JPH09214421A - Control system for antenna directivity characteristic of radio base station in mobile radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce transmission power and radio wave interference and to improve the effective utilization of frequencies by controlling an antenna provided in a base station so as to direct the antenna in a direction giving a higher radio signal level sent from a mobile radio equipment. SOLUTION: A composite antenna 10 provided to a radio base station 1 has two kinds of functions (operations). The one is a function of sending/ receiving a control signal to/from mobile radio equipments 100 (100-1-100-p) in existence in an optional position in a service area under the control at all times and of confirming and tracing the current position of the mobile radio equipments 100, and the other function is a function of using only part of a composite antenna for the communication with an optional mobile radio equipment 100 so as to prevent, radiation of undesired radio waves for the use of the other parts. In order to provide the functions above, the antenna is made up of plural basic antennas each having the identical characteristic so as to be in use through optional combinations under the control of a control section 14, the basic antennas have a narrow beam characteristic as the horizontal planer directivity and a tile angle control circuit 11 controls each tilt angle.

Description

Detailed Description of the Invention [0001] BACKGROUND OF THE INVENTION The present invention relates to mobile communication using small zones.
Control of the directional pattern of the radio base station antenna of the communication system
You. For details, cover each zone and service.
Communicates with each wireless base station that makes up the area
In order to perform communication with each mobile wireless device.
A mobile communication control station and a telephone connected to it by a transmission line
There is a system with a telephone included in the network,
In the radio communication between the line base station and the mobile radio,
The directional characteristics of the antenna provided in the wireless base station
Mobile radio movement within the service area managed by the base station
It is related to the technology of tracking and controlling. [0002] 2. Description of the Related Art Conventional mobile communication systems using small zones
Control the directional characteristics of the antennas installed in
As a technology for controlling, it is possible to reduce the multiple wave propagation peculiar to mobile radio.
It is known how to get rid of it. This is a wireless base station
The directivity of the stripped directional antenna is transmitted from the mobile radio.
Control from multiple mobile radios
The main propagation of the radio wave that reaches the wireless base station via the
It is limited to the road only (Reference 1: Japanese Patent Laid-Open No. 3-
254228). Also, it is technically similar to the above.
However, during communication between the wireless base station and mobile
Signals to and from each other to transmit and receive the second directional antenna of the radio base station.
Adjust the directivity of the antenna to the mobile radio
Radio signal from the communication device of the communication system is transmitted by the antenna
It is emitted from 360 ° in all directions and the electric field strength is in all directions.
Flooding of unnecessary radio waves caused by knocking, interference with electronic devices,
Know how to prevent communication interception by a third party
(Reference 2: Japanese Patent Laid-Open No. 5-206918). Sa
Angle of the radio base station antenna main pointing beam with the ground surface
To the adjacent service area (beam tilt)
The method of reducing the radio wave leakage and reducing the radio wave interference is also practical.
Used (Reference 3: 1984 IEICE
General National Convention No. 2452). Furthermore, this beam
Belt technology in the service area in the radial direction
Proposal to improve efficiency of frequency utilization
Proposals have also been made (Reference 4: IEICE Technical Report)
Report A, P92-85). [0003] Generally, a mobile radio system is used.
Communication uses space as a transmission medium as follows:
Therefore, it is affected by multiple wave propagation. For example, on a car phone
In this case, the mobile radio installed in the
The radio waves transmitted by the
Until it is reached, it will have to travel through multiple propagation paths.
You. That is, the mobile radio is viewed from the radio base station antenna.
There are few cases where it can be passed, and in general, the effect of topography and features such as buildings
Therefore, the propagation path is affected by reflection / diffraction etc.
It changes every moment. Moreover, this propagation path is not unique
There are usually multiple. This is called multipath propagation
It is a phenomenon to be seen. In addition, the mobile radio is
Even if you can see through, the transmission is affected by reflection and diffraction.
There are transport routes, and these carry the same multi-wave propagation as above.
Live. These radio waves have different propagation paths
The phases will be different. Therefore, the shadow of the multiple wave propagation as described above
The affected radio signal reaches the radio base station,
Phase difference when received by the antenna of
The signal strength of the total signal is
It will change from moment to moment. Also, mobile radio system
Directivity as a transmitting antenna of a wireless base station in communication
If not fired in all directions at 360 °, the electric field strength is
Across the azimuth, but the other party's mobile radio is only in a specific direction
Since it does not exist, the radio wave from the radio base station is directed in a specific direction.
Only the emitted radio waves are used effectively,
Radio waves become unnecessary radio waves and may interfere with other communications.
Or the possibility of interception of communication by a third party is increasing.
Was. Furthermore, the main pointing beam of the radio base station antenna is not
If the angle is not appropriate, radio wave leakage to the adjacent wireless zone
There was a possibility of increased leakage and increased radio wave interference. Up
The conventional countermeasures against the technical problems mentioned above have already been mentioned.
Measures have been taken, but the following technical
There was a problem. A directivity antenna provided in the first radio base station.
It is a measure to direct the main directivity of Tena to the mobile radio,
When the mobile radio moves at high speed, radio waves to the radio base station
The propagation path of the
Change, and it becomes impossible to track the main directivity of the antenna.
There is a steep. Next, the radio base via two different propagation paths
If the signals arriving at the station have almost equal power,
Effective as a result of directing the main directivity of the antenna to either of these
There was a waste of half the signal power. More wireless
Depending on the modulation scheme used in the system, for example,
In the system using CDMA, which has become popular,
As a wave, multiple signals that have propagated multiple waves are not harmful,
Rather, when it is useful for effective use of signal energy
There is a match. Or used in the current mobile communication system
Even in the narrowband time division multiplexing system, the signal processing after reception is performed.
By reason, multiple signals propagated by multiple waves are not always harmful.
It's starting to disappear. During communication between the second radio base station and the mobile radio
Wireless base station communication by mutually transmitting and receiving pilot signals
For directivity of the directional antenna for mobile phones to the mobile radio
The technology for adjusting the directivity is to move its directivity with a drive motor.
Things. This is when the communication target is specified
Is effective, but like a public mobile radio system
A large number of moves within the service area controlled by the radio base station.
There are multiple mobile radios that are
On the other hand, it is costly and practically difficult to apply. Ma
Move the directivity of the directional antenna for communication of the wireless base station
Even if you say to the radio, the mobile radio and the radio base station
Tilt angle of the main beam of the antenna that changes depending on the relative position
It has not been revealed until the control. Beam tilt of the third radio base station antenna
This is a technique, but this is the vertical in-plane directivity of the base station antenna.
