JPH0856182A - Mobile communication equipment using leakage coaxial cable, its system and method - Google Patents

Abstract

PURPOSE:To detect the position of a mobile body and its progress direction regardless of using a quasi-microwave leakage coaxial cable. CONSTITUTION:A slot array is provided in a leakage coaxial cable provided to an upper/lower stream of a radio equipment 1 over a small range of nearly + or -30 to 50m in the vicinity of the radio equipment 1. A noninverting unidirectional communication area 6 and inverted unidirectional communication area 7 are formed by applying amplitude modulation to a signal fed to the upper/lower stream of the radio equipment 1 in the noninverting and the inverting signal and the position and the progress direction of a mobile body moved on a lane are detected by the detection of the inversion. No slot array is provided for + or -nearly 200m in the forward direction. Moreover, a slot array is provided over a range of + or -nearly 200m in the forward direction to form a 2-way communication area 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication device, system and method using a leaky coaxial cable.

[0002]

2. Description of the Related Art As a road-vehicle information communication system, a system called VICS has recently attracted attention. In this system, as shown in FIG. 4, a beacon station composed of the wireless device 1 and the antenna device 10 is used.
It is located on the roadside as shown in.

The radio 1 further amplitude-modulates a signal modulated (mainly modulated) by a predetermined modulation method and transmits it from the antenna device 10 to the upstream and downstream of the lane. Antenna system 10
Is an antenna 11 that points either upstream or downstream, as shown in FIG. 6, and an antenna 1 that points in the opposite direction to the antenna 11.
2 and. The transmission signal supplied from the radio device 1 to the antenna 11 and the transmission signal supplied to the antenna 12 are amplitude-modulated by modulation signals whose phases are opposite to each other. Therefore, as shown in FIG. 5, a region 6 in which a signal amplitude-modulated by a positive-phase modulation signal is transmitted and a region 7 in which a signal amplitude-modulated by a negative-phase modulation signal is transmitted are It is formed upstream and downstream when viewed from 1. Areas 6 and 7 are about 30 m upstream and downstream when viewed from the radio 1.

In VICS, area 8 including areas 6 and 7 is a one-way communication area. That is, the radio 1
Is information to be provided to the vehicle side, for example, the self (radio device 1)
The information that supports the operation of the vehicle, such as the information indicating the location of the vehicle and the information indicating the congestion status of the road, is transmitted. Since the beacon stations are intermittently arranged as shown in FIG. 7, in the VICS, information cannot be transmitted / received at an arbitrary point, that is, the vehicle side cannot always continuously receive the information service.

In VICS, the vehicle is itself (vehicle)
You can know the position and direction of travel. That is, on the side of the vehicle traveling in the lane, it is detected whether the vehicle is now upstream or downstream of the beacon station, depending on whether the modulation phase of the amplitude modulation of the signal transmitted from the beacon station is positive or negative.
Further, this vehicle detects that it has arrived directly below the beacon station by detecting the inversion of the modulation phase of the received signal. Further, it detects its own traveling direction depending on whether the modulation phase changes from the positive phase to the negative phase or from the negative phase to the positive phase.

As mentioned above, one of the drawbacks of VICS is that
This means that only intermittent information services can be provided. In order to make up for such drawbacks, a quasi-microwave band communication system using a leaky coaxial cable which has been conventionally used in train communication or the like has been studied. That is, as shown in FIG. 8, a leaky coaxial cable 13 having a length of about 250 m is laid along the lane as shown in FIG. The leaky coaxial cable 13 is a cable capable of transmitting and receiving a signal to and from a vehicle moving body on a lane via a slot row (row of a wireless signal leaking section) formed on the surface thereof, and one end thereof is terminated by a terminator 5. ing. A leaky coaxial cable station adopting such a configuration is shown in FIG.
They are arranged without any gap as shown in. Since the communication area to be realized is continuous, the vehicle side can receive the information service at any point. Bidirectional communication is possible in the communication area 9 formed in this system. In the configuration of FIG. 8, the length of the leaky coaxial cable 13 is set to about 250 m on one side, which is shorter than that in the case of train communication, because the quasi-microwave band is used, so that the amount of attenuation increases.

