JPH08316730A - Multi-antenna system and information transmission system using multi-antenna - Google Patents

Abstract

PURPOSE: To reduce transmission power of a stationary station and a mobile station by interconnecting a large number of antennas to the stationary station so as to constitute a multi-antenna arranged in a way of alternately different directivity thereby enabling transmission reception of information at a broad band and enhancing the antenna efficiency. CONSTITUTION: A multi-array antenna 100 of a stationary station 101 is constituted by forming a group by plane unit antennas 11, 12 and 21, 22 and arranging the installing angle of them so that their directivity is alternately different from each other in a range of 90 deg.±45 deg.. A transmission signal from plural mobile stations is received by the antenna 100 and inputted a group selection circuit 90 via couplers 54a, 54b, a higher reception level of the different antenna group is selected and fed to a receiver 91. Thus, information requiring a broad frequency band is communicated efficiently with small power through plural channels with respect to the mobile stations and even when the mobile station is moved with turning, the propagation plane of the radio wave and the directivity of the antenna are matched with each other through selection of the antenna thereby continuing communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile body such as a self-propelled robot or an automobile which moves in a limited range, and mainly uses video information, audio information, etc. from the mobile body with a small power or a weak power. The present invention relates to an antenna capable of wirelessly transmitting efficiently and an information transmission system using the antenna.

[0002]

2. Description of the Related Art Generally, when transmitting and receiving video information to and from a moving body, a method of installing a large antenna and wirelessly transmitting a relatively strong electric wave at a specific frequency is used. Came.

In addition, electromagnetic coupling is used for information transmission between an elevator and a line used in an elevator or the like,
The electric power was weak, and it was an extremely close contact (about ten and a few millimeters) in the form of linear coupling, and the application range was limited. Further, the conventional planar antenna uses one opposing antenna for transmitting and receiving in space.

[0004]

SUMMARY OF THE INVENTION In the above-mentioned prior art, when transmitting and receiving video information between a mobile station and a fixed station side, in order to obtain video information of a particularly wide bandwidth as a good quality signal, Since it is necessary to increase the output of the station-side antenna, the output power of the transmitter increases, and in order to increase the antenna gain, the fixed-station-side antenna device has a large size, such as a parabolic antenna or Yagi antenna. It had the drawback of shaping.

As described above, in the prior art, the mobile station device,
Also, the antenna on the fixed station side is inevitably expensive. In addition, the antenna on the fixed station side has a drawback that the installation is restricted due to its large size. Also,
When the output of the transmitting antenna is large, there is a problem in that interference with other video information transmission systems may occur and the frequency to be used may be restricted, which is not suitable for practical use. Also, between the transmitting and receiving antennas, when transmitting video information, various standing waves are generated due to multiple paths propagating in transmission, and due to fading phenomenon and phase shift,
Signal disturbance and S / N (signal / noise) deterioration occur,
There is a drawback that the image quality is greatly deteriorated and is not suitable for practical use. Also, due to the directivity of the antenna, it has been extremely difficult to constantly face the mobile body and the fixed station side to obtain constant information.

Especially when the traveling direction of the mobile station extends in all directions, it has been extremely difficult to always maintain good quality video information transmission.

Further, according to the present invention, when video information is transmitted between a transmitting antenna and a receiving antenna, even if various standing waves occur due to multiple paths propagating in transmission, a fading phenomenon or a phase shift occurs. Due to signal disturbance, S / N (signal /
(Noise) degradation can be relatively ignored, the level of image quality can be maintained, and video information with a wide bandwidth can be used as high-quality video information and related information at any position between the mobile station and fixed station side. It is an object of the present invention to provide a method and a system by which constant information can be easily and easily obtained while always facing each other.

Another object of the present invention is to provide a device for a mobile station with a low output and to provide it simply and at low cost.

Further, control information is wirelessly transmitted from a fixed station,
A method that can be received by a dedicated antenna of a mobile station and wirelessly controlled and utilized by the information received by the mobile station,
The system is provided.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a planar unit antenna (a single antenna alone) over a traveling surface on which a moving body moves over a predetermined position and range. A multi-antenna is constructed by connecting a plurality of the antennas, which are connected to each other to form a multi-antenna, and the directivity (that is, the radiation pattern of radio waves) is staggered in the direction of arrangement of the unit antennas at regular intervals. The antennas of the fixed station are those in which the multi-antenna groups arranged in the same direction and the multi-antenna groups arranged in different directions are independently network-coupled. It was done.

