JPH08340284A - Multi-antenna device and information transmission system using multi-antenna - Google Patents

Abstract

PURPOSE: To realize the video information of a wide band width to the video information and related information of improved quality and to simply and easily provide the information quality of more than a fixed level continuously facing each other at all times between a mobile station and a fixed station side at any position by using a specified multi-antenna group. CONSTITUTION: A planar multi-antenna 100 is constituted by arranging and coupling many pieces of respective planar unit antennas 11, 12 and 21, 22.... Also, the multi-antenna 100 is connected to a fixed station 101 from respective couplers 54a and 54b, amplifiers 55a and 55b and coupling distributors 80a and 80b further. Then, radio waves from the mobile station are received by at least two multi-antenna groups whose phases are mutually different. In the fixed station, for the radio waves received by the respective multi-antennas, the larger group is selected and utilized for respective channels. Since common- mode components are dominant for the radio waves received in the same group, the reception output of the respective unit antennas 11, 12 and 21, 22 are added and emphasized.

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 device that enables efficient wireless transmission and an information transmission system using the antenna.

[0002]

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

In addition, electromagnetic coupling is used for information transmission between an elevator car used in an elevator or the like and a line, and its electric power is weak and extremely close to a line (about a dozen millimeters). The range of application was limited.

Further, the conventional planar antenna uses one opposing antenna for transmitting and receiving in space.

[0005]

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, It is necessary to increase the output of the station antenna. For this reason, the output power of the transmitter becomes large, and
In order to increase the gain of the antenna, the antenna device on the fixed station side has a drawback that it becomes large like a parabolic antenna or a Yagi antenna.

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.

In particular, it has been extremely difficult to continuously obtain information quality of a certain level or higher by always facing each other between the moving body and the fixed station due to the phase difference and the output difference of the radio wave propagation of the antenna.

Further, according to the present invention, when transmitting image information between the transmitting and receiving antennas, various standing waves are generated due to multiple paths propagating in transmission, and due to fading phenomenon and phase shift. , 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 an antenna and a system that can easily and easily obtain information quality of a certain level or higher continuously facing each other.

Another object of the present invention is to provide a device for a mobile station with a low output, which is simple and inexpensive.

[0010]

In order to solve the above problems, a multi-antenna apparatus for a fixed station according to the present invention is a flat unit over a traveling surface on which a moving body moves over a predetermined position and range. A large number of antennas (single antennas that also function as one antenna) are laid and connected to each other to form at least two multi-antenna groups. Further, the arrangement of unit antennas belonging to the same group is
A multi-antenna group was placed by arranging it in the range of radio wave propagation with in-phase components as the main component. Further, the unit antennas belonging to each group are arranged in a staggered manner so that those belonging to the same group are not adjacent to each other, and the unit antennas belonging to different groups are arranged so as to have mutually different phases.

Further, according to the present invention, selection means is provided for comparing the signal outputs from the multi-antenna groups having different phases with each other and selecting the larger one.

Further, in the information transmission system of 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 and the unit antenna on the fixed station side are kept close to each other, The output power of the antenna of the mobile station is transmitted with a small amount of power and further with a weak amount of power.

[0013]

The radio wave from the mobile station is received by at least two multi-antenna groups having mutually different phases. At the fixed station, the larger group of radio waves received by each multi-antenna is selected and utilized for each channel. Since radio waves received by the same group are mainly composed of in-phase components, the reception outputs of the unit antennas are added and emphasized.

In the information transmission system using such a multi-antenna, the output power of the antenna of the mobile station is reduced, and further, the output power of the antenna of the mobile station is further reduced while maintaining the distance between the antenna of the mobile station and the multi-antenna of the fixed station close to each other. It can be transmitted with weak power.

[0015]

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 large number 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 this antenna is laid.

Regarding a single plane antenna (hereinafter referred to as a unit antenna) itself, March 25, 1993
This is a well-known technology as described in "Latest planar antenna technology" published by Japan Technology Center, Inc. Here, the planar antenna or the planar antenna in the present invention refers to a planar arrangement of the elements constituting the antenna, and various shapes such as a curved surface and a corrugated shape are conceivable instead of a plane having an accurate meaning.

In FIGS. 1 and 2, 11, 12, and 2 are shown.
Each of 1, 22, ... Shows a planar dipole unit antenna. 51a and 51b are planar unit antennas 11,
12 and the leader lines (or feeder lines) of the planar unit antennas 21 and 22, 52a and 52b are well-known matchers for impedance matching, 53a and 53b are coaxial cables,
54a is a coupler for coupling (mixing) the planar unit antennas 11 and 12, 54b is a coupler for coupling (mixing) the planar unit antennas 21 and 22, and 55a and 55b are couplings. It is an amplifier connected to the device 54a and the coupler 54b.

