JP2707973B2 - Wireless data communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless data communication device, and more particularly to a wireless data communication device capable of controlling a transmission output depending on the quality of data reception.

[0002]

2. Description of the Related Art Generally, in a radio data communication apparatus, various data are transmitted while the transmission output is kept constant. However, in a transmission system in which the transmission output is fixed, if a plurality of devices communicating with each other are approaching, an unnecessary output is transmitted, and there is a problem that power is wasted. . In addition, when high power transmission is performed, there is a possibility that other devices communicating nearby may be affected by radio interference or the like.

To cope with this, Japanese Patent Laid-Open No.
The technology described in Japanese Patent No. 30426 is devised. This technology includes a receiving field strength detector that outputs a DC voltage corresponding to a receiving field strength, and a transmission output that is controlled by inputting the output DC voltage and continuously controls a sending output voltage corresponding to the receiving input field strength. A configuration including a power control circuit is employed. Thus, when the received electric field strength is strong,
The above problem has been solved by lowering the transmission output of the own device and increasing the transmission output of the own device when the received electric field strength is weak.

[0004]

However, according to the technique described in Japanese Patent Application Laid-Open No. Sho 62-30426, it is not possible to increase the transmission output in the event of disturbance such as external noise. In addition, when there is a device other than the communication partner and transmitting with the same electric field and the same strong electric field strength as the communication partner, the transmission output of the own device is weakened due to the influence, and the communication is not performed. Become stable. For this reason, it is difficult to apply the device of the above technology to a system such as a LAN that uses a plurality of devices and forms a network using radio waves of the same frequency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to reduce power consumption, to counter external noise and the like, and to enable many devices to communicate at the same frequency. It is an object of the present invention to provide a wireless data communication device that can perform the communication.

[0006]

In order to achieve the above object, a wireless data communication apparatus according to the present invention comprises an ACK or a NAK.
ACK or NAK having a transmitting unit for transmitting a radio signal including the signal and a receiving unit for receiving and demodulating the radio signal .
In the wireless data communication device, the A
An ACK / NAK detector for detecting CK or NAK, and the number and NA of ACKs detected by the ACK / NAK detector.
A control voltage generator that generates a DC voltage corresponding to the difference from the number of K, and a transmission output control circuit that changes a transmission output of the transmission unit to a transmission output corresponding to the DC voltage from the control voltage generator. Output control unit, comprising:
Compare the ACK / NAK detector, a second register a first register and NAK information ACK information is stored is stored, and the information in the ACK information and the demodulated signal of the first register in A first comparator for outputting a predetermined signal when it is determined that the ACK is included in the demodulated signal, and comparing the NAK information of the second register with the information in the demodulated signal to demodulate the signal. A second comparator that outputs a predetermined signal when it is determined that the signal contains NAK, and an ACK / NAK detection signal that indicates “1” when an output signal from the first comparator is input. A flip-flop that outputs an ACK / NAK detection signal indicating “0” to the control voltage generator when the control voltage generator outputs an output signal from the second comparator to the control voltage generator. But on A third comparator that outputs a signal indicating “1” when an ACK / NAK detection signal indicating “1” is input, and “1” when an ACK / NAK detection signal indicating “0” is input. A fourth comparator that outputs a signal indicating the following: an arithmetic unit that subtracts the number of signals received from the third comparator and the number of signals received from the fourth comparator, and a subtraction of the arithmetic unit. And an operational amplifier for generating a DC voltage corresponding to the result.

[0007]

According to the wireless data communication device using ACK or NAK, ACK or NAK is detected from the demodulated signal by the ACK / NAK detector of the output control unit, and the ACK / NAK detector is detected by the control voltage generator. A DC voltage corresponding to the difference between the number of detected ACKs and the number of NAKs is formed. Then, the transmission output control circuit changes the transmission output of the transmission unit to the transmission output corresponding to the DC voltage from the control voltage generator.

[0008] More specifically, ACK / NAK
ACK of the first register by the first comparator of the detector
The information and the information in the demodulated signal are compared, and the
When K is included, a predetermined signal is input from the first comparator to the flip-flop. The second comparator compares the NAK information in the second register with the information in the demodulated signal. If the demodulated signal contains a NAK, the predetermined signal is transmitted from the second comparator to the flip-flop. Is entered.

When the output signal is input from the first comparator, an ACK / NAK detection signal indicating "1" is output from the flip-flop to the control voltage generator, and the output from the second comparator. When the signal is input, an ACK / NAK detection signal indicating “0” is output to the control voltage generator.