Further, according to the present invention, the signals from the plane multi-antenna groups having different directivity directions are compared with each other and the larger one is selected.

Further, according to the present invention, the mobile station is provided with an antenna at a position close to a planar antenna, and the antenna of the mobile station is kept close to the unit antenna of the fixed station while maintaining the close spacing between the antenna of the mobile station and the unit antenna of the fixed station. The output power is transmitted with small power or weak power.

[0013]

The information from the mobile station is wirelessly transmitted, the information received by the multi-antenna is amplified, and the information is collected and then collected by the fixed station, and the directionality of the plane multi-direction is different depending on the traveling direction and position of the mobile station. The larger output of the antenna group is made to act as a comparative selection.

Furthermore, the information obtained from the television cameras of each of the plurality of mobile stations and related information are wirelessly transmitted, and at least the planar multi-antenna group of two systems is subjected to matching coupling by the planar multi-antenna, Information is amplified, the networks are mixed and combined, and the information is collected and then received by a fixed station for each of the two multi-antenna groups.

As a result, it is possible to maintain the image quality level of video information having a wide bandwidth, and to provide a system configuration in which high-quality video information and related information can be easily and easily obtained at any position. be able to. Further, the transmission power of the mobile unit is low and the mobile unit can be efficiently operated, so that the device can be provided at a low cost. In addition, since the multi-antenna on the fixed station side has a planar shape, it can be operated so as to cover the moving range of the moving body, and can be installed without requiring a large space. Further, by setting the output of the antenna to be a weak electric power, it is possible to operate within a use distance and a range so as to avoid interference with other video information transmission systems, and to set a frequency to be used arbitrarily.

Furthermore, the control information can be wirelessly transmitted from the fixed station and received by the dedicated antenna of each mobile station to control each mobile station wirelessly.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

1 and 2 are plan views of an example of a planar multi-antenna in which a plurality of planar antennas on the fixed station side are laid in the present invention. A mobile station (not shown in the figures) moves on a traveling surface on which the antenna is laid. In addition,
The single plane antenna itself is a well-known technique as described in “Latest Planar Antenna Technology” published by General Technology Center Co., Ltd. on March 25, 1993.
Here, the planar antenna in the present invention refers to a planar arrangement of elements forming the antenna, and various shapes such as a curved surface and a waveform are conceivable instead of a plane having an accurate meaning.

In FIGS. 1 and 2, 11, 12, and 2 are shown.
1, 22 and 31, 32 and 41, 42 each represented a planar dipole unit antenna. 51a,
Reference numeral 51b is a leader line (or feeder line) of the planar unit antenna 11 and the planar unit antenna 21, 52a and 52b are well-known matching devices for impedance matching, 53a and 5b.
3b is a coaxial cable, 54a is each planar unit antenna 1
A combiner 54b for combining (mixing) 1 and 12
Is a combination of the planar unit antennas 21 and 22 (mix)
Couplers 55a and 55b are connected to the couplers 54a and 54b, respectively.
Star). Thus, each planar unit antenna 1
The planar multi-antenna 100 is configured by arranging and coupling a large number of 1, 12 and 21, 22 and 31, 32, and 41, 42. This multi-antenna 100 includes couplers 54a and 54b and amplifiers 55a and 55a.
b from the coupling distributors 80a, 80b, etc.
It is connected to the.

Although not shown, in the present invention, a large number of such antennas are laid along the traveling surface.

As an example of the planar unit antenna, a triangular shape known as a planar dipole antenna is shown. Size l≈1λ / 6 to λ, θ≈30 °
The angle is 90 ° (an example of such a fan-shaped antenna is described, for example, in Ohmsha's "Wireless Engineering Handbook" p586, published on January 31, 1937, 11th edition).

The carrier wave having the transmission frequency at this time is, for example, about 100 MHz to 10 GHz. Also,
The electric field strength of weak radio waves is 500 μV at a position 3 m away
/ M or less.

Here, the feature of the present invention is that the multi-antennas composed of at least two groups are arranged so that the shape (that is, directivity) of radio wave radiation is in alternate directions. Further, the installation angle α of the antennas forming the two groups is usually arranged at 90 ° ± 45 °. The angle is preferably 90 ° ± 30 °, but 90 ° is optimal.

