JPH11298953A - Radio communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive radio communication apparatus for conducting radio communication indoor which suppresses multi-path effects caused by a wall or the like and which ensures high communication quality, without the need for a complicated control and a large-sized antenna, even in the case of radio transmission with a high transmission rate. SOLUTION: This device is provided with a 1st radio station 5 having, a 1st antenna with a directivity, where at least one beam 7 is set upward from the horizontal direction and a 2nd radio station 6 with a 2nd antenna by which at least the reception or transmission of an electromagnetic wave is available in the direction of the ceiling. Radio communication is conducted between the 1st radio station 5 and the 2nd radio station 6 by utilizing the reflection of electromagnetic waves at the ceiling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication apparatus used indoors or the like,
It can be used for wireless communication between one or more terminal stations and a base station.

[0002]

2. Description of the Related Art A radio communication apparatus for performing radio communication indoors is disclosed in, for example, a document "T. Tsutsumi and K. Ujiie," Altair P.
roducts of 19GHz Radio LAN System, "MWE'93 Microwav
e Workshop Digest, pp. 201-206, 1993. " In this type of wireless communication apparatus, TDMA (Time Division Multiple Access: TDMA) is used between a base station and a terminal station.
(Time Division Multiple Access) communication. Further, as shown in FIG. 22, a sector antenna capable of selecting a beam direction is used for each of a base station and a terminal station.

In the example shown in FIG. 22, a base station and a terminal station each use a sector antenna capable of selecting six types of beam directions. Further, by switching the direction of the beam of the sector antenna by the base station and the terminal station, the transmission path between them can be variously changed. The transmission path between the base station and the terminal station includes not only a direct wave but also a path using a reflected wave. By switching the direction of the beam of each sector antenna, a transmission path with good communication quality is selected.

When a base station and a terminal station use sector antennas each of which can select six types of beam directions,
36 transmission paths can be selected by combining the beam directions of these sector antennas. Further, by using a table in which the relationship between the combination of the beam direction of each sector antenna and the communication quality is recorded in advance, it becomes easy to select a transmission path having good quality. Therefore, when a failure occurs in the transmission path in use, the transmission path can be switched to a high-quality transmission path in a short time.

[0005] In indoor wireless communication, the communication quality greatly changes depending on the positions of a base station and a terminal station due to the influence of a reflected wave generated on the indoor wall surface. Therefore, it is necessary to improve the communication quality by switching the transmission path as shown in FIG. Also, the prior art of wireless communication devices is described in the document “SKBarton,” “Editorial Introduction: The High Per
formance Radio Local Area Network (HlPERLAN), "Wirel
ess Personal Communications 3 :, pp. 341-345, 1996. "
Is shown in

This prior art realizes wireless communication between a base station installed near a ceiling and a terminal station installed on a desk or the like. Also, the communication system does not suppress the round-trip reflected waves between the walls. Instead, the delay wave level is suppressed by an adaptive antenna.

[0007]

In a radio communication apparatus as shown in FIG. 22, an antenna having a large number of sectors is used to secure desired transmission quality. For this reason,
It is inevitable that the sector switching control becomes complicated. Also,
Since it is difficult to reduce the size of the antenna having a large number of sectors, the ratio of the antenna device to the entire size of the wireless communication device increases.

Further, in the conventional radio communication device, basically, the round-trip reflected wave between the walls cannot be suppressed, so that the beam width must be further narrowed in order to cope with a further increase in transmission speed. As a result, it is necessary to increase the number of sectors and the size of the antenna. In addition, when an adaptive antenna is used, the control circuit of the adaptive antenna becomes complicated, and there are problems such as low cost.
At present, a practical wireless communication device cannot be configured using an adaptive antenna.

The present invention suppresses the effects of multipath caused by walls and the like in a wireless communication device for performing wireless communication indoors, and eliminates the need for complicated control and a large antenna even when performing high-speed wireless transmission. To ensure high communication quality with low cost equipment.

[0010]

According to a first aspect of the present invention, there is provided a wireless communication apparatus comprising: a first wireless station having a directivity first antenna in which at least one beam is arranged upward from a horizontal direction; A second wireless station having a second antenna capable of receiving and / or transmitting an electromagnetic wave is provided upward, and between the first wireless station and the second wireless station, The wireless communication is performed by utilizing the reflection of the electromagnetic wave.

Since the directivity of the first antenna is higher than the horizontal direction, if it is assumed that this wireless communication apparatus is used in a general indoor space, electromagnetic waves radiated from the first antenna Most of the light goes to the ceiling of the room and is reflected by the ceiling. Then, the reflected wave from the ceiling or the like is received by the second antenna. Of course, the first wireless station may be a receiving station and the second wireless station may be a transmitting station.

In the wireless communication apparatus according to the present invention, communication is performed between the first wireless station and the second wireless station using a single reflection from a reflector above a ceiling or the like. Reflected waves are less likely to occur on the side walls of the device. For this reason, the influence of the reflected wave from the side wall is small, so that even if the wireless transmission speed is increased, a failure hardly occurs. In addition, since it is not necessary to narrow the beam of the antenna itself, the sector switching control can be simplified.

According to a second aspect of the present invention, in the wireless communication apparatus according to the first aspect, a directional antenna is used as the second antenna, and a direction of a main beam of the second antenna is directed upward in a substantially vertical direction. It is characterized by the following. First
Providing a directional antenna in each of the wireless station and the second wireless station makes it less likely to be affected by the reflected wave from the side wall.

According to a third aspect of the present invention, in the wireless communication apparatus according to the first aspect, wireless communication is performed between the first wireless station and the second wireless station using linearly polarized electromagnetic waves. I do. That is, the transmitting-side wireless station emits linearly polarized electromagnetic waves. According to a fourth aspect of the present invention, in the wireless communication apparatus according to the third aspect, a circularly polarized antenna or an antenna capable of switching a plurality of linearly polarized waves having different polarization directions from each other is used as the second antenna. I do.

When an electromagnetic wave is reflected, its direction of polarization changes. Therefore, for example, the direction of polarization of the electromagnetic wave radiated from the first antenna is different from that of the electromagnetic wave received by the second antenna. If the direction of polarization of the electromagnetic wave reaching the receiving side does not match the direction of polarization of the antenna of the receiving station, the reception level will decrease. By using a circularly polarized antenna or an antenna capable of switching a plurality of linearly polarized waves having different polarization directions from each other on the receiving side radio station, it is possible to receive reflected waves from the ceiling whose polarization direction has changed with high sensitivity. .

According to a fifth aspect of the present invention, in the wireless communication apparatus according to the first aspect, the communication between the first wireless station and the second wireless station includes:
The wireless communication is performed using circularly polarized electromagnetic waves. That is, the wireless station on the transmitting side emits circularly polarized electromagnetic waves. According to a sixth aspect of the present invention, in the wireless communication apparatus according to the fifth aspect, a linearly polarized antenna is used as the second antenna.

A circularly polarized electromagnetic wave can be received using a linearly polarized antenna. By transmitting a circularly polarized electromagnetic wave, even if a change occurs in the direction of polarization due to the influence of reflection on the ceiling, a large fluctuation does not occur in the reception level. Claim 7
In the wireless communication device according to the first aspect, a reflector disposed substantially horizontally is provided at a position higher than the first wireless station and the second wireless station.