[0010] Thereafter, when the ACK / NAK detection signal indicating "1" to the third comparator of the control voltage generator is inputted, a signal indicating "1" is output to the arithmetic unit from the third comparator Is done. ACK / N indicating “0” in the fourth comparator
When the AK detection signal is input, a signal indicating “1” is output to the fourth signal.
Are output to the arithmetic unit from the comparator. And in the arithmetic unit,
The number of signals received from the third comparator and the number of signals received from the fourth comparator are subtracted, and the operational amplifier outputs a DC voltage corresponding to the result of the subtraction.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a block diagram showing a wireless data communication device according to a first embodiment of the present invention. The wireless data communication apparatus according to the present embodiment includes a receiving unit 1 and a transmitting unit 2 that share an antenna 11, and an output control unit 3 that controls transmission output is provided between the receiving unit 1 and the transmitting unit 2. FIG. 2
Is transmitted and received.

As shown in FIG. 2, the signal D has a frame structure of a control section C and a data section B containing other data and the like. The control unit C stores a reception response signal (hereinafter, referred to as “ACK”) or a retransmission request signal (hereinafter, referred to as “NAK”). Specifically, when the data of the signal D sent from the partner device can be received without error, the ACK is stored in the control unit C and transmitted. When there is an error in the received data, the NAK is controlled. The data is stored in the section C and transmitted.

The receiving section 1 includes a duplexer 12 to which an antenna 11 is connected, and a high-frequency filter 13 for receiving which converts the signal D received by the duplexer 12 into an intermediate frequency signal.
And a frequency mixer 14, an intermediate frequency amplifier 15 for amplifying the intermediate frequency signal, and a demodulated signal S
1 and a demodulator 16 for outputting 1.

The transmitting section 2 comprises a power amplifier 20 for changing the amplification factor of the signal D by an amplification factor control signal S2 described later from the output control section 3, a high frequency filter 21 for transmission, and a duplexer 12 for transmission and reception. ing.

Meanwhile, the output control unit 3, and a ACK / NAK detector 4 and the control voltage generator 5 and the transmission output control circuit 6. As shown in FIG. 3, the ACK / NAK detector 4 includes a shift register 41, first and second registers 42 and 43, and first and second comparators 44 and 45.
And a flip-flop 46.

The shift register 41 takes in the demodulated signal S1 from the demodulator 16 and outputs it to the comparators 44 and 45. The register 42 sends ACK information stored in advance to the comparator 44, and the register 43 sends NAK information stored in advance to the comparator 45.

The comparator 44 receives the demodulated signal S1 from the shift register 41 and the ACK information from the register 42, and determines whether or not ACK is included in the control section C of the demodulated signal S1. Then, when it is determined that it is included, the output signal S3 is input to the flip-flop 46.

The comparator 45 includes a shift register 41
, And the NAK information from the register 43, and determines whether or not the control section C of the demodulated signal S1 contains a NAK. When it is determined that it is included, the output signal S4 is input to the flip-flop 46.

When the output signal S3 is input from the comparator 44, the flip-flop 46 outputs an ACK / NAK indicating "1".
The detection signal S5 is output to the control voltage generator 5, and the comparator 45
ACK / N indicating "0" when output signal S4 is input from
It has a function of outputting the AK detection signal S6 to the control voltage generator 5.

As shown in FIG. 4, the control voltage generator 5 includes third and fourth comparators 51 and 52 and a computing unit 53.
, A driver 54, and eight resistors 55-1 to 55-8.
And an operational amplifier 56. Comparator 51
When the ACK / NAK detection signal S5 indicating “1” is input, the signal S7 indicating “1” is input to the arithmetic unit 53, and the comparator 52 outputs the ACK / NAK detection signal S6 indicating “0”. Is input, a signal S8 indicating “1” is input to the arithmetic unit 53.

The arithmetic unit 53 has a function of subtracting the number of receptions of the signal S8 from the number of receptions of the signal S7, and outputting a signal S9 indicating the result to the driver 54. In the present embodiment, the signal S9 whose subtraction result is in the range of “3” to “−4” is output to the driver 54. However, the present invention is not limited to this, and the range of the subtraction result can be set freely.

The output end of the resistor 55-1～55-8 connected in parallel to the driver 54 is connected to the negative input terminal of the operational amplifier 56. The upper resistor 55-1 in the figure
The resistance value of the resistors 55-1 to 55-8 is set so that the resistance value of the resistors 55-1 to 55-8 becomes maximum, and the resistance value decreases as the resistance value becomes lower. Is set.

The driver 54 includes resistors 55-1 to 55-1.
A resistor corresponding to the result of the subtraction from the arithmetic unit 53 is selected from 55-8, and a predetermined voltage is output to the minus input terminal of the operational amplifier 56.

