JP2001024549A - Mobile object identification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a compact and inexpensive mobile object identification system capable of quickly reading out data from a plurality of responders in the same area. SOLUTION: A microwave signal generated from a signal source 105 of an interrogator 102 is modulated by a modulation part 115 and distributed to the transmitting side and the receiving side by a distribution circuit 106 and the transmitting side signal is transmitted from an interrogator side antenna 101. The transmitted microwave signal is received by a responder side antenna 104, ASK-modulated by a control signal outputted from a control part 108 and transmitted to the interrogator 102 through the antenna 104. The transmitted microwave signal is received by the antenna 101, distributed to the receiving side through a branching filter 107, demodulated by a received signal demodulation part 110 and processed by a data processing part 111, and the processed data are read out from responders 103a, 103b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object identification system having an interrogator and a transponder.

[0002]

2. Description of the Related Art A non-contact IC card system described in Japanese Patent Application Laid-Open No. 8-123919 has been known as a moving object identification system.

FIG. 6 shows a communication method of a conventional contactless IC card system. In this system, for example, even when a plurality of cards 601a, 601b, 601c enter the communication area, the read / write device 602 can access the cards 601a, 601b, 601c in the communication area, and the cards 601a, 601b, 601c. Is the first condition 603 specified by the read / write device 602 and its own ID
Response block 604 containing ID code rather than code
Is determined, and the read / write device 602 receives the response block 604 returned by the cards 601a, 601b, and 601c, detects data collision, and changes the condition based on this result to change the condition.
The retransmission request 605 of the response block including the D code is made.

[0004] For example, the card 601a receives T
After O, the other cards 601b and 601c are TO + T
After (ID), the response block 606 is retransmitted. The read / write device 602 is a card 601a having no collision.
From the response block 606a. Furthermore,
A retransmission request 607 is made, and the card 601b receives T from the retransmission request.
After O, the other card 601c resends the response block 608 after TO + T (ID). By repeating this, a response block is received from the card 601 without collision, and communication with a plurality of cards is performed.

[0005]

In this mobile object identification system, it is required to read information from a plurality of transponders in the same area in a short time at a small size and at low cost.

An object of the present invention is to construct a small and inexpensive system capable of reading information from a plurality of transponders in the same area in a short time in such a moving object identification system.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention comprises a plurality of stepwise modulators on a transponder side, wherein the communication quality is changed according to communication conditions. It is.

Thus, a mobile object identification system which is small and inexpensive and can read data of a plurality of transponders in the same area in a short time can be constituted.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a signal source for generating an output signal, a modulator for modulating an output signal from the signal source, and an output signal modulated by the modulator. An antenna that transmits a signal, a duplexer that separates a reflected wave as a response signal received by the antenna from an output signal, a demodulation unit that demodulates the response signal, a data processing unit that processes a signal from the demodulation unit, An interrogator having a control unit that controls the interrogator based on the data of the processing unit, and a signal transmitted from the interrogator, and a transponder antenna for transmitting a response signal to the interrogator antenna, The interrogator, comprising: a demodulator for demodulating a received signal; a controller for controlling a transponder based on data from the demodulator; a first, second, and third absorber having different absorption amounts from a switcher. Signal from the The reflected wave as a signal is obtained by a mobile identification system composed of responder having a modulator for the amplitude modulation.

Thus, the transponder modulates the amplitude of the signal from the interrogator using the absorbers having different absorption amounts, thereby reflecting waves having different degrees of modulation as response signals for each transponder, and By separating the response signals from the transponders according to the difference in the degree of modulation, and enabling the demodulation of the response signals from each transponder at the same time, the data of multiple transponders in the same area is small and inexpensive. It has the effect of being able to read in a short time.

According to a second aspect of the present invention, in the moving object identification system according to the first aspect, the modulator of the transponder responds to the signal from the interrogator by switching any two absorbers during communication. It is characterized by amplitude-modulating the reflected wave as a signal, and the transponder selects an arbitrary degree of modulation, thereby reflecting waves with different degrees of modulation as response signals for each communication, and the interrogator By separating the response signals from multiple transponders according to the difference in the modulation factor and enabling the response signals from each transponder to be demodulated simultaneously, the data of multiple transponders in the same area is small, inexpensive, and inexpensive. It has the effect of being able to read in a short time.