In this way, each planar unit antenna 11,
The planar multi-antenna 100 is configured by arranging and coupling a large number of 12 and 21, 22, .... In the drawing, many antennas are laid and a part of the antenna is shown. The multi-antenna 100 includes the couplers 54a, 54
b, amplifiers 55a and 55b, and coupling / distributor 80a and 8
0b is connected to the fixed station 101.

According to the present invention, a large number of such antennas are laid continuously along the traveling surface not only on the floor surface but also on the side wall surface, the ceiling surface and the like. Depending on the traveling pattern and character of the moving body, the location where the cable is laid is set at the position where it is most easily received.

Here, as an example of the planar unit antenna, a well-known triangular planar dipole antenna is shown.

The size is l≈1λ / 6 to λ (l is the length of a unit antenna, λ is the length of one wavelength), and θ≈30 ° to 9 °
The angle is 0 ° (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 of the transmission frequency at this time is, for example, about 100 MHz to 10 GHz, and the electric field strength of the weak radio wave is 500 μV / m or less at a position 3 m away.

Here, a feature of the present invention is that the phases of radio wave propagation of the unit antennas and their outputs are connected so that the in-phase components that complement each other are the main components, and they are configured as one group, and at least two such groups are formed. One or more unit antennas of each group are arranged so that the unit antennas belonging to the same group do not adjoin each other and are positioned alternately. 1 and 2 show a group of planar unit antennas 11 and 12 and a group b of planar unit antennas 21 and 22 that have the same directivity and the phase of the radio wave propagation of the antenna is mainly in-phase components. The two-system multi-antenna 100 is configured.

Further, the installation angle α (see FIG. 5) of the directivity of the unit antennas constituting the group varies depending on the curve of the running surface, but is usually arranged at ± 45 degrees, but preferably ± 30 degrees, 0 degrees (when the running surface is straight) is optimal.

FIG. 5 is a plan view showing the arrangement of the unit antennas belonging to the same group. The unit antenna 1 shown by the broken line in FIG.
2'for the unit antenna 11 and the grounding angle α is about 10
The following shows an example of installation.

FIG. 3 shows each mobile unit which is a mobile station and its antenna, and the multi-antenna 10 on the fixed station side shown in FIGS.
FIG. 6 is a side view of an example showing a positional relationship with 0.

In FIG. 3, as an example, the planar multi-antenna 100, the lead wire, the coaxial cable and the like are arranged on the shield ground plate 6 through the space or the dielectric 5, but other than the antenna. May be below the shield ground plate 6.
Reference numeral 61 is a traveling plate having a traveling surface on which the mobile stations 71 and 72 travel. The mobile station 71, 72 has its antenna 81,
Reference numeral 82 is 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 television cameras, and 711 and 712 are transmitters, and their output terminals are connected to antennas 81 and 82, respectively. 721, 722
Indicates a driving control device.

Considering multipath, the shortest distance between the antennas 81 and 82 of the mobile station and the multi-antenna 100 is 2
It is preferable to set it to λ or less, preferably λ / 2 or less, but if it is λ / 30 or less, the antennas are too close to each other and are easily affected by changes in the distribution of electrolytic strength. Therefore, the optimum value is λ / 3.

FIG. 4 shows a group selection circuit 90 provided for each channel.
FIG. 2 is a block diagram (for one channel) of the multi-antenna group, for example, two groups a and b with different antenna phases.
The output of the system is input and connected to the switching circuit 90.

This operation will be specifically described below with reference to FIGS. 1, 2, 3, and 4.

The fixed station 101 obtains a required signal level 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. 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.

As shown in FIG. 4, the video signal output of the receiver 91 is connected to the sync signal separation circuit 902 of the group selection circuit 90 to separate the sync signal, and the output of the sync signal is the sync signal level judgment. It is input to the 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, as is generally known, the sync signal is easily separated from the video signal in that it is distinguished from the video signal in terms of timing and is opposite in sign. 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 having such a property 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. Switching circuit 901
In response to this switching instruction, the antenna group is switched 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 into the base band. Reproduced in video information.