The positive input terminal of the operational amplifier 56 is grounded. The output terminal is connected to a negative input terminal via a resistor 57, so that the output is fed back. As a result, the control voltage signal S10 having a DC voltage of a level corresponding to the subtraction result of the arithmetic unit 53 is output from the operational amplifier 56 to the transmission output control circuit 6. Specifically, control voltage signal S10 having a smaller DC voltage level as the result of the subtraction is larger is output.

The transmission output control circuit 6 controls the control voltage signal S1.
It has a function of operating the DC voltage of 0 as a control signal and outputting to the power amplifier 20 an amplification factor control signal S2 for changing the amplification factor to an amplification factor corresponding to the DC voltage.

Next, the operation of this embodiment will be described.
In FIG. 1, the signal D caught by the antenna 11
Is input to the receiving high-frequency filter 13 and the frequency mixer 14 via the duplexer 12 of the receiving unit 1 and is converted into an intermediate frequency signal. After being amplified by the intermediate frequency amplifier 15, the signal is output from the demodulator 16 as a demodulated signal S 1.

[0027] The demodulated signal S1, after being temporarily taken into the shift register 41 of the output control section 3 shown in FIG. 3, is input to the comparator 44, 45. When the ACK is included in the control unit C of the demodulated signal S1, the output signal S3 is output from the comparator 44 to the flip-flop 46, and conversely, the NAK is included in the control unit C of the demodulated signal S1. If it is included, the comparator 45 outputs an output signal S4 to the flip-flop 46.

When the output signal S3 is input to the flip-flop 46, the ACK / NAK detection signal S5 indicating "1"
Is output to the control voltage generator 5, and when the output signal S4 is input to the flip-flop 46, ACK /
NAK detection signal S6 is output to control voltage generator 5 shown in FIG.

When the ACK / NAK detection signal S5 is input to the control voltage generator 5, the comparator 51 outputs "1".
Is output to the arithmetic unit 53, and conversely, ACK
When the / NAK detection signal S6 is input, the comparator 52 outputs a signal S8 indicating “1” to the arithmetic unit 53.

By the way, communication with other devices is stable, if the data signal D is received in addition to the device without an error, the device only the signal D from the other device containing ACK , The number of receptions of the signal D including the ACK increases. Accordingly, the number of times of input of the signal S7 input from the comparator 51 to the arithmetic unit 53 increases. For example, a signal S9 having a subtraction result of “3” is output to the driver 54. For this reason, the resistor 55-1 is selected by the driver 54, and a predetermined voltage is applied to the minus input terminal of the operational amplifier 56 via the resistor 55-1.

[0031] As a result, the control voltage signal S10 having the lowest level of the DC voltage is output to the transmission output control circuit 6,
The amplification factor of the power amplifier 20 is reduced to the minimum level by the amplification factor control signal S2 from the transmission output control circuit 6, so that the transmission output from the transmission unit 2 is reduced to the minimum level. As a result, wasteful power consumption can be reduced.

[0032] Conversely, unstable communication with other devices,
If the data of the signal D is erroneously received by another device, many signals D including the NAK are transmitted from the other device to the present device. Is greater than the number of receptions of the signal D including Therefore, the number of times the signal S8 is output from the comparator 52 is greater than the number of times the signal S7 is output from the comparator 51. For example, a signal S9 having a subtraction result of “−4” is sent from the arithmetic unit 53 to the driver 54. Is output. For this reason, the resistor 55-8 is selected by the driver 54, and a predetermined voltage is applied to the minus input terminal of the operational amplifier 56 via the resistor 55-8. As a result, the control voltage signal S10 having the highest DC voltage is output to the transmission output control circuit 6, and the amplification factor of the power amplifier 20 is increased to the highest level by the amplification control signal S2 from the transmission output control circuit 6. So that
The transmission output from the transmitter 2 rises to the highest level. Thus, stable communication can be performed thereafter.

[0033] Thus, according to the radio communication apparatus of this embodiment, since increases or decreases the transmission power in response to the communication state, it is possible to economization of power consumption. further,
Since no unnecessary output is output, there is no adverse effect on devices other than the transmission partner. Also, instead of electric field strength,
Since the transmission output can be changed depending on whether or not ACK or NAK is received, the transmission output can be increased and countered when there is disturbance such as external noise.

Embodiment 2 FIG . FIG. 5 is a block diagram showing a wireless data communication device according to a second embodiment of the present invention. The same elements as those shown in FIG. 1 will be described with the same reference numerals. The wireless data communication device according to the present embodiment is different from the wireless data communication device according to the first embodiment in that the wireless data communication device includes an ID assigning unit 22 and an ID analyzer 31.