According to a third aspect of the present invention, in the mobile object identification system according to the first aspect, the signal from the interrogator is responded by switching the first and second absorbers during the first communication. The amplitude modulation is performed on the reflected wave as a signal, and the amplitude is modulated by switching the first and third absorbers at the time of the second and subsequent communication, and the transponder is operated at the time of the first communication. The interrogator separates and demodulates the response signal of the transponder that failed to read the data in the first communication by the modulation degree by switching the modulation degree of the second and subsequent communication. Thus, there is an effect that data of a plurality of transponders in the same area can be read in a short time at a small size and at low cost.

According to a fourth aspect of the present invention, in the moving object identification system according to the first aspect, the absorption amount of the first absorber is 0 dB, the absorption amount of the second absorber is 10 dB, and the third absorption amount. The transponder performs amplitude modulation with a large modulation factor and amplitude modulation with a small modulation factor so that the interrogator responds to signals from a plurality of transponders. Is separated by the difference of the modulation degree, and the response signal from each transponder can be demodulated at the same time, so that the data of multiple transponders in the same area can be read in a short time at a small size and at low cost. It has the action of:

According to a fifth aspect of the present invention, in the moving object identification system according to the first aspect, the response signal of the transponder includes a data string including a solid recognition data string and an information data string, and the solid recognition data string. By switching the first and third absorbers at the time of transmission, the signal from the interrogator is amplitude-modulated into a reflected wave as a response signal, and at the time of transmitting the information data sequence, the first and second absorbers are switched. The amplitude modulation is performed, and the transponder switches between the modulation degree when transmitting the solid-state recognition data sequence and the modulation degree when transmitting the information data sequence, so that the solid-state recognition data sequence and the information are transmitted from a plurality of transponders. Even if the data stream is sent simultaneously, the interrogator can separate the response signal according to the difference in modulation factor and demodulate it at the same time. An effect that can be read in a short time vessels of data.

According to a sixth aspect of the present invention, there is provided a signal source for generating an output signal, a modulator for modulating an output signal from the signal source, an antenna for transmitting an output signal modulated by the modulator, and the antenna. A demultiplexer for demultiplexing a reflected wave as a response signal received as an output signal with an output signal, a demodulation unit for demodulating the response signal, a data processing unit for processing a signal from the demodulation unit, based on data of the processing unit An interrogator having a control unit for controlling the interrogator, a transponder antenna for receiving a signal transmitted from the interrogator and transmitting a response signal to an antenna of the interrogator, and a demodulator for demodulating a received signal. Unit, a control unit for controlling a transponder based on the data of the demodulation unit, and first, second, and third phase shifters having different phase amounts from the switching unit, and a signal from the interrogator is transmitted as a response signal. As anti It is obtained by a mobile identification system composed of responder having a modulator for phase-modulating the wave.

Thus, the transponder performs phase modulation of the signal from the interrogator using the phase shifters having different phase amounts, thereby reflecting waves having different degrees of modulation for each transponder as response signals. By separating the response signals from multiple transponders according to the difference in modulation degree and enabling the demodulation of the response signals from each transponder at the same time, the data of multiple transponders in the same area is small, inexpensive, and inexpensive. Can be read in a short time.

According to a seventh aspect of the present invention, in the mobile object identification system according to the sixth aspect, a signal from the interrogator is reflected as a response signal by switching any two phase shifters during communication. The transponder selects a desired degree of modulation to reflect waves having different degrees of modulation as response signals each time communication is performed, and the interrogator transmits signals from a plurality of transponders. By separating the response signals according to the difference in the modulation factor and enabling simultaneous demodulation of the response signals from each transponder, it is possible to read data from multiple transponders in the same area in a short time in a small and inexpensive manner. It has the effect of being able to.