Since the reflection characteristics of electromagnetic waves on the ceiling change according to the material of the ceiling, etc., there may be a case where reflected waves of sufficient intensity cannot be obtained from the ceiling depending on the environment in which the wireless communication device is used. By installing a reflector such as a metal near the ceiling, it is possible to always receive the reflected wave from the ceiling with sufficient strength without being affected by the material of the ceiling. Claim 8
Wireless communication device is arranged near a wall-shaped reflector that is oriented in a substantially vertical direction, at least a first beam that is directed upward from the horizontal direction and a second beam that is directed downward from the horizontal direction A first radio station having a first antenna having a usable directivity and having circular polarization characteristics, and a right-handed circle installed from a lower position than the first antenna and having a right-handed circular shape from above A second radio station including a second antenna capable of receiving both polarized and left-handed circularly polarized electromagnetic waves, and a polarization switchable between the right-handed and left-handed polarized waves of the second antenna; Direction switching means is provided to perform wireless communication between the first wireless station and the second wireless station using a direct wave and a reflected wave from above.

When the first radio station transmits, electromagnetic waves are radiated from the first antenna in the directions of the first beam and the second beam, respectively. Since the first beam is directed upward from the horizontal direction, the first beam is directed to a ceiling or the like in a room and is reflected by the ceiling or the like. In addition, since the second beam is directed lower than the horizontal, the second beam is directed to a position lower than the installation position of the first antenna of the first wireless station.

When the second radio station installed at a position lower than the first antenna is present at a position relatively close to the first antenna, the second radio station receives the signal from the first antenna. Receive waves directly. Also, if the second wireless station is located relatively far from the first antenna, the second
Wireless stations receive reflected waves from above, which are radiated from the first antenna and reflected from the ceiling or the like.

For example, when the first antenna emits a right-handed circularly polarized electromagnetic wave, the polarization of the direct wave is a right-handed circularly polarized wave, and the reflected wave from the ceiling is a left-handed circularly polarized wave. . In order to receive these electromagnetic waves at a sufficient level, an antenna having the same polarization as the incoming electromagnetic wave is required. Since the second wireless station is provided with a polarization direction switching means for switching between the right-handed circular polarization and the left-handed circular polarization of the second antenna, the polarization direction of the second antenna may be changed as necessary. Can be changed. By changing the direction of polarization of the second antenna, it is possible to receive both a direct wave from the first antenna and a reflected wave from a ceiling or the like.

The wireless communication apparatus according to the present invention performs wireless communication by combining two waves, a single wave from a reflector above a ceiling or the like and a direct wave obliquely directed. For this reason,
Due to the geometric positional relationship of each antenna and the direction of each beam, a round-trip reflected wave from a wall or the like is basically unlikely to be generated. Since the influence of the reciprocating reflected wave is small, the occurrence of a failure is suppressed without performing special control when increasing the wireless transmission speed.

Further, the wireless communication apparatus of the present invention can select a plurality of wireless zones formed by a direct wave and a reflected wave from a ceiling by using right-handed circularly polarized waves and left-handed circularly polarized waves properly. Electromagnetic wave interference between wireless zones can be suppressed.
As a result, not only can sector switching control be simplified, but it is also possible to cope with the formation of ambiguous wireless zones. The wireless communication device according to claim 9, further comprising a first beam and a second beam that are disposed near a wall-like reflector that is oriented vertically and that are oriented upward from a horizontal direction. A first radio station having a first antenna having a directivity in which a beam is directed toward the wall-shaped reflector and a second beam directed upward, and a first antenna having circular polarization. A second radio station including a second antenna capable of receiving both right-handed and left-handed polarized electromagnetic waves from above, and a right-handed polarized wave and a left-handed circular wave of the second antenna A polarization direction switching means for switching between the polarization direction and the polarization direction, and using the reflection of the electromagnetic wave on the wall-like reflector and the reflection of the electromagnetic wave upward, between the first wireless station and the second wireless station. The wireless communication is performed.

When the first radio station transmits, electromagnetic waves are radiated from the first antenna in the directions of the first beam and the second beam, respectively. The first beam is directed toward a reflector such as a side wall in a room, and the second beam is directed toward a ceiling or the like. The second beam is reflected on a ceiling or the like. Further, the first beam is reflected by a reflector such as a side wall, then travels to a ceiling or the like, and is further reflected by a ceiling or the like.

The polarization of the first reflected wave respectively reflected by the side wall and the ceiling is changed twice with respect to the polarization of the first antenna. Further, the polarization of the second reflected wave reflected only by the ceiling has undergone one change with respect to the polarization of the first antenna. Therefore, the first reflected wave and the second reflected wave have different polarization directions. For example, when the first antenna emits a right-handed circularly polarized electromagnetic wave, the polarization of the first reflected wave is a right-handed circularly polarized wave, and the second reflected wave is a left-handed circularly polarized wave. . In order to receive these electromagnetic waves at a sufficient level, an antenna having the same polarization as the incoming electromagnetic wave is required.

Since the second radio station is provided with a polarization direction switching means for switching between the right-handed circular polarization and the left-handed circular polarization of the second antenna, the polarization of the second antenna is changed as necessary. You can change the direction of the waves. By changing the direction of polarization of the second antenna, both the first reflected wave and the second reflected wave from the first antenna can be received. The wireless communication device of the present invention performs wireless communication by combining two waves of a first reflected wave and a second reflected wave from a reflective object such as a ceiling. For this reason, a round-trip reflected wave from a wall or the like is basically unlikely to be generated depending on the geometric positional relationship of each antenna and the direction of each beam. Because the influence of the round-trip reflected wave is small,
When increasing the wireless transmission speed, the occurrence of a failure is suppressed without performing special control.

In the wireless communication apparatus according to the present invention, a plurality of wireless zones formed by the first reflected wave and the second reflected wave can be selected by selectively using right-handed circularly polarized waves and left-handed circularly polarized waves. Therefore, interference of electromagnetic waves between a plurality of wireless zones can be suppressed. As a result, not only can sector switching control be simplified, but it is also possible to cope with the formation of ambiguous wireless zones.

According to a tenth aspect of the present invention, in the wireless communication apparatus according to the eighth or ninth aspect, the plurality of first wireless stations are arranged at positions apart from each other, and the plurality of first wireless stations form a plurality of first wireless stations. The characteristic of the polarization is determined so that the rotation directions of the circularly polarized waves in the wireless zones adjacent to each other are different from each other. When the first wireless station is used as a base station and the second wireless station is used as a terminal station, by installing a plurality of first wireless stations,
A plurality of wireless zones capable of communicating with the first wireless station are formed. In the area where multiple wireless zones overlap,
Electromagnetic waves from a plurality of first wireless stations may interfere with each other.

However, in the present invention, since the rotation directions of the circularly polarized waves in the mutually adjacent radio zones are different from each other, in the region where the plurality of radio zones overlap, the electromagnetic waves from the plurality of first radio stations are selected by selecting the polarization. Can be separated. Therefore,
Interference can be suppressed. According to an eleventh aspect, in the wireless communication apparatus according to the eighth aspect, a directional antenna having a null point in a horizontal direction is used as the first antenna.

By using a directional antenna having a null point in the horizontal direction, the generation of electromagnetic waves radiated in the horizontal direction is suppressed, so that a reciprocating reflected wave hardly occurs between a plurality of walls facing each other. Become. According to a twelfth aspect of the present invention, in the wireless communication apparatus according to the eighth or ninth aspect, a reflector disposed substantially horizontally is provided at a position higher than the first wireless station and the second wireless station. It is characterized by.

