JP2000299659A - Radio transmittor output controller and radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently reduce power consumption while securing satisfactory communication by turning a directional pattern to be a high directional pattern showing stronger directivity after establishing a communication link so as to reduce transmitting power. SOLUTION: Radio stations A, B adjust the directions of directional antennas 10, 20 so as to maximize the input level of them. Then, until the establishment of a communication link is confirmed, the directional adjustment of the antennas 10, 20 continues. When the establishment of the communication link is confirmed, the stations A, B realize a high directional pattern so as to intensify the directivity of the antennas 10, 20. In addition, the stations A, B control power amplifiers 12, 22 to reduce the transmitting power by the portion of intensifying the directivity of the antennas 10, 20. Thus, the power consumption of radio communication equipment can sufficiently be reduced while keeping a proper communicating state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio transmission output device and a radio communication system, and more particularly, to a radio transmission output control device and a radio transmission output control device suitable for reducing power consumption of the device. The present invention relates to a wireless communication system used.

[0002]

2. Description of the Related Art In a radio communication apparatus, the power consumption of a power amplification section that emits radio waves occupies a large proportion of the power consumption of the entire apparatus. For this reason, a reduction in transmission output is a major issue in reducing the power consumption of the device. Conventional wireless communication devices aim to reduce power consumption by detecting an input level of a reception signal from a partner or exchanging positional information with the partner and controlling its own transmission output based on the information. Was.

FIG. 16 shows the concept of a conventional wireless communication device. A conventional wireless communication device has a variable function of changing a transmission output in accordance with an input level of a reception signal from a partner device. That is, the conventional wireless communication apparatus, for example, when moving to a place where the radio wave condition is good, when the reception level measurement unit 209 detects an input level larger than the reference value, sets the power amplification unit in the transmission unit 202 to Control to reduce transmission power.

[0004]

In the conventional wireless communication apparatus, the variable range of the transmission output is determined in advance according to the notification distance. That is, the conventional wireless communication device aims to reduce power consumption within a variable range of the transmission output set in advance according to the communication distance. In other words, in a conventional device,
The range in which the power consumption can be reduced is limited only to the variable range of the transmission output determined by the notification distance, and it has been difficult to further reduce the power consumption.

When a conventional wireless communication device is used for mobile communication, it is necessary to use a non-directional antenna generally used in mobile communication. However, the omnidirectional antenna has less gain than the directional antenna because it has no directivity. Therefore, when a conventional wireless communication apparatus is used for mobile communication, it is necessary to set a relatively large transmission output in consideration of a small antenna gain. In this respect, it is difficult for the conventional wireless communication device to reduce power consumption in this respect as well.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and employs a directional antenna as an antenna.
It is a first object of the present invention to provide a wireless transmission output control device that achieves sufficient low power consumption while securing good communication performance by controlling the intensity of directivity and simultaneously controlling transmission output. I do. Further, the present invention employs a directional antenna for the antenna, and weakens the directivity at the time of antenna direction adjustment or handover using a mechanism for controlling the antenna directivity, thereby facilitating the establishment of a communication link. A second object is to provide a wireless transmission output control device and a wireless communication system. Furthermore, the present invention employs a directional antenna for the antenna, and secures the communication performance by changing the directivity when the communication state changes after the establishment of the communication link or when the wireless communication device moves during handover. It is a third object of the present invention to provide a wireless transmission output control device and a wireless communication system.

[0007]

According to the first aspect of the present invention,
A radio transmission output control device including a directional antenna capable of controlling directivity, wherein a directivity pattern of the directional antenna is set to a predetermined low directivity until a communication link is established with another radio station. A directivity control unit for setting the directivity pattern to a predetermined high directivity pattern showing a strong directivity as compared to the low directivity pattern after the communication link is established; and And a transmission output control unit that reduces a transmission output after the high directivity pattern is set.

According to a second aspect of the present invention, there is provided a radio transmission output control apparatus provided with a directional antenna capable of controlling directivity, wherein the radio link of a radio line is established after a communication link is established with another radio station. A line quality measuring unit that measures quality, a directivity control unit that adjusts the directivity of the directional antenna when the quality of the wireless channel is deteriorated, and a transmission output according to the directivity of the directional antenna. And a transmission output control unit for adjusting.

According to a third aspect of the present invention, in the wireless transmission output control apparatus according to the second aspect, when the quality of the wireless line is degraded, the directivity control unit controls the directivity of the directional antenna. More preferably, the transmission output control section maintains the transmission output.

According to a fourth aspect of the present invention, there is provided the radio transmission output control device according to the second aspect, wherein a level measuring section for measuring a reception level at the directional antenna and a direction for adjusting a direction of the directional antenna. Comprising an adjustment unit, when the quality of the wireless line is deteriorated, first, the directivity control unit weakens the directivity of the directional antenna, and the transmission output control unit strengthens the transmission output, then The direction adjustment unit performs direction adjustment such that the reception level in the directional antenna is maximized, and after the completion of the direction adjustment, the direction control unit strengthens the directionality of the directional antenna, and the transmission output A control unit weakens the transmission output.