According to an eighth aspect of the present invention, in the mobile object identification system according to the sixth aspect, the signal from the interrogator is switched by switching the first and second phase shifters during the first communication. The phase modulation is performed on the reflected wave as a response signal, and the phase modulation is performed by switching the first and third phase shifters at the time of the second and subsequent communications. By switching between the modulation factor at the time of communication and the modulation factor at the time of the second and subsequent communications, the interrogator separates the response signal of the transponder that failed to read data in the first communication by the difference in the modulation factor, The demodulation has an effect that data of a plurality of transponders in the same area can be read in a short time at a small size and at low cost.

According to a ninth aspect of the present invention, in the moving object identification system according to the sixth aspect, the phase amount of the first phase shifter is 0 degrees, the phase amount of the second phase shifter is 170 degrees, The phase amount of the third phase shifter is set to 180 degrees, and the interrogator performs a plurality of phase modulations with a large modulation degree and a small phase modulation with a transponder, thereby enabling a plurality of interrogators. By separating the response signal from the transponder according to the difference in the degree of modulation, it is possible to demodulate the response signal from each transponder at the same time,
It is small and inexpensive, and has the effect that data of a plurality of transponders in the same area can be read in a short time.

According to a tenth aspect of the present invention, in the moving object identification system according to the sixth aspect, the response signal of the transponder comprises a data string including a solid recognition data string and an information data string, and the solid recognition data string. The signal from the interrogator is phase-modulated into a reflected wave as a response signal by switching the first and third phase shifters at the time of transmission, and the first and second phase shifters are switched at the time of transmitting the information data sequence. In this case, the transponder switches between the modulation degree when transmitting the solid-state recognition data sequence and the modulation degree when transmitting the information data sequence, so that the solid-state recognition data sequence is transmitted from a plurality of transponders. And the information data string are sent at the same time,
By enabling the interrogator to separate the response signal according to the difference in modulation depth and demodulate it at the same time, it is small and inexpensive,
This has an effect that data of a plurality of transponders in the same area can be read in a short time.

The invention according to claim 11, wherein a signal source for generating an output signal, a modulator for modulating an output signal from the signal source, an antenna for transmitting an output signal modulated by the modulator, and the antenna A demultiplexer for demultiplexing a reflected wave as a response signal received as an output signal with an output signal, a demodulation unit for demodulating the response signal, a data processing unit for processing a signal from the demodulation unit, based on data of the processing unit An interrogator having a control unit for controlling the interrogator, a transponder antenna for receiving a signal transmitted from the interrogator and transmitting a response signal to an antenna of the interrogator, and a demodulator for demodulating a received signal. A control unit for controlling a transponder based on data of the demodulation unit, a switch, an attenuator, and first, second, and third phase shifters having different amounts of phase, and a signal from the interrogator. The response signal The reflected wave of is obtained by a mobile identification system composed of responder having a modulator for phase modulation.

Thus, the transponder uses the attenuator having a different attenuation and the phase shifter having a different phase to modulate the phase of the signal from the interrogator. By reflecting the wave as a response signal, the interrogator can separate the response signals from the plurality of transponders by the difference in the amount of reflection and the degree of modulation, and simultaneously demodulate the response signal from each transponder, It is small and inexpensive, and has the effect that data of a plurality of transponders in the same area can be read in a short time.

According to a twelfth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, an arbitrary two-way communication is performed during communication.
By switching between the two phase shifters, the signal from the interrogator is phase-modulated into a reflected wave as a response signal. , Reflecting waves with different modulation depths as response signals, enabling the interrogator to separate response signals from multiple transponders according to the modulation depth and demodulate the response signals from each transponder simultaneously. Therefore, it has an effect that data of a plurality of transponders in the same area can be read in a short time at a small size and at low cost.

According to a thirteenth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, at the time of communication, an attenuator is arbitrarily used, and an arbitrary two phase shifters are switched. Characterized in that the signal is phase-modulated into a reflected wave as a response signal,
When the transponder selects an arbitrary attenuation and modulation degree, the waves having different reflection amounts and modulation degrees are reflected as response signals for each communication, and the interrogator transmits the response signals from the plurality of transponders to signal strength and signal strength. By separating by the difference in modulation depth and enabling simultaneous demodulation of response signals from each transponder, it is possible to read data of multiple transponders in the same area in a short time in a small size and at low cost. Has an action.