[0007]

As described above, the system using the leaky coaxial cable has an advantage of enabling continuous information service, but on the other hand, VICS
However, there is a problem in that it is impossible to detect the position of the moving body and the direction of travel of the moving body. That is, since the communication area formed by the leaky coaxial cable essentially has a linear spread, even if the transmission signal is amplitude-modulated in both forward and reverse phases, the inversion of the amplitude modulation phase is detected. Is difficult. When using the quasi-microwave band,
This detection becomes more difficult due to the effects of fading and the like. When the quasi-microwave band is used, in addition, the amount of attenuation mentioned above becomes large, and the limitation of the length of the leaky coaxial cable becomes a problem.

[0008] The present invention has been made to solve the above problems, and improves the way of providing slot arrays in a leaky coaxial cable to realize an almost continuous information service. , The position of a moving body and the direction of travel can be detected. Another object of the present invention is to alleviate the length limitation of the leaky coaxial cable.

[0009]

In order to achieve such an object, a mobile communication device of the present invention has a slot row for transmitting and receiving radio signals, and is provided upstream and downstream along a route along which a mobile travels. A leaky coaxial cable arranged over the leaky coaxial cable; and a wireless device that transmits a signal to the mobile body via the leaky coaxial cable and receives a signal from the mobile body via the leaky coaxial cable. A signal that is amplitude-modulated with a modulation signal having a different phase is transmitted to the downstream side, and slot rows are formed at a position close to the wireless device on both upstream and downstream sides of the wireless device and a position remote from the wireless device. It is characterized by

A mobile communication system of the present invention is characterized in that a plurality of mobile communication devices of the present invention are arranged at predetermined intervals along the path.

According to the mobile communication method of the present invention, the amplitudes of the modulation signals of different phases are detected so that the mobile body traveling on the predetermined route can recognize the modulation phase of the received signal and detect its own position and traveling direction. The modulated signal is transmitted through a slot row located close to the radio on the upstream and downstream sides of the radio, and through a slot row remote from the radio.
It is characterized by transmitting and receiving a signal to and from a moving body traveling on the above route.

[0012]

According to the present invention, the slot array of the leaky coaxial cable is formed at the position close to the wireless device on both the upstream and downstream sides of the wireless device and at the position remote from the wireless device. Among these slot arrays, the slot array provided in the position close to the wireless device forms a communication area having a spread similar to that of the VICS beacon station, that is, a spread near a point. In the present invention, the signal transmitted from the wireless device to the upstream and downstream sides is a signal that is amplitude-modulated by modulation signals of different phases, so the position and traveling direction of the moving body can be detected by the same principle as VICS. It will be possible. Further, since the communication area having the same spread as that of the conventional leaky coaxial cable can be formed by using the slot array provided at the position remote from the radio device, continuous information service can be realized in this communication area. Furthermore, by providing a portion without a slot row between the slot row close to the radio and the slot row remote from the radio, the leakage loss is reduced and the attenuation of the leaky coaxial cable is reduced. Length restrictions are relaxed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. The same components as those in the conventional example shown in FIGS. 4 to 10 are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows the configuration of a leaky coaxial cable station according to an embodiment of the present invention. As shown in this figure, in this embodiment, about 30 to 50 upstream and downstream of the wireless device 1 are provided.
A slot row is provided in the leaky coaxial cable 2 in the range of m, a slot row is not provided in the leaky coaxial cable 3 in the range of about 200 m, and a slot is provided in the leaky coaxial cable 4 in the range of about 200 m up to the terminator 5. It has a configuration in which rows are provided. When a station having such a configuration is laid on the road side as shown in FIG. 2, the leaky coaxial cable 2 forms a communication area 8 having the same spread as that of the VICS beacon station,
Conventional leaky coaxial cable 1 by leaky coaxial cable 4
A communication area 9 having the same extent as 3 is formed. In addition, since the wireless device 1 transmits signals that are amplitude-modulated in the upstream and downstream with the modulation phases opposite to each other, in the communication areas 6 and 7 forming the communication area 8, the normal-phase or anti-phase amplitude-modulated signals are transmitted, respectively. It will be received on the vehicle side. Therefore, in this embodiment, the position and the traveling direction of the vehicle can be known on the same principle as VICS. Further, in the communication area 9, bidirectional communication and continuous information service are possible as in the conventional leaky coaxial cable 13.