With the technology to tilt electrically or mechanically in the depression direction
is there. As a method of tilting, the antenna body is mechanically
Method of inclining to each, antenna of each element while standing upright
By adjusting the feeding phase using a phase shifter, etc.
There is a method of inclining the wave front. This technology was recently developed
It has been applied and is applicable to all transfers within the service area.
If it is for a mobile radio or service area
Is divided into multiple strips in the radial direction, and within that area
Specific to existing mobile radios in
There is no detailed method to say that it will be done for mobile wireless devices of
It was development. [0008] The present invention uses a small zone.
Management in the wireless base station of the mobile wireless system
Efficient communication with each mobile radio in the service area
In order to achieve
Was. That is, the antenna that constitutes the composite antenna is
Fired (or received) in all 360 ° directions as a general characteristic
Is omnidirectional, or fires (or receives
Some have a directivity that is believed to be
Dividing the directivity of the constituent antennas into multiple angles
Dividable, each with sharp directivity
Basic antennas (they have almost the same characteristics)
It consisted. Then, the composite antenna is installed in the radio base station.
A transmitter / receiver for communication and a control device for controlling it.
It has an interface part that exchanges control signals with the storage device.
Configured as Antenna from information from this controller
The tilt angle can be controlled. Also, the above composite ante
In order to operate according to the system to which the operation of
Time division operation, analog in case of time division multiplex system
In the case of a system, we decided to operate in frequency division
Was. In addition, the mobile communication interfaced with the radio base station
Transmission control station, telephone network connected to it by transmission line
A mobile communication network is constructed with the telephone included in (40).
Was. [0009] The composite antenna according to the present invention provided in the radio base station.
Tena has two types of actions (functions). That is, the above
Time-divisional use of antennas as described in (Time-division multiplexing
The following functions (functions)
Will be. First, any place in the service area under the jurisdiction
Control signals are constantly transmitted and received to and from mobile radio devices existing in the area
Possible to check and track the current position of mobile radio
Noh. It is all the basic antennas that make up the antenna.
Cover all service area by using Tena
360 degree omnidirectional antenna and 120 degree directivity required for
An antenna with a
The signals sent from the
The direction of the mobile radio from the perspective of the radio base station (radio base station
It is possible to recognize the position from which it is seen, to be precise, the angle of arrival of radio waves)
You can do it. The position information of this mobile radio is controlled by the control unit.
Utilized for the next action (function) by sending to and processing
It becomes possible. That is, the mobile radio and the base station
Location information of the above-mentioned mobile wireless device when communicating (calling)
Using only the partial antennas required for communication
However, unnecessary radiation of radio waves due to the use of other partial antennas
Is the action of preventing. Also, information from this controller
This enables the tilt angle control of the antenna. The above will be described in more detail as follows.
become. The composite antenna provided in the radio base station has the same special characteristics.
Basic antenna with multiple narrow beam directivities
Each basic antenna is oriented in the same horizontal plane.
It has the ability to handle 360 degrees without adding fingers.
Oriented antennas and antennas with directivity within 120 degrees
It is possible. Also, the basic antenna has tilt angle control
It is configured to enable each of the
It is connected to the radio. And time-divisional use (hours and minutes
In the case of split multiplex system), these radios are
For each mobile radio in the service area
However, the control signal can always be transmitted and received. Further, the control unit of the radio base station is
On the other hand, there is a search radio equipped in the radio base station.
Or send the radio control signal from the communication radio from the antenna.
To trust, you can use all or part of the basic antenna
Controllable so that it can be transmitted using
The control signal transmitted from the line machine is received by the basic antenna.
Can be received using all or part of
It is configured so that the received signal levels can be constantly compared.
You. As a result, the control unit has multiple basic antennas.
The control signal level received by this was higher than the other one
Or, the direction indicated by multiple basic antennas is changed to the mobile radio
, And the basic antennas other than these are
Exclude it from being used for communication. Decide to use again
For one or more basic antennas
Determine and instruct the tilt angle control amount. With composite antenna
Is the one that should be used in the composite antenna in response to this instruction.
Or select multiple basic antennas and select the selected basic antenna.
Each tilt angle control that should be adapted to the mobile radio
You will communicate. In addition, mobile radio service
Basic suitable for use in wireless base stations due to movement inside the rear
The antenna is expected to change from moment to moment, but this
, The control signal from the mobile radio is always received.
The control channel of the composite antenna
It is possible to estimate the current position of
As shown in the figure, the composite antenna does not always move because it utilizes this.
Communication with the line machine can be carried out satisfactorily. Furthermore, a call between the radio base station and the mobile radio device
Even after the transition, the control unit is
There is no need to change the basic antenna to use, the selected base
Combined antenna with tilt angle control information for this antenna
F. Continue to give instructions and move to the composite antenna to follow these instructions.
A mobile radio and a communication radio provided in a radio base station,
Communication is always kept good. For the reasons mentioned above
Therefore, a system to which the present invention is applied is a mobile radio and a radio base.
Communication with the ground station is good, but the reason for good communication is
There are others. These will be described below. First, jamming
It is the reduction of the probability of receiving waves. From the mobile radio
The transmitted radio signal goes through multiple propagation paths to the radio base station.
Of the wireless signals with different angles of arrival.
Among them, the signal with high power is limited to multiple,
The number of basic antennas used by such a composite antenna is usually 2
It is because it becomes ~ 3. Therefore, in the wireless base station,
It is possible to block the interfering radio waves coming from the direction. The signal from the mobile radio is transmitted to the radio base station.
One of each of the basic antennas (multiple
It is set to be able to receive at all times. Why
Radio with all basic antennas
Covers all areas within the service area managed by the base station
This is because it is set to do. Therefore, the control unit
With the control of, the selection of the reception signal of each basic antenna is instantaneous.
Can be changed to. The above conditions are for mobile radio systems.
As described above, when the mobile radio moves at high speed,
It is extremely effective to continue. That is, the above-mentioned mobile wireless device
The direction of arrival of radio waves changes rapidly when the
However, there is a risk that the main directivity of the antenna cannot be tracked.
It can be greatly reduced. Third, each group of the composite antenna in the radio base station
The angle between the main pointing beam of this antenna and the ground surface (tilt
Control for each mobile radio in the service area
Wireless signals required for communication
Power consumption is lower than before, and communication can be performed satisfactorily.
