JP2002033611A - Method for adjusting antenna direction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for adjusting antenna direction that can easily and inexpensively adjust an antenna of a base station to an optimum direction. SOLUTION: A subscriber station antenna 31 provide to a subscriber station 3 placed at a point remotest in a cell of a base station 2 receives a radio wave 41 from a base station antenna 21, and the direction of the base station antenna 21 is adjusted so that a reception is at an optimum reception level calculated in advance while monitoring the reception level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting the antenna direction of a base station in a point-to-multipoint subscriber radio access system, and more particularly, to easily adjust the direction of an antenna for a base station which requires high-precision angle adjustment. The present invention relates to an antenna direction adjusting method capable of adjusting efficiently.

[0002]

2. Description of the Related Art In general, a point-to-multipoint subscriber radio access system is composed of a plurality of cells, and transmission and reception between a base station and a subscriber station are performed independently for each cell.

[0003] Therefore, it is important to minimize interference outside the cell due to radio waves of each base station. Normally, the antenna pattern on the vertical surface of the base station antenna is made steep, and this steep curve starts to fall. Is set to the farthest point of the cell of the base station, thereby suppressing leakage of radio waves to the outside of the cell.

For example, as shown in FIG. 5, a subscriber station indicated by a circle is in a cell 11, and a subscriber station indicated by a cross is in a neighboring cell 12, a base station constituting cells 11 and 12, respectively. Wireless communication via the.

[0005] Here, the base station 2 forming the cell 11 is:
The antenna 21 having antennas in four directions and supplying radio waves to the zone 11a adjacent to the cell 12 has a position RL1 at which the steep curve of the antenna pattern in the vertical direction starts to fall on the boundary line between the cell 11 and the cell 12. The angle of the antenna is adjusted so as to prevent interference of the cell 12 with radio waves.

Conventionally, such antenna direction adjustment is performed by adjusting the base station apparatus to an absolute horizontal level using an optical measuring instrument or the like, and thereafter, the angle in the horizontal direction and the vertical direction from the absolute horizontal level is adjusted by the cell. The direction of the antenna of the base station has been adjusted by using an optical measuring device or the like so that an appropriate angle is calculated in advance so that an appropriate radio wave can be supplied into the antenna.

[0007]

However, in the above method, since the antenna angle must be adjusted with high accuracy by the base station apparatus alone, the work efficiency is poor, and the antenna installation work such as using an optical measuring instrument is not sufficient. There is a problem that leads to an increase in cost.

Accordingly, an object of the present invention is to provide an antenna direction adjusting method capable of easily and inexpensively adjusting an antenna of a base station in an optimum direction.

[0009]

SUMMARY OF THE INVENTION An antenna direction adjusting method according to the present invention is a method for adjusting the antenna direction of a base station in a point-to-multipoint subscriber radio access system for communicating between a base station and a plurality of subscriber stations. In the plurality of subscriber stations, the reception level of the radio wave transmitted by the base station at the most remote subscriber station located at the farthest point from the base station is calculated in advance by simulation, and the The reception level of the radio wave transmitted from the antenna of the base station received by the antenna of the subscriber station is monitored, and the direction of the antenna of the base station is changed so that the monitored reception level becomes the reception level calculated by the simulation. It is characterized by adjusting.

Here, the reception level calculated by the simulation includes at least the height of the antenna of the base station, the height of the antenna of the most remote subscriber station, the antenna of the base station and the most remote subscriber station. And the transmission power level of the base station.

The most remote subscriber station transmits the monitored reception level to the base station by an upward radio wave, and the received level monitored by the most remote subscriber station received by the base station is a reception level. May be configured to adjust the direction of the antenna of the base station so that the reception level becomes the reception level calculated by the simulation.

In addition, a communication apparatus for transmitting a reception level for transmitting a reception level monitored by the most remote subscriber station is arranged near the remotest subscriber station, and a communication apparatus for transmitting a reception level is arranged near the base station. A receiving level receiving communication device for receiving the receiving level transmitted from the communication device is arranged, and the receiving level monitored by the farthest subscriber station received by the receiving level receiving communication device becomes the receiving level calculated by the simulation. Thus, the configuration can be such that the direction of the antenna of the base station is adjusted.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an antenna direction adjusting method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a schematic configuration of a base station in a point-to-multipoint subscriber radio access system according to the present invention.

In FIG. 1, the base station 2 comprises an antenna 21, an outdoor unit (ODU) 22, and an indoor unit (I
DU) 23 and an antenna direction adjusting device 24. The ODU 22 and the IDU 23 are coaxial cables 26.
(IF cable).

Here, the ODU 22 includes an amplifier 220 and a radio unit 221, and the IDU 23 includes a baseband processing unit 230, a terminal interface 231, and a control unit 232.

The antenna 21 receives a radio wave from a subscriber station. Radio section 221 performs frequency conversion on a received wave (RF signal) received from antenna 21 via amplifier 220, and outputs the result as an IF signal. The baseband processing unit 230 performs demodulation processing on the IF signal supplied via the coaxial cable 26, converts the signal into a baseband signal, and supplies the signal to the communication terminal via the terminal interface 231.