According to a fourteenth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, at the time of the first communication, the signal from the interrogator is attenuated by the attenuator, and the first and second shifts are performed. By switching the phase shifter, phase modulation is performed on the reflected wave as a response signal. During the second communication, the first and second phase shifters are switched without using an attenuator, and phase modulation is performed. In the communication, the attenuator is not used, and the phase modulation is performed by switching the first and third phase shifters. The transponder switches the reflection amount and the modulation degree at the time of communication. By separating and demodulating the response signal of the transponder for which the interrogator failed to read the data according to the difference in modulation, it is possible to read the data of multiple transponders in the same area in a short time at a small size and at low cost. Work Having.

According to a fifteenth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, the phase amount of the first phase shifter is 0 degrees, the phase amount of the second phase shifter is 170 degrees, The phase amount of the third phase shifter is set to 180 degrees, and the interrogator performs a plurality of phase modulations with a large modulation degree and a small phase modulation with a transponder, thereby enabling a plurality of interrogators. By separating the response signals from the transponders at different modulation factors and enabling the response signals from each transponder to be demodulated simultaneously, the data of multiple transponders in the same area is small and inexpensive and short. It has the effect of being able to read in time.

According to a sixteenth aspect of the present invention, in the moving object identification system according to the eleventh aspect, the attenuation of the attenuator is set to 10 dB, and the transponders have different reflection amounts. By using waves as response signals,
The interrogator separates response signals from multiple transponders at different modulation factors and enables simultaneous demodulation of the response signals from each transponder, resulting in a small and inexpensive multiple response in the same area. It has the effect that the data of the container can be read in a short time.

According to a seventeenth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, the response signal of the transponder is composed of a data sequence including a solid recognition data sequence and an information data sequence, and the solid recognition data sequence. When transmitting, do not use an attenuator,
By switching the first and third phase shifters, phase modulation is performed on the reflected wave as a response signal, attenuated by an attenuator when transmitting an information data sequence, and the phase is switched by switching the first and third phase shifters. The transponder switches the modulation degree when transmitting the solid-state recognition data sequence and the reflection amount when transmitting the information data sequence, so that the solid-state recognition data sequence and the information data are transmitted from a plurality of transponders. By allowing the interrogator to separate the response signals according to the difference in the amount of reflection and demodulate them at the same time, even if the sequence is sent at the same time,
It is small and inexpensive, and has the effect that data of a plurality of transponders in the same area can be read in a short time.

According to an eighteenth aspect of the present invention, in the mobile object identification system according to the eleventh aspect, the response signal of the transponder is constituted by a data string including a solid-state recognition data string and an information data string. At the time of transmitting the solid recognition data sequence, the signal from the interrogator is attenuated by the attenuator, and the first and third phase shifters are switched to phase-modulate the reflected wave as the response signal, and the first information data sequence At the time of transmission, the signal from the interrogator is attenuated by the attenuator, and the phase is modulated by switching between the first and second phase shifters. , By switching the third phase shifter, phase-modulates the reflected wave as a response signal, and switches the first and second phase shifters without using an attenuator at the time of transmitting the second and subsequent information data strings. Phase change It is characterized in that, by switching the modulation degree during responder is the first time communication, the degree of modulation at the time of the second or subsequent communication, interrogators first
By separating and demodulating the response signal of the transponder that failed to read data in the first communication according to the difference in modulation factor,
It is small and inexpensive, and has the effect that data of a plurality of transponders in the same area can be read in a short time.

The invention described in claim 19 is the first or sixth invention.
And the mobile object identification system according to any one of (11) and (12), which recognizes the transmission stop command from the interrogator and stops transmission of the response signal from the transponder. By stopping transmission of response signals in response to a transmission stop command from the interrogator, the number of transponders with which the interrogator communicates at the same time is reduced, facilitating the separation and demodulation of response signals. Has the effect that data of a plurality of transponders in the same area can be read in a short time.