FIG. 1 shows the planar unit antennas 11 and 12 a.
2 systems of a group and a group b of planar unit antennas 21 and 22. In FIG. 2, the planar unit antennas 41 and 42 and the planar unit antennas 31 and 32 are added to widen the width of the traveling surface.

FIG. 3 shows each mobile unit which is a mobile station, its antenna, and the multi-antenna 10 on the fixed station side shown in FIGS.
It is a side view of an example which shows the arrangement relation of 0.

In FIG. 3, a planar multi-antenna, a lead wire, a coaxial cable and the like are arranged on a shield ground plate 6 via a space or a dielectric 5. Reference numeral 61 is a traveling plate having a traveling surface on which the mobile stations 71 and 72 travel. The antennas 81 and 82 of the mobile stations 71 and 72 are provided close to the planar multi-antenna 100.
As an example of the antennas 81 and 82, a simple rod-shaped antenna is shown here. 91 and 92 are TV cameras, 71
1, 712 are transmitters, and the output terminals are antennas 81, 8
Connected to 2. Reference numerals 721 and 722 denote driving control devices.

Hereinafter, this operation will be described in detail with reference to FIGS.
This will be described with reference to FIGS. 3 and 4.

The fixed station 101 receives signals of the video information wireless transmission signal channel CH1 of the mobile station 71 and the video information wireless transmission signal channel CH2 of the mobile station 72 through the planar multi-antenna 100 to obtain a required signal level. The video information is collected by the couplers 80a and 80b having the mixing function, and the video information transmission channels CH1 and CH2 are received by the receiver 91. The receiver 91 uses the channel CH1 or CH2 as necessary.
Select to receive. Of course, the selection function may be omitted and dedicated receivers for the respective channels may be used.

FIG. 4 shows a group selection circuit 90 provided for each channel.
2 is a block diagram (for one channel) of the multi-antenna group, and as an example, outputs of two systems having different antenna directions are connected to the switching circuit 90. On the other hand, the receiver 91
The video signal output of is input again to the group selection circuit 90,
The sync signal is connected to the sync signal separation circuit 902, and the output of the sync signal is input to the sync signal level determination circuit 903. The sync signal level determination circuit 903 detects the change level of the sync signal level and inputs the output thereof to the switching circuit 901.

With such a configuration, the receiver 91 is always selectively supplied with a higher received level of the video signals received by the different antenna groups. More specifically, the receiver 91
The video signal output of is input to the group selection circuit 90 again and connected to the synchronization signal separation circuit 902. As is generally known, the sync signal has the opposite sign to the video signal and is easily separated. The separated sync signal is constant in proportion to the transmission quality regardless of the output of the video signal. The output of the sync signal is input to the sync signal level determination circuit 903. When the sync signal level drops below a certain level, the change level is detected and a switching instruction is output. In response to this switching instruction, the switching circuit 901 switches the antenna group to another system connection.

In this way, in the fixed station 101, the outputs of the planar multi-antenna group of two systems are input to the group selection circuit 90, and the information transmitted by the receiver 91 is demodulated to the base band. Reproduced in video information.

Because of this state, each mobile station 71, 72
When the vehicle linearly travels on the traveling surface 61 in a certain direction, the outputs of the antennas 81 and 82 have the same radio wave coupling of the radio wave propagation of transmission and reception in the group a of the planar multi-antenna 100. Since the radio wave propagation is good, the group selection circuit 90 of the fixed station 101 can select a good output signal of the group a and input it to the receiver 91.

When the mobile stations 71 and 72 travel on the traveling plate 61 in the direction perpendicular to the above direction,
The outputs of the antennas 81 and 82 are in the same direction in the radio wave coupling of the radio wave propagation of transmission and reception in the group b of the planar multi-antenna 100, and the radio wave coupling of the radio wave propagation is good. It is possible to select a good output signal of the group b and input it to the receiver 91.

Also, when the mobile station 71 travels on the traveling plate 61 in the direction perpendicular to the above and the mobile station 72 travels linearly on the traveling surface 61, the antenna group is selected for each mobile station. Therefore, each receiver can select and receive a high-quality output signal with good coupling of radio wave propagation.

With such a configuration, it is possible to simultaneously and wirelessly transmit video information in a wide band on a number of channels with high efficiency, high quality, low cost and simple configuration with small power and minute power. In addition, the video information of the mobile station is not limited to traveling linearly along the traveling surface, but traveling in the right angle direction to avoid obstacles, and further rotating in the opposite direction. Even when traveling, the radio wave propagation surface between the antennas and the directivity can be selectively opposed to each other to continuously transmit a high-quality signal.