According to a fifth aspect of the present invention, a plurality of slave stations including the wireless transmission output control device according to any one of the second to third aspects communicate with the plurality of slave stations by time division multiplex wireless communication. A wireless communication system including a master station, wherein the slave station includes a slave station communication control unit that controls time division multiplex communication in addition to the wireless transmission output control device, and is established between the slave station and the master station. The master station adjusts the directivity and the transmission output according to the quality of the radio line to be transmitted, and the master station establishes a non-directional antenna having no directivity and a radio line having a different channel for each slave station to perform time division multiplex communication. Master station communication control unit, a channel quality measurement unit that measures the quality of a wireless channel established for each slave station for each channel, and a master station transmission output control unit that can control the transmission output for each channel And the master station side transmission output control unit comprises: If the line quality of Yaneru is deteriorated, it is characterized in that to increase only transmit power of that channel.

According to a sixth aspect of the present invention, there is provided the radio transmission output control device according to any one of the second to fourth aspects, wherein the omnidirectional antenna having no directivity and the antenna for communication are omnidirectional. And a switching unit for switching between the directional antenna and the directional antenna, wherein the switching unit adjusts the directivity control unit and the transmission output control unit after quality deterioration of the wireless line is detected. Before the start, the antenna for communication is switched from the directional antenna to the omnidirectional antenna, and thereafter, at a predetermined timing, the antenna for communication is returned from the omnidirectional antenna to the directional antenna. It is characterized by the following.

According to a seventh aspect of the present invention, there is provided a radio transmission output control apparatus provided with a directional antenna capable of controlling directivity, comprising a non-directional antenna having no directivity and a base station using the directional antenna. While communicating with the station, a handover confirmation unit that confirms whether handover to an adjacent base station is possible using the omni-directional antenna, and if handover is possible, A handover unit that switches the antenna from the directional antenna to the omnidirectional antenna and performs a handover to the adjacent base station; a level measurement unit that measures a reception level in the directional antenna; and the directional antenna. A directivity control unit that controls the directivity of the directional antenna, and a direction adjustment unit that adjusts the direction of the directional antenna. When the handover is performed, first, the directivity control unit The directivity of the directional antenna is weakened, and then the direction adjustment unit performs direction adjustment so that the reception level in the directional antenna is maximized.After the direction adjustment is completed, the communication antenna becomes the omnidirectional. The antenna can be switched from the antenna to the directional antenna.

According to an eighth aspect of the present invention, there is provided a wireless communication system, wherein the mobile station includes the wireless transmission output control device according to the seventh aspect and communicates with the mobile station using a non-directional antenna having no directivity. And a plurality of base stations.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, the first embodiment of the present invention will be described with reference to FIGS.
Elements common to the drawings are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows an example of a wireless communication system to which the wireless transmission output control device according to the first embodiment of the present invention is applied. The wireless communication device of the wireless station A includes a directional antenna 10 capable of controlling directivity, a transmission / reception shared unit 11, a power amplification unit 1
2, transmitting unit 13, receiving unit 14, modem unit 15, control unit 1
6. An information terminal 17 and a level meter 18 are provided. Like the wireless station A, the wireless station B includes a directional antenna 20 capable of controlling the directivity, a transmission / reception sharing unit 21, a power amplification unit 22,
Transmitting section 23, receiving section 24, modem section 25, control section 26,
An information terminal 27 and a level meter 28 are provided. In order to start communication at the wireless stations A and B, it is necessary to adjust the direction of the antenna. Further, the wireless stations A and B can transmit and receive between the information terminals 17 and 27 after the communication link is established.

FIGS. 2 and 3 show an example of an antenna in which the directivity can be controlled. The antenna shown in FIG. 2 includes an array antenna 30, a phase shifter 31, a frequency conversion unit 32, and a directivity control unit 33, and can adjust the directivity pattern and directivity direction of the antenna. The antenna (Yagi antenna) shown in FIG. 3 includes a director 40, a feeder 41, and a reflector 42. According to the Yagi antenna, the directivity can be controlled by controlling the number of the directors 40 and the interval between the directors using the driving device 43.

According to the antenna shown in FIG. 2 or FIG.
Since the directivity can be controlled, it is possible to increase the antenna gain. In the system of the present embodiment,
The directional antennas 10 and 20 of the radio stations A and B can be realized by antennas as shown in FIG. 2 or FIG.

FIG. 4 is a flowchart showing a procedure of a series of processes executed by the radio stations A and B to establish a communication link and further start communication. Generally, the radio stations A and B generally know each other's direction and distance. For this reason, after the establishment of the communication link is requested, the radio stations A and B perform the process of adjusting the directions of the directional antennas 10 and 20 to each other.