On the other hand, baseband processing section 230 performs modulation processing on the baseband main signal supplied from the communication terminal, and outputs the result as an IF signal. Radio unit 221
Performs a frequency conversion process on the IF signal supplied via the coaxial cable 26 and supplies the signal to the antenna 21 via the amplifier 220 as a transmission wave (RF signal).

The control unit 232 includes a baseband processing unit 23
The monitoring information is collected by monitoring the operation status of the device 0.

The control unit 232 is connected to a maintenance terminal 25 for setting various data in the base station 2 and inputting / outputting maintenance information.

The maintenance terminal 25 includes an antenna direction adjusting unit 251. The antenna direction adjusting unit 251 further includes a CPU 251a, a ROM 251 storing a control program for causing the CPU 251a to function, and the like.
b, a red light emitting diode (LED) 251e and an LED driver 251c for driving the same, a green light emitting diode (LED) 251f, an LED driver 251d for driving the same, and a display unit 251g.

A method of adjusting the direction of the antenna 21 in the base station 2 configured as described above will be described in detail below.

FIG. 2 is a diagram showing a state of communication between a base station and a subscriber station constituting a cell.

In FIG. 2, in the cell constituted by the base station 2, the farthest subscriber station 3 located farthest from the base station 2 is provided with a subscriber station antenna 31.

The base station 2 transmits a downlink radio wave 41 for antenna direction adjustment at a fixed transmission output level from the base station antenna 21, and the subscriber station 3 transmits the subscriber station antenna 3
The reception level of the downlink radio wave 41 received at one end is
It is transmitted to the base station 2 on the uplink radio wave 42.

In the base station 2, the worker operates the subscriber station 3
The reception level at the end of the subscriber station antenna 31 of the downstream radio wave 41 transmitted from the mobile station on the upstream radio wave 42 can be monitored by the display unit 251g of the antenna direction adjustment unit 251. Generates an antenna direction adjustment signal so that the reception level becomes the optimum reception level indicating that the base station antenna 21 has been adjusted in the optimum direction, and operates the antenna direction adjustment device 24 to operate the base station antenna 21. The angle of the antenna 21 is adjusted.

Here, the optimum reception level of the downlink radio wave 41 for antenna direction adjustment at the end of the subscriber station antenna 31 is calculated as follows.

The transmission power of the base station antenna 21 is P, the gain is Gb, the absolute gain of the subscriber station antenna 31 is Gc,
The relative gain is Grx, the propagation loss of the coaxial cable 26 between the ODU 22 and the IDU 23 of the base station 2 is L1,
Assuming that the propagation loss with respect to the distance between the base station antenna 21 and the subscriber station antenna 31 is L2, the optimum reception level RL1 is obtained as follows: RL1 = P + Gb + Gc + Grx-L1-L2 (1)

Further, in the vicinity of the optimum reception level RL1 calculated from the above equation, an optimum reception level range is determined, the upper limit of which is RLu and the lower limit is RLl. The direction of the base station antenna 21 is adjusted so that the level RL satisfies RLu ≦ RL ≦ RLl (2).

FIG. 3 is a flowchart showing the procedure for adjusting the antenna direction.

In FIG. 3, for example, when an operator presses a start button (not shown) provided in the antenna direction adjusting unit 251 in FIG.
51 transmits an antenna direction adjustment start signal to the control unit 232 to start antenna direction adjustment (step 50).
0).

When the control unit 232 receives the antenna direction adjustment start signal, the base station 2 generates a down-going radio wave 41 for antenna direction adjustment, and sets the antenna 21 at a fixed transmission level.
The call is transmitted (step 501).

The subscriber station 3 transmits the reception level RL of the downlink radio wave 41 at the end of the subscriber station antenna 31 to the base station 2 on the uplink radio wave 42.

When the base station 2 receives the uplink radio wave 42 from the subscriber station antenna 31 again, the control unit 232 extracts a signal of the reception level RL, and the extracted signal is received by the antenna direction adjustment unit 251. The signal of the level RL is transferred (step 502).

The antenna direction adjusting unit 251 includes the control unit 23
When the signal of the reception level RL is received from No. 2, the value is displayed on the display unit 251g (step 503), and the optimum reception level upper limit RLu and the optimum reception level lower limit RLl calculated in advance and stored in the ROM 251b are referred to. Then, it is determined whether or not the value of the reception level RL is within the optimum reception level range (step 504).

If the value of the reception level RL is within the optimum reception level range, the green L is output via the LED driver 251d.
The ED 251f is turned on (step 505). For example, a command to end the antenna direction adjustment work is sent from the outside to the antenna direction adjustment unit 251 such as the operator pressing a stop button (not shown) provided in the antenna direction adjustment unit 251 in FIG. When input (YES in step 506),
The antenna direction adjustment work ends. However, if there is no command from outside (NO in step 506), step 502 is repeated again.

As described above, even if it is determined by the antenna direction adjusting unit 251 that the base station antenna 21 has been adjusted in the optimal direction, the final decision is left to the operator. Highly reliable antenna direction adjustment can be performed.

