JP3330038B2 - Antenna switching device and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plurality of antennas.
Antenna switching device and method for selectively using
For example, mounted on moving objects such as vehicles, trains, ships, etc.
Antennas, especially those driven to point at satellites.
Regarding application to tena.

[0002]

2. Description of the Related Art When an antenna is mounted on a mobile object, it is only necessary to select an installation location so that a single antenna can cover a covered area (the entire area to be transmitted / received). And blocking may occur in the covered area.

Therefore, conventionally, a plurality of antennas are mounted on a mobile body, and the antennas are switched and selected based on a relationship between a geometric antenna directional angle and a preset blocking area. The antenna is avoided so that the entire area can be covered.

[0004]

Since the conventional antenna selection device is configured as described above, the antenna switching is performed only by the relationship between the antenna directivity angle and the blocking region.
There has been a problem that the switching operation of the antenna cannot be performed stably with respect to the posture and position fluctuation of the moving body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has an antenna selection method capable of performing a switching operation stably with respect to a posture or position change of a moving body even around an edge of a blocking area. An object is to obtain a device and an antenna selection method.

[0006]

According to the present invention, there is provided an antenna switching method for switching and using first and second antennas mounted on a mobile object and controlled to point to a satellite. For each antenna, the sharing area of the antenna is set in advance so as not to include a blocking area, which is an area where the antenna cannot see the satellite, and in use, the directivity angles of the first and second antennas are set. and detecting the carrier-to-noise level, first seen from the detection results antenna sometimes first antenna is directed the allocated area, the second antenna has and the first directed to the allocated area When the antenna is not pointing in the sharing area, the second antenna is pointed, and both the first and second antennas point in the sharing area. One of the antenna sometimes depending on carrier-to-noise level does not, we decided to select each. Preferably, when the first and second antenna is not directed to its allocated area either, when the carrier-to-noise level is below a specified level at the antenna which has been selected so far, not been selected until then The other antenna is selected. Alternatively, both the first and second antennas are directed to the sharing area.
If not, when the carrier-to-noise level is below a specified level at the antenna which has been selected until then, so far it is other antenna that was not selected in the carrier-to-noise level at the antenna specified level or higher A certain antenna is selected.

According to the present invention, the satellite
Use while switching the controlled first and second antennas
Antenna switching device for performing the first and second
First and second angle detection for detecting a directivity angle of an antenna
And a carrier-to-noise ratio at the first and second antennas.
Means for detecting bell and antenna switching method according to the present invention
And a switching controller for executing the control.

[0008]

[0009]

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

Embodiment 1 FIG. 1 is a block diagram showing an antenna selecting apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numerals 1 and 4 denote antennas mounted on a mobile body, and reference numerals 2 and 5 denote directional angles of antennas 1 and 4 with respect to satellites. Angle detectors for detection, 3 and 6, drive controllers for driving the antennas 1 and 4 so as to direct the satellites, respectively, 7 a switch for switching the reception signals of the antennas 1 and 4,
Reference numeral 8 denotes a receiver for detecting the carrier-to-noise level of the received signal input via the switch 7, and reference numeral 9 denotes a switching controller, which determines the directional angles of the antennas 1 and 4 detected by the angle detectors 2 and 5 in advance. The antenna switching determination is performed by comparing the set and stored sharing areas A and B, and the antenna is determined by comparing the carrier to noise level of the received signal supplied from the receiver 8 with the previously set carrier to noise level. A switching determination is performed, and an antenna switching control signal is output.

FIG. 2 shows an example of installation of antennas on a mobile unit 10. The two antennas 1, 4 are controlled by a drive controller 3, 6 shown in FIG. Driven.

FIG. 3 shows a driving range of each of the antennas 1 and 4 viewed from above the moving body 10 and a blocking region for each antenna. In FIG. 3, the circumferential direction is the AZ direction, and the radial direction of the circle is the radial direction. The direction is the EL direction, and the center of the circle is the zenith.

[0014] The coverage area is divided into three areas. The hatched area A is the area shared by the antenna 1 determined by the directional angle, and the hatched area B is the antenna 4 determined by the directional angle.
, And the region C is a region shared by either the antenna 1 or the antenna 4 which is determined based on the carrier-to-noise level. The range of the bold line is the driving range of the antenna 1, the range of the broken line is the driving range of the antenna 4, the black range S 1 is a blocking region for the antenna 1, and the black range S 4 is a blocking region for the antenna 4.

Basically, the area A is a blocking area for the antenna 4 but is a visible area for the antenna 1, and the area B is a blocking area for the antenna 1 but is a visible area for the antenna 4. Area C is an area that can be seen with any antenna.

However, in general, blocking is a region having a complicated shape, and it is complicated to determine a shared region in accordance with that. However, in the present invention, the accuracy is not so much required, and the region setting is performed in the region C. Is determined so that there is no blocking in the area A for the antenna 1 and there is no blocking in the area B for the antenna 4.

The determined area is set and stored in the switching controller 9, and the angle detector 2,
By comparing with the directivity angle detected in 5, the positions of the antennas 1 and 4 are detected in real time, and it is determined which antenna can be switched (READY).