FIG. 5 shows unit antennas belonging to the same group, (a) corresponding to FIG. 1 and (b) corresponding to FIG. As shown in the figure, generally, the distance between the unit antennas 11 and 12 is L, the distance between the mobile station antenna 81 or 82 and the unit antenna 11 is A, and the mobile station antenna 81 or 82.
If the distance between the antenna and the unit antenna 12 is B, the phase and the output difference of the signals received and combined by the antennas 11 and 12 from the antennas 81 and 82 of the mobile station are in phase when the phase difference is λ, and the mobile station And the output of the reception level according to the distances A and B of the fixed station antenna is the sum.

When the distance L between the unit antennas has a phase difference λ / 2, the phases are completely opposite to each other, and the mobile station and the antennas 11 and 12 are
The output becomes a difference between the reception levels depending on the distances A and B, and the output becomes extremely small.

For example, if the distance between the antennas 11 and 12 is L≈
When 2λ is set, the distance A between the mobile station antenna and the unit antenna 11 and the distance B between the mobile station antenna and the unit antenna 12 are set.
However, at the positions of A≈3λ / 4 and B≈5λ / 4, B−A =
It becomes λ / 2. Similarly, at the positions of A≈5λ / 4 and B≈3λ / 4, AB = λ / 2. (Actually, it is not planar but three-dimensional, and it is not a straight line, but the basic idea is the same.) In other words, depending on the value of L, the mobile station receives radio waves of opposite phases.

In order to solve this, the present invention installs the unit antennas 11 and 12 of the multi-antenna group a so that they can receive in-phase signals, and another multi-antenna group b is provided between the group a and It is designed to receive radio waves of phases.

When the mobile stations 71 and 72 travel linearly in a fixed direction on the traveling surface 61, the transmission and reception radio wave propagation in the group a of the planar multi-antenna 100 is almost the same. In the range where the outputs become the sum, the group selection circuit 90 of the fixed station 101 can select a high-quality output signal of the group a and input it to the receiver 91. In the range where the outputs of the transmission and reception radio waves in the group b of the planar multi-antenna 100 have almost the same phase, the group selection circuit 90 of the fixed station 101 selects the high-quality output signal of the group b. It can be input to the receiver 91. With such a configuration, video information in a wide band can be wirelessly transmitted with low power and low power efficiently, with high quality, at low cost, and with a simple configuration. Further, the video information of the mobile station does not always move linearly along the traveling surface. Even when the traveling surface is curved, the radio wave propagation surface between the antennas and the phase output can be selectively corresponded to each other to continuously transmit a high-quality signal. Further, when the mobile station travels linearly in a fixed direction, the directivities of the antennas 81 and 82 and the multi-antenna 100 match, and it goes without saying that higher quality signals can be continuously transmitted.

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. 6 is a diagram showing a system configuration example 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. 7 shows the configuration of the mobile station. It is a figure.

In FIG. 6, the fixed station 101 has a receiver 91.
Radio transmitters 921 and 922 having a function of modulating a control signal for controlling the traveling direction and traveling speed of the mobile station and transmitting the modulated signal to the mobile station while watching the video output displays of 1 and 912 are provided. 931 and 932 are the antennas.

Since the transmission information from the mobile station to the fixed station requires a wide band in the video signal, the information transmitted by this wireless transmitter is simple, so that the bandwidth is, for example, 100 kHz.
z or less, the frequency is 10 MHz to 100 MHz, and wireless communication with specific low power is sufficient.

The mobile stations 710 and 720 in FIG. 7 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.

The mobile station 710 of the channel CH1 having the above configuration will be described. First, on the fixed station 101 side, the receiver 91 of the channel CH1 of the fixed station 101 is described.
1, while watching the received video output display from the mobile station 710, the operator sends to the mobile station 710 a control signal for controlling the traveling direction, traveling speed, etc., from the wireless transmitter 921, which is different from the video reception frequency. The signal is modulated by the frequency and wirelessly transmitted from the wireless transmitter 921 through the antenna 931. Mobile station 7
The control signal receiving antenna 731 of 10 receives this control signal, and in the control signal receiver 741, the received signal of the control signal is converted into an intermediate frequency and demodulated. The control device 751 operates by the demodulated control signal, and the traveling direction, traveling speed, etc. are controlled. This is channel C
The same applies to the mobile station 720 of H2.

In this way, the group configuration of at least two systems a and b of the planar multi-antenna laid in large numbers enables stable transmission of video information from the mobile station to the fixed station side, and further, , It is possible to transmit and receive data information such as control signals from the fixed station to the mobile station related to the video information.

Such an information transmission system is, for example,
It can also be used to exchange information between the elevator car (mobile station) and the elevator control and monitoring device.

