JP3101834B2 - Wireless transmission power control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio transmission power control system, and more particularly to a radio communication apparatus for controlling the transmission power of a radio terminal apparatus which performs radio communication under the control of a radio communication center apparatus. The present invention relates to a transmission power control system that automatically controls a minimum appropriate level that can be secured.

[0002]

2. Description of the Related Art Many wireless terminals of this type use a battery as a power source. Therefore, it is desirable that the transmission power be maintained at a minimum appropriate level at which wireless communication with a partner station can be ensured. The transmission power of a conventional wireless terminal device has always been fixed at a constant level.

[0003]

In the above-mentioned conventional wireless terminal device, transmission and reception must be performed at the maximum power within the operation range so that communication can be performed at all locations within the operation range where wireless communication is possible. The transmission power is set to a fixed value based on the location where it must be.

[0004] Therefore, even in a place where communication is possible with low power, unnecessary excessive power is transmitted and unnecessary power is consumed unnecessarily, and especially in a wireless terminal device which supplies power by using a battery. Has the drawback that unnecessary power consumption accelerates battery consumption, reduces the operating time of actually using wireless terminals, and causes a great deal of opportunity loss in wireless terminal devices for public service. .

[0005] Further, when the transmission power is simply reduced to extend the operation time, it often occurs that wireless communication in a remote place cannot be normally secured.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks, to extend the operating time of a wireless terminal device to a necessary and minimum appropriate power that suppresses excessive or excessive power without fixing the transmission power, and to improve the reliability of transmission and reception. Another object of the present invention is to provide a wireless transmission power control method that can be operated so as to ensure the reliability.

[0007]

The structure of the present invention is a wireless transmission power control method for controlling the transmission power of a wireless terminal device that performs wireless communication under the control of a wireless communication center device. Receives a radio wave of constant power transmitted from the partner station, and automatically compresses or increases its own transmission power level based on the received level, and controls it to the minimum appropriate level necessary for securing wireless communication. Alternatively, the S / N ratio of the radio wave transmitted from the own station is obtained, and the output of the transmitted radio wave of the own station is maintained at a constant S / N ratio that is necessary and minimum level for securing the wireless communication. As described above.

The system of the present invention is a wireless transmission power control system for controlling the transmission power of a wireless terminal device that performs wireless communication under the control of a wireless communication center device. To determine whether or not the signal has been correctly received by a report from the partner station. If no transmission error has been detected, transmit the signal at low power to ensure wireless communication with the partner station.
When it is confirmed that a transmission error has been detected, a means is provided for automatically controlling the transmission power so that the transmission is performed at a high power capable of securing wireless communication with the partner station.

Further, the system of the present invention is a wireless transmission power control system for controlling the transmission power of a wireless terminal device for performing wireless communication under the control of a wireless communication center device, wherein the distance between a local station and a partner station is controlled. It is provided with a means for measuring and automatically controlling the transmission power to a minimum appropriate level necessary for ensuring wireless communication based on the distance to the partner station.

[0010]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a main configuration of a wireless terminal device according to a first embodiment of the present invention.

A wireless terminal device according to a first embodiment shown in FIG. 1 includes an antenna 1 for both transmission and reception, a reception radio wave level measuring unit 2 for measuring the level of a radio wave received by the antenna 1, and a radio wave for transmitting a radio wave. It comprises a transmission section 3, a battery power supply 4, and a transmission / reception switch 5.

An actual wireless terminal device includes, in addition to the above-described components, ordinary equipment circuits such as a reception processing system, a display system, and an operation system. FIG. Is omitted.

Next, the operation of the embodiment of FIG. 1 will be described.

Referring to FIG. 1, a received radio wave 101 is received by an antenna 1 and is input to a received radio wave level measuring unit 2 as a received signal 103.

The received radio wave level measuring unit 2 measures an input level of a signal of a frequency used by a communication partner. The measurement result obtained by measuring the level of the reception radio wave 101 is output as a reception level signal 201, and the radio wave transmission unit 3
Provided to

The radio wave transmitter 3 receives the reception level signal 20
1 to adjust the transmission power and output an output signal 301.

The output signal 301 is output from the antenna 1 as the transmission radio wave 102. The power of the received radio wave level measurement unit 2 and the radio wave transmission unit 3 is supplied from a battery power supply 4.

Next, referring to FIG. 2 and FIG.
The operation of the first embodiment will be described in more detail.

As shown in FIG. 2, the wireless communication center device 71
Radio waves are always transmitted from antenna 1 with constant power,
The received radio wave 101 is received by the wireless terminal device (1) 6a and the wireless terminal device (2) 6b.

The received radio wave 101 is captured by the antenna 1 and input to the received radio wave level measuring unit 2 as a received signal 103.

In the radio terminal device (1) 6a, the measured value of the received radio wave level of the received radio wave level measuring unit 2 is a point P shown in the characteristic diagram of FIG. 3, and a point Q in the radio terminal device (2) 6b. And All of these measured values are supplied to the radio wave transmitter 3 of each wireless terminal device, and the wireless terminal device 6a sends out the transmission power indicated by the point P in FIG. 3, and the wireless terminal device 6b sends out the transmission power indicated by the point Q in FIG. .