The above embodiment is an embodiment relating to one information transmission from the mobile station to the fixed station. Next, an embodiment of bidirectional communication will be described.

FIG. 5 is a diagram showing an example of a system configuration for transmitting a control signal from the fixed station to the mobile station in addition to the video information transmission system from the mobile station to the fixed station, and FIG. 6 shows the configuration of the mobile station. It is a figure.

In FIG. 5, while observing the video output display of the receiver of the fixed station 101 of FIG. 1, the fixed station 101 modulates a control signal for controlling the traveling direction A, traveling speed S, etc. of the mobile station,
Radio transmitters 921, 92 having a function of transmitting to mobile stations
2 are provided. 931 and 932 are the antennas. Since the information transmitted from the mobile station to the fixed station requires a wide band as a video signal, the information transmitted by this wireless transmitter is simple. Therefore, for example, the bandwidth is 100 kHz or less, the frequency is 10 MHz to 100 MHz, and the electrolysis is performed. Strength is 3
m is a distant position, and wireless communication by frequency modulation of 500 μV / m or less is sufficient.

The mobile stations 710 and 720 in FIG. 6 include television cameras 91 and 92, transmitters 711 and 712, antennas 81 and 82 for transmitting video information, control signal receiving antennas 731 and 732 for receiving control signals, and reception. Control signal receiver 74 for converting the generated control signal to an intermediate frequency and demodulating it
1, 742, and control devices 751 and 752 for controlling the traveling direction and traveling speed of the mobile station.

With the above configuration, the mobile station 710 of the channel CH1 will be described. First, on the fixed station 101 side, the receiver 91 of the channel CH1 of the fixed station 101 is described.
While viewing the received video output display from the mobile station 710 by 1, the operator sends a control signal for controlling the traveling direction, traveling speed, etc. to the mobile station 710 from the wireless transmitter 921 to a carrier frequency different from the video reception frequency. Modulate with and wireless transmitter 9
Wireless transmission is performed from the antenna 931 from 21. Mobile station 71
The control signal receiving antenna 731 of 0 receives this control signal, and the control signal receiver 741 converts the received signal of the control signal into an intermediate frequency and demodulates it. The control device 751 operates by the demodulated control signal, and the traveling direction, traveling speed, etc. are controlled. This is the channel CH
The same applies to the two mobile stations 720.

As described above, with the configuration of at least two systems of the planar multi-antenna laid in large numbers, it is possible to stably transmit the video information from the mobile station to the fixed station side. It is possible to send and receive data information such as control signals from the fixed station to the mobile station.

The moving body not only moves linearly along the traveling surface, but also travels in a right angle direction in order to avoid obstacles, and further rotates in the opposite direction and travels. In some cases, in this embodiment, the fixed station selectively opposes the propagation surface of the radio wave between the antennas and the directivity, and while continuously receiving a high-quality signal, the data such as the control signal is received. The information can control the traveling direction, speed, etc. of the mobile station. Therefore, as an example of the moving body in FIG.
For example, a luggage carrier and a radio-controlled robot are optimal.

Here, the video information transmission bandwidth with respect to the carrier of the video information transmission frequency differs depending on the modulation method, but if frequency modulation is used, the wider the band, the better the signal / noise ratio and the ambient noise. , More effective video information transmission is possible. For example, the transmission bandwidth is preferably about 6 MHz or more. When the traveling surface extends over a long distance, the planar multi-antenna 100 is divided into blocks,
Reducing the effects of noise and disturbances is easily achieved.

It should be noted that each mobile station has information related to it, such as audio information or GPS, in addition to the image of the television camera.
(Global Positioning System by Satellite) After modulating information such as position data of a signal (generally, the function of a modulator for modulation in a transmitter is a method which is usually performed) Is also good.

In the above description, the dipole antenna has been described as an example of the unit antenna of the fixed station, but it goes without saying that the present invention can be implemented without being limited to this. Although the antenna of the mobile station is described as a rod-shaped antenna as an example, a spiral antenna may be used.