It is sufficient that the area C can be covered by any one of the antennas. The switching controller 9 receives the carrier-to-noise level of the received signal, and switches to the other antenna when the level deteriorates and falls below a specified level. Make a logical decision. By doing so, even if there is blocking in the area C, it is possible to switch to the antenna side that should be covered by the carrier-to-noise level determination of the received signal.

FIG. 4 is a timing chart for explaining the above switching operation.

Next, the operation will be described.

[0021] Figure 5 is a Furocha over you want to explain the operation, first, when the operation is started, the switch controller 9 inputs the directional angle of the antenna 1 and 4 detected by the angle detector 2 and 5 (step ST1 ), it determines the antenna by comparing the allocated area a which is previously set and stored as the directivity angle of the antenna 1 is directed to a region a of sharing range (step ST
2).

If the result of the determination is YES, a switching control signal for selecting the antenna 1 is output from the switching controller 9, and the switching unit 7 receiving this switching control signal switches and selects the antenna 1 (step ST3). .

On the other hand, if the result of the determination in step ST2 is N
If O, the directional angle of the antenna 4 is compared with the pre-stored sharing area B to determine whether the antenna is pointing in the area B in the sharing range (step ST4).

If the determination result is YES, a switching control signal for selecting the antenna 4 is output from the switching controller 9, and the switching unit 7 receiving this switching control signal switches and selects the antenna 4 (step ST5).

If the determination results in the above-mentioned steps ST2 and ST4 are both NO, it is determined whether or not an initial closing is performed (step ST6), and if YES, the antenna 1 is switched and selected (step ST7). Thereafter, the switching controller 9 determines whether or not the carrier-to-noise level supplied from the receiver 8 is equal to or higher than a preset carrier-to-noise level (step ST8).
Is selected and held (step ST9), and if NO, the antenna 4 is switched and selected (step ST10). On the other hand, if the decision result in the step ST6 is NO, the switching controller 9
Determines whether antenna 1 is selected (step S
T11) If YES, it is determined whether the carrier-to-noise level supplied from the receiver 8 is equal to or greater than a predetermined value stored in advance (step ST12), and if YES, the antenna 1 is selectively held (step ST13). If NO, the antenna 4 is switched and selected (step ST14).

On the other hand, if the decision result in the step ST11 is NO, the switching controller 9 decides whether or not the supplied carrier-to-noise level is equal to or higher than a prescribed value stored and stored (step ST15). If it is, the antenna 4 is selectively held (step ST16), and if NO, the antenna 1 is switched and selected (step ST17).

As described above, according to the first embodiment, the antennas are switched by using both the determination of the shared area of each antenna 1 and 4 and the determination of the carrier-to-noise level of the received signal. In addition, even in the vicinity of the edge of the blocking area, a stable switching operation can be performed with respect to the posture and position fluctuation of the moving body, and there is an effect that communication can be continuously performed while maintaining communication quality.

Embodiment 2 In the first embodiment, since the signals received by the antennas 1 and 4 are input to one receiver 8 via the switch 7, the directional angle of the antennas 1 and 4 at the start of the first operation is limited to the area C. When you are in
It cannot be determined whether antenna 1 or antenna 4 should be selected.

For this reason, first, if the carrier-to-noise level of the connected antenna is equal to or higher than a specified value, the connection state is maintained, and if the carrier-to-noise level is equal to or lower than the specified value, the antenna is switched to another antenna.

That is, in the first embodiment, the antenna 1,
When the directivity angle of 4 is in the region C, the carrier-to-noise level of the other antennas cannot be known unless the antenna is switched, and it is necessary to switch again if the carrier-to-noise level of the switched antenna is below the specified value. It is.

FIG. 6 is a block diagram showing an antenna selecting apparatus according to a second embodiment of the present invention in which the above-described antenna switching is eliminated. Receivers 8a and 8b correspond to antennas 1 and 4, respectively. The antennas 1, 4 always detect the carrier-to-noise level of the received signal. In FIG. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

Next, the operation will be described.

FIG. 7 is a Furocha over you want to explain the operation, first, when the operation is started, the switch controller 9 inputs the directional angle of the antenna 1 and 4 detected by the angle detector 2 and 5 (step ST21 ), it determines the antenna by comparing the allocated area a which is previously set and stored as the directivity angle of the antenna 1 is directed to a region a of sharing range (step S
T22).

If the result of the determination is YES, a switching control signal for selecting the antenna 1 is output from the switching controller 9, and the switching unit 7 receiving this switching control signal switches and selects the antenna 1 (step ST23). .

On the other hand, if the decision result in the step ST22 is NO, the directivity angle of the antenna 4 is compared with the pre-stored sharing area B to determine whether the antenna is pointing in the area B of the sharing range. Judgment (Step ST2
4).

If the determination result is YES, the switching controller 9
Outputs a switching control signal for selecting the antenna 4, and the switch 7 receiving this switching control signal switches and selects the antenna 4 (step ST25).