Was. In addition, wireless communication leaked to areas other than your own service area
Signal to reduce interference with other parties.
And it became possible. Fourth, mechanically configure the antenna
Since the basics for moving are removed, control is simple and easy.
Was. In the above explanation, the mobile radio system is time division multiplexed.
As for the system, the present invention is an analog system.
The same applies to the case of. Place of analog system
If it is not multiplexed like a time division multiplex system
The present invention may be applied by the frequency division method. Sand
In the case of an analog system, with a control wireless channel
A frequency different from the radio channel used for calling is used.
Therefore, the above-mentioned time division use of control signal and call signal is used.
It is sufficient to change to the wave number division use. [0015] DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to a time division digital multiplex mobile communication system.
A description will be given using an example adapted to a stem. Analog
The stem can be adapted in a simplified form. Figure
Reference numeral 1 indicates a system configuration. In Figure 1, a large number of shifts to the left
Mobile radios 100-1100-2, ... And mobile radios
100-p (hereinafter, mobile radio device unless otherwise confusing
(Represented by 100) exists and is surrounded by a broken line to the right of
The wireless base station 1 is shown. With mobile radio 100
The wireless base station 1 is wirelessly coupled. Radio base
There are many stations 1 in the system (see Fig. 11).
However, there is no particular need, so draw only one station and omit the rest.
I have. The mobile communication control station 30 and the
There is a telephone network 40 on the right next to it.
It is connected by lines. Hereinafter, each part of the system configuration shown in FIG. 1 will be explained.
I will tell. First, the wireless base station 1 will be described. Wireless base station
Reference numeral 1 denotes transmission / reception of signals to / from the mobile wireless device 100 and mobile communication
To efficiently exchange signals with the control station 30,
This will be described in detail below. First of all,
The composite antenna 10 that transmits and receives will be described. composite
The antenna 10 is composed of many antennas. this
Since their antennas have the same characteristics,
Tena A₁, A₂・ ・ ・, A_N(Be careful not to cause confusion
If it is not, the basic antenna A is used as a representative)
I do. Each of the basic antennas A has a sharp directional characteristic (transmission / reception
The transmitted radio wave has a vertical polarization plane. These concrete
The physical structure is shown in FIG. FIG. 2 is a plan view of the composite antenna 10.
Then, N = 12. The figure shows the service of the wireless base station
The area is the Omni Zone (circular centered around the wireless base station)
Used in case. In FIG. 2, 12 basic antennas A and
Then, if each is created using a group of corner antennas,
6 corner antenna groups each (not visible in the figure)
However, it has an upper and lower two-stage configuration. Therefore, the corner
The total number of antennas is 6 × 12 = 72. Real
When using it, install the upper and lower antennas vertically.
However, in the case of the same figure, when this is separated step by step
It shows the result. Also, the polarization plane of the radio waves used is vertically polarized.
Wave, the electric field is perpendicular to the plane of the paper and is the main beam direction of the antenna
Is parallel to the paper surface when there is no beam tilt. In FIG. 2 (a) or (b), an angle of 60 degrees is set.
The six thick lines formed indicate the metal reflectors of the corner antenna.
In addition, the ○ mark indicates that the excitation element is large in the center of the corner antenna.
Spread to the outside and converge to the inside near the metal reflector (metal
The gain is 0 on the striking plate.)
The directional characteristics of the na group are shown. The corner antennas
The number of antennas used is 4 to 8. And each
The corner antenna is connected to the tilt angle control circuit 11.
You. The corner ante shown in FIGS. 2 (a) and 2 (b)
For vertical installation of the upper and lower two stages of the na group,
Install the antenna with the relative position of the antenna configuration shifted by 30 degrees.
Directional characteristics of these tufted corner antennas
When viewed as a two-stage integrated antenna, each corner
The null point (point of gain 0) of the antenna is removed,
Muni characteristics will be obtained. Note that the wireless base station
Service area is not an omni zone, but a fan-shaped zone (no
A circle with the line base station as the center
(Or sector)), the corner an
A part of the tena is used, for example, four pieces. The above explanation is complex
As a function of the combined antenna 10, a signal from the mobile wireless device 100 is received.
However, on the contrary, the search radio described later
13 and communication radio 15 to mobile radio 100
Of course, it has the function to send out the signal. Next, the composite antenna 10 and the tilt angle control circuit
The connection with 11 will be described with reference to FIG. In the present invention
The function of the tilt angle control circuit 11 is as follows:
The vertical in-plane directional characteristics of the
The main beam of each basic antenna)
The mobile radio. This is the main beam
By controlling the angle formed with the surface of the opposite direction to the required angle
The control of this angle is usually tilted to the surface. But
Apply a wireless signal to an antenna with tilt angle control
That is the case of application to a normal uncontrolled antenna
Compared to, the electric power leaking out of the service area of the wireless base station
Power is reduced, and it is extremely effective in preventing interference with other communications
It is. In addition, it is possible to reduce power consumption because it is possible to reduce invalid power.
It becomes possible. On the contrary, the radio transmitted from the mobile radio
When receiving signals, the direction of the main beam goes to the mobile radio
Since it is aimed, reception of jamming waves coming from other directions
Has the effect of reducing the
It is extremely effective in preventing interference and effective in improving reception quality.
is there. Now, in the area surrounded by the broken line in the upper part of FIG.
Combined antenna 10, tilt angle control in the area surrounded by the broken line below
The control circuit 11 is drawn. Composite antenna 10 is on the right
Basic antenna A in order₁, A₂・ ・ ・, A_NFrom
It is shown that it is being done. Each basic antenna is
Is formed from multiple corner antenna groups, and
Each of them is formed of W corner antenna groups. An example
For example, basic antenna A₁Is a corner antenna group a₁₁, A
₁₂... a_w1Are formed from. Also tilt
The angle control circuit 11 is also surrounded by a broken line, but tilt angle control
The connection between the circuit 11 and the antenna is fine for each corner antenna.
It is differentiated, but the connection on the radio side is the search radio
In the case of machine 13, the basic antenna unit
In the case of a radio, a communication radio with one basic antenna 1
Will be combined with 5. And with the former antenna
The connection is always made, while the connection with the latter radio is made.
As will be described later, at a certain time, with the search radio 13,
At other times, it is time-shared like the communication radio 15.
Be combined. In the following, when connected to the search radio 13,
I will explain the case. FIG. 3 shows the tilt angle control in such a case.
