; acquiring location information of a roadside unit performing wireless communication in a second frequency band adjacent to the first frequency band; and performing beamforming using the plurality of antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit.

14. A program for causing a computer to execute a communication method in an in-vehicle communication device mounted on a vehicle, comprising: performing wireless communication in a first frequency band using multiple antennas; acquiring location information of the vehicle; acquiring location information of a roadside unit performing wireless communication in a second frequency band adjacent to the first frequency band; and performing beamforming using the multiple antennas to form a null in the direction of the roadside unit based on the acquired location information of the vehicle and the acquired location information of the roadside unit.

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