Since the reflection characteristics of electromagnetic waves on the ceiling in a room change according to the material of the ceiling, reflected waves from the ceiling may not be sufficiently strong depending on the environment in which the wireless communication device is used. By installing a reflecting plate made of metal or the like above, that is, on the ceiling or the like, a reflected wave from above can always be received with sufficient strength without being affected by the material of the ceiling or the like.

According to a thirteenth aspect, in the wireless communication apparatus according to the eighth or ninth aspect, the second wireless station includes a two-point feeding microstrip antenna, a hybrid circuit, and a double pole double throw switch. Two input terminals of the hybrid circuit are connected to two output terminals of the double pole double throw switch, and two output terminals of the hybrid circuit are connected to two feed points of the two-point feeding microstrip antenna. And

By feeding power to two places of the two-point feeding microstrip antenna via the hybrid circuit,
A phase difference of 90 degrees can be provided between the two feeding points. Thereby, a right-handed circularly polarized wave or a left-handed circularly polarized electromagnetic wave can be emitted. Further, by switching the state of a double pole double throw (DPDT) switch connected to the hybrid circuit, the phase lead / lag between two feeding points of the two-point feeding microstrip antenna is switched. Can be. As a result, the polarization of the emitted electromagnetic wave is switched to right-handed circularly polarized light or left-handed circularly polarized light.

Therefore, the right-handed circularly polarized wave and the left-handed circularly polarized wave can be selectively generated using a single element antenna. Claim 14
The wireless communication apparatus according to claim 8 or 9, further comprising a polarization direction control means for controlling said polarization direction switching means based on a reception level of said second wireless station. .

The reception level greatly changes depending on whether or not the direction of polarization of the incoming electromagnetic wave coincides with the direction of polarization of the antenna receiving the electromagnetic wave. By controlling the polarization direction switching means in accordance with the level of the reception level actually detected by the second wireless station, the direction of the polarization of the arriving electromagnetic wave and the direction of the polarization of the antenna receiving the electromagnetic wave can be controlled. Can automatically switch the direction of polarization so that

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 and 9 show the configuration of a wireless communication apparatus according to this embodiment. This embodiment corresponds to claims 1, 3 and 4. FIG. 1 is a block diagram showing a configuration example of the base station device 5 and the terminal station device 6. FIG. 9 is a perspective view showing an arrangement example of the base station device 5 and the terminal station device 6.

In this embodiment, the first antenna, the first wireless station, the second antenna, and the second wireless station of the first aspect are respectively composed of an antenna 51, a base station device 5, and an antenna 6
1 and the terminal station device 6. The wireless communication device includes a base station device 5 and a terminal station device 6. As shown in FIG. 1, the base station device 5 includes an antenna 51, a wireless transmitter 5
2, a signal processing circuit 53 and a host computer 54 are provided. The terminal station device 6 includes an antenna 61, a radio receiver 62, a signal processing circuit 63, and a host computer 6.
4 is provided.

The information sent from the host computer 54 is subjected to signal processing by a modem or the like built in the signal processing circuit 53, and then transmitted to the wireless transmitter 52 and the antenna 51.
Is transmitted as an electromagnetic wave. The electromagnetic wave transmitted by the base station device 5 is received by the antenna 61 of the terminal station device 6,
The signal is converted into a low-frequency signal by the wireless receiver 62, processed by a modem or the like in the signal processing circuit 63, and input to the host computer 64.

In this embodiment, the antenna 5 of the base station device 5
1 is a linearly polarized directional antenna. In practice, a horn antenna or the like can be used as the antenna 51. In addition, a circularly polarized omnidirectional antenna is used as the antenna 61 of the terminal station device 6. As the antenna 61, a microstrip antenna or the like can be used.

The base station device 5 and the terminal station device 6 are arranged indoors and perform wireless communication in one room. In the example shown in FIG. 9, the base station device 5 is installed on the desk 3 in the center of the room, and the terminal station device 6 is installed at another position. A predetermined information terminal device 4 is connected to the terminal station device 6. In this example, as can be seen from the antenna beam pattern 7, the direction in which the antenna gain of the antenna 51 of the base station device 5 is the maximum is directed upward in the vertical direction, that is, toward the ceiling 1. Therefore, as shown by the transmission path 8, the electromagnetic wave radiated from the base station device 5 is reflected once on the ceiling 1. Then, the reflected wave from the ceiling 1 is received by the terminal station device 6.

Since the antenna beam pattern 7 faces upward from the horizontal direction, a plurality of side walls 2 facing each other are formed.
The round-trip reflected wave generated between the two is greatly reduced. Since a round-trip reflected wave between the side walls 2, which is a main cause of the communication quality deterioration, is suppressed, stable communication is secured. Further, in this embodiment, the radio communication is performed using the reflected wave from the ceiling 1 without using the direct wave, so that it is not necessary to install the base station device 5 or the antenna 51 near the ceiling 1 and the desk 3 It just needs to be installed on the top.

Therefore, the system can be constructed without troublesome installation work for the base station and work for power supply wiring. Also, since the antenna device of the terminal station device 6 also uses the reflected wave from the ceiling direction, better communication quality can be secured if the directional characteristics are directed toward the ceiling direction. There is an advantage that no sectorization is required.

In this embodiment, since the reflection at the ceiling 1 is used, a change occurs in the polarization direction between the electromagnetic wave radiated by the base station device 5 and the electromagnetic wave received by the terminal station device 6. If the polarization of the electromagnetic wave arriving at the terminal station device 6 does not match the polarization of the antenna 61, it becomes difficult to receive the electromagnetic wave.

In this embodiment, since the transmitting antenna 51 emits a linearly polarized electromagnetic wave, for example, when the antenna 51 emits a vertically polarized electromagnetic wave, the horizontally polarized electromagnetic wave reaches the terminal station device 6. I do. When the antenna 51 emits horizontally polarized electromagnetic waves, vertically polarized electromagnetic waves reach the terminal device 6. However, in this embodiment, the terminal station device 6 uses the antenna 61 having the polarization characteristic of circular polarization (right-handed circular polarization or left-handed circular polarization).
Irrespective of whether the polarization of the electromagnetic wave arriving at the antenna is vertical or horizontal, it is possible to receive the electromagnetic wave arriving with a predetermined sensitivity or higher.

In other words, since the terminal station device 6 can receive the electromagnetic wave from the base station device 5 without being aware of the influence of the polarization change due to the reflection on the ceiling 1, it is necessary to perform a special polarization control. And control is simplified. Note that an antenna device that can selectively use horizontal polarization and vertical polarization may be used instead of the antenna 61. However, in that case, it is necessary to perform polarization switching control in consideration of the influence of the polarization of the electromagnetic wave radiated from the base station device 5 and the reflection at the ceiling 1.

In this embodiment, the case of indoor wireless communication has been described. However, the present invention can be similarly implemented when the reflection device can be installed above the base station device 5 even outdoors. . As the antennas 51 and 61, many commonly used antenna devices such as a horn antenna, a dipole antenna, and a microstrip antenna can be used as needed.

(Second Embodiment) FIG. 2 shows the configuration of a wireless communication apparatus of this embodiment. This embodiment corresponds to claims 1 and 3. This embodiment is a modification of the first embodiment, and differs only in the type of antenna used.
The same components as those in the first embodiment are indicated by the same reference numerals.

