JPH08288901A - Radio communication method - Google Patents

Abstract

PURPOSE: To provide the radio communication method in which high speed radio communication is attained even when an open propagation path is interrupted. CONSTITUTION: In the radio communication method where radio communication is conducted between a base station 2 and at least one terminal station 5, the base station has two kinds of antennas 11, 12, and the 1st antenna 11 has a directivity to form a radio zone around the base station. A reflection means 13 reflecting at least one radio wave is provided in the vicinity of the radio zone, and the 2nd antenna 12 has a sharp directivity in the direction of the reflection means 13, and the terminal station 5 receives radio wave from the 1st and 2nd antennas 11, 12. Furthermore, the reflection means 13 installed in the vicinity of the radio zone is a reflection means whose mirror surface is corrected to form a radio zone the directivity of which formed by the reflection means 13 and the 2nd antenna is nearly in matching with that of the radio zone by the 1st antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high-speed wireless communication using a radio wave in the quasi-millimeter wave band or the millimeter wave band at a transmission rate of more than 10 Mbps, and the line-of-sight propagation path is blocked by a shield such as a person or a car. The present invention also relates to a wireless communication means that enables communication even in the case of a failure.

[0002]

2. Description of the Related Art FIGS. 7A and 7B show an example of conventional wireless communication means.

1 is a base station antenna, 2 is a base station, 3 is a wireless zone, 4 is a terminal station antenna, 5 is a terminal station, 6 is a user, 7 is a line of sight, 8 is a building, and 9 is a shield. It is a thing.

In FIG. 1A, a line-of-sight propagation path (7) is obtained between the base station antenna (1) and the terminal station antenna (4) outdoors, and the base station (2) and the terminal station are shown. (4)
It shows a state in which wireless communication is possible with.

However, in FIG. 7B, the line of sight (7) between the base station antenna (1) and the terminal station antenna (4) is blocked by a shield (9) such as a person or a car. It shows the state. As the transmission speed of wireless communication increases, the frequency band also increases, and it becomes necessary to use radio waves in the quasi-millimeter wave band or millimeter wave band. Then, since the wavelength of the radio wave is very short with respect to the shield, diffraction is less likely to occur,
A line-of-sight propagation path is required for wireless communication. In addition to making diffraction less likely to occur, free space propagation loss increases in proportion to the square of the frequency, so if the transmission power is constant, a building far away in the quasi-millimeter wave band or millimeter wave band (8)
It becomes difficult to receive the reflected wave due to. Therefore, a line-of-sight propagation path is still required for wireless communication. That is, the transmission speed using the quasi-millimeter wave band or millimeter wave band is 10 Mb
For high-speed wireless communication exceeding ps, 800 ~
Shielding by people and objects, which was not a problem in cellular communication using the 900 MHz band, became a big problem,
There was a drawback that communication would be cut off once the shielding occurred.

Further, in order to improve the transmission quality such as the bit error rate (BER) and the packet discard rate (FER) of wireless communication, the directivity of the base station antenna (1) and the terminal station antenna (4) is sharpened. That is, it is necessary to narrow the beam width, in which case it becomes more difficult to receive the reflected waves from the distant structure (8), and the instantaneous interruption rate due to shielding will increase further. .

On the other hand, there are conventionally known route diversity or site diversity techniques as countermeasures against the above-mentioned shielding. These are a radio zone (3) formed by an antenna (1) of one base station (2) and another one. This is a method of overlapping a plurality of wireless zones formed by antennas of the base station. This conventional technique has a drawback in that it is necessary to install the base stations close to each other, a large number of base stations are required, and the cost becomes high.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks, and allows line-of-sight propagation even in high-speed wireless communication using a quasi-millimeter wave band or a millimeter wave band radio wave with a transmission rate of more than 10 Mbps. It is an object of the present invention to provide a wireless communication means that enables communication even when a road is blocked by a shield such as a person or a car and that requires a small number of base stations.