The circuit 11 sends the search radios 13 for search from the lower right.
Connected to the receivers 13-1, 13-2, ... 13-N
ing. Then, in the tilt angle control circuit 11, for example,
For example, the circuit connected to the search transmitter / receiver 13-1 is chilled.
The variable angle control circuit 11 is divided into W parts and
Phaser φ₁₁, Φ₁₂, ..., φ_w1(Hereinafter variable phase shifter
(sometimes abbreviated as φ)). And
Possible by a control signal from the control unit 14 input from the right side
Phase shifter φ₁₁, Φ₁₂, Φ_w1Signal passing through
Each feeding phase is controlled and each corner antenna group
a₁₁. a₁₂... a_w1Each antenna features
Sex changes. As a result, the split antenna A₁Chill as
It becomes possible to control the angle. Similar to above
Antenna group a₂₁, A₂₂, ..., a_2wEtc.
Also, each basic antenna A₁, A₂, ...,
A_NTilt angle at a desired value independent of each other
Will be controlled. The communication radio is used for tilt angle control
Even if it is connected to the path 11, the compound amp
The tilt angle of the tenor can be controlled. Note that the above description
Performs tilt angle control using the composite antenna as the transmitting antenna.
However, on the contrary, the composite antenna and the receiving antenna
The same applies when performing tilt angle control by
You can reverse the explanation of. Next, the tilt angle control circuit 11 and the switch circuit
A connection method with 12 will be described with reference to FIG. Switch
H circuit 12 is a portion surrounded by a thick broken line shown in FIG.
It is located on the lower left side of the control / call signal selector switch SW.
And a switch matrix section S. Below,
Input signal from the tilt angle control circuit 11 to the switch circuit 12
The case will be described. Tilt angle control circuit from above in FIG.
The output of 11 is the control / call signal switch SW
Is input to Switch off the control / call signal switch
Replacement switch SW₁, SW₂, SW₃, ... SW_NFrom
It is configured. Control / call signal selector switch SW
The function of (the following switch) is like the name, mobile radio
Separate the signal from the machine 100 into a control signal and a call signal
Things. These signals are transmitted in a time division manner.
Are housed in control / call time slots, respectively.
ing. On the other hand, in the control unit 14, the mobile radio 10 has already been
From the control or communication signal sent from
Is detected and the control / call time slot is
It is in a separable state. Timing signal detection method
There are various methods, but for example, the operation of the radio base station 1
Control of the switch circuit 12 at the time of start-up / SW switching unit SW
Is fixed to the state where terminal 2 is turned on,
To keep the control signal from machine 100 ready
The timing is grasped according to the law, and thereafter it is equipped in the own wireless base station.
Maintains timing with an accurate clock generator that is
Let Alternatively, the timing information from the mobile communication control station 30
There is a method such as getting the information sent. Well, as above
The control unit 14 can separate control / call time slots
The basic antenna of the composite antenna is
Na A₁, A₂, A₃, ... A_NReceived independently by
The control signals are the SW of the changeover switch unit SW.₁,
SW₂, SW₃, ... SW_NCall signal to each terminal 2 of
In the case of each, to each terminal 1, each time slot
Can be connected to. However, changeover switch SW₁, SW
₂, SW₃, ... SW_NIs controlled by the control unit 14.
Depending on the signal, all changeover switches are in terminal 1 or
Is configured to switch to terminal 2 simultaneously
You. First, the signal from the mobile radio 100 is a control signal.
The case of issue will be further explained. In this case, each basic antenna
The output from is connected to each terminal 2 of the changeover switch.
Search transmitter / receiver 13 of the search radio 13 shown on the lower right
1, 13-2, ..., 13-N. No move next
A case where the signal from the line machine 100 is a call signal will be described. This
In the case of, the output from each basic antenna is
It is connected to terminal 1 and shown in the lower left of Fig. 2.
Sent to the box section S. The switch matrix section S has M
²Switch S₁₁, S₂₁, ..., SM₁・ ・
., S_1M, S_2M, ..., S_MMIs equipped with
And any combined output from N basic antennas
ON / OFF of the switch by the control signal from the control unit 14
Depending on the operation, the M
Communication radios 15-1, 13-2, ... 13-M throat
Is configured to connect to other communication radios.
You. In the switch matrix section S of FIG.
A switch is installed at each point, and the white triangle
Off, black triangle indicates on. The state in Figure 4 is
Switch S₁₁, S₂₁And S₃₁Is on
From the basic antennas A1, A2 and A3
Signal is input to the communication radio 13-1.
You. In the above description, the function of the switch circuit 12 is tilt.
In the case of receiving the signal from the angle control circuit 11,
On the contrary, it is moved from the search radio 13 and the communication radio 15 described later.
It also has the function of sending signals to the mobile radio 100.
It goes without saying. Next, the functions of the search radio 13 and the control unit 14
Will be described with reference to FIG. Sent from mobile radio 100
The control signals are N search transmitting / receiving units 13-1, 13-
2, ... 13-N is input. Here, the received signal level
Bell and reception quality are detected and transmitted to the control unit 14 respectively.
You. The control unit 14 receiving these N signals controls
Compare signal levels and quality. As a result, for example
The search transmitting / receiving unit that has transmitted the reception quality is 13-1, 1
3-2, 13-3, 13-4, these signals
The beam tilt angle of the received basic antenna is as described above.
Wireless communication from the mobile radio 100.
Adjust to receive signals better. And
Search again for the reception result of the control signal from the mobile wireless device 100.
The wireless device 13 will contact you. As a result, the search radio
The control unit 14 which has received the received signal from the
Compared with each other, for example, a high reception level higher than the top three was obtained.
Basic antenna is A₁, A₂, And A₃Then, no movement
The current position of the wire machine 100 is the basic antenna A₁, A₂,as well as
A₃Judge as the direction of the main beam of. However, this judgment
The actual position of the mobile wireless device 100 is the basic antenna A.
₁, A₂, And A₃Is in the main beam direction of
Not between the mobile radio 100 and the radio base station 1.
Reflection or diffraction of radio waves due to the influence of a certain building, terrain or feature
Therefore, the radio wave propagation path is from the wireless base station 1 to the mobile wireless device 100.
It is said that there is a route different from the route when looking directly at
And, when received by the wireless base station 1, the basic antenna
A₁, A₂, And A₃Reception at the base station is higher than other basic antennas
It means high in all. The above is nothing from the current position of the mobile radio 100.