If the value of the reception level RL is out of the optimum reception level range, the antenna direction adjusting section 251 sets the LE
The red LED 251e is turned on via the D driver 251c (step 507).

The CPU 251a compares the current reception level RL with the optimum reception level RL1, and as a result, calculates antenna adjustment parameters such as the adjustment direction and angle of the base station antenna 21 (step 508). The calculated antenna adjustment parameters are transmitted to the control unit 232.

The control unit 232 transfers the antenna adjustment parameter to the antenna direction adjusting device 24 via the IDU 23 and the ODU 22, and
4 drives various drivers (not shown) based on the antenna adjustment parameters to adjust the direction of the base station antenna 21 (step 509).

Here, the flow in the case where the direction adjustment of the base station antenna 21 is performed by the automatic control of the antenna direction adjusting unit 251 has been described.
The operator may directly operate the antenna direction adjusting device 24 to adjust the direction of the antenna 21. In this case, the operator operates the display unit 25 of the antenna direction adjustment unit 251.
While monitoring 1 g, the antenna direction adjusting device 24 is adjusted so that the value of the reception level RL falls within the optimum reception level range.
Is operated to adjust the direction of the base station antenna 21.

The above-mentioned optimum reception level RL1 is
This is a value when the farthest subscriber station 3 is located on the border of the cell constituted by the base station 2. Therefore, when the subscriber station 3 is located inside the border of the cell, the location is considered. It is necessary to calculate the optimum reception level RL1 obtained.

Conversely, if the position where the farthest subscriber station 3 is located is defined as the boundary of the cell constituted by the base station 2, the value obtained from the equation (1) is used as the optimum reception level R as it is.
L1.

FIG. 4 shows another embodiment of the present invention.
As described above, the reception level display communication devices 27 and 32 are separately provided in the base station 2 and the subscriber station 3, respectively, so that the reception level RL of the downlink radio wave 41 at the end of the subscriber station antenna 31 is obtained. May be configured to be monitored.

[0045]

As described above, according to the present invention, the radio wave transmitted from the base station antenna is received by the subscriber station located at the farthest point of the cell of the base station, and the received radio wave is received. Since the direction of the base station antenna is adjusted while monitoring the level to be the optimum reception level calculated in advance, the base station antenna can be easily adjusted in the optimum direction, so that the efficiency of installation work can be improved and Cost reduction can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a base station device in a point-multipoint subscriber wireless access system according to the present invention.

FIG. 2 is a diagram showing a first embodiment of the antenna direction adjusting method according to the present invention.

FIG. 3 is a flowchart illustrating an example of an operation of adjusting the antenna direction of the base station illustrated in FIG. 1;

FIG. 4 is a diagram showing a second embodiment of the antenna direction adjusting method according to the present invention.

FIG. 5 is a diagram schematically illustrating a point-to-multipoint subscriber wireless access system.

[Explanation of symbols]

 11, 12 cell 2 base station 21 base station antenna 22 outdoor unit 23 indoor unit 24 antenna direction adjusting device 25 maintenance terminal 26 coaxial cable 220 amplifier 221 radio unit 230 baseband processing unit 231 terminal interface 232 control unit 251 antenna direction adjustment Unit 251a CPU 251b ROM 251c, 251d LED driver 251e, 251f Light emitting diode 251g Display unit 3 Most remote subscriber station 31 Subscriber station antenna 27, 32 Received level display communication device 41 Upward radio wave 42 Downward radio wave

Claims (4)

[Claims] 1. A method for adjusting the antenna direction of a base station in a point-to-multipoint subscriber radio access system for communicating between a base station and a plurality of subscriber stations, comprising: The reception level of the radio wave transmitted by the base station at the most remote subscriber station located at the farthest point from the station is calculated in advance by simulation, and the reception level of the base station received by the antenna of the most remote subscriber station is calculated. An antenna direction adjusting method, comprising: monitoring a reception level of a transmitted radio wave; and adjusting a direction of an antenna of the base station so that the monitored reception level becomes a reception level calculated by the simulation. 2. The reception level calculated by the simulation includes at least the height of the antenna of the base station, the height of the antenna of the most remote subscriber station, the antenna of the base station and the height of the most remote subscriber station. 2. The antenna direction adjusting method according to claim 1, wherein the distance is calculated based on a distance from an antenna and a transmission power level of the base station. 3. The most remote subscriber station transmits the monitored reception level to the base station by an uplink radio wave, and the received level monitored by the most remote subscriber station received by the base station is the simulation. 2. The antenna direction adjusting method according to claim 1, wherein the direction of the antenna of the base station is adjusted so as to have the reception level calculated by: 4. A communication device for transmitting a reception level for transmitting a reception level monitored by the most remote subscriber station in the vicinity of the most remote subscriber station, and a communication device for transmitting a reception level in the vicinity of the base station. A reception level receiving communication device for receiving the reception level transmitted from the communication device is arranged, and the reception level monitored by the remotest subscriber station received by the reception level reception communication device becomes the reception level calculated by the simulation. The antenna direction adjusting method according to claim 1, wherein the direction of the antenna of the base station is adjusted as described above.