JP2000236294A - Method and device for mobile communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain mobile communications equipment which easily reduces interference with simple constitution. SOLUTION: A base station transmitter receiver 4, when it communicates with a mobile station 5, controls an antenna changeover switch 3 to select an antenna 1. When the received electric field level from the mobile station 5 which is detected is not larger than a previously set specific threshold, the antenna 1 is still used to continue the communication with the mobile station 5. However, when the received electric field level is larger than the specific threshold, an antenna changeover switch 3 is controlled to switch the antenna 1 to an antenna 2, through which the communication with a mobile station 5 is carried on. If the received electric field level becomes equal to or below the specific threshold during the communication with the mobile station 5 through the antenna 2, the base station transmitter receiver 4 controls the antenna changeover switch 3 to switch the antenna 2 to the antenna 1, through which the communication with the mobile station 5 is carried out. Since the antennas 1 and 2 which have a narrow a communicable region as possible are used to communicate, interference with other communication using radio waves of the same frequency can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication method and an apparatus for communicating with a mobile station using a plurality of antennas.

[0002]

2. Description of the Related Art In a conventional mobile communication device such as a mobile phone, an antenna having a higher ground height has a longer radio wave range, and therefore can communicate over a wide range from a mobile communication device. Since reception is possible over a wide range, there is a high possibility that interference will occur with other communications using radio waves of the same frequency.

[0003] In order to reduce co-frequency interference, it is conceivable to minimize mobile communication transmission power.

[0004] However, even if the transmission range is restricted by suppressing the transmission power so as to reduce interference with communication using other radio waves of the same frequency, radio waves of another same frequency are used. There is a problem that the interference received from the communication cannot be reduced.

A mobile communication device for preventing interference with another mobile communication device is disclosed in, for example, Japanese Patent No. 2636718.
A configuration described in Japanese Patent Application Laid-Open No. H10-209,086 is known.

In the device disclosed in Japanese Patent No. 2636718, a plurality of types of antennas having different half-width angles of directivity in a horizontal plane are provided in a receiving base station of a mobile communication device at a radio terminal. When there are multiple channels that can be assigned with multiple antennas for communication requests with
By preferentially selecting the antenna that maximizes the sum of the decibel value of the desired wave power received by each antenna and a constant determined for each antenna according to the half-width angle of directivity in the horizontal plane of the antenna, interference Has been reduced.

[0007]

However, the technique disclosed in the above-mentioned Japanese Patent No. 2636718 discloses a method for suppressing power consumption of a mobile communication apparatus and controlling uplink power when a plurality of antennas can be used for communication with the mobile communication apparatus. In addition to improving the frequency use efficiency by reducing the line interference and improving the frequency use efficiency by reducing the interference by the antenna directivity, there is a problem that the structure becomes complicated.

[0008] The present invention has been made in view of the above points, and an object of the present invention is to provide a mobile communication method and an apparatus for easily reducing interference with a simple configuration.

[0009]

According to a first aspect of the present invention, there is provided a mobile communication method for communicating with a mobile station using the antenna in a minimum communicable area among a plurality of antennas having different communicable areas. Things. A mobile communication method according to a second aspect is the mobile communication method according to the first aspect, wherein the antennas have different ground heights. A mobile communication method according to a third aspect is the mobile communication method according to the first or second aspect, wherein an antenna is switched depending on whether or not a received electric field level from a mobile station exceeds a predetermined threshold.
The mobile communication method according to claim 4 is the mobile communication method according to claim 1 or 2, wherein a frame error rate of a signal received from the mobile station is lower than a predetermined threshold value.
The antenna is switched. The mobile communication device according to claim 5, wherein a plurality of antennas having different communication area ranges, an antenna changeover switch for switching the plurality of antennas, and the antenna changeover switch minimizes a mobile station among the plurality of antennas. A base station transceiver for switching to an antenna in a communicable area. A mobile communication device according to a sixth aspect is the mobile communication device according to the fifth aspect, wherein the antennas have different ground clearances. A mobile communication device according to a seventh aspect is the fifth aspect.
In the mobile communication device according to the sixth aspect, the base station transceiver switches an antenna with an antenna switch according to whether or not a received electric field level from the mobile station exceeds a predetermined threshold. The mobile communication device according to claim 8 is the mobile communication device according to claim 5 or 6, wherein the base station transceiver switches antennas according to whether a frame error rate of a signal received from the mobile station is lower than a predetermined threshold. The antenna is switched by a switch.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a configuration of a mobile communication device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a mobile communication device according to the present invention.

As shown in FIG. 1, the mobile communication device is composed of a plurality of mobile stations 5 such as portable radios and mobile phones, and base stations for transmitting and receiving communications with the mobile stations 5.

The base station includes a base station transceiver 4 for transmitting and receiving, that is, communicating with a mobile station 5 by radio. Further, the base station transceiver 4 is connected to an antenna switch 3 for connecting the plurality of antennas 1 and 2. The antenna 1 is installed at a high position above the ground, and the antenna 2 is installed at a low position above the ground.

The base station transceiver 4 stores a predetermined threshold value for identifying the reception electric field level of the signal from the mobile station 5, detects the reception electric field level of the signal of the mobile station 5, and stores it. A control signal to the antenna changeover switch 3 is generated depending on whether the received electric field level exceeds or falls below the threshold value, for example, as compared with the threshold value. Further, the antenna switch 3 switches the antennas 1 and 2 as appropriate under the antenna switching control from the base station transceiver 4.

Next, the operation of the above embodiment will be described with reference to the flowchart shown in FIG.