A strict explanation of the arrival direction of radio waves to the line base station 1,
Below, simply “The current position of the mobile radio 100 is the basic
Na A₁, A₂, And A₃Direction, or even easier
"A₁Is best received by A₁As the direction of
A positional relationship between the mobile wireless device 100 and the wireless base station 1 will be described.
You. As a result, the basic antenna A₁, A₂, And A₃To
Determined as the antenna used for communication with the mobile radio 100,
This information is transmitted to the base station modulator / demodulator 25. This information
The base station modem 25 that has received the
The usage status is investigated, and communication is performed facing the mobile wireless device 100.
As a communication wireless device for communication, for example, a communication wireless device 15-1
The decision is made and the call signal is transmitted to the mobile communication control station 30.
To the control unit 14. In the control unit 14, a switch circuit
12 matrix switches S switches and controls / calls
The signal switching unit SW is operated to receive the signal from the communication wireless device 15-1.
No. is the basic antenna A₁, A₂, And A₃Can be sent to
In addition, the control signal is set so that the tilt angle is controlled.
Signal to the switch circuit 12 and the tilt angle control circuit 11
You. As a result, the signal from the wireless base station 1 is transmitted to the mobile wireless device 1
Sent to 00. In addition, the signal from the mobile radio 100
Is also transmitted to the communication radio 15-1 by the operation of the control unit 14 described above.
Can be sent. Further, the mobile communication control station 30
Wireless base station 1, mobile communication
With the mobile radio 100 via the control station 30, the telephone network 40, etc.
It becomes possible to communicate with a telephone in the telephone network 40. In a mobile communication system, a mobile radio or a mobile
The position of the band wireless device naturally moves during communication. did
Therefore, the relative position between the mobile radio and the radio base station changes.
And the mobile radio reaches the radio base station accordingly.
The radio wave propagation path will also change. Therefore, in the present invention
The control signal of the mobile radio 100 is independent of the movement of the mobile radio 100.
In the time slot, all basic antennas of the composite antenna are
The control signal from the mobile radio is always received using the antenna.
However, using the method described above, the
Continue the search to ensure good reception. Next, the base station modulator / demodulator 25 is shown in FIG.
A more detailed description will be given. On the right side of FIG. 6, the control unit 14 and communication
Wireless signal transmitter / receiver having interface with line machine 15
There is 78, and exchanges signals. What is the former control unit 14?
Control signals are transmitted and received, and in cooperation with this, the mobile radio 10
No information for communication should be obtained by obtaining information on the direction of the current position of 0.
The line machine 15 is determined. In addition, the latter communication radio 1
5 exchanges control / communication signals with the mobile communication control station 3
Cooperate with 0 to enable good communication until the communication ends
A series of signal processing operations for First, the wireless base station
The operation of each circuit of No. 1 is shown in FIG.
The timing signal received from the clock signal generated from 71
The timing signal from the raw circuit 70 causes a time lag.
Get adjustments to prevent it from happening. In addition, a large number of
When there is a wireless base station, the timing is determined by mobile communication.
Timing generation (not shown) built in the signal control station 30
Although it is performed in the circuit, it does not relate to the operation description of the present invention.
It is omitted here. Now, the signal is received by the radio signal transmitter / receiver 78.
The signal is the timing from the above timing generation circuit 70.
Decoding circuit that operates with timing adjusted by signals
It is demodulated at 63. Furthermore, it is decoded by the decoder 61.
Then, it is sent to the wired signal transmitting / receiving unit 60. Wired communication
The signal transmitting / receiving unit 60 interfaces with the mobile communication control station 30.
And the decoded signal above is
It is sent to your office 30. On the other hand, enter the wired signal transmitter / receiver 60
The incoming signal from the mobile communication control station 30 enters the coder 62.
Forced and coded. After that, it is modulated by the encoding circuit 64.
However, these operations are performed by the timing generation circuit 70.
The operation is adjusted by the timing signal. Then nothing
The signal is sent to the line signal transmitter / receiver 78, and the communication radio 1
Sent to 5. On the other hand, since it is sent to the mobile wireless device 100,
From the mobile communication control station 30 to the wired signal transmitting / receiving unit 60
Call signal (including some control signals) is input to the coder 62
And coded. After that, it is modulated by the encoding circuit 64.
However, these operations are performed by the timing generation circuit 70.
The operation is adjusted by the timing signal. Then wireless
It is sent to the system signal transmitter / receiver 78, and the communication radio 15
Sent to Note that the communication radio 15 does not move in the opposite direction.
The functions necessary for communicating with the line machine 100 are provided.
However, the same known digital movement as the mobile radio 100 is known.
Similar to that used in communication systems,
Description is omitted. Furthermore, the mobile communication control station 30 and the telephone network 4
Since 0 is also known, detailed description thereof will be omitted. Was
The system that is important in the present invention of these devices
The procedure for transmitting the signal will be described separately. The system operation according to the present invention will be described below with reference to FIGS.
8 and FIG. 9. Is the figure a mobile radio device 100?
3 shows a flow chart of the calling operation. First, shown in FIG.
The mobile radio 100 installed in the system
Control unit 14, base station modulator / demodulator 25, communication radio 15-
1. All the device groups in FIG. 1 including the mobile communication control station 30
It is assumed that the operation is starting. The mobile radio 100 has control for calling.
Time slot given to the mobile radio 100 of the channel
To send a call control signal to the wireless base station 1
(Step S101). This signal is transmitted by the radio base station 1
Although it is received by the combined antenna 10, the received signal is actually
Basic antenna A for each direction of mobile radio₁,
A₂・ ・ ・, A_NReceived in pieces. These divided reception
The signals are respectively the search transmitter / receiver 11- of the search radio 13.
1, 11-2, ..., 11-N (step
S102). The contents of the received signal at each search transceiver
Also, the reception level is investigated and transmitted to the control unit 14. Control unit
14 analyzes these signals and determines that the signal level is
Tena A₁The signal from is the highest, followed by antenna A₂When
A₃, And antenna A₄If, then these four
Mobile radio calling in the direction of the main beam of the basic antenna
Assuming that 100 exists, the basic antenna A₁~ A₄of
The beam tilt angle is changed, and the
Adjust so that the wireless signal of
(Step S103). Even with the above adjustment results, the signal level is basically
Antenna A₁The signal from is the highest, followed by antenna A
₂, And antenna A₃If found to be
The mobile radio 100 has main beam directions of these three antennas.