According to the twentieth aspect of the present invention,
And an interrogator having an antenna for transmitting an output signal and a receiving antenna for receiving a response signal, and a transponder for communicating with the interrogator. By separating the antenna and the receiving antenna, the interrogator separates and demodulates the response signal, and reduces the interference by the transmission signal. It has the effect of being able to read.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a block diagram of a moving object identification system according to Embodiment 1 of the present invention.
For one interrogator 102, two responders 103a, 1
03b. In FIG. 1, the interrogator-side antenna 101 and the responder-side antenna 104 are
The antenna functions as an antenna for microwave communication between the three antennas, and is composed of, for example, a single or a plurality of patch antennas.

The microwave signal generated by the signal source 105 of the interrogator 102 is modulated by the modulator 115 and then distributed by the distribution circuit 106 to the transmitting side and the receiving side.
The signal on the transmitting side is transmitted from the interrogator-side antenna 101 through the duplexer 107.

The transmitted microwave signal is transmitted to the transponder 103.
a and 103b are received by the transponder-side antenna 104 and ASK-modulated by changing the reflectance by the ASK modulator 109 according to a control signal issued from the controller 108, and transmitted to the interrogator 102 from the transponder-side antenna 104. Is done.

The ASK modulator 109 includes a reflection condition switch 113, a 0 dB absorber 112a, and a 10dB absorber 11a.
The control unit 108 performs ASK modulation by selecting and switching any two absorbers based on the random number generated by the random number generation unit 117 at each communication.

The ASK-modulated microwave transmitted from the transponders 103a and 103b is transmitted to the interrogator-side antenna 101.
, And distributed to the receiving side by the duplexer 107,
Data processing unit 111 demodulated by reception demodulation unit 110
And reads the data from the transponders 103a and 103b.

As described above, each transponder 103a, 103b
However, by modulating the amplitude of the signal from the interrogator 102 using an arbitrary absorber having a different absorption amount each time communication is performed,
The response signal from each of the transponders 103a and 103b has a different modulation factor for each communication.
The response signals from the responders 103a and 103b are separated by the difference in the modulation degree, and the response signals from the respective responders 103a and 103b can be demodulated at the same time. Even if response signals are transmitted at the same time, the interrogator 102
A mobile object identification system capable of reading the data of a and 103b in a short time can be realized.

In the above description, the absorber 112a,
112b and 112c are 0 dB, 10 dB, and 20 dB.
Although the description has been given of the example in which the configuration is made up of stages, the present invention can be similarly implemented by dividing the configuration into more stages.

In the above description, the first transponder 10
Although the description has been given of an example in which two transponders 3a and the second transponder 103b are used, the present invention can be similarly implemented even when three or more transponders exist.

The transponders 103a and 103b from which the interrogator 102 can read data by communication are
Upon receiving the transmission stop signal issued from the interrogator 102,
You may comprise so that transmission of data may be stopped.

(Embodiment 2) FIG. 2 is a block diagram showing a moving object identification system according to Embodiment 2 of the present invention.
2 is different from the first embodiment of FIG.
The point is that ASK modulation with a different modulation degree is performed according to the number of times of communication. In FIG. 2, the interrogator-side antenna 201 and the responder-side antenna 204 include an interrogator 202 and a responder 203a,
The antenna functions as an antenna for microwave communication between the antennas 203b, and is composed of, for example, a single or a plurality of patch antennas.

The microwave signal generated by the signal source 205 of the interrogator 202 is modulated by the modulator 215 and then distributed to the transmission side and the reception side by a distribution circuit. Interrogator antenna 201
Sent by The transmitted microwave signal is transmitted to the transponder 2
03a and 203b are received by the transponder-side antenna 204, and the AS
By changing the reflectivity by the K modulator 209, the AS
K-modulated, and interrogator 202
Sent to.

The ASK modulator 209 includes a reflection condition switch 213, a 0 dB absorber 212a, and a 10dB absorber 21.
2b and a 20 dB absorber 212c.
In the first communication, the ON-OFF ratio is set to 10 by switching between the 0 dB absorber 212a and the 10dB absorber 212B.
ASK modulation of dB is performed.