In this embodiment, a horizontally polarized antenna 51B is used for the base station device 5B, and a vertically polarized antenna 61B is used for the terminal station device 6B. Therefore, similarly to FIG. 9, an electromagnetic wave is radiated from the base station apparatus 5B toward the ceiling 1, and a reflected wave from the ceiling 1 can be received by the terminal station apparatus 6B. (Third Embodiment) FIGS. 3 and 10 show a wireless communication apparatus of this embodiment. This embodiment corresponds to claims 1 to 4.

FIG. 3 shows a base station device 5C and a terminal station device 6C
FIG. 3 is a block diagram showing the configuration of FIG. FIG. 10 is a perspective view showing an arrangement example of the base station device 5C and the terminal station device 6C of this embodiment. The same components as those in the first embodiment are indicated by the same reference numerals. In this embodiment, both the base station device 5C and the terminal station device 6C have transmission and reception functions.

When the base station 5C transmits, the information sent by the host computer 54 is transmitted to the signal processing circuit 53.
After the processing in B, a signal is transmitted as an electromagnetic wave from the antenna 51 via the wireless transmitter 52 and the antenna switching circuit 56. When the base station apparatus 5C receives the signal, the incoming electromagnetic wave is received by the antenna 51, and this signal is input to the wireless receiver 55 via the antenna switching circuit 56.
The low-frequency signal output from the wireless receiver 55 is subjected to signal processing by a modem or the like inside the signal processing circuit 53B,
It is input to the host computer 54.

When the terminal station device 6C receives the signal, the arriving electromagnetic wave is received by the antenna 61, and this signal is input to the radio receiver 62 via the antenna switching circuit 66. The low-frequency signal output from the wireless receiver 62 is input to the host computer 64 after being subjected to signal processing by a modem or the like inside the signal processing circuit 63B.

When the terminal station device 6C transmits, the information transmitted by the host computer 64 is transmitted to the signal processing circuit 63.
After being processed in B, it is transmitted as an electromagnetic wave from the antenna 61C via the wireless transmitter 65 and the antenna switching circuit 66. The antenna 51 of the base station device 5C is a first linearly polarized directional antenna. The antenna 61C of the terminal station device 6C is a circularly polarized directional antenna.

The base station device 5C and the terminal station device 6C are located indoors and perform wireless communication in one room. In the example shown in FIG. 10, the base station device 5C is installed on the desk 3 in the center of the room, and the terminal station device 6C is installed at another position. A predetermined information terminal device 4 is connected to the terminal station device 6C. In this example, as can be seen from the antenna beam pattern 7, the direction in which the antenna gain of the antenna 51 of the base station device 5C is the maximum is directed upward in the vertical direction, that is, toward the ceiling 1. Therefore, as shown by the transmission path 8, the electromagnetic wave radiated from the base station device 5 is reflected once on the ceiling 1. Then, the reflected wave from the ceiling 1 is received by the terminal station device 6.

As can be seen from the antenna beam pattern 9, the direction in which the antenna gain of the antenna 61C of the terminal station device 6C is maximum is directed upward in the vertical direction, that is, toward the ceiling 1. Since the antenna beam patterns 7, 9 face upward from the horizontal direction, a plurality of side walls 2 facing each other are formed.
The round-trip reflected wave generated between the two is greatly reduced. Since a round-trip reflected wave between the side walls 2, which is a main cause of the communication quality deterioration, is suppressed, stable communication is secured. Further, it becomes possible to suppress the transmission of the unnecessary wave or the round wave from the base station apparatus 5C.

(Fourth Embodiment) FIG. 4 shows a wireless communication apparatus of this embodiment. This embodiment corresponds to claims 1, claim 2, claim 5 and claim 6. FIG. 4 shows a base station device 5.
FIG. 9 is a block diagram illustrating a configuration of a terminal device D and a terminal station device 6D.

This embodiment is a modification of the third embodiment, and is the same as the third embodiment except for the antenna 51D of the base station device 5D and the antenna 61D of the terminal station device 6D. The antenna 51D is a circularly polarized antenna having directivity. The antenna 61D is a linearly polarized antenna having directivity. The base station device 5D and the terminal station device 6D are arranged in the same manner as in FIG.

In this embodiment, since the electromagnetic wave radiated from the antenna 51D of the base station device 5D is circularly polarized, even if the polarization direction changes due to the reflection at the ceiling 1, the reflection arriving at the terminal station device 6D. Waves can be received with sufficiently high sensitivity using the linearly polarized antenna 61D. (Fifth Embodiment) FIGS. 5 and 11 show a wireless communication apparatus of this embodiment. This form corresponds to claims 1, 2 and 5.

FIG. 5 shows a base station device 5E and a terminal station device 6E.
FIG. 3 is a block diagram showing the configuration of FIG. FIG. 11 is a perspective view showing an example of the arrangement of the base station device 5E and the terminal station device 6E of this embodiment. The configuration other than the antenna 51E of the base station device 5E and the antenna 61E of the terminal station device 6E is the same as that of the third embodiment.

The antenna 51E of the base station device 5E is a directional antenna that generates right-handed circularly polarized waves. The antenna 61E of the terminal station device 6E is a directional antenna that generates left-hand circularly polarized waves. As the antennas 51E and 61E, for example, a helical antenna or a two-point feeding microstrip antenna can be used. The base station device 5E and the terminal station device 6E are arranged indoors, and perform wireless communication in one room. In the example shown in FIG. 11, the base station device 5E is installed on the desk 3 in the center of the room, and the terminal station device 6E is installed at another position. A predetermined information terminal device 4 is connected to the terminal station device 6E.

In this example, as can be seen from the antenna beam pattern 7, the direction in which the antenna 51E of the base station apparatus 5E has the maximum antenna gain is directed upward in the vertical direction, that is, toward the ceiling 1. Therefore, as shown by the transmission path 8, the electromagnetic wave radiated from the base station device 5 is reflected once on the ceiling 1. Then, the reflected wave from the ceiling 1 is received by the terminal station device 6E.

As can be seen from the antenna beam pattern 9, the direction in which the antenna gain of the antenna 61E of the terminal station device 6E is the maximum is directed upward in the vertical direction, that is, toward the ceiling 1. The antennas 51E and 61E are both circularly polarized waves 1
Generate 0. However, the rotation directions of the circularly polarized waves 10 of the antennas 51E and 61E are opposite to each other. The right-handed circularly polarized electromagnetic wave radiated from the antenna 51E of the base station device 5E is reflected by the ceiling 1 and reaches the terminal station device 6E as a left-handed circularly polarized electromagnetic wave. Since the characteristics of the antenna 61E of the terminal station device 6E are left-handed circularly polarized waves,
E can receive the reflected wave from the ceiling 1 with high sensitivity.

When the terminal station apparatus 6E transmits, the left-handed circularly polarized electromagnetic wave radiated from the antenna 61E of the terminal station apparatus 6E is reflected by the ceiling 1 and becomes the right-handed circularly polarized electromagnetic wave. Reach 5E. Since the characteristic of the antenna 51E of the base station device 5E is right-handed circular polarization, the base station device 5E can receive the reflected wave from the ceiling 1 with high sensitivity. If the rotation direction of the polarization of the electromagnetic wave arriving at the base station device 5E or the terminal station device 6E does not match the rotation direction of the polarization of the receiving antenna, the reception level decreases. Therefore, other than the single reflection from the ceiling is suppressed. Thereby, deterioration of communication quality due to multipath waves is further reduced.