It is assumed that it exists in the direction of
(Step S104). With the base station modem 25
Communication that can be used within its own radio base station by receiving this signal
When the radio 15 for communication is investigated, the radio 15-1 for communication is
Recognize that it is open (new communication is possible)
(To be precise, the wireless channel to be used by the mobile communication control station 30
Although it will determine the channel, it affects the operation explanation of the present invention.
Since it is not done here, the base station modulator / demodulator 25 is used as a representative
Therefore, the controller 15-1 is used and the controller 14 is used.
Contact (step S105). The control that received this signal
In the control section 14, the composite antenna 1
0 for each basic antenna A₁, A₂, And A₃And wireless for communication
The communication wireless device 15-
The output of 1 is the basic antenna A₁, A₂, And A₃Be guided to
Connection is performed (step S106). By the above operation, the communication radio 15-1
When receiving a call control signal from the mobile wireless device 100,
A response signal is transmitted to the wireless device 100 (step S10).
7). This signal is received by the mobile radio 100 and
The ear signal is transmitted (step S108). This da
The ear signal is received by the communication radio 15-1 and
The data is transferred to the ground station modulator / demodulator 25 (step S10).
9). The base station modulator / demodulator 25 receives this signal (see
(Step S110), dial signal to mobile communication control station 30
Is transferred (step S111). Mobile communication control station 30
Then, receive this signal and send a dial signal to the telephone network 40.
Transfer and send a ringing signal to the called telephone in the network
Both send a call signal to the base station modulator / demodulator 25.
(Step S112, hereinafter FIG. 8). Base station modem 2
In step 5, this is transferred to the communication radio 15-1 (step
S113), the communication wireless device 15-1 sets this to the mobile wireless device.
A response signal is transmitted to the machine 100 (step S11).
4). When the mobile radio 100 receives this signal, it calls.
Hang up the handset (step
S115). The mobile radio 100 and the called telephone
If you hang up the two-way receiver, the call will start.
(Step S116). Now, the mobile radio 100 and the called telephone
Communication is ongoing and there is no communication for communication with the base station modem 25.
When the line machine 15-1 is in the relay operation of both signals
Also, the search transmitter / receiver units 11-1 and 1 of the search wireless device 13
1-2, ..., 11-N are the basic antennas A, respectively.
₁, A₂, And A₃Of the mobile radio 100 obtained from
Signal level is being measured, and these measured signal levels are
Is transmitted to the control unit 14 (step S117). So
As a result, if there is no change in the order of the signal level, the conventional state
However, if there is a change in ranking,
This antenna A₁The signal from is the highest, followed by the antenna
A₂, Does not change, but antenna A₃Than A₄from
If it is found that the reception level is high, immediately
Contact the base station modem 25 (step S118)
Together with the base station modem 25,
Each basic antenna that should be used₁, A₂,
And A₄Control signal to switch circuit 12 to change to
Send. As a result, each basic antenna of the composite antenna 10
Na A₁, A₂, And A₄And the communication radio 15-1
(Step S119, hereinafter FIG. 9). Note that this
Also in this case, the beam tilt angle control described above is naturally executed. Up
The same monitoring as described above is performed by the mobile wireless device 100 and the wireless base station 1.
It will continue until the communication is completed. At the end of the call, the mobile radio 100 hangs up the handset.
It is done by turning on. Mobile radio 100 at this time
The end signal is transmitted (step S120). This message
Signal is received by the wireless device 15-1 and the base station modulator / demodulator
25 (step S121). Base station modulation / demodulation equipment
In step 25, this is transferred to the mobile communication control station 30 (step
(S122), the mobile communication control station 30 receives the signal.
(Step S123), and further retransfer to the telephone network 40
The destination of the exchange that accommodates the destination telephone in the network
Open the connection with the telephone. This is the mobile radio 100
The call origination operation ends. Next, the case where the mobile wireless device 100 receives an incoming call will be described.
You. Calling signal from a telephone housed in the telephone network 40
Is sent to the mobile communication control station 30, and the mobile communication control station 30
Confirm the current location of the mobile radio 100 of the other party, and
Wireless base station 1 to
Radio base station including channel number and time slot information
The call control signal is transmitted to the base station modulation / demodulation device 25 of No. 1.
In the base station modulation / demodulation device 25 that receives this signal, the control unit 1
Contact 4. Upon receipt of this notification, the control unit 14 searches
All search transmitters / receivers included in the wireless device 13
13-1, 13-2, ... 13-N is operated,
The output of these is the basic antenna A₁, A₂, ... and A
_NSwitch circuit 12 and tilt angle control circuit 11
An incoming call control signal is sent to the mobile wireless device 100 via the same.
At this time, the tilt angle control circuit is not operated and the standard condition is restored.
Keep it fixed. Mobile radio receiving this incoming control signal
In the device 100, the time assigned to the mobile wireless device 100
A control signal for incoming call response is transmitted using the lot. This
The incoming call response control signal of is the composite antenna 10 of the radio base station 1.
Will be received at. These received signals are transmitted by the mobile radio as described above.
Antenna A according to the direction in which the machine 100 is located₁, Λ₂,
... A_NAre received separately by way of the switch circuit 12.
The search transmitter / receiver 11-1 of the search wireless device 13,
It is transmitted to the search transmitter / receiver 11-2, ..., 11-N.
You. The contents of the received signal and the received
The bell is investigated and transmitted to the control unit 14. In the control unit 14,
These signals are analyzed and the signal level is the basic antenna A₁Or
Signal is the highest, followed by antenna A₂And A₃And more
Antenna A₄If so, the four basic ante
Mobile radio 100 that has arrived and responded in the main beam direction
And the basic antenna A₁~ A₄Beam of
The tilt angle is changed, and the radio from the mobile radio 100
Adjust for better signal reception. Even with the above adjustment results, the signal level is basically
Antenna A₁The signal from is the highest, followed by antenna A
₂, And antenna A₃If found to be
Mobile radio 100 has antenna A₁Exists in the main beam direction of
It is assumed that it does and moves to the following operation. In the control unit 14
Is communicated by the base station modulator / demodulator 25.
Machine 13-2 is open (newly communicable)
Since it recognizes that,
Each basic antenna A of antenna 10₁, A₂, And A₃And
The connection with the credit radio 13-2 is turned on, and the communication radio
The output of machine 13-2 is the basic antenna A₁, A₂, And A₃
To be guided to. The operation thereafter is the mobile radio 10
Step S107 when calling from 0 (see FIG. 7)
Communication between the mobile wireless device 100 and the wireless base station
Ends and the operation is stopped. In addition, the above system
In the system example, the basic antenna used in the composite antenna 10
In the case where the number of na is set to 3, a number other than 3, for example,
Of course, 2 or 4 is possible. The above system operation is performed on one radio carrier.
