JPH08139635A - Radio communication equipment - Google Patents

Abstract

PURPOSE: To provide a radio communication equipment of low power consumption by ordinarily operating only a starting circuit on the reception side and supplying a power source when the ON/OFF pattern of a carrier from the transmission side is matched with that of its own equipment. CONSTITUTION: At the time of transmission, a previously decided pattern code is generated from a control circuit 50 and according to the pattern, a switch 4 is turned on/off. A carrier signal outputted from a transmission circuit is turned on/off according to the pattern signal and transmitted from an antenna 1. Continuously, the transmission of FSK modulated data is performed. At the time of reception, only the starting signal is ordinarily operated, a radio wave radiated from the transmission side is received by the antenna 1, the carrier is detected by a pattern detecting circuit 15 and when its ON/OFF pattern is matched with the pattern previously set to its own equipment, a signal at a HIGH level is outputted. Corresponding to this signal, a switch 3 is turned on and the power source is supplied to a reception circuit 30 and the control circuit 50 or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device,
In particular, the present invention relates to an improvement for reducing power consumption during reception standby.

[0002]

2. Description of the Related Art Conventionally, a wireless communication device, especially a device on the receiving side, is generally used as a receiving state regardless of whether or not a received radio wave arrives.

[0003]

However, the power consumption during the receiving operation is not small, and there is a drawback that the battery life becomes extremely short if the battery-powered wireless communication device always performs reception. In order to solve this, a method of extending the life of the battery by the intermittent reception operation has been realized, but this method has a problem that it is not effective when the operation interval must be shortened.

In view of the above points, an object of the present invention is to
An object is to provide a wireless communication device with low power consumption and fast reception response.

[0005]

In order to achieve such an object, according to the present invention, a carrier detection circuit for detecting a carrier of a received radio wave, a pattern of a signal output from the carrier detection circuit and its own device are provided. A pattern detection circuit that collates with a predetermined pattern and O
A switch for supplying power to turn on / off, which is turned on by a start signal output from the pattern detection circuit.
And a receiving circuit that operates when power is supplied through the power supply switch and that has the function of demodulating received radio waves, and operates when power is supplied through the power supply switch. Then, a transmission circuit having a function of modulating transmission data, a carrier on / off circuit for turning on / off a carrier output from the transmission circuit, and an operation when power is supplied through the power supply switch, At the time of reception, if the data demodulated by the receiving circuit has an identification address of its own device, the demodulated data is interpreted, and if there is no identification address, the function of turning off the power supply switch and a predetermined function at transmission are set. Turn on / off the carrier on / off circuit according to a pattern.
A control circuit having a function of turning off the carrier to turn on / off the carrier and subsequently turning on the carrier on / off switch to send a signal from the transmission circuit is provided.

[0006]

On the transmitting side, the carrier is turned on / off according to a predetermined pattern, and then data is transmitted by FSK modulation or the like. The data also includes the identification address of the communication partner. On the receiving side, only the starting circuit is constantly operating, and the carrier from the transmitting side is detected and the ON / OFF pattern is compared. Only when the pattern matches that of the own device, power is supplied to the circuits other than the starting circuit. Then, if the demodulated data in the receiving circuit has the identification address of its own device, the data is subsequently interpreted.
When the identification address is different from its own identification address, the power supply to the circuits other than the starting circuit is immediately stopped.

[0007]

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of a wireless communication device according to the present invention. In the embodiment, an apparatus having both functions of the transmitting side and the receiving side of the starting circuit is shown as an example. In the figure, 1 is a transmitting / receiving antenna, 2 is a high frequency band pass filter, 3 is a power supply switch, 4 is a carrier on / off circuit, 10 is a starting circuit, 20 is a battery, 30 is a receiving circuit, 40 is a transmitting circuit, and 50 is a control. Circuit.

The high frequency band pass filter 2 determines the frequency band of the radio wave transmitted or received by the transmission / reception antenna 1, and the received radio wave is guided to the starting circuit 10 and the receiving circuit 30. On the other hand, the transmission signal is sent from the transmission circuit 40 via the switch 4. The starting circuit 10 detects the carrier of the received signal, collates the ON / OFF pattern that turns the carrier ON / OFF, and generates a signal that turns ON the switch 3 when the patterns match. A more detailed description of the starting circuit 10 will be given later.

The switch 3 is turned on by the output signal of the starting circuit, but is also turned on by a driving signal from the outside. When turning off the switch 3, the control circuit 5
It can be turned off from 0 or by a signal from the outside through the control circuit 50. The battery 20 is a power supply that supplies power to each circuit, and always supplies power to the starting circuit 10 and power supply switch 3 to the receiving circuit 30, the transmitting circuit 40, the carrier switch circuit 4, and the control circuit 50.
Supply power through.