In this embodiment, the leaky coaxial cable 3 is not provided with a slot row. Therefore, in the leaky coaxial cable 3, loss due to leakage does not occur, so that the coaxial line length from the wireless device 1 to the terminator 5 can be increased. Moreover, since the length of the entire station can be adjusted by adjusting the length of the leaky coaxial cable 3, the degree of freedom in designing and laying is increased. In addition, since the length of the station is increased by the amount of the leaky coaxial cable 3, the number of stations per unit distance is reduced, which is economical.

FIG. 3 shows the system configuration in this embodiment. Although the stations of FIG. 1 may be arranged without a gap as shown in this figure, the VICS shown in FIG.
It is also possible to mix stations and conventional leaky coaxial cable stations shown in FIG. If you do this,
Flexible system design is possible.

[0017]

As described above, according to the present invention,
A slot array of the leaky coaxial cable is formed at a position close to the radio on both upstream and downstream sides of the radio and a position remote from the radio, and a signal amplitude-modulated with a modulation signal of a different phase is transmitted to the radio. Since it was sent from upstream to downstream,
It becomes possible to detect the position and the traveling direction of the moving body by using the slot row provided in the position close to the wireless device. Further, it is possible to realize a substantially continuous information service by using a slot array provided at a position remote from the wireless device. Further, since a portion without a slot row is provided between the slot row close to the radio equipment and the slot row remote from the radio equipment, the attenuation amount of the leaky coaxial cable can be reduced and the length limitation can be relaxed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a quasi-microwave band leaky coaxial cable station according to an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of a bidirectional communication area and a unidirectional communication area in the quasi-microwave band leaky coaxial cable station of the embodiment.

FIG. 3 is a diagram showing an arrangement of quasi-microwave band leaky coaxial cable stations in a system using this embodiment.

FIG. 4 is a diagram showing a configuration of a beacon station in VICS.

FIG. 5 is a diagram showing an arrangement of one-way communication areas in VICS.

FIG. 6 is a diagram showing an antenna arrangement of beacon stations in VICS.

FIG. 7 is a diagram showing an arrangement of beacon stations in VICS.

FIG. 8 is a diagram showing a configuration of a conventional quasi-microwave band leaky coaxial cable station.

FIG. 9 is a diagram showing an arrangement of bidirectional communication areas in a conventional quasi-microwave band leaky coaxial cable station.

FIG. 10 is a diagram showing an arrangement of a conventional quasi-microwave band leaky coaxial cable station.

[Explanation of symbols]

 1 Radio Equipment 2 Leaky Coaxial Cable with Slot Lines in Short Range 3 Leaky Coaxial Cable without Slot Lines 4 Leaky Coaxial Cable with Slot Lines in Long Range 5 Terminator 6 One-way Communication Area (Positive Phase) 7 Pieces Directional communication area (reverse phase) 8 Unidirectional communication area 9 Bidirectional communication area

Claims (3)

[Claims] 1. A leaky coaxial cable having a slot row for transmitting and receiving radio signals and arranged upstream and downstream along a route along which a mobile body travels, and a signal is transmitted to the mobile body via the leaky coaxial cable. In a mobile communication device including a wireless device that receives a signal from a mobile object via a leaky coaxial cable, the wireless device transmits signals that are amplitude-modulated with modulation signals of different phases for upstream and downstream, A mobile communication device, wherein a slot row is formed at a position close to the wireless device on both the upstream and downstream sides of the wireless device and a position remote from the wireless device. 2. A mobile communication system, wherein a plurality of mobile communication devices according to claim 1 are arranged at predetermined intervals along the path. 3. A wireless device for transmitting a signal amplitude-modulated with a modulation signal having a different phase so that a moving body traveling on a predetermined route can recognize the modulation phase of a received signal and detect its own position and traveling direction. Upstream and downstream, through a row of slots located close to the radio, and through a row of slots remote from the radio to send and receive signals to and from mobile units traveling on the above routes. A mobile communication method characterized by: