JPS62178027A - Line setting system in mobile radio communication - Google Patents

Abstract

PURPOSE:To safely and accurately use a line by automating the initial setting of a picture information transmission line completely between a base station and a mobile station such as an aircraft so as to minimize the line interruption due to a hindrance at the time of a TV radio wave being an azimuth reference and a radio wave of an ordering line are in the arrival range. CONSTITUTION:The direction of a TV radio wave 12 from a transmission antenna 11 of a TV broadcast station 10 is found via a direction finder antenna 21 of a helicopter station 20, and a picture information transmission antenna 22 is directed to a base station 60 to send a test signal. Further, the station 20 sends an azimuth command to the station 60 via an ordering line whip antenna 23, the station 60 receiving command directs a picture information reception antenna 62 in the direction of antenna 22 to set a picture information line 2. Then the station 60 switches the mode into the automatic tracing, the signal representing the line setting end to the station 20 through the ordering line 1 and the station 20 switches the mode of the antenna 20 to the automatic direction. Then the line interruption due to a fault within a prescribed range is minimized and the utilizing efficiency of the line is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a line setting method for mobile radio communication, in particular, to transfer image information from an aircraft layer such as a helicopter (hereinafter referred to as a "heli station") to a ground station that is a base. This invention relates to a line setting method that automatically directs the antennas of the base station and helicopter station toward the other station in the initial setting of a line for transmitting data to a base station (hereinafter referred to as a "base station").

(Prior art) When communicating by voice for news gathering, information collection, transmission of commands, etc. by helicopter, it is usually VH.
The line is set up using an omnidirectional antenna or a broad directional antenna in the F or LIHF band,
The reach is long and there are no particular difficulties in setting up the line.

However, when performing image transmission such as television relay, the required frequency band is wide and a high S/N is required, so a high receiving electric field is required. Furthermore, since the microwave band is used as the carrier wave, the range is short, and there is a problem in that the line is likely to be disconnected if the helicopter goes behind cover.

When transmitting image information from a helicopter station to a base station over a relatively short distance, use an omnidirectional antenna on the helicopter station side, a directional antenna on the base station side, and equip the receiving station with an automatic tracking device. , Automatic tracking of the direction of a helicopter is being carried out. The automatic tracking device here is one that receives radio waves from a transmitting station, automatically finds the direction, and automatically directs the antenna in that direction.

On the other hand, when long-distance transmission is required, the antenna power of the transmitting station cannot be increased further to ensure the required electric field because the antenna power of the helicopter is limited to 5 watts.

For this reason, a directional antenna is also used on the helicopter station side, and an automatic pointing device is installed to automatically direct the antenna in the direction of the base station. The automatic pointing device here is one that sends the azimuth of the heli station measured by the base station to the heli station as a command, and the heli station calculates the azimuth of the base station from this command and directs the antenna in that direction. Here, the command signal is continuously transmitted through a line different from the image signal, for example, a meeting line.

(Problems to be Solved by the Invention) A problem in the mobile radio communication described above is the initial setting of the line. The directivity of a helicopter station's antenna is generally broad, with a half-width of approximately 30 degrees, so some errors are acceptable, but the directivity of a base station's antenna is sharp and its half-width is approximately 2 degrees, so the helicopter's If the location is not clear, it is not easy to find this direction. Therefore,
First, the approximate location is obtained through a meeting line using an omnidirectional antenna, the helicopter station manually points the antenna toward the base station, the base station also manually captures the helicopter station's radio waves, and then switches to automatic mode and performs the above procedure. It enters into automatic directed behavior. Capturing radio waves from helicopter stations at base stations is a technique that requires extremely high skill, and has become an operational problem.

The next problem is when the helicopter goes behind something such as a mountain or a building. In this case, since the image signal uses the microwave band, there is a high possibility that the line will be disconnected, and if the image signal line is disconnected, the base station will not be able to automatically track the current position of the edge station. It becomes impossible to send the corresponding command. Therefore, the antennas of the base station and the edge station remain oriented in the direction immediately before the helicopter enters the cover. If the helicopter comes out of the shadows again, the received electric field may drop to such an extent that automatic tracking is no longer possible and the line may be interrupted. At this time, we tried to restore the line by manually adjusting the direction of the antenna at the base station.
If recovery is not possible, it will be necessary to redo the initial settings, but such work is troublesome and has the disadvantage that image signals cannot be transmitted during this time.

The present invention provides means for solving the problems described above, and its first purpose is to automatically perform initial settings that require skill and to easily and quickly set up a line.

The second purpose is to immediately set up a line even if the edge station is behind cover or the like and the line is interrupted, thereby minimizing the time during which the line is interrupted.

(Means for Solving the Problems) The present invention equips a helicopter station with an automatic direction finder, and can receive signals from television broadcasting stations with large antenna power that can be received from the nearest station anywhere in the country.

By detecting the direction of this broadcasting station using the radio wave as a reference radio wave, and calculating the direction of the base station from this direction, the antenna for transmitting image information is directed in the direction of the base station, and the antenna for transmitting image information is pointed in the direction of the base station. An azimuth command signal from the edge station is sent to the base station, and the base station initializes the image line by directing an antenna for receiving image information in this direction. Once the line is established, the normal method is for the base station to switch to an automatic tracking device and perform automatic tracking. As this automatic tracking device, a known monopulse type device may be used, and for example, the device disclosed in Japanese Patent Laid-Open No. 56-74670 “Tracking Device” filed by the applicant can be used. During automatic tracking, the base station sends a command for the direction of the helicopter station to the helicopter station, and the helicopter station automatically directs the antenna in the direction of the command. Although a known direction finder such as a goniometer may be used as the automatic direction finder at the helicopter station, it is also possible to use a helical antenna, etc., swung over a predetermined angular range, as it has a simple configuration and can be manufactured in a small size. It is preferable to use a method of finding the peak of the antenna output. In the present invention, the base station does not perform automatic tracking after the initial setting, but continuously calculates the direction of the base station based on the television radio waves with high antenna power as in the initial setting. Alternatively, a method may be adopted in which a command signal is sent to the base station and the antenna is directed in that direction. However, in this case, since direction finding by the helicopter is not performed in real time, a base station with sharp directivity may temporarily lose the direction of the helicopter, so after setting up the line, switch to automatic tracking as described above. is preferable.

In the above description, a case has been described in which television radio waves are used as radio waves used as a reference for direction, but shortwave broadcast radio waves or other continuous transmission waves may be used as long as there is an electric field necessary for direction finding. Alternatively, you may use dedicated radio waves,
It is also possible to use the radio waves of the meeting line itself.

In the past, automatic direction finders were not used because they were more complicated and heavier than automatic pointing devices, making them unsuitable for mounting on helicopters. However, recent advances in the miniaturization of various parts and the miniaturization of computer-based data analysis devices In addition to advances in technology for making the antenna smaller and lighter, the present invention employs a simple method of shaking the antenna, and simplifies the configuration of the receiving circuit to receive television radio waves with large antenna power. The system was successfully developed, and it became possible to mount an automatic direction finder on a helicopter station.

(Function) As explained above, in the present invention, the helicopter station determines the direction of the base station based on the direction of the television radio waves, directs the helicopter station's antenna in this direction, and sends a command signal to the base station. Initial setting of the line can be performed by directing the antenna of the sending base station in the direction of the heli station.

When a helicopter is in flight, there are no obstacles between the reference radio wave radiation source and the helicopter station antenna, so television radio waves propagate in free space, and can travel over considerable distances from the television transmitting station.
For example, sufficient reception is possible even at a distance of about 150 km. In addition, the meeting line can also be sufficiently received. Therefore, according to the present invention, it can be considered that automatic line initialization is always possible within the flight range normally required for helicopters.

If the helicopter goes behind cover and the image signal line is disconnected, automatic tracking by the base station will no longer be possible, but television radio waves can often be received, and the meeting line is rarely disconnected, so the default setting is By switching to , both antennas can maintain the direction of the other station even in the shadows. Therefore, when the helicopter emerges from behind cover, the image line is immediately restored. Even if television signals cannot be received or the meeting line is disconnected, once the line is restored, the initial settings will be automatically performed again as described above, allowing the line to be restored quickly. can.

(Example) Next, embodiments will be described with reference to the drawings.

FIG. 1 is a diagram illustrating the configuration of a method for initially setting a wireless communication line between a heli station and a base station by detecting the direction of television broadcast waves at the heli station. Television broadcast radio waves 12 from a transmitting antenna 11 of a television broadcast station (hereinafter abbreviated as "rTV station") 10 are direction-searched via an antenna 21 of a helicopter station 20, and an antenna 22 for transmitting image information is sent to a base station 60. A test signal is sent to the target. On the other hand, the heli station 20 sends a base station azimuth command signal to the base station 60 via the whip antenna 23 via the meeting line 1. The base station 60 receives the azimuth command signal via the antenna 61 and directs a directional antenna 62 for receiving image information in that direction. When the test signal has been received, the image information line 2 has been set up, so the base station 60 switches to automatic tracking, sends a line setting completion signal to the edge station 20 on the meeting line 1, and then connects this meeting line. It sends the helicopter station's orientation command signal through the terminal. The helicopter station 20 switches the antenna 22 to automatic pointing in response to a line setting completion signal, and then automatically directs the antenna 22 toward the base station 60 in response to a command signal from the base station 60.
Sends an image information signal. In this case, when automatic tracking is not performed at the base station 60, a command signal is sent from the helicopter station 20 to the base station 60 via the meeting line 1 following the initial setting, and the base station determines the directivity based on this command signal. Automatic pointing of the antenna 62 is performed.

FIG. 2 is a configuration diagram of the antenna and each device in the helicopter station 20. The direction of television radio waves can be determined by rotating the antenna of an automatic direction finder, such as a helical antenna, in a horizontal plane and determining the angle at which the induced voltage is maximum (if the television radio waves are horizontally polarized). To do this, the helical antenna 21 is rotated by a predetermined angle via the rotating device 25 according to instructions from the processor 24, and the output of the television receiver 26 is applied to the processor 24 to detect the direction of the television radio waves. As a rotating device,
Sensors, servo motors, tacho generators, sa.

- A known configuration consisting of a Boa amplifier may be used.

In order to know the direction of television radio waves, as shown in FIG. All you have to do is ask. This angle θ indicates the angle of the television radio wave with respect to the helicopter. This value of θ is added to the calculation device 51.

FIG. 4 shows the positional relationship among the edge station 20, the base station 60, and the TV station 10, where the base station direction β is the direction α of the television radio wave and the T
If the distance d from the V station 10 is known, the position of the heli station 20 is determined, so it can be calculated from this by a computer. The azimuth α of the television radio waves can be determined from the angle θ with respect to the helicopter determined as described above and the azimuth angle of the helicopter itself. Therefore, the azimuth signal from the flags bulb 52 and the azimuth gyro (DC) 53 that detect the direction of the earth's magnetic field and the direction θ of the television radio waves are supplied to the arithmetic unit 51, and the communication between the helicopter and the TV station 10 is An estimated value of distance d is added to calculation device 51 by distance manual device 55 . This distance d is known through the meeting line 1 or read from a map, and manually inputted using the distance manpower device 55. As shown in FIG. 5, the second method of knowing the location of the helicopter station is to know the location of the helicopter station 20 by knowing the azimuths α1 and α2 of the first television station 10A and the second television station 10B. is determined, so
It can also be determined by calculation. This method is simple because it is not necessary to input the distance data d to the calculation device 51. For this purpose, the processor 24 automatically switches the rotating device 25 and the television receiver 26, sequentially determines the directions of the TV station 10A and the TV station 10B, inputs this data to the calculation device 51, and inputs the azimuth angle α1 and the direction of the TV station 10B. α2
All you have to do is ask for.

On the other hand, in order to detect the elevation angle given to the image information transmitting antenna 22, a rolling signal and a pitching signal are applied from a vertical gyro (VG) 54 to the arithmetic unit 51. The azimuth angle and elevation angle data calculated by the arithmetic unit 51 from these signals and the determined position data of the helicopter station are sent to the image information transmitting antenna 22 via the cable 36 to the azimuth angle rotation device 32 and the elevation angle rotation device. 33 respectively to direct the antenna 22 in the direction of the base station 60. The reason why the element of elevation angle is added here is to prevent the electric field from fluctuating depending on the attitude of the helicopter, since the SHF antenna has sharp directivity. An electromagnetic horn or a parabolic antenna is used as the antenna, but a parabolic antenna can be made smaller.

Meeting line 1 is UHF band 350MHz ~ 470MHz
In the frequency band z, it is configured using a voice transmitter/receiver 42 and a whip antenna 23. This configuration allows for sufficient long-distance communication. In the initial setting, an azimuth command signal is received from the computing device 51 and sent to the base station 60, and after the base station enters automatic tracking, a command signal is received from the base station and sent to the computing device 51. The arithmetic unit 51 calculates data to be given to the image information transmitting antenna 22 based on this command signal, the aforementioned rolling, A word, and pitching signals. The voice signals are sent to a base station 60 (not shown) in addition to the voice transceiver 42, and the voice signals from the base station are extracted from the voice transceiver 42 (also not shown) to form a voice line. Further, an image information signal from an image input device 35 such as a television camera is supplied to the antenna 22 via the transmitter 34 and transmitted to the base station 60.

FIG. 6 is an equipment configuration diagram of the base station 60. At the time of initial setting, a command signal from the helicopter station 20 is received by the meeting line 1 via the antenna 61 and the transceiver 63,
This signal is supplied to an automatic tracking device 65 via an interface 64 to direct the SHF antenna 62 in the direction of the edge station 20, and its output is applied to an SHF receiver 66 to obtain an image output. When the line is set, switch to automatic tracking,
The command signal created by the interface 64 is sent to the edge station 20 via the meeting line 1. When the base station 60 does not perform automatic tracking, the automatic tracking device 65 may be replaced with an automatic pointing device (not shown), and the configuration may be such that automatic pointing is performed in response to a command signal from the heli station.

As the meeting line antenna 61, a non-directional antenna such as an antenna with a ground wire or a coaxial antenna may be used. From the transmitter/receiver 63, an audio signal input/output circuit 67 is branched to conduct a meeting by audio. As the automatic tracking device 65, a known device may be used as described above, for example, the one described in Japanese Patent Application Laid-Open No. 56-74670 “Tracking Device” filed by the applicant.
You may also use Next, the outline of this tracking device will be explained.

7A and 7B are external views of a device in which a tracking device is mounted on a pan head and manually performs tracking, and FIGS. 8 to 11 are diagrams illustrating its operation. The automatic tracking device used in the present invention can be constructed by combining it with a rotation device that rotates the antenna in response to a signal from the above device.

This device has four horn antennas 108 to 111 facing toward a parabolic reflector 101, inputs the output to a tracking receiver 103, and when the parabolic reflector does not match the arrival direction of radio waves, and the output signal E of the vertical horn antenna 108, 110 by utilizing the fact that the phase differs depending on the position of the vertical horn antenna.

It takes the difference in G and the difference in the output signals F and H of the horizontal horn antenna 109 and 111, adjusts the direction of the antenna with a servo mechanism so that this difference becomes 0, and finds the direction of the incoming radio wave. . E, F, G, and H are the rat race circuit 123 shown in FIG. 124 and 125, and from the rough trace circuit 123 as shown in FIG. 11(A).
From ΔBL(M)=(E-G), 124, ΔAZ(M)=(F-H) shown in FIG. 11(B), 125
outputs the total sum St1M=([E+F+G+H). FIG. 10 is a system diagram of the tracking receiver 103, and the above ΔBL and ΔAZ are pin diodes 127 and 128.
11, modulated by switching signals (C) and (D) with 90 degree phase differences shown in FIG.
) will result in a signal with the waveform shown. A SUM signal is added to this signal by a rat race circuit 131, and the signal is converted to an intermediate frequency through a bandpass filter 133 and a mixer 134, and further amplified. Further, an AGC circuit 139 is provided to cope with a wide range of changes in the input signal level.

The amplified signal is transmitted to the detector 141 (F
), which is split into two and sent to demodulators 142 and 1.
In addition to 43, the DC component is removed. Demodulators 142 and 143
The same switching signal as that applied to pin diodes 127 and 128 is applied to .
Δ[EL and ΔAZ are separated to form waveforms as shown in FIG. 11 (G) and (H). This is passed through low-pass filters 146 and 147 to (1) and (J) in FIG.