The ASK-modulated microwave transmitted from the transponders 203a and 203b is transmitted to the interrogator-side antenna 201.
, And distributed to the receiving side by the duplexer 207,
Data processing unit 211 demodulated by reception demodulation unit 210
And reads the data from the transponders 203a and 203b.

When the data can be read by the first communication, the transmission signal is modulated by the control signal issued from the control unit 214 of the interrogator 202, and
A data transmission stop request is transmitted to 3a and 203b. Transponders 203a and 203b that have not received the stop request
Is an AS having an ON-OFF ratio of 20 dB by switching between the 0 dB absorber 212 a and the 20 dB absorber 212 c.
The signal is K-modulated and the signal is retransmitted.

As described above, each of the transponders 203a and 203b
However, by setting the ON-OFF ratio at the time of the first communication small and increasing the ON-OFF ratio at the time of the second communication and thereafter, the interrogator 202 fails to read data in the first communication. By separating and demodulating the response signals of 203a and 203b at different modulation factors, even if a plurality of transponders 203a and 203b in the communication area transmit response signals at the same time, the interrogator 202 allows the plurality of transponders 203a and 203
A mobile object identification system capable of reading the data of 3b in a short time can be realized.

In the above description, the absorber 212 is set to 0
Although the description has been made of an example in which the configuration is made in three stages of dB, 10 dB, and 20 dB, the present invention can be similarly implemented by dividing the configuration into multiple stages.

In the above description, the first transponder 20
Although the description has been given of an example in which two transponders 3a and the second transponder 203b are used, the present invention can be similarly implemented even when three or more transponders are present.

In the above description, all the transponders 20
3a and 203b have been described as an example of a configuration in which the modulation degree is switched in the second and subsequent communications, but the transponders 203a and 203b
A configuration in which the modulation factor is switched at a different number of times of communication depending on b can be similarly implemented.

(Embodiment 3) FIG. 3 is a block diagram of a moving object identification system according to Embodiment 3 of the present invention.
3 is different from the first embodiment in FIG.
The point is that PSK modulation using phase shifters having different phase amounts is performed. In FIG. 3, the microwave signal generated by the signal source 305 of the interrogator 302 is distributed to the transmitting side and the receiving side by the distribution circuit 306.
07 and transmitted from the interrogator-side antenna 301.

The transmitted microwave signal is transmitted to the transponder 303.
The PSK modulation is performed by changing the phase by the PSK modulation unit 309 according to the control signal transmitted from the control unit 308 and transmitted to the interrogator 302 from the transponder antenna 304.

The PSK modulator 309 includes a reflection condition switch 313, a 0-degree phase shifter 312a, and a 170-degree phase shifter 312.
b, a 180-degree phase shifter 312c and a 0-degree phase shifter 312a and a 170-degree phase shifter 312b during the first communication.
To perform PSK modulation.

The PSK-modulated microwave transmitted from the transponders 303a and 303b is transmitted to the interrogator-side antenna 301.
, And distributed to the receiving side by the duplexer 307,
Data processing unit 311 demodulated by reception demodulation unit 310
And reads the data from the transponders 303a and 303b.

When the data can be read by the first communication, the transmission signal is modulated by the control signal issued from the control unit 314 of the interrogator 302, and the transponder 30 responds.
A data transmission stop request is transmitted to 3a and 303b. Transponders 303a and 303b that have not received the suspension request
Performs PSK modulation by switching between the 0-degree phase shifter 312a and the 180-degree phase shifter 312c, and performs signal retransmission.

As described above, each responder 303a, 303b
However, by changing the modulation degree of the response signal between the second communication and the second and subsequent communication, the interrogator 302 fails to read data in the first communication,
By separating and demodulating the response signal of 303b according to the difference in modulation degree, a plurality of transponders 303a,
Even if 03b simultaneously sends a response signal, it is possible to realize a mobile object identification system in which the interrogator 302 can read the data of the multiple responders 303a and 303b in a short time.