When communicating with the mobile station 5, the base station transceiver 4 first controls the antenna switch 3 to switch to the antenna 1 (step A1).

Next, the base station transceiver 4 determines whether or not the detected electric field level from the mobile station 5 is higher than a predetermined threshold (step A).
2). Then, the detected received electric field level from the mobile station 5 is not higher than a predetermined threshold value set in advance.
That is, when it is determined that the received electric field level from the mobile station 5 is equal to or less than the predetermined threshold value, the process returns to step A1, and the communication with the mobile station 5 is continued while the antenna 1 remains.

If it is determined in step A2 that the electric field level received from the mobile station 5 is higher than a predetermined threshold, the antenna changeover switch 3 is controlled to switch to the antenna 2 (step A3). Return. In this state, communication with the mobile station 5 is continued.

If it is determined that the received electric field level is equal to or less than the predetermined threshold value while the communication with the mobile station 5 is being performed using the antenna 2, the process returns to step A1 and returns to the base station. The device 4 controls the antenna switch 3 to switch to the antenna 1 (step A1), and communicates with the mobile station 5 using the antenna 1.

As described above, since a plurality of antennas 1 and 2 having different communicable areas are provided and communication is performed using the minimum communicable area, that is, the antennas 1 and 2 having as narrow a communicable area as possible, radio waves having the same frequency are transmitted. It is possible to suppress interference to other used communication and to suppress interference received from other communication using radio waves of the same frequency.

Also, antennas 1 and 2 having different communicable areas are provided.
Second, since the installation ground height is different, interference with other communication using radio waves of the same frequency can be easily suppressed with a simple structure.

In the above embodiment, the plurality of antennas 1 and 2 having different communicable areas have been described with different installation ground heights. However, any method such as different transmission and reception sensitivities can be used.

Next, another embodiment of the present invention will be described with reference to the flowchart shown in FIG.

In the embodiment shown in FIG. 3, the criterion for antenna switching based on the received electric field level in the embodiment shown in FIGS. 1 and 2 is determined based on a frame error.

That is, the base station transceiver 4 is connected to the mobile station 5
A predetermined threshold value for identifying a frame error rate of a signal received from the mobile station 5 is stored, a frame error rate of a signal received from the mobile station 5 is detected, and compared with the stored threshold value. A control signal to the antenna changeover switch 3 is generated depending on whether or not exceeds the threshold.

Then, as shown in FIG. 3, when communicating with the mobile station 5, the base station transceiver 4 first controls the antenna switch 3 to switch to the antenna 1 (step B1).

Next, the base station transceiver 4 determines whether or not the detected frame error rate of the received signal from the mobile station 5 is lower than a preset threshold (step B2). Then, the detected frame error rate of the received signal from the mobile station 5 is not lower than a predetermined threshold value, that is, the frame error rate of the received signal from the mobile station 5 is equal to the predetermined threshold value. If it is determined to be less than or equal to the following, the process returns to step B1, and the antenna 1
The communication with the mobile station 5 is continued as it is.

If it is determined in step B2 that the frame error rate of the signal received from the mobile station 5 is lower than a predetermined threshold, the antenna switch 3 is controlled to switch to the antenna 2 (step B3). Step B2
Return to In this state, communication with the mobile station 5 is continued.

If it is determined that the frame error rate has become equal to or more than the predetermined threshold value while communication with the mobile station 5 is being performed using the antenna 2, the process returns to step B1 and returns to step B1. The transceiver 4 controls the antenna switch 3 to switch to the antenna 1 (step B).
1) communicate with the mobile station 5 via the antenna 1;

[0030]

According to the present invention, among a plurality of antennas having different communicable areas, communication is performed by using an antenna in the smallest communicable area, so that interference is given to other communications using radio waves of the same frequency. This can be suppressed, and interference received from other communication using radio waves of the same frequency can be suppressed.

Further, since the communicable area is made different by changing the installation ground height, interference with other communications using radio waves of the same frequency can be easily suppressed with a simple structure.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication mobile device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the above.

FIG. 3 is a flowchart showing an operation of the communication mobile device according to another embodiment of the present invention.

[Explanation of symbols]

 1, 2 antenna 3 antenna switch 4 base station transceiver 5 mobile station

Claims (8)

[Claims] 1. A mobile communication method comprising: performing communication with a mobile station using the antenna in a minimum communicable area among a plurality of antennas having different communicable areas. 2. The mobile communication method according to claim 1, wherein said antennas have different ground heights. 3. The mobile communication method according to claim 1, wherein an antenna is switched depending on whether or not a received electric field level from the mobile station exceeds a predetermined threshold. 4. The mobile communication method according to claim 1, wherein the antenna is switched depending on whether a frame error rate of a signal received from the mobile station is lower than a predetermined threshold. 5. A plurality of antennas having different communicable areas, an antenna changeover switch for switching the plurality of antennas, and an antenna having a minimum communicable area with a mobile station among the plurality of antennas by the antenna changeover switch. A mobile communication device comprising: a base station transceiver for switching to a mobile station. 6. The mobile communication device according to claim 5, wherein the antennas have different ground heights. 7. The mobile communication according to claim 5, wherein the base station transceiver switches an antenna with an antenna switch according to whether or not a received electric field level from the mobile station exceeds a predetermined threshold. apparatus. 8. The base station transceiver according to claim 5, wherein the antenna is switched by an antenna switch according to whether a frame error rate of a signal received from the mobile station is lower than a predetermined threshold. Mobile communication device.