Furthermore, the moving body is
Not only traveling linearly but also traveling in a meandering manner to avoid obstacles, in this embodiment, a fixed station selects a receiving antenna group to continuously receive a better signal. At the same time, the traveling direction, speed, etc. of the mobile station can be controlled by the data information such as the control signal. Therefore, as an example of the moving body in FIG. 7, for example, a luggage carrier or a radio-controlled robot is most suitable.

Here, the video information transmission bandwidth with respect to the carrier of the video information transmission frequency differs depending on the modulation method. 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 the video of the television camera, such as audio information, or GPS.
(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.

According to the embodiment described above, the image quality level of the video information having a wide bandwidth can be maintained, and the high quality video information and the related information can be easily and easily obtained at any position. In addition, the transmission power of the mobile unit is small and the mobile unit can be efficiently operated, so that the device can be provided at a low cost. Moreover, since the multi-antenna on the fixed station side has a planar shape, it is possible to install the multi-antenna 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.

[0055]

According to the present invention, video information having a wide bandwidth is provided as high-quality video information and related information at any position continuously facing the mobile station and the fixed station. Thus, the necessary information can be easily and easily obtained. In particular, even when the mobile station is meandering in a certain direction, it is possible to relatively ignore signal disturbance and S / N (signal / noise) deterioration due to phase shift, and maintain the level of image quality. As high-quality video information and related information, it is possible to easily and easily obtain continuously fixed information between the mobile station and the fixed station at any position, always facing each other.

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 a 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

Further, 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.

Furthermore, 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 multi-antenna and a system configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a planar 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 basic configuration diagram showing an antenna plane shape and a positional relationship of the present invention.

FIG. 6 is a block diagram showing a configuration of a planar multi-antenna and a bidirectional information communication system according to an embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a mobile station, a multi-antenna, and a bidirectional information communication system according to an embodiment of the present invention.

[Explanation of symbols]

 71, 72 Mobile station 81, 82 Mobile station antenna 11, 12, 21, 22 Unit antenna, 52a, 52b Matching device, 53a, 53b Coaxial cable 54a, 54b Combiner, 55a, 55b Amplifier, 90 Transmission level selecting circuit, 91 Receiver, 100 Planar multi-antenna 101 Fixed station

Claims (9)

[Claims] 1. A plurality of planar unit antennas are laid on a traveling surface on which a mobile body moves and connected to each other to form at least two multi-antenna groups, and further, the unit antennas belonging to the same group are arranged. A multi-antenna device for an information transmission system, characterized in that the phases of received radio waves are arranged in a range of radio wave propagation mainly composed of in-phase components, and adjacent unit antennas belong to different groups. 2. The multi-antenna apparatus for an information transmission system according to claim 1, wherein the unit antenna forming the multi-antenna is a planar antenna. 3. The multi-antenna apparatus for an information transmission system according to claim 1, wherein the unit antennas belonging to the same group are arranged with a difference in directivity direction of ± 45 degrees or less. 4. A multi-antenna apparatus for an information transmission system, wherein the multi-antenna according to claim 1 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. 5. A plurality of planar unit antennas are laid on a traveling surface on which a mobile body moves, and are connected to each other to form at least two multi-antenna groups. Further, the unit antennas belonging to the same group are arranged. , The phase of the received radio wave is arranged in the range of radio wave propagation of the in-phase component, and adjacent unit antennas are configured to belong to different groups, a fixed station multi-antenna, an antenna provided for the mobile station, and An information transmission system using a multi-antenna, characterized in that information is wirelessly transmitted between antennas on a fixed station side. 6. A plurality of planar unit antennas are laid on a traveling surface on which a mobile body moves, and are connected to each other to form at least two multi-antenna groups. Further, the unit antennas belonging to the same group are arranged. , The phase of the received radio wave is arranged in the range of radio wave propagation of the in-phase component, and adjacent unit antennas are configured to belong to different groups, a fixed station multi-antenna, an antenna provided for the mobile station, and Information using a multi-antenna characterized in that the fixed stations wirelessly transmit information in close proximity between the antennas on the side of the fixed station, and the fixed stations compare the received outputs of the multi-antenna groups and select the larger one. Transmission system. 7. The information according to claim 5, wherein an antenna provided in the mobile station and a unit antenna belonging to the same group on the fixed station side are provided close to each other at a wavelength of 2λ or less of a radio transmission frequency. Multi-antenna device for transmission system. 8. The mobile station according to claim 5, 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 using a multi-antenna characterized by the following. 9. The multi-antenna according to claim 5, 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 using multi-antenna.