[0046]

According to the present invention, video information having a wide bandwidth is required as high-quality video information and related information at any position, always facing each other between the mobile station and the fixed station. Information can be obtained easily and easily. In particular, even when the mobile station travels in all directions, signal fading due to fading phenomenon and phase shift, and S / S
The deterioration of N (signal / noise) can be relatively ignored, the level of image quality can be maintained, and high-quality video information and related information can always be opposed between the mobile station and the fixed station side at any position. Then, constant information can be obtained easily and easily.

Further, the transmission power of the mobile station is low and the mobile station can be operated efficiently, so that the apparatus can be provided simply and at low cost. Furthermore, by setting the output of the antenna to a weak electric power, it operates within the operating distance and range to avoid interference with other video information transmission systems, and the operating frequency is set arbitrarily without legal restrictions. It is possible to

Furthermore, since the multi-antenna on the fixed station side has a planar shape, it can be operated so as to cover the moving range of the moving body and can be installed without requiring a large space.

Further, the control information can be wirelessly transmitted from the fixed station and received by the dedicated antenna of each mobile unit so that each mobile station can be easily controlled wirelessly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a planar configuration of a multi-antenna and a system configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a plane configuration of a multi-antenna and a system configuration according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a mobile station configuration and a multi-antenna according to an embodiment of the present invention.

FIG. 4 is a block diagram of a transmission level selection circuit according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a planar configuration of a multi-antenna and a system configuration according to an embodiment of the present invention.

FIG. 6 is a block diagram showing a mobile station configuration and a multi-antenna according to an embodiment of the present invention.

[Explanation of symbols]

7, 7'Mobile station 8, 8'Mobile station antenna 11, 12, 21, 22, 31, 32, 41, 42 Antenna element, 52, 52 'Matching device, 54, 54' Combiner, 55, 55 'Amplifier , 80, 80 'Coupling distributor, 90, 90' Transmission level selection circuit, 91, 91 'Receiver, 100 Planar multi-antenna

Claims (9)

[Claims] 1. In a system for transmitting and receiving information between a mobile station and a fixed station via an antenna, the antennas on the fixed station side are alternately arranged so that a plurality of antennas have alternate directivity over the moving range of the mobile station. A planar multi-antenna device for an information transmission system, characterized by being arranged in an array. 2. In a system for transmitting and receiving information between a mobile station and a fixed station via an antenna, the fixed station side antenna is a multi-antenna group in which a plurality of unit antennas having the same directivity direction are arranged. A plurality of sets of multi-antenna groups are provided, and the unit antennas forming the multi-antenna groups are arranged in a staggered manner so that unit antennas having the same directivity direction are not adjacent to each other. A planar multi-antenna apparatus for an information transmission system, characterized in that information is wirelessly transmitted between antennas on the station side. 3. The information transmission system according to claim 2, wherein the antenna provided in the mobile station and the multi-antenna on the fixed station side are provided close to each other at a wavelength of 2λ or less of a radio transmission frequency. Planar multi-antenna device. 4. The planar multi-antenna apparatus for an information transmission system according to claim 2, wherein the multi-antennas of each group are arranged in a directivity direction of 90 ° ± 45 °. 5. The multi-antenna apparatus for an information transmission system according to claim 1, wherein the multi-antenna is arranged on at least one of a moving road surface, a moving ceiling surface, and a moving wall surface on which the mobile station runs. 6. The unit antenna forming the fixed station antenna is a planar antenna.
Alternatively, the multi-antenna device for the information transmission system according to claim 2. 7. A system for transmitting / receiving information between a mobile station and a fixed station via an antenna, wherein the fixed station side antenna is a multi-antenna group in which a plurality of unit antennas having the same directivity direction are arranged. A plurality of sets of the multi-antenna group are provided, and the multi-antenna groups are alternately arranged so that the unit antennas forming the multi-antenna group are not adjacent to each other with unit antennas having the same directivity direction. An information transmission system characterized in that, in the fixed station for wirelessly transmitting information in proximity to the antennas on the fixed station side, the reception outputs of the multi-antenna groups having different directivities are compared and the larger one is selected. 8. The mobile station according to claim 7, wherein the mobile station is equipped with a television camera, and video and related information from the mobile station television camera are wirelessly transmitted and received by the fixed station via the multi-antenna. An information transmission system characterized in that 9. The multi-antenna according to claim 7, wherein the multi-antenna is arranged over a moving range of the mobile body so that a propagation surface of a radio wave radiated from the multi-antenna faces a radio-wave propagation surface of the mobile body antenna. Information transmission system.