When only one call (telephone) signal is placed (S
CPC system), or multiple channels on one wireless carrier.
When the talk (telephone) signal is time-division multiplexed (T
It is possible to operate in any case of the DMA system).
However, the operation of the present invention will be described more specifically in the latter case.
Explain the work. As an example of a system, four are provided on one wireless carrier.
It is assumed that the call signal of is capable of time division multiplexing. Figure 10 is P
Wireless system of DC system (digital cellular system)
Example of signal frame structure in channel (channel number 1)
Show. Used for communication in 1 frame (20 ms) of FIG.
4 time slots (S₁~ S₄) And control signals
One time slot (C₁)
Each slot of the current call time slot number 1 to 3 (S₁
~ S₃) Indicates that the calling or receiving operation already described is completed.
Mobile radios 100-1 to 100-3 and telephone network 40.
Suppose you are in a call with each of the phones inside. FIG. 11 shows the operation of the system to which the present invention is applied.
In the figure for explaining, the circle in the center indicates the wireless base station 1.
However, the regular hexagon defines the service area occupied by each wireless base station.
Show. Long drawn from the wireless base station 1 to the outside
The ellipse is a communication antenna using the radio wave of wireless channel 1.
It represents the main beam of radio waves emitted from a part of 20
Of which three beams are directed to three cars
Mobile radios 100-1 and 100-2 installed inside
And 100-3 are being communicated. other
The two beams use another numbered radio channel
The mobile radio 100 is in communication with the mobile radio 100.
It is omitted in the figure. Also, in the figure, the wireless base station 1
Each other surrounding wireless base station communicates with the mobile wireless device.
It is also depicted how they are doing. At this time, the wireless base station 1
From the mobile wireless device 100-4 existing in the service area
A new call control signal is a tie for the control signal of wireless channel 1.
Suppose that it has been sent to the wireless base station 1 using a mobile slot.
You. The radio base station 1 sends this signal to the mobile communication control station 30.
And asked for instructions on how to use the wireless channel.
By the way, the call time slot of the vacant wireless channel 1
Number 4 (S₄) Is instructed. So this
It is assumed that the call is accepted by using the call. The above operation of the present invention will be described below.
You. First, the call control signal is transmitted from the mobile wireless device 100-4.
The signal is the time slot for the control signal of radio channel 1.
(C₁) Is used for this control signal
Not sent when the slot is used for other communication
Therefore, it does not cause interference with other communications. No movement
Reception of the call control signal from the line machine 100-4 is performed by the composite antenna.
It is received by the router 10 and sent to the search radio 13,
All of these timings are for control signal times shown in FIG.
Is it only done within the lot and not at any other time?
This also does not cause any interference with other communications.
Hereinafter, the transmission / reception radio wave beam detection for the composite antenna 10 will be described.
Searching and tracking is each time slot S₄And C₁Done every
In addition, the switch circuit 12, the base station modulator / demodulator 25,
Each operation of the communication radio 15, the mobile communication control station 30, etc.
Im Slots S₄And C₁Because it is executed in synchronization with
It does not cause any interference with the communication. On the other hand, the mobile radios 100-1 to 100-1 currently in communication
Various operations related to communication between 100-3 and the wireless base station 1
All time slots (S₁~
S₃), And the time for the control signal, which is performed by checking the availability
Slot (C₁) Is used to execute
For communication between the mobile wireless device 100-4 and the wireless base station 1.
It does not affect the actions that change. Also wireless
Other radio channels of the base station 1 (2, 3 other than the number 1, ...
.., etc.) for other mobile radio devices 100-5, 100
-6, ..., etc. are in communication, the frequency to be used is
Because they are different, they do not cause radio interference. In addition, SCPC
In the case of the system, each time slot of the above radio channel 1
(S₁~ C₁) On different radio channels
You can think of it as a signal. Next, the wireless base station 1 according to the present invention has
Direction of main beam of antenna and moving speed of mobile radio 100
Will be described. That is, mobile radio as described above
Mobile radio even during location search and call origination of mobile device 100
Since 100 is moving, centering on the wireless base station 1
How much to move in the radial direction,
If the movement is large, the direction of the main beam of the antenna will differ
Explain the problem of moving in the direction
You. A vehicle equipped with the mobile radio 100 is a radio base station 1
9 hours per hour on the highway that touches the circumference of 500 meters
It is assumed to be moving at 6 km. Location of control signals required for calling operation
If the required transmission and reception is 1 second, the distance traveled by the car in 1 second
Separation 96km × (10/3600) = 36m. Becomes On the other hand, a car moved from the radio base station 1
The angle to see m (36/500) × (360 / 2π) = 4.13
(Every time). On the other hand, as already described in FIG. 2, the present invention is applied.
Since the directional antenna has a main beam width of 30 degrees or more,
There is no need to worry that it will be completely out of the beam direction. Further
In addition, in the system to which the present invention is applied, a plurality of basic antennas are used.
1 frame of signal for time division multiplexing system
(Eg 20 ms) or every few frames constantly
Is the signal level received by the basic antenna being measured?
Also from this point, there is no such concern. Further, in the present invention, the signal is included in one frame.
Send and receive for searching the level of control signal time slot
11-1 etc., and the result is the time of the call signal.
Assuming the same condition at the lot level, but the signal
Mobile radio such as 20 ms for one frame time
This assumption because it is extremely short compared to the moving speed of the aircraft 100
There is no problem. From the above, the system according to the present invention is
It works well with either SCPC or TDMA.
It became clear to make. Finally, by applying the present invention, a mobile communication system
Of the same wireless channel that is repeatedly used in different locations
By reducing the coordination distance, the effective frequency utilization
Explain that improvement is possible. It already explained
The radio waves used by the wireless base station for mobile radio
Unlike the conventional system, only the direction in which the mobile radio exists
Limited to, and equipped with radio base stations
When using an antenna, the main directivity should be
And the angle directed downwards is larger than before.
And the radio signal transmitted from the radio base station to the mobile radio device.
The power of the signal is reduced compared to the conventional system.
Distance to use the same wireless channel
Even if the (cooperative distance) is decreased, the probability of occurrence of interference does not increase.