The receiving circuit 30 is frequency shift keying (FSK).
Etc. has a function of performing demodulation. The transmission circuit 40 has a function of performing modulation such as FSK. Carrier on / off circuit 4
Is a switch for turning on / off the output of the transmission circuit 40 given to the high frequency band pass filter 2. Control circuit 50
Analyzes the data if the FSK demodulated data in the receiving circuit 30 has an identification address (preset) of its own device, and immediately switches the switch 3 if the identification address is different from its own identification address. It has a function of turning off and stopping the power supply to all circuits except the starting circuit 10.

Further, the control circuit 50 has a function of generating a pattern signal for turning on / off the carrier according to a predetermined pattern at the time of transmission. The switch 4 is turned ON / OFF by this pattern signal.
The pattern can be set and changed as appropriate.

Next, the starting circuit 10 will be described in detail. In the starting circuit 10, 11 is a matching circuit for impedance matching, 12 is a diode detection circuit for detecting the output of the matching circuit 11, and 13 is a bandpass filter for cutting the DC component of the output of the detection circuit 12 and reducing noise. , 14 are amplifiers that appropriately amplify the output of the bandpass filter 13, and 15 is a pattern detection circuit that detects that the signal input from the amplifier 14 has a predetermined pattern. When the pattern exists, a drive signal for turning on the switch 3 is output.

FIG. 2 shows an example of the configuration of the pattern detection circuit, FIG.
Is a voltage waveform diagram of each part thereof. The signal from the amplifier 14 is converted by the level converter 61 into a signal level suitable for the logic circuit in the subsequent stage. This output ((a) in FIG. 3) is input to the shift register 62 and the integrating circuit 63.

The integrating circuit 63 is composed of a resistor R and a capacitor C, and its output ((b) in FIG. 3) is input to the clock circuit 64. The clock circuit 64 includes an AND gate 65 and
Inverter 66 for inverting and outputting the output of the AND gate
And an integrating circuit 67 for integrating the output of the inverter 66 and inputting the integrated output to the AND gate 65.
A clock having a cycle corresponding to the time constant determined by the resistor R and the capacitor C of 7 is obtained from the output terminal of the inverter. The clock ((c) in FIG. 3) is generated when the output of the integrator circuit 63 ((b) in FIG. 3) is at a certain level or higher (when the logic level is the HIGH level).

The shift register 62 is made up of four edge-triggered flip-flops connected in series, and the clock output from the clock circuit 64 ((c) in FIG. 3) is added to each flip-flop. There is. The output of each flip-flop is input to one input terminal of each exclusive OR circuit (XOR) of the exclusive OR circuit array 68. A predetermined pattern code (given from a port of a microcomputer or from a HIGH / LOW setting device not shown) is inputted to the other input of XOR. In the case of FIG. 2, the pattern code is 0101.

The output of the exclusive OR circuit array 68 is input to the AND circuit (AND gate) 69, and the output of the AND gate becomes the HIGH level when all the outputs of each XOR become the HIGH level (FIG. 3). (D)).

The operation of such a configuration will be described below. (1) Operation during transmission The switch 3 is forcibly turned on, and power is also supplied from the battery 20 to the transmission circuit 40 and the control circuit 50. A predetermined pattern code is generated from the control circuit 50, and the switch 4 is turned ON / OFF according to this pattern. As a result, the carrier signal output from the transmission circuit is turned ON / OFF according to this pattern signal, and is transmitted from the antenna 1 via the bandpass filter 2. Then, FSK
The modulated data is transmitted. The data also includes the identification address of the communication partner. Switch 3 at the end of transmission operation
Turn off.

(2) Operation at the time of reception At the time of reception, only the starter circuit is constantly operating to detect the carrier of the received wave and compare the ON / OFF pattern thereof. The receiving circuit is activated only when the pattern matches the pattern set in the own device. Then, FSK demodulation is performed in the activated receiving circuit. If the FSK-demodulated data has the identification address of its own device, the data is interpreted.
When the identification address is not its own identification address, the switch 3 is immediately turned off and the power supply other than the starting circuit is stopped.

The operation of the starting circuit is as follows.
The radio wave radiated from the transmitting side is received by the antenna 1, and only the signal in the required frequency band is passed by the bandpass filter 2. The matching circuit 11 receives this signal, impedance matching is performed, and the signal is input to the diode detection circuit 12. The output of the detection circuit 12 is passed through a bandpass filter 13 to remove a direct current component and reduce noise, and then an amplifier 14 appropriately amplifies the signal to obtain a pattern detection circuit 15
Lead to.

The pattern detection circuit 15 detects the carrier and checks whether its ON / OFF pattern matches the pattern predetermined for the device. If they match, a HIGH level signal is output. The switch 3 is turned on by this HIGH level signal, and the receiving circuit 3
0, power is supplied to the control circuit 50 and the like.

As described above, at the time of reception, only the starting circuit 10 is always in the state of being supplied with power, and the other circuits when the ON / OFF pattern of the carrier coincides with the predetermined pattern defined in the own device. Only powered. Furthermore, if there is a mismatch in the verification of the identification address in the demodulated data such as FSK, it is immediately switched to the power supply only to the starting circuit 10 as in the original case. In this way, power consumption can be reduced. Also, since the start-up circuit is always operating, the reception response is fast.

