JPH07154320A - Mobile communication system - Google Patents

Abstract

PURPOSE:To arbitrarily set the beam width of a radio wave corresponding to the wideness of a dead zone as well as the simplification of an equipment for repetition and the reduction of cost by using a simplified curved reflection board as a repeater. CONSTITUTION:The radio wave from a base station 1 is reflected to a dead zone 3 by a curved reflection board 2. At such a time, since the reflection board 2 is provided with curved structure, the direction of the reflected wave is not fixed but the wave is reflected over the range of certain beam width. In this case, when enlarging a transmission gain and a reception gain due to the reflection board 2, since the gain is proportional to the valid area of the reflection board 2, the gain can be enlarged by enlarging a curvature radius or the length of the reflection board 2 in the longitudinal direction.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to mobile communication systems.

[0002]

2. Description of the Related Art In a conventional mobile communication system, as shown in FIG. 3, a radio base station facing antenna 8 is provided as a repeater arranged between a radio base station 1 and a dead zone 3 on radio waves. It has a relay transmitter / receiver 9 and an omni or sector antenna 10 for facing a blind area.

[0003]

This conventional mobile communication system requires a device using an active element for a repeater. Therefore, in addition to the main body of the repeater, a power supply device, a monitoring system for detecting a failure of the relay device, etc. Ancillary equipment will also be installed. Therefore, there were problems such as securing the installation location of the repeater equipment and problems with the power supply method. In addition, when the scale of repeater equipment becomes large, especially when the area size of the blind area where the wireless relay system is intended to be used is small (that is, the number of subscribers in the area is small), the capital investment ratio per subscriber is small. There is also the problem of getting bigger.

It is an object of the present invention to provide a mobile communication system in which the relay device is simplified and therefore the cost can be reduced.

[0005]

In the mobile communication system of the present invention, since the service area is a blind area on which the radio wave from the radio base station does not reach, the angle formed by both ends in the curvature direction is the blind area. Wireless relay is performed using a curved reflector having a curved structure that is half or more than the beam width of the reflected wave that covers an area.

[0006]

In order to solve the above-mentioned problems, the present invention uses a reflector which does not include an active element in the repeater. However, since the flat reflector used in the conventional wireless relay system between fixed stations has a narrow beam width of reflected waves, it is not so effective when a wide beam width of radio waves is required as in a mobile communication system. Absent. Therefore, in the present invention, the curved reflector is used for the repeater as a means for widening the beam width of the reflected wave.

FIG. 2 is a structural diagram of a curved reflector used in the present invention. In FIG. 2, the angle between the incident wave 4 and the reflected wave 5 on the curved reflecting plate 2 is θ _1, and the angle between the incident wave 6 and the reflected wave 7 is θ ₂ . In this case, the beam width of the reflected wave | θ ₂ -θ ₁ | become. If the angle between both ends of the curved reflector 2 is θ ₃ , then θ ₃ = θ ₂ * 1 /
The relational expression of 2-θ ₁ * 1/2 = (θ ₂ −θ ₁ ) / 2 holds. That is, θ ₂ − which is the beam width of the reflected wave
If θ ₁ is determined, it will be understood that the angle between both ends of the curved reflector 2 should be at least half the beam width.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a relay system diagram of a mobile communication system according to an embodiment of the present invention.

Radio waves from the radio base station 1 are radiated to the dead zone 3 by the curved reflector 2. At this time, since the reflection plate has a curved structure, the reflected wave is emitted not in a fixed direction but in a certain beam width range. This beam width is
As shown in, it is determined by the structure of the curved reflector 2.

When the transmission gain and the reception gain of the curved reflector 2 are increased, the gain is proportional to the effective area of the reflector. Therefore, the radius of curvature R or the length of the curved reflector 2 in the vertical direction should be increased. Can be realized by Further, when the reflector is too large in the one-piece structure, it is possible to join conventional flat reflectors having a small area to form a large curved reflector.

[0012]

As described above, according to the present invention, since a simple curved reflector is used as a repeater, it is possible to simplify the repeater device and reduce the cost, and it is important in a mobile communication system. Therefore, it is possible to radiate radio waves to a wide area.

[Brief description of drawings]

FIG. 1 is a relay system diagram of a mobile communication system according to an embodiment of the present invention.

FIG. 2 is a structural diagram of a curved reflector according to the present invention.

FIG. 3 is a diagram showing an example of a conventional mobile communication system relay system.

[Explanation of symbols]

1 Radio Base Station 2 Curved Reflector 3 Dead Area 4, 6 Incident Wave 5, 7 Reflected Wave θ ₁ , θ ₂ , θ ₃ Angle

Claims (2)

[Claims] 1. In a mobile communication system, in order to set a dead area on a radio wave that a radio wave from a radio base station does not reach as a service area, an angle formed by both ends in a curvature direction is a reflected wave that covers the dead area. A mobile communication system characterized in that wireless relay is performed by using a curved reflector having a curved structure having a beam width of half or more. 2. The mobile communication system according to claim 1, wherein the curved reflector is formed by connecting flat reflectors having a small area.