[0009]

A feature of the present invention for achieving the above object is that in a wireless communication method for performing wireless communication between a base station and at least one terminal station, the antenna of the base station is There are two types of antennas, the first antenna has directivity for forming a wireless zone around the base station, and a reflection means for reflecting at least one radio wave is provided in the vicinity of the wireless zone. In the wireless communication method, the antenna of 1 has sharp directivity with the directing direction facing the reflecting means, and the terminal station receives the radio waves from the first and second antennas.

In the wireless communication method, the directivity formed by the second antenna and the reflective means in the reflecting means installed near the wireless zone is substantially the same as that in the wireless zone by the first antenna. Can be a reflective means that is mirror-modified to form a wireless zone.

Further, in the above wireless communication method, the base station may include diversity means for performing diversity communication using the first antenna and the second antenna of the base station.

In the above wireless communication method, the terminal station may include a first antenna facing the base station and a second antenna facing at least one of the reflecting means. It is possible to provide diversity means for performing diversity communication using the above antenna.

[0013]

The wireless communication means of the present invention is described in the above "Means for solving the problem" even in high-speed wireless communication using a quasi-millimeter wave band or a millimeter wave band and having a transmission rate of more than 10 Mbps. Since it is such a wireless communication means, even when the line-of-sight propagation path between the first antenna of the base station and the terminal station is obstructed by a shield such as a person or a car, It becomes possible to communicate with the second antenna.

Further, it is not necessary to overlap a plurality of radio zones formed by one base station antenna with radio zones formed by other base station antennas, and the number of base stations can be reduced.

[0015]

1 is a diagram showing a first embodiment of the present invention.

2 is a base station, 3 is a wireless zone, 4 is a terminal station antenna, 5 is a terminal station, 6 is a user, 7 is a line of sight, 8 is a building, 11 is a first base station antenna, Reference numeral 12 is a second base station antenna, 13 is a reflector, and 14 is a second propagation path.

In the figure, outside the propagation path (7) between the first base station antenna (11) and the terminal station antenna (4), a second base station antenna (12) is provided outside. It shows that the second propagation path (14) is formed by the reflection plate (13).

The base station (2) is composed of a transmission switching circuit, a data processing circuit, an interface circuit, a radio transmitting / receiving circuit, etc., and is installed, for example, on a public telephone box or a wall surface of a building.

The first base station antenna (11) is an antenna having omni directivity, bi-directivity or sectoral directivity for forming a radio zone (3) around the base station, and is a whip. It is realized by an antenna, a dipole antenna, a collinear antenna, a biconical antenna, a loop antenna, a microstrip antenna, a horn antenna, or an array antenna or sector antenna in which a plurality of these are arranged.

The second base station antenna (12) is at least one antenna having a sharp directivity directed to the reflector (13), and includes a whip antenna, a dipole antenna, a collinear antenna, and a bi-directional antenna. It is realized by a conical antenna, a loop antenna, a microstrip antenna, a horn antenna, a parabolic antenna, a lens antenna, or an array antenna or sector antenna in which a plurality of these are arranged. It is desirable that the second base station antenna has a sharp directivity and a half-value angle of at most 10 degrees, has a directivity directed only to the reflector (13), and has no unnecessary radiation such as side lobes and back lobes.

The terminal station (5) is a portable device including a data processing circuit, an interface circuit, a radio transmitting / receiving circuit and the like.

The terminal station antenna (4) is an antenna having omnidirectionality, omnidirectionality, or sharp directivity, and the directivity must be appropriately selected depending on the transmission speed and propagation environment. The terminal station antenna is realized by a whip antenna, a dipole antenna, a collinear antenna, a biconical antenna, a loop antenna, a microstrip antenna, a horn antenna, or an array antenna in which a plurality of these are arranged. This figure shows an embodiment using an omni-directional terminal station antenna (4).

The reflection plate (13) is a reflection means composed of a metal plate or a metal thin film installed on a building (8) around the wireless zone (3) such as a building, a tree or a telephone pole. The shape of the metal plate or the metal thin film may be a flat surface, a paraboloid of revolution, a spheroid of revolution, a sphere, or a combination thereof. The reflector may be composed of one metal plate or metal thin film, or may be composed of a plurality of metal plates or metal thin films.