Further, for example, the electromagnetic wave radiated upward by the base station device 5E is reflected on the ceiling and is again returned to the base station device 5E.
When the wave arrives at E, the direction of rotation of the polarized wave of the antenna 51E does not match the direction of rotation of the reflected wave, so that the interference between the emitted electromagnetic wave and the reflected wave is suppressed. For this reason,
There is an advantage that the condition of the directional characteristics required for the antenna 51E of the base station device 5E is relaxed, and the cost can be easily reduced.

(Sixth Embodiment) FIGS. 6 and 12 show a wireless communication apparatus of this embodiment. This form is defined in claim 1
It corresponds to claim 2, claim 5 and claim 7. FIG. 6 is a block diagram illustrating a configuration of the wireless communication device. FIG.
It is a perspective view which shows the example of arrangement | positioning of the base station apparatus 5E of this form, and the terminal station apparatus 6E. As shown in FIG. 6, the base station device 5
The configurations of E and the terminal station device 6E are the same as those of the fifth embodiment.

In this embodiment, as shown in FIGS. 6 and 12, a reflector 11 is provided on the ceiling 1. Reflector 11
Is a flat plate made of a conductive metal material. In addition, the reflection plate 11 has a high reflectance to electromagnetic waves. As shown in FIG. 12, the reflector 11 is connected to the base station device 5E.
It is arranged above. In this embodiment, since uniform ceiling reflection characteristics can be secured, characteristic changes due to differences in the material and structure of the ceiling 1 can be prevented. Therefore, the system design is facilitated and the communication quality is effectively improved.

The reflecting plate 11 is not limited to a metal plate, but may be a film-like dielectric formed of metal in a thin film. Further, a metal mesh or a wire net may be used. Also,
Regarding the installation form of the reflection plate 11, it is possible not only to attach it to the ceiling 1, but also to install it behind the ceiling. In order to compare the performance of the wireless communication device of this embodiment with that of a conventional wireless communication device, a simulation was performed on each characteristic by ray tracing. 18 to 2 show the results.
It is shown in FIG.

FIG. 18 is a plan view showing the distribution of the in-band deviation of the horizontal plane by the wireless communication apparatus of the present invention. FIG. 19 is a graph showing the in-band deviation and the cumulative probability by the same wireless communication device as in FIG. FIG. 20 is a plan view showing the distribution of the in-band deviation of the horizontal plane by the conventional wireless communication device. FIG.
21 is a graph showing the in-band deviation and the cumulative probability by the same wireless communication device as in FIG. 20.

In each of the simulations shown in FIGS. 18 to 21, it is assumed that communication is performed with a frequency band of 5 GHz, a modulation method of QPSK, and a transmission speed of 40 Mbps. In each simulation, the room in which the base station device 5E and the terminal station device 6E are arranged has a shape of 20 m (vertical) × 20.
m (width) x 3 m (height). In the conventional examples shown in FIGS. 20 and 21, both the base station and the terminal station use circular polarization.
The base station was installed at a high point in the center of the wall, and the deviation of the reception level of the terminal station when communicating with the terminal station arranged at each position using direct waves was determined as the in-band deviation.

The specific calculation conditions are as follows. Base station position: Center of wall, height 2.9m Terminal station height: 0.7m Base station and terminal station are in horizontal plane, beam is directly opposite (vertical plane is fixed) Base station beam width: horizontal plane: 30 degrees, vertical plane : 30 degrees Terminal station beam width: Horizontal plane: 90 degrees, vertical plane: 60 degrees Base station tilt angle: -30 degrees Terminal station tilt angle: 30 degrees In this calculation, the base station beam width and the terminal station beam width are fixed. Then, only the tilt angle was changed as a parameter, and a combination of the tilt angles having the best communication quality was selected.

Referring to FIG. 20, it can be seen that almost good communication quality is ensured except in the back of the room. FIG.
Referring to FIG. 1, the location ratio satisfying the condition within the in-band deviation of 7 dB is 90%. In the simulations shown in FIGS. 18 and 19, the base station device 5E is installed at a low place in the center of the wall, the electromagnetic wave is emitted from the base station device 5E toward the ceiling, and the reflected wave reflected once by the ceiling 1 Is assumed to be received by the terminal station device 6E arranged at various positions.

The specific calculation conditions are as follows. Position of base station apparatus 5E: center of wall, height 0.7m Height of terminal station apparatus 6E: 0.7m Base station apparatus 5E and terminal station apparatus 6E face the horizontal plane and the beam is directly opposed (the vertical plane is fixed). Beam width of apparatus 5E: horizontal plane: 30 degrees, vertical plane: 30 degrees Beam width of terminal station apparatus 6E: horizontal plane: 90 degrees, vertical plane: 60 degrees Tilt angle of base station apparatus 5E: 40 degrees Tilt of terminal station apparatus 6E Angle: 35 degrees In this calculation, the beam width of the base station device 5E and the beam width of the terminal station device 6E are fixed, only the tilt angle is changed as a parameter, and the combination of the tilt angles with the best communication quality is selected. did.

Referring to FIG. 18, it can be seen that good communication quality is almost completely ensured except at the back of the room. This is a characteristic substantially equivalent to FIG. Referring to FIG. 19, the location ratio satisfying the condition within the in-band deviation of 7 dB is 92%. This result means that the communication quality is improved compared to the conventional example of FIG. (Seventh Embodiment) FIG.
This is shown in FIGS. This embodiment corresponds to claims 1, 8, 13, and 14.

FIG. 7 is a block diagram showing the configuration of the wireless communication device. FIG. 8 is a block diagram showing the configuration of the polarization switching antenna 67 of FIG. FIG. 13 is a front view showing an example of the arrangement of the base station device 5F and the terminal station device 6F of this embodiment. As shown in FIG. 7, the base station device 5F includes two antennas 57 and 58, an antenna switching circuit 59, and a wireless transmitter 5
2, a signal processing circuit 53 and a host computer 54. The terminal station device 6F includes a polarization switching antenna 67, a radio receiver 62, a signal processing circuit 63, a host computer 64, a level comparison circuit 68, and a polarization control circuit 69.

Two antennas 57, 5 of base station apparatus 5F
Numeral 8 is a directional antenna for forming right-handed circularly polarized waves. The beam directions of the two antennas 57 and 58 are directed to different directions. In other words, the direction of the beam of the antenna 57 is above the horizontal, and the direction of the beam of the antenna 58 is below the horizontal. The antenna switching circuit 59 switches the two antennas 57 and 58 periodically and alternately. Therefore, the base station 5F emits electromagnetic waves in two beam directions. Note that two antennas 57 and 58 may be connected in parallel to use two beams simultaneously.

The polarization switching antenna 67 of the terminal station device 6F
Is a circularly polarized antenna, which can switch the direction of polarization rotation. That is, the characteristic can be adjusted to either one of right-handed circular polarization and left-handed circular polarization. The level comparison circuit 68 outputs a signal level output from the wireless receiver 62,
That is, the reception level of the terminal station device 6F is compared with a predetermined threshold value, and the result is output as a binary signal.

The polarization control circuit 69 includes a level comparison circuit 68
Is periodically monitored. When the reception level of the terminal station device 6F is smaller than the threshold value (when the rotation directions of the polarizations do not match), the polarization switching antenna 67 is controlled to automatically switch the rotation direction of the polarization. . The polarization switching antenna 67, as shown in FIG.
Microstrip antenna 71, microstrip lines 72 and 73, branch line hybrid circuit 7
4. Double Pole Double Throw (DPDT)
A switch 75 and a termination circuit 76 are provided.

