JP2002237778A - Communication equipment between road side and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that construction and extension of a system is not easy since one base station is required for one antenna in communication equipment between a road side and a vehicle. SOLUTION: System construction is facilitated and frequency is efficiently used by preparing two antenna devices for one base station, radiating to an opposite lane back to back and using two antennas with the same frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road-to-vehicle communication device for performing communication between a vehicle-mounted communication device mounted on a vehicle and a roadside communication device provided on a road.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a conventional road-vehicle communication device. In FIG. 5, 1 is an antenna device, 2 is a base station device, 3 is a radio unit, 4 is a control unit, 5 is a central management center,
6 is a vehicle, 7 is a lane. The roadside of the road-to-vehicle communication device includes a centralized management center 5, a base station 2, and an antenna device 1. The base station 2 includes a radio unit 3 and a control unit 4. In the road-vehicle communication system, information from the central control center 5 is transmitted to the control units 4 of the plurality of base stations 2, and information processed by the control unit 4 is modulated by the radio unit 3 and transmitted to the antenna device 1, The signal is transmitted from the antenna device 1 to the on-vehicle communication device mounted on the vehicle 6. Conversely, information transmitted from the vehicle-mounted device mounted on the vehicle 6 is transmitted from the antenna device 1 to the wireless unit 3 and demodulated, and then transmitted to the control unit 4 and processed by the control unit 4. Is transmitted to the central management center 5.

[0003]

In the conventional road-vehicle communication apparatus, one antenna apparatus corresponds to one base station. However, when the number of antennas is increased in order to expand the communication area, the number of base stations must be increased by the same number as the number of antennas, and there is a problem that system expansion is not easy. In particular, a normal road has two or more lanes for two-way traffic, and two or more antennas are required per section in order to secure a communication area corresponding to two lanes.

When the number of base stations increases, the number of frequencies to be used for communication becomes necessary. However, when the usable frequency band is limited, the number of frequencies can be easily increased. However, there is a problem that the number of base stations to be added is limited and the communication area cannot be sufficiently expanded.

[0005] The present invention has been made to solve such a problem, and an object of the present invention is to reduce the number of base stations to be added when the number of antennas is increased to expand a communication area.

[0006]

A road-vehicle communication device according to a first aspect of the present invention communicates with a vehicle-mounted communication device mounted on a vehicle running on a road to provide information to the vehicle-mounted communication device. In a communication device, a radio wave emitting surface providing two communication areas is installed on a road so as to face in opposite directions, and a direction connecting the two communication areas is arranged to be oblique to a traveling direction of a vehicle. , Two antennas communicating with the on-vehicle communication device at the same frequency, and a base station connected to the two antennas and outputting information to be provided to the on-vehicle communication device.

A road-vehicle communication apparatus according to a second aspect of the present invention comprises:
In the invention of the above, the two antennas and the radio wave radiating surface are installed so as to face different directions, and their communication areas are arranged at positions different from the two communication areas,
It is provided with another antenna for communicating with the on-vehicle communication device at the same frequency.

[0008] A road-vehicle communication apparatus according to a third aspect of the present invention comprises:
In the invention, the two antennas sequentially perform time-division communication.