FIG. 5 shows two directional patterns which can be realized by the directional antennas 10 and 20. As shown in FIG. 5, the directional antennas 10 and 20 can realize a low directivity pattern 45 for irradiating a beam in a wide range and a high directivity pattern 46 for irradiating a beam in a narrow range.

According to the low directivity pattern 45, communication between the directional antennas 10 and 20 can be easily established as compared with the high directivity pattern 46. Therefore, the radio stations A and B first realize the low directivity pattern 45 to weaken the directivity of the directional antennas 10 and 20 (step 3).
01) Then, the directions of the directional antennas 10 and 20 are roughly adjusted (step 302). At this time, the transmission output is set relatively large in consideration of the low antenna gain.

Next, the radio stations A and B are connected to the level meter 1
While detecting the input level of the received signal using 8, 28,
Directional antenna 1 so that their input levels are maximized
The directions of 0 and 20 are adjusted (step 303). Then, it is confirmed that the communication link has been established (step 3).
Until 04), the direction adjustment of the directional antennas 10 and 20 is continued.

When the establishment of the communication link is confirmed, the radio stations A and B realize the high directivity pattern 46 shown in FIG. 5 in order to increase the directivity of the directional antennas 10 and 20 (step 305). Further, the radio stations A and B are directional antennas 1
The power amplifiers 12 and 22 are controlled to reduce the transmission output by the increased directivity of 0 and 20 (step 306). Test data is transmitted and received between the control units 16 and 18 in order to determine whether the established communication link can be maintained in that state (step 307). The processing in steps 306 and 307 is performed so that the transmission output used in the wireless stations A and B is reduced to the minimum output at which test data can be transmitted and received.

In a state where the transmission outputs of the radio stations A and B are sufficiently reduced, it is determined whether or not the transmission and reception of the test data is properly performed (step 308). As a result, if it is determined that the test data has not been properly transmitted / received, the processing after step 305 is executed again.
On the other hand, when it is determined that the test data is transmitted properly, communication between the wireless stations A and B is started.

As described above, according to the system of this embodiment, the directivity of the directional antennas 10 and 20 is reduced until a communication link is established between the radio stations A and B. These direction adjustments can be made. Therefore, according to the present embodiment, it is possible to easily establish a communication link between the wireless stations A and B, even though a directional antenna is used. Further, according to the system of the present embodiment, after the directions of the directional antennas 10 and 20 are adjusted,
The directivity can be increased to increase the antenna gain, and the transmission output of the wireless communication device can be reduced to a minimum value that can secure a communication link. For this reason,
According to the present embodiment, it is possible to sufficiently reduce the power consumption of the wireless communication device while maintaining an appropriate communication state.

In the above embodiment, the processing of steps 301 and 305 is executed so that the "directivity control unit" of the first embodiment is replaced with the step 3
The "transmission output control unit" according to claim 1 is realized by executing the processing of step 06.

Embodiment 2 FIG. Next, a second embodiment of the present invention will be described with reference to FIG. The system of the present embodiment has the configuration shown in FIG. 1 as in the device of the first embodiment.

The quality of the radio channel can be measured by converting the reception level in the receiving unit 14 into the channel quality per time in the control unit 16. FIG. 6 shows wireless stations A,
4B is a flowchart illustrating a procedure of a series of processes performed to control transmission output based on the line quality after the start of communication.

In the system according to the present embodiment, the radio stations A and B start communication after a communication link is established, as in the first embodiment. The line quality between the radio stations A and B frequently changes due to terrain effects, climatic effects, changes in ambient conditions, and the like. The causes of line quality degradation are:
Specifically, it is conceivable that the reception state changes due to fading, multipath, deviations in the antenna direction adjustment due to wind or disturbance, rainfall attenuation due to rain, and the like.

In the system according to the present embodiment, the radio stations A and B first measure the radio channel quality by the control unit 16 after the communication is started (step 310). next,
It is determined whether or not the measured line quality is equal to or less than a reference value (step 311). As a result of the above determination, when it is determined that the line quality is not lower than the reference value, the processes of steps 310 and 311 are repeatedly performed thereafter.

On the other hand, if it is determined in step 311 that the line quality is equal to or less than the reference value, the directional antennas 10, 2
The directivity of 0 is strengthened (step 312), and it is confirmed whether the line quality is improved as a result (step 313). The directivity pattern is changed to the high directivity pattern 46 by executing the process of step 312.
(See FIG. 5).

If it is determined in step 313 that the line quality has been improved, it can be determined that the directions of the directional antennas 10 and 20 have been properly adjusted. In this case,
It is checked whether the line quality is equal to or higher than the reference value (step 314). As a result, when it is determined that the line quality is equal to or higher than the reference value, it is determined that an appropriate communication state has been realized, and thereafter, communication is continued in that state. On the other hand, if it is determined that the line quality is not higher than the reference value,
After determining that the transmission output is insufficient and controlling the transmission output (step 315), the communication is continued.