The polarization switching antenna 67 shown in FIG. 8 is formed as a planar circuit on a dielectric substrate (not shown).
The double-pole double-throw switch 75 is binary-controlled by a signal applied to the control input 75e, and enters the first state or the second state. In the first state, the terminals 75a and 75c
Are connected, and the terminal 75b and the terminal 75d are connected. In the second state, the terminals 75a and 75d are connected, and the terminals 75b and 75c are connected.

When the double pole double throw switch 75 is in the first state, the power supply terminal 67a is connected to the terminal 74a of the branch line hybrid circuit 74 via the double pole double throw switch 75. Also, the branch line hybrid circuit 74
Is terminated by a terminating circuit 76 via a double pole double throw switch 75. On the other hand, the double pole double throw switch 75 is
In the case of the state, the power supply terminal 67a is connected to the terminal 74b of the branch line hybrid circuit 74 via the double pole double throw switch 75. A terminal 74 a of the branch line hybrid circuit 74 is terminated by a terminating circuit 76 via a double pole double throw switch 75.

In the branch line hybrid circuit 74, the terminals 74a and 74c have the same phase, and a phase difference of 90 degrees occurs between the terminals 74a and 74d. Further, the terminal 74b and the terminal 74d have the same phase, and a phase difference of 90 degrees occurs between the terminal 74b and the terminal 74c. The two terminals 74c and 74d of the branch line hybrid circuit 74 are connected to the two feed terminals 71a and 71b of the microstrip antenna 71, respectively.

Since a 90-degree phase difference is generated between the two feeding terminals 71a and 71b of the microstrip antenna 71 by the branch line hybrid circuit 74, the phase difference between the feeding terminals 71a and 71b is adjusted according to the lead / lag. A right-handed circularly polarized wave or a left-handed circularly polarized wave is formed by the microstrip antenna 71.

By switching the state of the double-pole double-throw switch 75, the branch line hybrid circuit 74
The lead / lag of the phase between the two terminals 74c and 74d is switched. In other words, by switching the state of the double pole double throw switch 75, the microstrip antenna 71 switches between right-handed circular polarization and left-handed circular polarization. As shown in FIG. 13, the base station apparatus 5F is installed above the indoor side wall 2, and the terminal station apparatus 6F is installed on the desk 3 arranged on the floor 12. The base station device 5F transmits the upper beam 17
And a lower beam 18 is formed.

The direct wave 13 of the lower beam 18 forms a radio zone in which communication with the base station apparatus 5F is possible as the right-turn zone 15. Electromagnetic waves radiated in the direction of the upper beam 17 are reflected by the ceiling 1 to form a ceiling reflected wave 14. The wireless zone formed by the ceiling once reflected wave 14 is formed as a left-turn zone 16. That is, a right-handed circularly polarized electromagnetic wave reaches the right-handed zone 15, and a left-handed circularly-polarized electromagnetic wave reaches the left-handed zone 16. In this example, the right-turn zone 15 and the left-turn zone 16 are formed in regions adjacent to each other.

In this embodiment, since the arrival angle of the transmission path from the base station device 5F to the terminal station device 6F is close to the zenith direction of the terminal station device 6F, the beam direction of the polarization switching antenna 67 of the terminal station device 6F is changed to some extent. By facing upward, it is possible to prevent mixing of reciprocating reflected waves generated between the side walls 2. However, when ceiling reflection is used, there is a problem that a margin of a circuit design is reduced due to attenuation due to reflection. It is general to deal with this kind of problem by using a transmission amplifier or the like. Another solution is to improve the antenna gain by sectorization.
However, the structure of the device becomes complicated and complicated control is required.

In this embodiment, an upper beam 17 directed toward the ceiling and a lower beam 18 directed directly toward the terminal station device 6F are provided in the base station device 5F, so that a radio zone capable of communicating with the base station device 5F is provided. It is divided into two, a right-turn zone 15 and a left-turn zone 16.

By dividing the wireless zone into two,
Antenna gain can be improved by up to 3 dB. In the two wireless zones formed by the base station device 5F, the directions of rotation of the polarized waves are opposite to each other, so that the interference between the direct wave 13 in the right-handed zone 15 and the once-reflected ceiling 14 in the left-handed zone 16 is caused. Is suppressed. Therefore, the design of the wireless zone is facilitated.

In this embodiment, the terminal station device 6F includes a polarization switching antenna 67 capable of coping with both right-handed circular polarization and left-handed circular polarization, and the polarization control circuit 69 includes a polarization switching antenna. The polarization of 67 is automatically switched. Therefore,
Regardless of whether the terminal station device 6F is arranged in the right-turn zone 15 or the left-turn zone 16, the terminal station device 6F can wirelessly communicate with the base station device 5F.

In this embodiment, the polarization switching antenna 67
Although the case where the polarization is automatically switched has been described, the configuration may be changed so that the polarization of the polarization switching antenna 67 is switched by a user's manual switch operation. (Eighth Embodiment) FIG. 14 shows an example of the arrangement of the base station apparatus 5F and the terminal station apparatus 6F of this embodiment. This form
It corresponds to claim 1, claim 9, claim 13, and claim 14.

In this embodiment, the same base station apparatus 5F and terminal station apparatus 6F as in the seventh embodiment are used. However, the arrangements of the base station device 5F and the terminal station device 6F are changed as shown in FIG. As shown in FIG. 14, in this embodiment, both the base station device 5F and the terminal station device 6F are horizontally set on the desk 3. Also, the base station device 5F
Is disposed at a relatively low position near the side wall 2. One beam 18B of the base station device 5F faces the upper part of the side wall 2 obliquely above. The other beam 17B is directed to the ceiling 1 obliquely above.

The electromagnetic wave radiated by the beam 17B is
The light is reflected by the ceiling 1 to form a once-reflected wave 14B. The ceiling once reflected wave 14B divides one wireless zone into a left-turn zone 1
6 is formed. That is, the right-handed circularly polarized electromagnetic wave radiated from the base station apparatus 5F is reflected once by the ceiling 1 and becomes the left-handed circularly reflected once-reflected ceiling 14B. Left turn zone 1
At 6, the ceiling once reflected wave 14 </ b> B of left-handed circular polarization arrives.

The electromagnetic wave radiated by the beam 18B is obliquely incident on the upper portion of the side wall 2, and forms a reflected wave in the direction toward the ceiling 1. This reflected wave is reflected by the ceiling 1 to form a twice reflected wave 13B. Twice reflected wave 1
3B forms one wireless zone as a right-handed zone 15. That is, the right-handed circularly polarized electromagnetic wave radiated from the base station device 5F is reflected once by the side wall 2 to become left-handed circularly polarized light, and is further reflected once by the ceiling 1 to become right-handed circularly polarized light. Twice reflected wave 13B. A right-handed circularly polarized wave twice reflected wave 13B arrives at the right-handed rotation zone 15.

Therefore, as in the seventh embodiment, right-handed zones 15 and left-handed zones 16 having mutually different polarization rotation directions are formed in regions adjacent to each other. (Ninth Embodiment) FIG. 15 shows an example of the arrangement of the base station device 5F of this embodiment. FIG. 15 is a plan view showing an arrangement example of the base station device 5F in one room. This embodiment corresponds to claim 10.

In this embodiment, the same base station apparatus 5F and terminal station apparatus 6F as in the seventh embodiment are used. The base station device 5F is arranged on the side wall 2 as in FIG. Further, two base station apparatuses 5F (A) having the same configuration,
5F (B) are installed at positions separated from each other as shown in FIG.

[0093] The base station devices 5F (A) and 5F (B) are arranged on wall surfaces facing each other with their positions in the horizontal direction being shifted. The base station device 5F (A) forms a right-turn zone 15 (A) and a left-turn zone 16 (A). Also, the base station device 5F
(B) forms a right-turn zone 15 (B) and a left-turn zone 16 (B). As shown in FIG. 15, four wireless zones are formed in this room as right-turn zones 15 (A) and 15 (B) and left-turn zones 16 (A) and 16 (B). In the wireless zones adjacent to each other, they are arranged so that the directions of polarization rotation are opposite.

In this embodiment, since the rotation directions of the polarized waves in the wireless zones adjacent to each other are different, interference between the wireless zones is suppressed. Therefore, the design of the wireless zone is facilitated. In this embodiment, two opposite side walls 2 are provided.
Although the two base station devices 5F are arranged, two base station devices 5F may be arranged on the same side wall 2 with their horizontal positions shifted. In this case, by using the antennas 57 and 58 of the two base station apparatuses 5F having different rotation directions of the polarization, the rotation directions of the polarizations of the adjacent wireless zones are reversed as in FIG. be able to.

(Tenth Embodiment) FIG. 16 shows an example of the arrangement of the base station device 5F and the terminal station device 6F in this embodiment. This embodiment corresponds to claim 11. This embodiment is a modification of the seventh embodiment, and uses the same base station device 5F and terminal station device 6F as in the seventh embodiment. Special consideration is given to the direction in which the beam of the antenna of the base station device 5F is formed.

That is, in this embodiment, the null point of the vertical directivity of the antenna of the base station device 5F is arranged so as to face the horizontal direction. Otherwise, the configuration is the same as that of the seventh embodiment. In this embodiment, since the radiation of the electromagnetic wave from the base station device 5F in the horizontal direction is particularly suppressed, the generation of the reciprocating reflected wave generated between the side walls 2 facing each other is suppressed. Therefore, long delay waves that lead to deterioration of communication quality are suppressed, and stable communication quality is ensured.

(Eleventh Embodiment) FIG. 16 shows an example of the arrangement of the base station device 5F and the terminal station device 6F of this embodiment. This embodiment corresponds to claim 12. This embodiment is a modification of the seventh embodiment, and uses the same base station device 5F and terminal station device 6F as in the seventh embodiment. The seventh embodiment is the same as the seventh embodiment except that a reflecting plate 20 disposed horizontally on the ceiling 1 is provided.

In this embodiment, a reflected wave used for wireless communication between the base station device 5F and the terminal station device 6F is reflected by the reflector 20, so that uniform ceiling reflection characteristics are ensured. That is, it is possible to prevent a change in characteristics due to a difference in the material and structure of the ceiling 1. This facilitates system design and helps to improve communication quality. The reflection plate 20 can be formed by forming a metal in a thin film on a metal plate or a film-like dielectric. Further, a metal mesh or a wire net may be used as the reflection plate 20. Also, the reflection plate 20
Regarding the installation, it is possible to place not only on the ceiling but also on the ceiling.

As shown in FIG. 14, one of the base station apparatuses 5F
When two beams are directed to the upper side of the side wall 2, it is effective to provide a reflector at the reflection position of the side wall 2. In addition,
The present invention can be implemented even if the components of the first to eleventh embodiments are combined and deformed. For example, the polarization switching antenna 67 and the level comparison circuit 6 in FIG.
When the antenna 8 and the polarization control circuit 69 are used instead of the antenna 61E of FIG. 6, the rotation direction of the polarization of the terminal station device 6E can be automatically changed according to the change of the installation position of the terminal station device 6E. .

[0100]

As described above, in the radio communication apparatus according to the present invention, at least one beam of the antenna device on the base station side is directed above the horizontal, so that it is possible to remove electromagnetic waves other than the ceiling once reflected wave. Can be. This makes it possible to suppress long delay waves due to wall reflection and the like. Therefore, communication quality is improved.

Further, by directing the directional characteristics of the terminal station substantially upward in the vertical direction, communication can be performed between the base station and the terminal using only the ceiling reflected wave. Also,
When linear polarization is used as the polarization of the electromagnetic wave used for communication between the base station and the terminal station, a commonly used linear polarization antenna device can be used, and the entire antenna device can be simplified. This makes it possible to use an antenna device for which a manufacturing technique has already been established, so that mass production can be easily realized. Therefore, cost reduction can be easily realized.

When an antenna device capable of selecting circularly polarized wave or vertical polarized wave and horizontal polarized wave is used as the antenna device of the terminal station, linearly polarized wave is transmitted from the base station side and reflected by the ceiling. Even if the polarization plane changes, communication can be performed on the terminal station side. Thereby, stable communication quality is ensured. Therefore, line design can be facilitated.

Further, when circular polarization is used as the polarization of electromagnetic waves used for communication between the base station and the terminal station, a decrease in level due to a difference in polarization plane due to ceiling reflection caused when linear polarization is used. Can be prevented. Thereby, level fluctuation can be easily suppressed. Therefore, stable communication can be realized. In addition, when the reflector is provided substantially vertically above the base station, good reflection characteristics can be obtained regardless of the material of the ceiling or the reflector. Thereby, communication quality can be easily ensured. Therefore, line design becomes easy.

Also, the electromagnetic wave used for communication between the base station and the terminal station is circularly polarized, the antenna device on the base station side is installed near the wall and higher than the height of the terminal station, and the antenna device of the base station is installed. By providing at least two beams in the ceiling direction and below the horizontal as the directional characteristics of the terminal station, by configuring the terminal station to be able to switch between the right-handed and left-handed waves, a plurality of direct waves and ceiling once reflected waves A wireless zone is formed. Moreover, in the wireless zones adjacent to each other, the directions of rotation of the polarized waves are reversed, so that interference of electromagnetic waves between the zones is suppressed. Therefore, the design of the wireless zone is facilitated.

Further, the electromagnetic wave used for communication between the base station and the terminal station is circularly polarized, and the antenna device on the base station side is installed near the wall. And at least two beams are provided, and the terminal station is configured to be switchable between a right-handed and a left-handed wave, so that a twice-reflected wave reflected once on the wall and the ceiling and a one-time reflected wave only on the ceiling, respectively. A plurality of wireless zones are formed by the reflected waves. Moreover, in the wireless zones adjacent to each other, the directions of rotation of the polarized waves are reversed, so that interference of electromagnetic waves between the zones is suppressed. Therefore, the design of the wireless zone is facilitated.

Further, by combining a plurality of radio zones formed by a plurality of base stations and changing the direction of polarization rotation in the radio zones adjacent to each other, it is possible to form a large number of radio zones in which interference is suppressed. Therefore, the design of the wireless zone becomes easier. Further, in the vertical directional characteristics of the antenna device of the base station, the round-trip reflected waves between the walls are further suppressed by directing the null point in the horizontal direction. This makes it possible to suppress interference due to long delay waves. Therefore, good communication quality can be ensured.