This is because As a result, the frequency of use of the same radio channel
The effective utilization of the frequency increases by the amount of increasing. [0044] In the mobile communication system to which the present invention is applied,
Has made it possible to achieve the following effects.
First used by the wireless base station to communicate with the mobile radio
This is the point where radio waves can be used effectively. Wireless base station
One of the antenna systems that have a mobile radio
Antenna that can receive signals effectively coming from the direction (Basic
The antenna can be used only for other directions.
It will be possible to block the interfering radio waves coming from
Therefore, the transmission power from the mobile wireless device is the value that was previously required.
It is possible to maintain the same quality with less power.
Was. Similarly, the transmission power from the wireless base station
An antenna that can effectively propagate in the direction in which a mobile radio device exists
Can be limited to (basic antenna) only
The same product with less power than the value conventionally required
It is possible to maintain the quality. In addition,
When using an antenna, the number of antennas used is usually 2-3.
Therefore, it is possible to reach the wireless base station via multiple propagation paths.
Of the line signals, multiple high-power signals are all
Selective reception by the antenna and lead to the wireless reception unit in the wireless base station
As a result, the above-mentioned mobile radio is fast
If you move in the direction of
Significantly reduces the risk of being unable to track Tena's main orientation
Can be reduced. Third, other communication in the same system
The point is that the radio wave interference that affects the signal is reduced. This is the first
As described above, the radio waves transmitted from the wireless base station are wasted.
Because it is possible to prevent firing in any direction. Sa
Wireless signals that leak to areas other than their own service area
Can slightly reduce radio wave interference to other callers
Noh. As a result, the same radio channel is used
The probability of interference increases even if the distance (cooperative distance) is reduced
Without increasing the frequency of use of the same wireless channel
It can be expected that the effective utilization of frequency will be greatly improved.
However, the effect of the present invention seems to be extremely large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an example of a system configuration according to the present invention. FIG. 2 is a diagram showing characteristics of the antenna of the present invention. FIG. 3 is a diagram showing a part of the system configuration of FIG. 1; FIG. 4 is another diagram showing a part of the system configuration of FIG. 1; FIG. 5 is another diagram showing a part of the system configuration of FIG. 1; FIG. 6 is another diagram showing a part of the system configuration of FIG. 1; FIG. 7 is a flowchart showing a flow of operations of the system according to the present invention. FIG. 8 is a flowchart showing the operation flow of the system according to the present invention together with FIG. 7. 9 is a flowchart showing the flow of operations of the system according to the present invention together with FIG. 9. FIG. 10 is a diagram showing an example of a frame structure applied to a system according to the present invention. FIG. 11 is a diagram for explaining the operation of the system according to the present invention. [Description of Reference Signs] 1 radio base station 10 composite antenna 11 tilt angle control circuit 12 switch circuit 13 search transmitting / receiving unit 15, 15-1, 15-1, ... 15-M communication radio 25 base station modulator / demodulator 30 Mobile Communication Control Station 40 Telephone Network 60 Wired Signal Transmitter / Receiver 61 Decoder 62 Coder 63 Decoding Circuit 64 Encoding Circuit 70 Timing Generator 71 Clock Generator 75 Base Station Controller 78 Wireless System Signal Transmitter / Receiver 100, 100-1 , 100-2, ... 15-p mobile radio

Claims (1)

Claim: What is claimed is: 1. A radio base station (1) for covering a plurality of zones and forming a service area, and a radio channel for communicating with the radio base station across the zones. It is included in a mobile communication control station (30) for managing communication with each mobile radio device (100) and a telephone network (40) connected to the mobile communication control station by a transmission line. There is a telephone set, and a composite antenna included in the wireless base station for wireless mobile communication performed between the wireless base station and the mobile wireless device is composed of a plurality of basic antennas having the same characteristics, and a horizontal plane. It has a narrow beam characteristic as an inward directivity characteristic, can be used in any combination under the control of the control unit provided in the radio base station, and can be controlled in tilt angles respectively. In the communication between the mobile wireless device and the wireless base station, the control unit specifies one or more of the basic antennas suitable for communication, and determines the tilt angle control amount of each of the basic antennas. A control system of a radio base station antenna directivity characteristic in a mobile communication system, which enables a radio provided in the radio base station to perform good communication with the mobile radio by executing the respective controls. 2. During communication between the radio base station of claim 1 and the mobile radio, as the mobile radio moves within the service area, the basic antenna in use is changed and the tilt angle is changed. A control system of a radio base station antenna directivity characteristic in a mobile communication system, which enables the control according to claim 1 to be found when it is found that the control unit needs to be changed. 3. The mobile radio device and the radio base station are moved relative to each other as the mobile radio device moves within the service area during communication between the radio base station and the mobile radio device according to claim 1. When the control unit finds that it is necessary to change the tilt angle of each main directivity of one or more basic antennas suitable for use in the radio base station due to a change in distance, A control system of a radio base station antenna directivity characteristic in a mobile communication system capable of executing the control described in the above section every moment. 4. The use of the basic antenna used by the radio base station according to claim 1 can be limited only to the direction in which the mobile radio device is present, and the base of claim 3 By controlling the tilt angle of the antenna, the main directivity of the radio base station antenna is directed downward on average, and so on. Control system. 5. The use of the basic antenna used by the radio base station according to claim 1 can be limited only to a direction in which the mobile radio device is present, and the base of claim 3 By controlling the tilt angle of the antenna, the main directivity of the radio base station antenna is directed downward on average, and so on, to reduce the leakage of radio waves to the adjacent service area existing outside the service area of the radio base station. , A control system of directivity characteristics of a radio base station antenna in a mobile communication system capable of reducing radio wave interference. 6. The use of the basic antenna used by the radio base station according to claim 1 can be limited only to a direction in which the mobile radio device is present, and the base of claim 3 The directivity of the radio base station antenna in a mobile communication system that enables the effective frequency utilization of the system to be improved by, for example, the main directivity of the radio base station antenna being directed downward on average by controlling the tilt angle of the antenna. Control system. 7. The use of the basic antenna used by the radio base station according to claim 1 can be limited only to the direction in which the mobile radio device is present, and the base of claim 3 By controlling the tilt angle of the antenna, the main directivity of the radio base station antenna is directed downward on average, and so on, which reduces the cooperative distance of the same radio channel repeatedly used in the system and improves the effective frequency utilization. A control system for the directivity of a radio base station antenna in a mobile communication system that enables the control.