If it is determined in step 313 that the line quality has not been improved, it is considered that an adjustment error has occurred in the directions of the directional antennas 10 and 20. in this case,
The directivity of the directional antennas 10 and 20 is weakened (step 316), and the transmission output is controlled in the power amplifier 12 so as to compensate for the reduced antenna gain (step 317). It is determined whether or not to do so (step 318).

As a result, when it is determined that the line quality is improved, it is again confirmed whether or not the line quality is equal to or higher than the reference value (step 319). If the quality is equal to or higher than the reference value, the directions of the directional antennas 10 and 20 are adjusted so that the error is corrected (step 320), and the directivity of the directional antennas 10 and 20 is enhanced. (Step 321) Further, the communication is continued in a state where the transmission output is weakened by an amount corresponding to the enhanced directivity (Step 322).

On the other hand, if it is determined in step 318 that the line quality is not higher than the reference value, it is determined that the notification cannot be maintained in the current situation (step 323). Communication is interrupted.

If it is determined in step 318 that the line quality has not been improved, it is determined that communication cannot be maintained between the wireless stations A and B, and communication with other wireless stations is not performed. A procedure for establishing a link is performed (step 324), and communication between the wireless stations A and B is interrupted.

As described above, according to the system of this embodiment, if the line quality deteriorates due to a change in the surrounding conditions of the wireless communication after the establishment of the communication link, the directional antennas 10, 2
While adjusting the directivity of 0 to change the antenna gain,
By adjusting the transmission output in accordance with the change in the gain, it is possible to reduce the power consumption of the wireless communication device while maintaining the best possible communication state.

In the above embodiment, the "line quality measuring unit" according to the second aspect executes the processing of step 312 or the processing of steps 316 and 321 by executing the processing of step 310. Accordingly, the “directivity control unit” according to claim 2 is configured to execute step 31
The "transmission output control unit" according to claim 2 is realized by executing the processing of steps 6 and 321.

In the above embodiment, the "directivity control unit" according to the third aspect is realized by executing the processing of step 312. Further, in the above embodiment, the level meters 18 and 28 correspond to the “level measuring section” according to the fourth aspect, and
By executing the process of step 320, the “direction adjusting unit” according to claim 3 is changed to steps 316 and 3.
The “directivity control unit” according to claim 3 is executed by executing the processing of step 21, and the “transmission output control unit” according to claim 3 is executed by executing the processing of steps 317 and 322. Has been realized.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to FIGS. FIG.
1 shows an example of a wireless communication system to which a wireless transmission output control device of the present embodiment is applied. As shown in FIG. 7, the system according to the present embodiment includes a master station and a slave station.

The radio communication device of the master station is an omnidirectional antenna 5
0, power amplification unit 51, transmission unit 52, reception unit 53, modulation and demodulation unit 54, TDMA (Time Division Multiple Access: Time Division Mu
ltipleAccess) control unit 55, a control unit 56, and an information terminal 57. 1: N time division multiplex communication is performed between the master station and the slave stations. The control unit 56 of the master station measures the line quality for each slave station based on the reception level of each channel used in the time division multiplex communication.

The radio communication apparatus of each slave station includes a directional antenna 60 capable of controlling directivity, a power amplifying section 61, a transmitting section 62,
A receiving unit 63, a modulation / demodulation unit 64, a TDMA control unit 65, a controller 66, an information terminal 67, and a level meter 68 are provided. In the control unit 66, similarly to the control unit 56 of the master station,
The radio channel quality with the master station is measured based on the reception level of each channel used in the time division multiplex communication.

In order for each slave station to start communication with the master station, it is necessary to adjust the direction of the directional antenna 60 of the slave station toward the omnidirectional antenna 50 of the master station. Further, transmission and reception between the information terminals 57 and 67 become possible after a communication link is established between the master station and the slave station. Master station omnidirectional antenna 5
0 can be realized by a whip antenna, a brown type antenna, or the like.
As in the case of (1), the present invention can be realized by the array antenna shown in FIG. 2 or the Yagi antenna shown in FIG.

In the 1: N time-division multiplexing communication used in the present embodiment, similarly to the second embodiment, the quality of the radio channel changes due to changes in various communication conditions. Hereinafter, with reference to FIG. 8 and FIG. 9, a method for coping with the deterioration of the line quality in the time division multiplex communication will be described.

FIG. 8 is a flowchart for explaining a procedure of processing executed by the master station after the establishment of a communication link to cope with the deterioration of the line quality. In the system of the present embodiment, the master station allocates a slave station to each channel of the time division multiplex communication to perform communication with the slave station, and
The information of the MA control unit 55 is totaled by the control unit 56 for each channel, and the line quality per time is measured for each slave station based on the obtained reception level information for each channel (step 330).