A road-to-vehicle communication device according to a fourth aspect of the present invention specifies a plurality of antennas provided on the road having different communication regions and a communication region provided on the road and irradiated by each of the antennas. And a marker for outputting information to the in-vehicle communication device of the vehicle.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a diagram showing Embodiment 1 of the present invention. In FIG. 1, 1 is an antenna device, 2 is a base station device, 3 is a radio unit, 4 is a control unit, and 5 is a control unit.
Is a central management center, 6 is a vehicle, and 7 is a lane. The roadside of the road-to-vehicle communication device includes a centralized management center 5, a base station 2, and an antenna device 1. The base station 2 includes a radio unit 3 and a control unit 4. The antennas 1a and 1b are directional antennas, and the antennas 1a and 1b are arranged with their respective antenna back surfaces (rear surfaces of radio wave radiation surfaces) facing each other so that the directivity directions of the antennas 1a and 1b are opposite to each other. . At the same time, antenna 1
The antenna is arranged such that the communication area A of the antenna a and the communication area B of the antenna 1b are located in different lanes (lanes opposite to each other) (that is, the direction connecting the communication areas A and B is the traveling direction of the road). Placed at an angle to the camera). As a result, the communication area A and the communication area B do not interfere with each other, and the communication areas of adjacent antennas having different frequencies can be spread and arranged. For example, FIG.
As shown in the figure, the communication area A1 of the antenna 1a having the same frequency
And the communication area B1 of the antenna 1b are arranged in different lanes, and the communication area A2 of the adjacent antenna 11a having a different frequency from the antenna 1a is arranged close to the same lane as the communication area A1. The frequency can be used redundantly (in the communication areas A and B) while suppressing the interference between them, and the communication areas are sufficiently packed and arranged in the lane (for example, the communication areas A1, A2, A3, B1, B2) ,
B3).

In the road-to-vehicle communication system configured as described above, information from the central management center 5 is transmitted to the plurality of base stations 2.
The information processed by the control unit 4 is modulated by the radio unit 3 and transmitted to the antenna devices 1a and 1b. RF signals of the same frequency are transmitted from the radio unit 3 to the antenna devices 1a and 1b. Then, the antenna device 1a
The information of the same frequency is transmitted from the antenna device 1b to the vehicle-mounted communication device mounted on the vehicle 6a running on the lane 7a, and from the antenna device 1b to the vehicle-mounted communication device mounted on the vehicle 6b running on the lane 7b. Information transmitted from the on-vehicle device mounted on the vehicle 6a is transmitted from the antenna device 1a to the wireless unit 3 and demodulated, and then transmitted to the control unit 4. Information transmitted from the in-vehicle device mounted on the vehicle 6b is transmitted from the antenna device 1b to the wireless unit 3, demodulated, and then transmitted to the control unit 4. The information processed by the control unit 4 is transmitted to the central management center 5. Here, the same wireless unit 3 is used for the two antennas 1a and 1b by switching the connection between the wireless unit 3 and the antenna device 1a and the connection between the wireless unit 3 and the antenna device 1b in a time-division manner. And fewer equipment components.

With the above configuration, it is possible to provide a wide communication area with a smaller number of base stations as compared with a conventional configuration in which one base station is assigned to one antenna. Therefore, when constructing a road-to-vehicle communication system that supports driving on a road with poor visibility such as a mountainous area having many curves, it is necessary to install a large number of antennas in accordance with the curvature of the curve. According to this, the number of base stations can be reduced, and the configuration of the system becomes easy. In addition, since the directions of the antennas are opposite to each other, the same frequency can be used without concern for radio wave interference, and the frequency can be used effectively.

Embodiment 2 FIG. FIG. 3 shows a second embodiment of the present invention. In this figure, a diagram in which three lanes intersect is taken as an example. In the road-vehicle communication system, information from the central management center 5 is transmitted to the control units 4 of the plurality of base stations 2.
The information processed by the control unit 4 is modulated by the radio unit 3 and transmitted to the antenna devices 1a, 1b, and 1c as RF signals of the same frequency. Then, the antenna device 1a
From the vehicle-mounted communication device mounted on the vehicle 6a traveling on the lane 7a, from the antenna device 1b to the vehicle-mounted communication device mounted on the vehicle 6b traveling on the lane 7b,
From c, information of the same frequency is transmitted to the on-vehicle communication device mounted on the vehicle 6c running on the lane 7c. Vehicle 6
The information transmitted from the in-vehicle device mounted on a is transmitted from the antenna device 1a to the wireless unit 3 and demodulated.
It is transmitted to the control unit 4. Similarly, information transmitted from the in-vehicle devices mounted on the vehicles 6b and 6c is transmitted from the antenna devices 1b and 1c to the wireless unit 3, demodulated, and then transmitted to the control unit 4. The information processed by the control unit 4 is transmitted to the central management center 5.