According to the above-mentioned embodiment, even when the line-of-sight propagation path (7) is blocked by a shield such as a person or a car,
It becomes possible to perform wireless communication between the base station (2) and the terminal station (4). Further, even when the second propagation path (14) is blocked by a shield such as a person or a car, the base station (2)
It becomes possible to perform wireless communication between the terminal station and the terminal station (4). Therefore, the interruption rate due to the blocking of the wireless line is improved, and the communication quality is improved.

FIG. 2 is a diagram showing a second embodiment of the present invention, which is an embodiment using two pairs of the second base station antenna (12) and the reflector (13) in FIG. .

The number of the second base station antenna (12) and the number of the reflectors (13) need to be at least one or more. The larger the number, the lower the instantaneous interruption rate due to the shielding of the wireless line. Communication quality improves.

FIG. 3 is a diagram showing an embodiment of the reflection means of the wireless communication means of the present invention.

Reference numeral 2 is a base station, 3 is a radio zone formed by a first base station antenna, 8 is a building, 11 is a first base station antenna, 12 is a second base station antenna, 13 is a reflector, Reference numeral 15 is a wireless zone formed by the reflector and the second base station antenna.

In the figure, the shape of the reflection plate is represented by the reflection plate (1
3) and the directivity formed by the second base station antenna (15) are mirror-corrected so as to substantially match the radio zone (3) formed by the first base station antenna. Shows. Specifically, the mirror surface shape of the reflecting plate made of a metal plate or a metal thin film may be a paraboloid of revolution, a spheroid of revolution, a sphere, or a combination thereof. The reflector may be composed of one metal plate or metal thin film, or may be composed of a plurality of metal plates or metal thin films.

As in the embodiment, the radio zone (3) formed by the first base station antenna (11) and the reflector (1)
Since the wireless zone (15) formed by 3) and the second base station antenna (15) substantially coincides with each other, interference with other wireless zones is reduced and unnecessary radio waves are not emitted.

FIG. 4 is a diagram showing an embodiment of the base station of the wireless communication means of the present invention.

11 is the first base station antenna, and 12 is the second base station antenna.
Is a base station antenna, 21 is a diversity circuit, and 22 is a transmission / reception circuit.

The figure shows two second base station antennas (12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a)), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a), 12 (a))).
It is an example concerning the control means of the antenna when (b)) is used. The diversity circuit (21) includes a reception quality detection circuit that detects reception quality such as signal strength or code error rate, a selection circuit that selects an antenna, or a combination circuit that combines antenna output signals. Diversity is a method of selecting or combining a plurality of branch (antenna) outputs and improving the reception quality when only one antenna is used. In the present invention, a first base station antenna (11) and a plurality of second base station antennas (12 (a),
12 (b)) can be used to perform route diversity, site diversity, or path diversity, so that communication can be performed even when the line-of-sight propagation path is blocked by a shield such as a person or a car. .

FIG. 5 is a diagram showing another embodiment of the terminal station antenna of the wireless communication means of the present invention.

Reference numeral 31 is a mobile terminal, 32 is an antenna, and 33 is a beam.

In the description of FIG. 1, the terminal station antenna is
It is an antenna having omnidirectional or omni directivity or sharp directivity, and the directivity needs to be appropriately selected depending on the transmission speed and the propagation environment, whip antenna, dipole antenna, collinear antenna, biconical antenna, loop antenna, The microstrip antenna, the horn antenna, or an array antenna or a sector antenna in which a plurality of these are arranged has been described, but the figure shows that the transmission speed using radio waves in the quasi-millimeter wave band or millimeter wave band is 10 Mbps. In the case of performing high-speed wireless communication exceeding the above range, an example in which sharp directivity is required for the terminal station antenna is shown. The beam (33) half-value angle is approximately several tens of degrees or less.

The antenna (32) is an antenna capable of directing the beams (33 (a), 33 (b)) in a plurality of different directions by an electrical or mechanical switching operation, and is an array antenna or a phased antenna. It is realized by an array antenna or a sector antenna, or an antenna that mechanically scans a single antenna.

The plurality of beams (33) directed in different directions.
(A) and 33 (b) are beams corresponding to the directions of the line-of-sight propagation path (7) and the second propagation path (14) described in FIGS. 1 and 2, respectively.