Next, the master station checks whether or not the line quality is equal to or less than the reference value in units of slave stations (step 33).
1). As a result, if it is determined that the line quality is not lower than the reference value, the process of step 330 is executed again. On the other hand, if it is determined that the line quality is equal to or less than the reference value, the power amplifier 5
2 is performed to increase the amplification degree (step 33).
2). According to the above processing, good line quality can be ensured with all slave stations.

FIG. 9 is a flowchart for explaining a procedure of processing executed after establishment of a communication link in order to cope with deterioration of line quality in a slave station performing 1: N time division multiplex communication. In FIG. 9, steps 340 to 354 are:
This corresponds to steps 310 to 324 shown in FIG. That is, in the present embodiment, each slave station basically performs processing according to the flowchart (FIG. 6) described in the second embodiment.

Specifically, when the quality of the radio link is degraded, each of the slave stations first strengthens the directivity of the directional antenna 60, that is, changes the directivity pattern to the high directivity shown in FIG. It is checked whether the radio line quality is improved as a pattern (steps 340 to 343). As a result, when the line quality is improved, the transmission output is controlled to an appropriate value and the communication is continued (steps 344 and 345). On the other hand, if the above processing does not improve the line quality, the directional antenna 60
Since there is a possibility that a direction adjustment error has occurred, the directivity is weakened, and the transmission output is increased to compensate for the decrease in antenna gain, and it is confirmed whether or not the radio channel quality is improved (step 346-348).

As a result, when the line quality is improved to the reference value or more, it can be determined that a direction adjustment error has occurred in the directional antenna 60. In this case, the direction adjustment error is corrected, the directivity of the directional antenna 60 is increased, and the transmission output is reduced to continue the communication (steps 349 to 35).
2). On the other hand, if the line quality does not improve as a result of the processing of steps 346 to 348, or if the line quality improves to such an extent that the line quality does not reach the reference value, it can be determined that maintaining communication is difficult. In this case, communication with the master station is interrupted (steps 353, 354).

As described above, according to the system of the present embodiment, after the communication link is established between the master station and the slave station, when the surrounding conditions of the wireless communication change and the line quality deteriorates. In the master station, the transmission output is controlled in units of transmission channels for each slave station, and the directivity of the directional antenna 60 and the transmission output are controlled in the slave station so that the notification performance is ensured with as little power consumption as possible. Are controlled. For this reason, according to the system of the present embodiment, it is possible to secure stable notification performance irrespective of fluctuations in conditions of wireless communication and to reduce power consumption of each wireless station.

In the above embodiment, the TDMA
6. The "slave station communication control unit" according to claim 5, wherein
In addition, the TDMA control unit 55 corresponds to the “master station side communication control unit” in claim 5, respectively, and the processing in step 330 is executed to execute “line quality measurement” in claim 5. The “unit” realizes the “master station side transmission output control unit” by executing the processing of step 332.

Embodiment 4 FIG. Next, FIGS. 10 and 11
Embodiment 4 of the present invention will be described with reference to FIG.
FIG. 10 shows the configuration of the wireless transmission output control device of the present embodiment. The device according to the present embodiment includes an omnidirectional antenna 70, a directional antenna 71, a switching unit 72, a transmission / reception sharing unit 73, a power amplification unit 74, a transmission unit 75, a reception unit 76, a modulation / demodulation unit 77, a control unit 78, an information terminal. 79, a level meter 80, and a reception level measuring unit 81 are provided.

In the radio transmission output control apparatus of the present embodiment, the reception section 76 can detect the reception level from the partner station, and the control section 78 can measure the line quality per unit time. Further, the apparatus of the present embodiment can switch between the two antennas 70 and 71 and use the antenna 70 or 71 during communication and the reception level measuring unit 81 at the time of the switching. Can be measured.

FIG. 11 is a flowchart for explaining the procedure of processing executed in the radio station after the establishment of a communication link in order to cope with the deterioration of the line quality due to changes in various communication conditions. If the quality of the radio line deteriorates, the radio station
First, the antenna for communication is switched from the directional antenna 71 to the non-directional antenna 70 to minimize the instantaneous interruption of communication (steps 360 to 362).

Next, the radio station appropriately controls the power amplifier 74 to increase the transmission output in order to compensate for the decrease in the antenna gain and to restore the desired line quality (step 363).

Next, the radio station connects the reception level measuring section 81 to the directional antenna 71 to monitor the reception level from the partner station, and changes the direction of the directional antenna 71 so that the direction adjustment error disappears. Adjustment is performed (step 364).

When the direction adjustment of the directional antenna 71 is completed, the radio station confirms the reception level of the directional antenna 71, calculates a required transmission output based on the reception level, and then performs an antenna for communication. Is switched from the omnidirectional antenna 70 to the directional antenna 71 (step 365). Next, the power amplifying unit 74 is appropriately controlled so that the transmission output from the directional antenna 71 is optimized, and the desired communication performance is secured (step 366).

As described above, according to the wireless transmission output control apparatus of the present embodiment, if the line condition is deteriorated due to a change in the surrounding conditions of the wireless communication after the establishment of the communication link, the omnidirectional transmission is temporarily stopped. While securing the notification performance using the aerial antenna 70,
It is possible to adjust the direction of the directional antenna 71 and calculate the transmission output required to obtain a notification using the directional antenna 71. And after those processes are finished,
By switching the antenna for communication from the omnidirectional antenna 70 to the directional antenna 71, it is possible to reduce the transmission output required to secure communication. Therefore, according to the wireless transmission output device of the present embodiment, it is possible to achieve a sufficient reduction in power consumption while securing a stable notification performance regardless of a variation in conditions of wireless communication or the like.

In the above embodiment, the "switching unit" according to the sixth aspect is realized by executing the processing of steps 362 and 365.

Embodiment 5 FIG. Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 12 shows a configuration of a mobile communication system to which the wireless transmission output control device according to the fifth embodiment of the present invention is applied. FIG. 13 shows a configuration of a wireless communication device of a base station used in the system of the present embodiment. FIG. 14 shows a configuration of a wireless communication device of a mobile station used in the system of the present embodiment.

As shown in FIG. 13, the base station includes an omnidirectional antenna 90, a transmission / reception sharing unit 91, a power amplification unit 92, a transmission unit 93, a reception unit 94, a modulation / demodulation unit 95, and a control unit 96. On the other hand, as shown in FIG. 14, the mobile station includes an omnidirectional antenna 100, a directivity control antenna 101, a driving device 102, a switching unit 103, a transmission / reception sharing unit 104, a power amplification unit 105, a transmission unit 106, a reception unit 107, Modem 10
8, control unit 109, information terminal 110, level meter 11
1 and a reception level measuring unit 112.

In the mobile communication system of the present embodiment, control information for handover and information such as data and voice are transmitted and received on separate channels.
The mobile station uses the omnidirectional antenna 100 to
Handover control can be performed by detecting reception levels from a plurality of base stations. FIG. 12 and FIG.
The handover control will be described with reference to FIG.

FIG. 15 is a flowchart for explaining the contents of a series of processes executed in the mobile station 84 to realize the handover control. Normally, the mobile station 84 communicating with the base station A 82 operates the directional antenna 101 so that the reception level at the directional antenna 101 is maximized.
Is adjusted by the driving device 102 to secure the notification (step 370).

The mobile station 84 measures the quality of the radio channel by the receiving unit 107 and the control unit 108 during communication with the base station A 82, and when the quality is good, the directivity of the directivity control antenna 101 is measured. At the same time, the antenna gain is improved (step 371), and the power amplifier 105 is controlled to optimize the transmission output to reduce the power consumption (step 372).

The mobile station 84 confirms whether handover with the adjacent base station B83 is possible (step 37).
3) If handover is not possible, base station A8
2 is measured (step 374), and thereafter, the same processing (processing shown in FIG. 6) as in the device of the second embodiment is performed.

On the other hand, if handover with the adjacent base station B83 is possible, a handover for switching the communication partner from the base station A82 to the base station B83 is performed (step 375). At the time of performing the handover, the directional antenna 101 is being used for communication with the base station A82. Therefore, the directivity control antenna 101 is connected to the adjacent base station B8.
Handover cannot be performed in the third direction. For this reason, the handover is performed by the omnidirectional antenna 10.
0 is implemented.

In the mobile station 84, the above handover is performed using a channel different from a channel used for communication of data, voice, and the like. Therefore, the omnidirectional antenna 100 is switched for handover with the adjacent base station B83. At this time, the mobile station 84 monitors the reception level and the like by the reception level measuring unit 112 and transmits information on communication with the adjacent base station 83B to the control unit 109.

When the handover is completed and the adjacent base station B8
3 becomes possible, the mobile station 84 weakens the directivity of the directional antenna 101 and then uses the driving device 102 to increase the reception level of the signal transmitted from the base station B83 to the maximum. The direction of the directional antenna 101 is adjusted (step 376).

After completing the direction adjustment of the directional antenna 101, the mobile station 84 increases the directivity of the directional antenna 101 to increase its gain (step 377). Further, the mobile station 84 controls the power amplifying section 105 in consideration of the gain improvement of the directional antenna 101, and reduces the transmission output to a minimum value at which communication can be ensured (step 378).

As described above, in the system of the present embodiment, the mobile station 84 efficiently performs handover using the directional antenna 101 and the non-directional antenna 100.
That is, during normal movement, the mobile station 84 performs automatic control for directing the directional antenna 101 toward the base station, and controls the directivity and the transmission output in accordance with the line quality to achieve good communication. Reduce power consumption while maintaining performance. Then, at the time of handover, the mobile station 84
After performing handover control using the omnidirectional antenna 100 and starting communication with the adjacent base station, the direction of the directional antenna 101 is adjusted to the handovered base station,
The power consumption is reduced by optimizing the directivity and the transmission output. Therefore, according to the system of the present embodiment, stable communication performance and excellent power consumption characteristics can be realized not only during normal communication but also before and after handover.

In the above embodiment, the reception level measuring section 112 is the "level measuring section" according to the seventh aspect.
The “handover confirmation unit” according to claim 7 is executed by executing the processing of step 373, and the “handover confirmation unit” is executed by executing the processing of step 375. The “directivity control unit” and the “direction adjustment unit” according to claim 7 are realized by executing the processes of steps 376 and 377.

[0072]

Since the present invention is configured as described above, it has the following effects. Claim 1
According to the described invention, until the communication link is established,
Since the directivity of the directional antenna is weak, a communication link can be easily established. Further, after the communication link is established, the directivity of the directional antenna is strengthened and the transmission output is weakened. Therefore, it is possible to reduce the power consumption of the wireless communication device while securing appropriate communication quality.

According to the second aspect of the present invention, when the line quality is degraded due to a change in the surrounding conditions of the wireless communication after the communication link is established, the directivity of the directional antenna and the transmission output are reduced. , It is possible to restore good line quality.

According to the third aspect of the invention, when the line quality is deteriorated, the line quality can be improved without increasing the power consumption by increasing the directivity of the directional antenna.

According to the fourth aspect of the present invention, when the line quality is deteriorated, the directivity of the directional antenna is reduced, and
By increasing the transmission output, it is possible to form a situation where the direction adjustment of the directional antenna can be easily performed.
Therefore, according to the present invention, line quality can be easily improved by performing direction adjustment. Further, according to the present invention, the transmission output is reduced after the completion of the direction adjustment, so that the power consumption of the wireless communication device can be sufficiently suppressed.

According to the invention described in claim 5, a plurality of slave stations communicating with the master station can achieve good communication performance with low power consumption. On the other hand, a master station that communicates with a plurality of slave stations evaluates the line quality for each slave station and increases only the transmission output of the poor quality line. Therefore, according to the communication system of the present invention, it is possible to obtain good communication quality while sufficiently suppressing power consumption of the master station.

According to the invention described in claim 6, communication using a directional antenna is normally performed. Then, when the deterioration of the line quality is detected, the direction adjustment of the directional antenna is performed while maintaining the communication using the omnidirectional antenna, and the communication using the directional antenna again when the line quality is improved. Can be started. Therefore, according to the present invention, it is possible to sufficiently suppress the degradation of communication quality due to the degradation of line quality while realizing low power consumption of the device.

According to the seventh aspect of the present invention, it is possible to perform handover using an omnidirectional antenna while performing communication using a directional antenna. Then, at the time of handover, it is possible to adjust the direction of the directional antenna toward a new communication destination while securing communication using the omnidirectional antenna, and restart communication using the directional antenna. Therefore,
ADVANTAGE OF THE INVENTION According to this invention, while realizing low power consumption of an apparatus, the degradation of communication performance at the time of a handover can be suppressed sufficiently.

According to the eighth aspect of the present invention, it is possible to realize a wireless communication system in which individual mobile stations can enjoy the effects of the seventh aspect of the present invention.

[Brief description of the drawings]

FIG. 1 is a block diagram of a wireless communication system including a wireless transmission output control device according to a first embodiment of the present invention.

FIG. 2 is a diagram of an example of a directional antenna applicable to the wireless transmission output control device according to the first embodiment of the present invention.

FIG. 3 is a diagram of another example of a directional antenna applicable to the wireless transmission output control device according to the first embodiment of the present invention.

FIG. 4 is a flowchart for explaining the contents of processing executed in the wireless transmission output control device according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a directivity pattern realized in the wireless transmission output control device according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating the contents of processing executed in a wireless transmission output control device according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a wireless communication system including a wireless transmission output control device according to a third embodiment of the present invention.

FIG. 8 is a flowchart illustrating the contents of a process executed in a master station according to Embodiment 3 of the present invention.

FIG. 9 is a flowchart for explaining the contents of processing executed in a slave station in Embodiment 3 of the present invention.

FIG. 10 is a block diagram of a wireless transmission output control device according to a fourth embodiment of the present invention.

FIG. 11 is a flowchart illustrating the contents of processing executed in a wireless transmission output control device according to a fourth embodiment of the present invention.

FIG. 12 is a conceptual diagram of a wireless communication system including a wireless transmission output control device according to a fifth embodiment of the present invention.

FIG. 13 is a block diagram of a base station used in the wireless communication system according to the fifth embodiment of the present invention.

FIG. 14 is a block diagram of a mobile station used in the wireless communication system according to the fifth embodiment of the present invention.

FIG. 15 is a flowchart for describing the details of a process executed in a mobile station according to Embodiment 5 of the present invention.

FIG. 16 is a block diagram of a conventional wireless transmission output control device.