[0014] In this way, a single base station can be used instead of the number of antennas and base stations required for the road-vehicle communication at a crossroad. The construction of the device becomes easy. In addition, since the directions in which the antennas are directed are different from each other, the same frequency can be used without fear of radio wave interference, and the frequency can be used effectively.

Embodiment 3 FIG. 4 shows a third embodiment of the present invention. In FIG. 4, 1 to 7 are the same as in FIG. 1, and 8 is a marker. Examples of the marker type include a magnetic marker embedded in a roadside.

Information indicating which antenna illuminates the lane is transmitted from the marker. When the in-vehicle device receives the radio wave from the roadside antenna,
Next, it receives information from the marker and recognizes which antenna is illuminated by the antenna in the lane. The in-vehicle device recognizes which communication area the vehicle is in based on the information from the marker, and can extract information necessary for the own device from information transmitted from the roadside antenna. In particular, the communication area A of the antenna 1a and the communication area B of the antenna 1b perform communication at the same frequency. According to this embodiment, whether the vehicle is traveling in the communication area A, It is possible to recognize whether the vehicle is traveling inside.

[0017] Thus, even when a plurality of antennas are arranged for one base station, it is possible to know which antenna the vehicle-mounted apparatus is in the communication area illuminated by. Necessary information can be extracted from the transmitted information.

[0018]

According to the first and third aspects of the present invention, it is possible to provide a wide communication area with a smaller number of base stations as compared with a conventional configuration in which one base station is assigned to one antenna.

According to the second aspect, in the road-vehicle communication at the intersection, the number of antennas and base stations required for the number of intersections is reduced to one base station.

According to the fourth aspect, even when a plurality of antennas are arranged for one base station, it is possible to determine which antenna the vehicle-mounted device is in the communication area illuminated by. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a road-vehicle communication device according to the present invention;

FIG. 2 is a diagram showing a communication area according to the first embodiment of the road-vehicle communication device according to the present invention;

FIG. 3 is a diagram showing a second embodiment of the road-to-vehicle communication device according to the present invention;

FIG. 4 is a diagram showing a third embodiment of the road-vehicle communication apparatus according to the present invention;

FIG. 5 is a diagram showing a conventional road-vehicle communication device.

[Explanation of symbols]

 1a Antenna device 1b Antenna device 1c Antenna device 2 Base station 3 Radio unit 4 Control unit 5 Central control center 6a Vehicle 6b Vehicle 6c Vehicle 7a Lane 7b Lane 7c Lane 8a Marker 8b Marker

Claims (4)

[Claims] 1. A road-vehicle communication device that communicates with an on-vehicle communication device mounted on a vehicle running on a road and provides information to the on-vehicle communication device has a radio wave radiating surface that provides two communication areas, Two antennas installed on the road so as to face each other, arranged so that the direction connecting the two communication areas is oblique to the traveling direction of the vehicle, and communicating with the vehicle-mounted communication device at the same frequency; A base station connected to the two antennas and outputting information to be provided to the on-vehicle communication device. 2. The two antennas and the radio wave radiating surface are installed so as to face different directions, and their communication areas are arranged at positions different from the two communication areas, and communicate with the vehicle-mounted communication device at the same frequency. The road-to-vehicle communication device according to claim 1, further comprising another antenna for performing communication. 3. The road-to-vehicle communication apparatus according to claim 1, wherein the two antennas perform communication sequentially in a time-division manner. 4. An in-vehicle communication system for a vehicle, comprising: a plurality of antennas provided on a road having different communication areas, and information for specifying communication areas illuminated by the respective antennas provided on the road. A road-to-vehicle communication device comprising: a marker that outputs to the device.