The present invention is not limited to the embodiments, and various modifications are possible. For example, as shown in FIG. 4, a control circuit 50a including a microcomputer having a sleep mode can be used as the control circuit 50. Note that the power consumption in this sleep mode is significantly lower than that in the normal operation mode. The signal from the starting circuit 10 is input to the interrupt terminal of the microcomputer 50a. When a signal is input from the activation circuit 10, the microcomputer 50a switches from the sleep mode to the operation mode, turns on the switch 3, and supplies power to the reception circuit 30 and the transmission circuit 40. Further, the activation pattern can be changed by the microcomputer 50a.

FIG. 5 shows another embodiment of the pattern detection circuit. A major difference from the pattern detection circuit shown in FIG. 2 is that the clock circuit is omitted and the power consumption is further reduced. In FIG. 5, the output of the level converter 61 is input to the flip-flop array 62a composed of four flip-flops. The output of the level converter 61 input to the D input terminal is used as the clock of the first flip-flop FF1, and the non-inverted output (Q output) of the first flip-flop FF1 is used as the clock of the second flip-flop FF2. Is used in the integration circuit INT1 and a signal obtained by integrating the Q output of the first flip-flop FF1 in the integration circuit INT2 is used as the clock of the third flip-flop FF3. Is the integration circuit INT for the Q output of the first flip-flop FF1.
The signal integrated in 3 is used.

Although FIG. 2 and FIG. 5 are examples of the 4-bit pattern detection circuit, there is no problem even if they are other than 4-bit.

FIG. 6 shows an example in which the present invention is applied to a moving body identifying apparatus, and is applied to a wireless apparatus such as a moving body identifying apparatus which modulates a reflected wave of a radio wave. On the interrogator A side,
ON / OFF of carrier according to a predetermined pattern
Then, the carrier is continuously transmitted and the receiving operation is started. On the responder B side, the starting circuit 10 is always operating, and receives the carrier transmitted from the interrogator A and detects the carrier. Only when the ON / OFF patterns of the carrier match, the control circuit 50a is switched from the sleep mode to the operation mode, and the power switch 3 of the battery 20 is turned on. When the control circuit 50a enters the operation mode, it transmits its own identification number via the transmission circuit.

The responder B receives the carrier including the command or data from the interrogator A, inputs the detection circuit output of the starting circuit 10 to the receiving circuit, and demodulates the command or data. According to the command, necessary data is transmitted via the transmission circuit 40. When the required communication is completed, the responder B turns off the power switch 3, and the control circuit 50a enters the sleep mode. According to such a device, an arbitrary pattern can be designated, so that a plurality of tags can be read by polling.

[0027]

As described above, the present invention has the following effects. (1) Since the start-up circuit is always in operation, the quick response is good,
Received response is fast. (2) The start-up circuit can be realized with low power consumption and the battery life can be extended. (3) Since the ON / OFF pattern of the carrier is collated in the start-up circuit, malfunctions that unnecessarily start up the receiving circuit are reduced, thereby further reducing power consumption. (4) Since the activation circuit can be operated in an arbitrary pattern, it is easy to selectively activate only the desired wireless communication device among the plurality of wireless communication devices.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a wireless communication device according to the present invention.

FIG. 2 is a configuration diagram showing an example of a pattern detection circuit.

3 is an operation waveform diagram of each part in the circuit of FIG.

FIG. 4 is a configuration diagram showing another embodiment of the present invention.

FIG. 5 is a configuration diagram showing another example of a pattern detection circuit.

FIG. 6 is a diagram showing an application example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 antenna 2 high frequency band pass filter 3,4 switch 10 starting circuit 11 matching circuit 12 diode detection circuit 13 band pass filter 14 amplifier 15 pattern detection circuit 20 battery 30 receiving circuit 40 transmitting circuit 50 control circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Koji Akiyama 2-9-32 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A carrier detection circuit for detecting a carrier of a received radio wave, a pattern detection circuit for collating a pattern of a signal output from the carrier detection circuit with a predetermined pattern of its own device, and an external signal A switch for supplying power to be turned on / off, which is turned on by a start signal output from the pattern detection circuit, and which operates when power is supplied through the power supply switch to receive a signal. A receiving circuit having a function of demodulating radio waves, a transmitting circuit having a function of operating when power is supplied through the power supply switch and modulating transmission data, and a carrier output from the transmitting circuit A carrier on / off circuit that turns on / off, and operates when power is supplied through the power supply switch, and when receiving, There are the interprets the demodulated data if the identification address of its own device to the data demodulated by the receiving circuit, the power supply switch if no identification address O
FF function and ON / OFF of the carrier on / off circuit according to a predetermined pattern at the time of transmission
To turn on / off the carrier, and then turn on the carrier.
A wireless communication device comprising a control circuit having a function of transmitting a signal from a transmission circuit to N.