The ID assigning device 22 is a device for assigning its own ID (call code) information and ID information of a transmission partner to the transmission signal D. The ID analyzer 31 outputs the demodulated signal S1
Is a device for analyzing the ID information from and identifying the communication partner. The ID analyzer 31 has a function of outputting an output initialization signal S11 for instructing initialization of a transmission output to the control voltage generator 5 when it is determined that the communication partner has changed as a result of the ID information analysis. doing.

According to such a configuration, signal D ID information of itself and the communication partner has been added by the ID adding unit 22,
The power amplifier 20 via the modulator 23 and the drive amplifier 24
Are transmitted to the other device at the same frequency from the antenna 11 via the transmitting high-frequency filter 21 and the duplexer 12 with the transmission output increased or decreased.

[0037] Then, the signal D from the other antenna 11
The signal is input to the demodulator 16 via the duplexer 12, the receiving high-frequency filter 13, the frequency mixer 14, and the intermediate frequency amplifier 15, and is output as the demodulated signal S1. Then, when the communication partner is nearby, the amplification factor of the power amplifier 20 is reduced and the communication is repeated as in the first embodiment.

In parallel with this operation, the ID analyzer 31 analyzes the ID information of the partner of the demodulated signal S1 and determines whether or not the contents of the ID information have changed. When the communication partner changes from a nearby partner to a distant partner, the ID information of the partner included in the demodulated signal S1 changes. Therefore, the output initialization signal S11 is transmitted from the ID analyzer 31 to the control voltage generator 5. Is output. As a result, the driver 5 of the control voltage generator 5
4 is controlled to select, for example, resistor 55-8;
The transmission output is initialized.

[0039] That is, the transmission output to close the communication partner is small and immediately to restore the transmission power for the remote party, and enabling stable communication by the same frequency. Therefore, according to the wireless data communication device of the present embodiment, it is possible to perform stable communication by adjusting the transmission output only to the communication partner, so that a network is formed by using a plurality of devices and using radio waves of the same frequency. The present device can be applied to a system such as a LAN. The other configuration, operation, and effect are the same as those of the first embodiment, and the description is omitted.

[0040]

As described above, according to the wireless data communication apparatus of the present invention, the output control unit transmits a signal corresponding to the difference between the number of times of receiving a radio signal including ACK and the number of times of receiving a radio signal including NAK. Since the transmission output of the unit is increased or decreased, the transmission output can be increased or decreased according to the communication state, and as a result, the power consumption can be reduced.
In addition, since unnecessary output is not output, there is no adverse effect on devices other than the transmission partner. Further, since the transmission output can be changed depending on whether or not ACK or NAK is received instead of the electric field strength, the transmission output can be increased and countered when there is disturbance such as external noise.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a wireless data communication device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a frame structure of a signal transmitted and received.

FIG. 3 is a block diagram of an ACK / NAK detector.

FIG. 4 is a block diagram of a control voltage generator.

FIG. 5 is a block diagram showing a wireless data communication device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving part 2 Transmitting part 3 Output control part 4 ACK / NAK detector 5 Control voltage generator 6 Transmission output control circuit 11 Antenna 22 ID assigning device 31 ID analyzer

Claims (1)

(57) [Claims] 1. A wireless data communication device using ACK or NAK, comprising: a transmitting unit for transmitting a wireless signal including ACK or NAK; and a receiving unit for receiving and demodulating the wireless signal.
ACK / NAK detecting the ACK or NAK from the demodulated signal.
A NAK detector, a control voltage generator for generating a DC voltage corresponding to a difference between the number of ACKs detected by the ACK / NAK detector and the number of NAKs, And a transmission output control circuit for changing the transmission output to a transmission output corresponding to the DC voltage from the detector . In the output control unit , the ACK / NAK detector has a first ACK information stored therein. A second register storing the register and the NAK information, and comparing the ACK information of the first register with the information in the demodulated signal to determine a predetermined signal when it is determined that the demodulated signal contains ACK. A first comparator that outputs
A second comparator that compares the NAK information of the second register with the information in the demodulated signal and outputs a predetermined signal when it is determined that the demodulated signal contains a NAK;
When an output signal from the first comparator is input, an ACK / NAK detection signal indicating "1" is output to the control voltage generator, and when an output signal from the second comparator is input, "0" is output.
And a flip-flop that outputs an ACK / NAK detection signal indicating the above to the control voltage generator, wherein the control voltage generator generates an ACK / NA indicating the above “1”.
A third comparator that outputs a signal indicating “1” when the K detection signal is input, and an ACK / NA indicating the above “0”
A fourth comparator that outputs a signal indicating “1” when a K detection signal is input, and subtracts the number of signals received from the third comparator and the number of signals received from the fourth comparator. A wireless data communication device comprising: a computing unit that performs a subtraction operation; and an operational amplifier that generates a DC voltage corresponding to a subtraction result of the computing unit.