FIG. 6 is a diagram showing another embodiment of the terminal station of the wireless communication means of the present invention.

Reference numeral 21 is a diversity circuit, 22 is a transmission / reception circuit, 31 is a mobile terminal, 32 is an antenna, and 33 is a beam.

The figure shows a terminal station antenna (a) having two sharp beams (33 (a), 33 (b)) directed to the first base station antenna (11) and a reflector (13) respectively. 32) is an embodiment relating to the antenna control means in the case of using 32). The diversity circuit (21) is shown in FIG.
As described above, the reception quality detection circuit detects the reception quality such as the signal strength or the code error rate, the selection circuit that selects the antenna, or the combining circuit that combines the antenna output signals. Diversity is a method of selecting or combining a plurality of branch (antenna) outputs and improving reception quality when only one antenna is used. In the present invention, a plurality of beams (33 (a), 33 (b)) can be used to perform route diversity, site diversity, or path diversity, so that the line-of-sight propagation path is blocked by an obstacle such as a person or a car. It is possible to communicate even in case of failure.

[0042]

As described above, the wireless communication means of the present invention can be used as a base station even in high-speed wireless communication using a quasi-millimeter wave band or millimeter wave band transmission rate exceeding 10 Mbps. Even if the line-of-sight propagation path between the antenna 1 and the terminal station is blocked by a shield such as a person or a car, it is possible to communicate with the second antenna of the base station via the reflecting means, and the wireless It is possible to reduce the instantaneous interruption rate of the line, reduce the time required to retransmit the data, and improve the throughput.

In the wireless communication means of the present invention, it is not necessary to overlap a plurality of wireless zones formed by one base station antenna with wireless zones formed by other base station antennas, and the number of base stations is increased. Can be reduced and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a wireless communication means of the present invention.

FIG. 2 is a diagram showing a second embodiment of the wireless communication means of the present invention.

FIG. 3 is a diagram showing an embodiment of a reflection means of the wireless communication means of the present invention.

FIG. 4 is a diagram showing an embodiment of a base station of the wireless communication means of the present invention.

FIG. 5 is a diagram showing another embodiment of the terminal station antenna of the wireless communication means of the present invention.

FIG. 6 is a diagram showing another embodiment of the terminal station of the wireless communication means of the present invention.

FIG. 7 is a diagram showing a first example of conventional wireless communication means.

[Explanation of symbols]

 1 Base Station Antenna 2 Base Station 3 Radio Zone 4 Terminal Station Antenna 5 Terminal Station 6 User 7 Prospecting Propagation Path 8 Building 9 Shield 11 First Base Station Antenna 12 Second Base Station Antenna 13 Reflector 14 14th Propagation path 2 15 Second wireless zone 21 Diversity circuit 22 Transmitter / receiver circuit 31 Mobile terminal 32 Antenna 33 Beam

Claims (4)

[Claims] 1. A wireless communication method for performing wireless communication between a base station and at least one terminal station, wherein the antenna of the base station has two types of antennas, and the first antenna is of the base station. Having a directivity for forming a wireless zone in the periphery, and having a reflecting means for reflecting at least one radio wave in the vicinity of the wireless zone, the second antenna has a sharp directivity with a directing direction directed to the reflecting means. The wireless communication method, comprising: the terminal station receiving radio waves from the first and second antennas. 2. In the wireless communication method, the directivity formed by the second antenna and the reflective means in the reflective means installed in the vicinity of the wireless zone is
2. The wireless communication method according to claim 1, wherein the reflecting means is a reflecting means that is mirror-finished so as to form a wireless zone that substantially matches the wireless zone of the first antenna. 3. The wireless communication method according to claim 1, wherein the base station comprises diversity means for performing diversity communication using the first antenna and the second antenna of the base station. The wireless communication method according to claim 1. 4. The wireless communication method according to claim 1, wherein the terminal station has a first antenna facing the base station, and at least one second antenna facing the reflecting means.
4. The wireless communication method according to claim 1, further comprising: a plurality of antennas, and a diversity means for performing diversity communication using the plurality of antennas.