As described above, in the first embodiment, appropriate transmission power is transmitted in accordance with the received radio wave level, excluding excess and shortage. The characteristics shown in FIG. 3 are set in advance to obtain an appropriate level in consideration of the performance of the wireless terminal device, the specificity of the operating environment, and the like.

FIG. 4 is a block diagram showing a main configuration of a wireless terminal device according to a second embodiment of the present invention.

In the second embodiment, the transmission power level is controlled based on the received radio wave level in the first embodiment described above, whereas the S / N ratio of the radio wave transmitted from the own station is controlled. The transmission power level is controlled.

In the embodiment shown in FIG. 4, an S / N ratio measuring unit 8 for measuring the S / N ratio of the radio wave transmitted from the own station, and an S / N ratio
A radio wave transmitting unit 9 for controlling transmission power based on the measurement result of the ratio measuring unit 8 is provided. Other components that the wireless terminal device normally has are described in the same manner as in FIG. Omitted.

Next, the operation of the second embodiment shown in FIG. 4 will be described.

Referring to FIG. 4, the output of the radio wave transmitting section 9 is transmitted as a transmission radio wave 901 using the antenna 1 and is received by another antenna 1a of its own station. The S / N ratio is measured by the / N ratio measurement unit 8, and an excess / deficiency signal for controlling the transmission power so that the radio wave transmission unit 9 can transmit at a constant S / N ratio is transmitted to the radio wave transmission unit. 9 is provided as a basic feature.

Next, the operation of the embodiment shown in FIG. 4 will be described in more detail with reference to FIG.

FIG. 5A shows a received radio wave when the S / N ratio measuring unit 8 measures a background noise signal received when the radio wave transmitting unit 9 is not performing a transmitting operation.

In FIG. 5, f indicates the frequency used in the radio wave transmitting unit 9, and A indicates the received power of the background noise at that frequency.

Next, FIG. 5B shows a received radio wave when the S / N ratio measuring unit 8 measures a radio wave received when the radio wave transmitting unit 9 is performing a transmitting operation. The received power of the signal at the frequency f corresponding to FIG. 5A is B. The S / N ratio is calculated based on the values of A and B, and the signal is transmitted so that the signal can be transmitted at a constant S / N ratio. An excess or deficiency signal of the power is supplied to the radio wave transmitter 9.

When an excess or deficiency signal indicating that the transmission power is too large is transmitted, the radio wave transmitter 9 lowers the transmission power and
When an excess or deficiency signal indicating that the transmission power is too small is transmitted, the radio wave transmitter 9 increases the transmission power.

In this manner, a constant S / N ratio that keeps the transmission level at an appropriate level is maintained, and the transmission power at an appropriate level without excess or shortage is controlled.

FIG. 6 is a block diagram showing the configuration of the third embodiment of the present invention.

The third embodiment shown in FIG. 6 is characterized in that the transmission power of the own station is controlled to be too large or too small based on the error detection information of the transmission data of the own station at the partner station. The configuration is as follows.

That is, in the third embodiment shown in FIG.
The wireless terminal device 10 includes a transmission error detection unit 11 that detects an error in the received transmission data from the wireless communication center device 7.
And a radio wave transmitting unit 12. Note that description of other ordinary components of the wireless terminal device is omitted as in the first and second embodiments.

Next, the operation of the third embodiment will be described.

Referring to FIG. 6, the wireless communication center device 7
And the wireless terminal device 10 communicate with each other, and the output of the wireless communication center device 7 is input to the transmission error detecting unit 11 of the wireless terminal device 10 as a transmission radio wave 701 to demodulate a message from the wireless communication center device 7. . If the demodulated data is a retransmission request that specifies retransmission of transmission data,
A transmission power control signal that increases transmission power and eliminates a reception error of the wireless communication center device 7 is transmitted to the radio wave transmitter 12.
The radio wave transmitting unit 12 receiving the signal controls the transmission power so as to increase the transmission power.

Next, the operation of the third embodiment will be described in further detail with reference to FIG.

The transmission power in the radio wave transmitter 12 is:
The initial value is set to low power.

The wireless terminal device 10 includes a radio wave transmitting unit 12
Transmits the message 1 shown in FIG. 7 to the wireless communication center device 7 by the transmission radio wave 1201. The wireless communication center device 7 transmits a normal response to the wireless terminal device 10 indicating that the signal has been normally received by the transmission radio wave 701.

The transmission error detecting section 11 demodulates the data of the normal response, and informs the radio wave transmitting section 12 that the transmission power is appropriate.

The radio wave transmitting section 12 keeps the transmission power as it is.

Next, the radio terminal device 10 transmits the message 2 to the radio communication center device 7 from the radio wave transmitting unit 12 by the transmission radio wave 1201.

If the wireless communication center device 7 cannot receive the data normally, the wireless communication center device 7 sends the retransmission request to the wireless terminal device 10.
Tell The transmission error detection unit 11 demodulates the data of the retransmission request and informs the radio wave transmission unit 12 that the transmission power is insufficient.