Further, by providing a reflector at a place where the electromagnetic wave from the base station reflects, good reflection characteristics can always be obtained irrespective of the material of the ceiling or the reflecting object. Thereby, communication quality can be easily ensured. Therefore, the line design becomes easy.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a base station device 5 and a terminal station device 6 according to a first embodiment.

FIG. 2 is a block diagram illustrating a configuration example of a base station device 5B and a terminal station device 6B according to a second embodiment.

FIG. 3 is a block diagram illustrating configurations of a base station device 5C and a terminal station device 6C according to a third embodiment.

FIG. 4 is a block diagram illustrating configurations of a base station device 5D and a terminal station device 6D according to a fourth embodiment.

FIG. 5 is a block diagram illustrating a configuration of a base station device 5E and a terminal station device 6E according to a fifth embodiment.

FIG. 6 is a block diagram illustrating a configuration of a wireless communication device according to a sixth embodiment.

FIG. 7 is a block diagram illustrating a configuration of a wireless communication device according to a seventh embodiment.

8 is a block diagram illustrating a configuration of a polarization switching antenna 67 of FIG.

FIG. 9 is a perspective view showing an arrangement example of a base station device 5 and a terminal station device 6 according to the first embodiment.

FIG. 10 is a perspective view illustrating an arrangement example of a base station device 5C and a terminal station device 6C according to the third embodiment.

FIG. 11 is a perspective view showing an arrangement example of a base station device 5E and a terminal station device 6E according to the fifth embodiment.

FIG. 12 is a perspective view illustrating an arrangement example of a base station device 5E and a terminal station device 6E according to the sixth embodiment.

FIG. 13 is a front view showing an arrangement example of a base station device 5F and a terminal station device 6F according to the seventh embodiment.

FIG. 14 is a front view showing an arrangement example of a base station device 5F and a terminal station device 6F according to the eighth embodiment.

FIG. 15 is a plan view showing an arrangement example of a base station device 5F according to a ninth embodiment.

FIG. 16 is a front view showing an arrangement example of a base station device 5F and a terminal station device 6F according to the tenth embodiment.

FIG. 17 is a front view illustrating an arrangement example of a base station device 5F and a terminal station device 6F according to the eleventh embodiment.

FIG. 18 is a plan view showing a distribution of an in-band deviation of a horizontal plane by the wireless communication device of the present invention.

FIG. 19 is a graph showing the in-band deviation and the cumulative probability by the same wireless communication device as in FIG. 18;

FIG. 20 is a plan view showing a distribution of an in-band deviation of a horizontal plane by a conventional wireless communication device.

21 is a graph showing the in-band deviation and the cumulative probability by the same wireless communication device as in FIG.

FIG. 22 is a plan view showing an example of a transmission path by a conventional wireless communication device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceiling 2 Side wall 3 Machine 4 Information terminal device 5 Base station apparatus 6 Terminal station apparatus 7 Antenna beam pattern 8 Transmission path 9 Antenna beam pattern 10 Circularly polarized wave 11 Reflector 12 Floor 13 Direct wave 14 Ceiling once reflected wave 15 Right turn Zone 16 Left rotation zone 17 Upper beam 18 Lower beam 51 Antenna 52 Radio transmitter 53 Signal processing circuit 54 Host computer 55 Radio receiver 56 Antenna switching circuit 57, 58 Antenna 59 Antenna switching circuit 61 Antenna 62 Radio receiver 63 Signal processing circuit 64 Host computer 65 Wireless transmitter 66 Antenna switching circuit 67 Polarization switching antenna 68 Level comparison circuit 69 Polarization control circuit 71 Microstrip antenna 72, 73 Microstrip line 74 Branch line hybrid circuit 75 Bipolar Throw switch 76 termination circuit

Claims (14)

[Claims] 1. A first radio station having a first antenna having directivity in which at least one beam is disposed above a horizontal direction, and at least one of reception and transmission of electromagnetic waves upward. And a second wireless station having a second antenna capable of performing: wireless communication between the first wireless station and the second wireless station using reflection of an electromagnetic wave in an upper direction; A wireless communication device characterized by the above-mentioned. 2. The wireless communication device according to claim 1, wherein
A wireless communication apparatus, wherein a directional antenna is used as the second antenna, and a main beam of the second antenna is directed substantially vertically upward. 3. The wireless communication device according to claim 1, wherein
A wireless communication apparatus, wherein wireless communication is performed between the first wireless station and the second wireless station using linearly polarized electromagnetic waves. 4. The wireless communication device according to claim 3, wherein
A wireless communication apparatus, wherein a circularly polarized antenna or an antenna capable of switching a plurality of linearly polarized waves having different polarization directions from each other is used as the second antenna. 5. The wireless communication device according to claim 1, wherein
A wireless communication device, wherein wireless communication is performed between the first wireless station and the second wireless station using circularly polarized electromagnetic waves. 6. The wireless communication device according to claim 5, wherein
A wireless communication device, wherein a linearly polarized antenna is used as the second antenna. 7. The wireless communication device according to claim 1, wherein
At a position higher than the first wireless station and the second wireless station,
A wireless communication device comprising a reflector disposed substantially horizontally. 8. A first beam which is arranged near a wall-like reflector which is directed substantially vertically and which is at least directed upward from the horizontal direction and a second beam directed downward from the horizontal direction. 1st with possible directivity and circular polarization
A first radio station having an antenna, and a second antenna installed at a lower position than the first antenna and capable of receiving both right-handed and left-handed electromagnetic waves from above A second radio station comprising: and a polarization direction switching means for switching between the right-handed circular polarization and the left-handed circular polarization of the second antenna, wherein the first radio station and the second radio station Wireless communication using a direct wave and a reflected wave from above. 9. A first beam and a second beam disposed near a vertically oriented wall-shaped reflector and directed upward from a horizontal direction, wherein the first beam is provided on the wall. A first radio station including a first antenna having a directivity in which a second beam is directed upward in a direction of a reflector in a shape of a circle and having a polarization characteristic of circular polarization; A second radio station including a second antenna capable of receiving both right-handed and left-handed polarized electromagnetic waves; and a right-handed and left-handed polarized wave of the second antenna. A polarization direction switching means for switching, and wirelessly communicates between the first wireless station and the second wireless station using reflection of the electromagnetic wave on the wall-shaped reflector and reflection upward. A wireless communication device characterized by the above-mentioned. 10. The wireless communication apparatus according to claim 8, wherein the plurality of first wireless stations are arranged at positions separated from each other, and a plurality of wireless zones formed by the plurality of first wireless stations. A radio communication apparatus characterized in that polarization characteristics are determined such that rotation directions of circular polarization in mutually adjacent radio zones are different from each other. 11. The wireless communication device according to claim 8, wherein a directional antenna having a null point in a horizontal direction is used as the first antenna. 12. The wireless communication apparatus according to claim 8, wherein a reflector disposed substantially horizontally is provided at a position higher than the first wireless station and the second wireless station. A wireless communication device characterized by the above-mentioned. 13. The wireless communication device according to claim 8, wherein the second wireless station includes a two-point feeding microstrip antenna, a hybrid circuit, and a double-pole double-throw switch. Wherein two input terminals are connected to two output terminals of the double-pole double-throw switch, and two output terminals of the hybrid circuit are connected to two feeding points of the two-point feeding microstrip antenna. Communication device. 14. The radio communication apparatus according to claim 8, further comprising: a polarization direction control unit that controls the polarization direction switching unit based on a reception level of the second radio station. A wireless communication device characterized by the following.