Direct current components ΔEL (DC) and ΔA2 (DC
) is output. If this output is added to an azimuth angle rotation device and an elevation angle rotation device (not shown) of the antenna, and the antenna is rotated so that ΔEL (DC) and ΔAZ (DC) become 0, the antenna can be directed in the direction in which the radio waves arrive. can.

Any known rotating device may be used.

The image information signal is the output signal of the horn antenna 112 placed at the center of the horn antennas 108 to 111, and is converted into the SHF shown in FIG.
In addition to the receiver 66,

Next, various operational problems will be explained with reference to FIG. When the base station 60 is near the television broadcasting station 10, the distance between the heli station 20 and the base station 60 is If the distance between the helicopter station and the base station and the broadcast station is approximately 100 degrees, the angle between the helicopter station and the base station and the broadcast station will become smaller, and it will easily fall within the range of the helicopter station's directivity (approximately 30 degrees). For example, if the distance between the base station and the broadcast station is 1 km, this condition is satisfied if the helicopter station is 2 km or more away from the base station.

At this time, the helicopter station 20 can provide the electric field necessary for reception by the base station simply by pointing the antenna 21 at the broadcasting station 10.

When the helicopter station 20 operates at a short distance from the base station 60,
Even if the helicopter goes behind cover and the image signal is cut off, as mentioned above, it is unlikely that both the television radio waves and the radio waves from the meeting line 1 will be cut off.
'The directions of the antennas 22 and 62 of both J6 and the base station 60 maintain the direction of the other station, and the image line is restored as soon as the helicopter comes out of the shadows. When working remotely, meeting lines or television signals may be cut off. At this time, the antenna 2 of the helicopter station 20 and the base station 60
2 and 62 maintain the direction they were in when the line was disconnected, so the deviation in direction when coming out of the shadows is caused by the base station hitting an obstacle such as a mountain (shown by contour lines) as shown in Figure 12. It is equal to the angle θ between the In this case, the directivity of the antenna 22 of the heli station 20 is an order of magnitude wider than the directivity of the antenna 62 of the base station 60, so the directivity of the antenna of the base station (
(approximately 2 degrees). When the distance between the base station 60 and the helicopter station 20 is n (=50 km) and the width of the obstacle 71 that cuts off radio waves is d (=1 km), θ is 1 degree and 9 minutes, so the helicopter cannot get out of the shadows. The image information line will be restored immediately. The width of the obstacle where θ is 2 degrees is the distance 1
5 for 50km, 1 for 26km and 53km.
Since the distance is 175 m compared to 75 km and 10 km, it can be seen that the direction of the antenna maintains the direction of the other station in the case of a normal-sized building at a short distance and a normal-sized hill at a long distance. If the width of the obstacle exceeds this limit, the line may not be restored immediately, but in this case, when you come out of the shadow, the line will be automatically initialized and the line will be restored within a practical time. I can do it.

FIG. 13 is an example of application to the case where a line is set up between two helicopters. At this time, the heli station 72, which operates as a base station, sends out a dedicated continuous wave, and the heli station 73, which serves as an image information transmission station, is equipped with an automatic direction finder and performs direction finding using the dedicated wave. The image information transmitting antenna is directed toward the helicopter station 72, and an azimuth command is sent to the helicopter station 72 via the meeting line. When the heli station 72 receives this command, it directs the image information antenna toward the heli station 73 using its antenna directing device. In this case, if the approximate location is confirmed in advance through a meeting line and the antenna for the continuous transmission waves is directed in that direction in advance, the line setting can be carried out smoothly and quickly. Edge station 73
The configuration is similar to that shown in FIG. 2, but the above-mentioned dedicated wave is used instead of the television radio wave as the radio wave that serves as the reference for direction. The helicopter station 72 also has a similar configuration to that in FIG.
The automatic tracking device becomes an automatic pointing device, and requires an external dedicated wave transmitter.

FIG. 14 is an example of application in which a helicopter station is used to relay between ground stations. Although a large helicopter is shown in the figure, since the equipment can be made compact, even a small helicopter can perform the relay service satisfactorily. In this case, the configuration is as shown in FIG. 1 between the TV station 10 that transmits radio waves serving as a reference wave, the relay helicopter station 80, and the receiving base station 60, and the configuration between the relay helicopter station 80 and the transmitting ground station 81 is as shown in FIG. The configuration is similar to that shown in Figure 13. Automatic tracking can be performed between the edge station 80 and the receiving base station 60 by the automatic tracking device of the base station 60. By using the relay helicopter station 80 in this manner, image information can be reliably sent in real time even from inconvenient locations such as mountainous areas with high mountains. In this case, the relay distance can be further extended by connecting the edge station to another relay station.