The above steps ST22 and ST24
Are NO, it is determined whether or not the power is initially turned on (step ST26). If YES, the switching controller 9 supplies the carrier-to-noise level supplied from the antenna 1 from the antenna 4. It is determined whether it is better than the carrier noise level (step ST27). If YES, the antenna 1 is switched and selected (step ST28). If NO, the antenna 4 is switched and selected (step ST2).
9).

On the other hand, if the decision result in step ST26 is NO
If so, the switching controller 9 determines whether the antenna 1 is selected (step ST30). If YES, the switching controller 9 determines whether the supplied carrier-to-noise level is equal to or greater than a prescribed value stored and stored in advance ( If the answer is YES in step ST31, the antenna 1 is selectively held (step ST32). N
If it is O, it is determined whether the carrier-to-noise level supplied from the antenna 4 is equal to or higher than a predetermined value stored in advance (step ST33), and if yes, the antenna 4 is switched and selected (step ST34), and NO If so, antenna 1
Is selected and held (step ST35).

On the other hand, if the decision result in the step ST30 is NO, the switching controller 9 decides whether or not the supplied carrier-to-noise level is equal to or more than a prescribed value stored and stored in advance (step ST36). For example, the antenna 4 is selectively held (step ST37). If NO, it is determined whether the carrier-to-noise level supplied from the antenna 1 is equal to or greater than a predetermined value stored and stored (step ST38), and YE is determined.
If S, the antenna 1 is switched and selected (step ST3).
9) If NO, the antenna 4 is switched and selected (step ST40).

As described above, according to the second embodiment, the receivers 8a and 8b are provided for the respective antennas 1 and 4, and the determination of the carrier-to-noise level of the received signal of each antenna 1 and 4 is performed. By performing the above, the same effect as that of the first embodiment can be obtained, and unnecessary switching operation can be eliminated, and the switching operation can be improved.

In the first and second embodiments, an example in which the two antennas 1 and 4 are switched has been described. However, the blocking occupies a wide area and the covered area cannot be covered unless three or more antennas are used. Even in such a case, the antenna switching can be performed by the same switching logic if the sharing area of each antenna is determined.

[0042]

As described above, the antenna according to the present invention is provided.
According to the switching device, both the first and second antennas
For the viewable range, the first or second antenna alone
Is provided with a range that does not share the
, The first and second antennas
Of which the carrier to noise level in the received signal is better
Choose a good one and connect it to the subsequent circuit
Carrier to noise level due to blocking and other effects.
Less susceptible to bell degradation.

In particular, the range shared by the first and second antennas
Block for each other antenna
Is an area where noise occurs, but can be seen from that antenna.
Block by setting in advance so that
Carrier pair near the edge of the
Can be set to make selection based on noise level
For example, for example, the quality of communication using the first and second antennas
To maintain continuous communication under favorable signal conditions.
Realize trust.

Further , the above-described control is performed by turning off the switch.
Supply of the tenor switching control signal, that is, directivity angle and sharing
Simple form with the same form as selection control based on range relationship
Can be realized.

Then, the present invention is applied to an antenna on a mobile body.
In particular, when applied to
The effect is that stable switching operation can be realized.
You.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an antenna selection device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an antenna installation example on a moving body.

FIG. 3 is a diagram showing a driving range of each antenna as viewed from above a moving body and a blocking region for each antenna.

FIG. 4 is a timing chart showing an antenna switching operation.

FIG. 5 is a flowchart showing the operation of the first embodiment.

FIG. 6 is a configuration diagram illustrating an antenna selection device according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols]

1,4 antenna, 2,5 angle detector, 7 switcher,
8, 8a, 8b Receiver, 9 Switching controller, 10 Mobile.

Claims (4)

(57) [Claims] 1. An antenna switching method for switching and using first and second antennas mounted on a mobile object and controlled to point to a satellite, wherein each of the first and second antennas is determined in advance. The sharing area of the antenna is set so as not to include the blocking area which is an area where the satellite cannot be seen, and in use, the directivity angles and the carrier-to-noise level of the first and second antennas are detected, a first antenna <br/> when the first antenna when viewed from the detection result is directed to the allocated area, and has a second antenna directed to the allocated area is a first antenna that a second antenna when not oriented allocated area, the <br/> when the first and second antenna is not directed to its allocated area either carrier- Antenna switching method, characterized in that one of the antennas in accordance with the sound level, respectively selected. 2. A antenna switching method according to claim 1, wherein, when the first and second antenna is not directed to its allocated area either, the carrier-to-noise level at the antenna which has been selected until then prescribed level An antenna switching method characterized by selecting another antenna that has not been selected before when the number of antennas falls below. 3. The antenna switching method according to claim 1, wherein when both the first and second antennas are not directed to the sharing area, the carrier-to-noise level of the antenna selected up to that point becomes a specified level. An antenna switching method which selects another antenna which has not been selected until then, and whose carrier-to-noise level is equal to or higher than a specified level. 4. An antenna switching device for switching and using first and second antennas controlled to direct a satellite, the first and second antennas detecting first and second directional angles of the first and second antennas. A second angle detector, a first and a second
An antenna switching device comprising: means for detecting a carrier-to-noise level in the antenna of (1), and a switching controller for executing the antenna switching method according to claim 1.