The radio wave transmitting unit 12 increases the transmission power and transmits the message 2 again.

In this manner, the transmission power is controlled to an appropriate level based on the quality of the reception state of the transmission data at the partner station, and it is possible to secure wireless communication at an appropriate level of transmission power.

FIG. 8 is a block diagram showing the configuration of the fourth embodiment of the present invention.

The wireless terminal device according to the fourth embodiment shown in FIG. 8 includes a distance detecting unit 13 for detecting a distance from a communication partner station,
And a radio wave output unit 14 whose transmission power level is controlled by a transmission power control signal output from the distance detection unit 13.

Note that, in FIG. 8, the description of the ordinary components included in the wireless terminal device is omitted as in the first to third embodiments.

In the fourth embodiment, the distance between the location where the own station is located and the location where the communication partner station is located is known, and the transmission power is automatically controlled according to the magnitude of this distance to set the appropriate level. It is assumed that.

Next, the operation of this embodiment will be described with reference to FIGS. 9 and 10.

Here, the wireless terminal device (1) shown in FIG.
The case where 6a performs wireless communication with the wireless communication center device 7 is taken as an example.

The time information A shown in FIG. 9 is transmitted and notified from the antenna 71 to the wireless terminal device (1) 6a from the wireless communication center device 7. On the other hand, FIG.
At the same time as the time information A from the antenna 151 to the wireless terminal device (1) 6a.

The wireless terminal device (1) 6a
3, the reception time difference T between the time information A and the time information B is calculated, and the distance to the wireless communication center device 7 is calculated from the reception time difference T. If the distance is short, the power is small, and if the distance is long, the power is large. Is transmitted to the radio wave output unit 14. In this way, automatic control of the transmission power level based on the distance to the communication partner station becomes possible.

The first to fourth embodiments described above are
Although shown as four examples each applied independently,
Obviously, these functions can be easily combined and provided in each wireless terminal device.

[0058]

As described above, the reception level, S /
Realizing wireless communication with the minimum necessary power of the appropriate level by automatically adjusting the transmission power level to an appropriate value that can be received by the communication partner according to the N ratio, the reception state of the communication partner station, and the distance. In a wireless terminal device that supplies power with a battery, there is an effect that the reliability of communication can be improved and unnecessary consumption of the battery can be prevented.

Further, since the transmission is always performed with an appropriate transmission power that is neither excessive nor excessive, there is an effect that the reliability of transmission and reception can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of a wireless terminal device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of an operation state of the embodiment in FIG. 1;

FIG. 3 is a transmission / reception level characteristic diagram showing an example of transmission / reception levels in the embodiment of FIG.

FIG. 4 is a block diagram illustrating a main configuration of a wireless terminal device according to a second embodiment of the present invention.

FIG. 5 is a frequency characteristic diagram showing an example of received radio wave power in the embodiment of FIG.

FIG. 6 is a block diagram illustrating a main configuration of a wireless terminal device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing an example of transmission of a transmission radio wave and transmission of a response radio wave in the embodiment of FIG. 6;

FIG. 8 is a block diagram illustrating a system configuration according to a fourth embodiment of the present invention.

9 is a diagram illustrating an example of reception time information in the embodiment of FIG.

FIG. 10 is a diagram illustrating an example of an operation state of the embodiment in FIG. 8;

[Explanation of symbols]

 Reference Signs List 1, 1a antenna 2 reception radio wave level measurement unit 3 radio radio wave transmission unit 4 battery power supply 5 transmission / reception switch 6a radio terminal device (1) 6b radio terminal device (2) 7 radio communication center device 8 S / N ratio measurement unit 9 radio Radio transmission unit 10 Wireless terminal device 11 Transmission error detection unit 12 Wireless radio transmission unit 13 Distance detection unit 14 Wireless radio output unit 15 Time information transmission station

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B ⁷ /24-7/26 102 H04Q 7/00-7/38 H04L 1/00-1/16

Claims (2)

(57) [Claims] A wireless transmission power control method for controlling the transmission power of a wireless terminal device performing wireless communication under the control of a wireless communication center device. Receives radio waves, automatically compresses or increases the transmission power level of the own station based on the reception level, and controls the transmission power level to the minimum appropriate level necessary for securing wireless communication, or the radio signal transmitted by the own station. S /
Means for obtaining the N ratio and controlling the transmission power of the own station so as to maintain a constant S / N ratio at which the output of the transmission radio wave of the own station becomes a minimum appropriate level necessary for securing wireless communication. A wireless transmission power control method, characterized in that: 2. A wireless transmission power control method for controlling the transmission power of a wireless terminal device that performs wireless communication under the control of a wireless communication center device, wherein transmission data of the own station is accurately received by a partner station. Is reported by a report from the partner station, and in the case of a report that it was received correctly, it is transmitted at low power enough to secure wireless communication with the partner station, and received correctly.
A wireless transmission power control system comprising means for automatically controlling transmission power so as to transmit a high power that can secure wireless communication with a partner station in the case of notifying that there is no wireless communication.