[Explanation of symbols]

10, 20, 60, 71, 101 directional antenna,
50, 70, 90, 100, 200 Omnidirectional antenna,
43, 102 drive unit, 72, 103 switching unit, 11, 21, 73, 91, 104, 201 transmission / reception shared unit, 12, 22, 51, 61, 74, 92, 1
05 Power amplification unit, 13, 23, 52, 62, 7
5, 93, 106, 202 transmitting section, 14, 24,
53, 63, 76, 94, 107, 203 receiving unit,
15, 25, 54, 64, 77, 95, 108, 20
4 Modulator / demodulator, 16, 26, 56, 66, 78, 9
6,109,206 control unit, 55,65,205
TDMA control unit, 17, 27, 57, 67, 79, 1
10 information terminal, 18, 28, 80, 111 level meter, 81, 112 reception level measurement unit,
82 base station A, 83 base station B, 84 mobile station, 30 array antenna, 31 phase shifter, 32
Frequency converter 33 directivity controller 40
Director, 41 feeder, 42 reflector, 207
Codec, 208 display operation unit.

Claims (8)

[Claims] 1. A radio transmission output control apparatus comprising a directional antenna capable of controlling directivity, wherein the directivity pattern of the directional antenna is established until a communication link is established with another radio station. Is a predetermined low directivity pattern, after the communication link is established, the directivity pattern is a predetermined high directivity pattern indicating a strong directivity compared to the low directivity pattern directivity control unit and And a transmission output control unit configured to reduce a transmission output after the directivity pattern is set to the high directivity pattern. 2. A radio transmission output control device having a directional antenna capable of controlling directivity, wherein a line quality is measured after a communication link is established with another radio station. A measuring unit, a directivity control unit that adjusts the directivity of the directional antenna when the quality of the wireless line is deteriorated, and a transmission output control unit that adjusts a transmission output according to the directivity of the directional antenna. A wireless transmission output control device, comprising: 3. When the quality of the wireless line is degraded,
The directivity control unit strengthens the directivity of the directional antenna,
The wireless transmission output control device according to claim 2, wherein the transmission output control unit maintains the transmission output. 4. A radio communication system comprising: a level measurement unit that measures a reception level in the directional antenna; and a direction adjustment unit that adjusts a direction of the directional antenna. The directivity control unit weakens the directivity of the directional antenna, and the transmission output control unit increases the transmission output, and then the direction adjustment unit controls the direction so that the reception level at the directional antenna is maximized. The radio transmission according to claim 2, wherein the radio controller performs an adjustment, and after completion of the direction adjustment, the directivity controller increases the directivity of the directional antenna, and the transmission output controller weakens the transmission output. Output control device. 5. A radio station comprising: a plurality of slave stations including the wireless transmission output control device according to claim 2; and a master station communicating with the plurality of slave stations by time division multiplex wireless communication. A communication system, wherein the slave station includes a slave station side communication control unit that controls time division multiplex communication in addition to the wireless transmission output control device, and a quality of a wireless line established with the master station. The master station adjusts the directivity and the transmission output according to the above, and the master station establishes a non-directional antenna having no directivity and a radio line having a different channel for each slave station to perform time division multiplex communication. A control unit, a channel quality measuring unit that measures the quality of a wireless channel established for each slave station for each channel, and a master station-side transmission output control unit that can control transmission output for each channel. The transmission output control unit on the master station Wireless communication system, characterized in that but that when degraded, increasing only the transmission output of the channel. 6. An omnidirectional antenna having no directivity, and a switching unit for switching a communication antenna between the omnidirectional antenna and the directional antenna, wherein the switching unit comprises: After the quality deterioration is detected, before the adjustment process of the directivity control unit and the transmission output control unit is started, the antenna for communication is switched from the directional antenna to the omnidirectional antenna, and thereafter 5. The radio transmission output control device according to claim 2, wherein a communication antenna is returned from the omnidirectional antenna to the directional antenna at a predetermined timing. 7. A radio transmission output control device provided with a directional antenna capable of controlling directivity, comprising: a non-directional antenna having no directivity; and communicating with a base station using the directional antenna. Between,
A handover confirmation unit that confirms whether handover to an adjacent base station is possible using the omnidirectional antenna, and, if handover is possible, a communication antenna is transmitted from the directional antenna to the radio antenna. A handover unit that switches to a directional antenna and performs handover to the adjacent base station; a level measurement unit that measures a reception level in the directional antenna; and a directional control that controls the directivity of the directional antenna. And a direction adjustment unit that adjusts the direction of the directional antenna. When the handover is performed, first, the directional control unit weakens the directivity of the directional antenna, and then adjusts the direction. The unit performs direction adjustment so that the reception level in the directional antenna is maximized, and after completion of the direction adjustment, the communication antenna is the omnidirectional antenna. Radio transmission output control apparatus, characterized in that switched to et the directional antenna. 8. A mobile station comprising the wireless transmission output control device according to claim 7, and a plurality of base stations communicating with the mobile station using an omnidirectional antenna having no directivity. Wireless communication system.