(Effects of the Invention) As explained above, according to the present invention, it is possible not only to completely automate the initial setting of the image information transmission line, which requires skill, in the line that transmits image information from the helicopter to the base station, but also to completely automate the initial setting of the image information transmission line, which requires skill. As long as the standard television radio waves and meeting line radio waves are within reach, line disconnections due to obstacles can be minimized no matter how far away, making the line safe and reliable and increasing the line utilization rate. .

The present invention can be used not only for a line for sending image information from a helicopter to a ground station such as a base station, but also for setting a line for sending image information from a ground station to a helicopter. Furthermore, it can be used to set up lines between stations on the ground, set up lines between helicopters, and can also be used for relaying by helicopter, so it has an extremely wide range of applications.

In the above description, a helicopter is used as the aircraft, but it goes without saying that other aircraft may be used.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the relationship between each station, Figure 2 is a block diagram of equipment installed on a helicopter, Figure 3 is an illustration of the principle of direction finding, and Figure 4 is the direction of the base station based on TV radio waves. Figure 5 is a diagram explaining the principle of calculating the direction of a base station based on two TV radio waves, Figure 6 is a block diagram of equipment installed at the base station, Figure 7A
and B is an external view of the tracking device, Fig. 8 is a layout diagram of the horn antenna of the tracking device, Fig. 9 is an explanatory diagram of the rough trace circuit, Fig. 10 is a block diagram of the tracking receiver, and Fig. 11 is the tracking reception Figure 12 is an explanatory diagram of the influence of obstacles on the image information line, Figure 13 is an explanatory diagram of the line setting method between helicopters, and Figure 14 is a diagram of the relay line setting method for large helicopters. It is an explanatory diagram. 1...Meeting line 2...Image information line 10
, = Television broadcasting station 20... Edge station 21... Antenna for direction finding 22... Antenna for transmitting image information 23... Whip antenna for meeting line 60... Base station 61... Meeting line Antenna 62...
・Antenna for image information reception 72...Helicopter station for reception 73...Helicopter station for transmission 80...Helicopter station for relay 81...Ground station for transmission @Figure 3 Figure 4 +-b- No. 7 Figure A B Figure 8-Y Figure 10 Figure 1I Figure 12 Figure 13 Figure 14

Claims (1)

[Claims] 1. The direction of the reference radio wave is detected by a transmitting station equipped with an automatic direction finder, the direction of the receiving station is calculated from the direction, and the direction of the receiving station is set as the target direction. A directional antenna of a wireless line is directed to the receiving station, and the receiving station is directed to the direction of the transmitting station, and the receiving station is directed to the direction of the transmitting station. A line setting method in mobile radio communications in which a target radio line is set by pointing the directional antenna of the radio line. 2. The line setting method for mobile radio communication according to claim 1, wherein the reference radio wave is a television broadcast radio wave. 3. The line setting method for mobile radio communication according to claim 1, wherein the reference radio waves are continuous transmission waves other than television broadcast radio waves. 4. A line setting method for mobile radio communications according to claims 1 to 3, wherein the transmitting station equipped with the automatic direction finder is an aircraft. 5. A receiving station transmits a dedicated continuous transmission wave, and a transmitting station equipped with an automatic direction finder receives the continuous transmission wave, detects the direction of the receiving station, and locates the target wireless line in that direction. A directional antenna is directed, and the direction of the transmitting station with respect to the receiving station is transmitted to the receiving station via a radio line that is separate from the intended radio link, and the receiving station determines the direction of the intended radio link in the direction of the transmitting station. A line setting method for mobile radio communications in which a target radio line is set by pointing a directional antenna. 6. The line setting method for mobile radio communication according to claim 5, wherein both the transmitting station and the receiving station are aircrafts. 7. A line setting system for mobile radio communication according to claim 5, wherein the transmitting station is a ground station and the receiving station is an aircraft.