In the above description, the phase shifter 312 is set to 0
Although the description has been given of an example in which the configuration is made up of three stages of degrees, 170 degrees, and 180 degrees, the present invention can be similarly implemented by dividing the configuration into more stages.

In the above description, the first transponder 30
Although the description has been given of an example in which two transponders 3a and the second transponder 303b are used, the present invention can be similarly implemented even when three or more transponders exist.

In the above description, an example is described in which PSK modulation is implemented by combining the 0-degree phase shifter 312a and the 170-degree phase shifter 312b or the 0-degree phase shifter 312a and the 180-degree phase shifter 312c. However, a configuration in which the 0-degree phase shifter 312a is combined as a 10-degree phase shifter and a 20-degree phase shifter can be similarly implemented.

In the above description, an example using PSK modulation has been described. However, a 0 degree phase shifter, an 80 degree phase shifter, a 90 degree phase shifter, a 170 degree phase shifter, and a 180 degree phase shifter are used. , 260-degree phase shifter, and 270-degree phase shifter.

In the above description, the modulation degree of the response signal is changed between the first communication and the second and subsequent communication. However, several times, for example, the third and fourth and subsequent communication are performed. May be configured to change the degree of modulation of the answer signal during the communication.

In the above description, the modulation degree of the response signal is changed at the time of the first communication and at the time of the second and subsequent communication. However, the modulation degree is appropriately changed at the time of the communication. May be.

(Embodiment 4) FIG. 4 is a block diagram showing a moving object identification system according to Embodiment 4 of the present invention.
4 is different from the first embodiment in FIG.
The point is that PSK modulation in which a phase shifter and an attenuator having different phase amounts are combined is performed. In FIG. 4, the signal source 4 of the interrogator 402
05 generated by the distribution circuit 406
, And the signal on the transmission side is transmitted from the interrogator-side antenna 401 through the duplexer 407.

The transmitted microwave signal is transmitted to the transponder 403.
The PSK modulation section 409 changes the phase according to the control signal emitted from the control section 408 and is subjected to PSK modulation, and is transmitted from the transponder side antenna 404 to the interrogator 402.

The PSK modulator 409 includes a reflection condition switch 413, an attenuator 417, and 0-degree phase shifters 412a and 180.
A signal attenuated by the attenuator 417 during the first communication is a 0-degree phase shifter 412b.
The PSK modulation is performed by switching the phase shifter 412b with the phase shifter 412b.

The attenuator 417 has an attenuation of, for example, 10 dB. The PSK-modulated microwave transmitted from the transponders 403a and 403b is transmitted to the interrogator-side antenna 401.
, And distributed to the receiving side by the duplexer 407,
Data processing unit 411 demodulated by reception demodulation unit 410
And reads the data from the transponders 403a and 403b.

When the data can be read by the first communication, the transmission signal is modulated by the control signal issued from the control unit 414 of the interrogator 402, and
A data transmission stop request is transmitted to 3a and 403b. Transponders 403a and 403b that did not receive the stop request
Performs PSK modulation on a signal that is not attenuated by the attenuator 417 by switching between the 0-degree phase shifter 412a and the 180-degree phase shifter 412b, and retransmits the signal.

As described above, each of the transponders 403a and 403b
The interrogator 402 changes the degree of modulation and the amount of reflection of the response signal of the first communication and the second and subsequent communication.
Separates and demodulates the response signals of the transponders 403a and 403b that failed to read data in the first communication by the difference in the modulation factor and the amount of reflection, so that the plurality of transponders 403a and 403b in the communication area can simultaneously Even if the response signal is transmitted, a mobile object identification system can be realized in which the interrogator 402 can read the data of the multiple responders 403a and 403b in a short time.

In the above description, the example in which the attenuation of the attenuator 417 is 10 dB has been described.
The present invention can be similarly implemented by using an attenuator having another attenuation amount such as 5 dB.

In the above description, the first transponder 40
Although the description has been given of the example in which two transponders 3a and the second transponder 403b are used, the present invention can be similarly implemented even when three or more transponders exist.

In the above description, the attenuator 417 is set to 1
Although the description has been made of the example in which the number of attenuators is one, a configuration in which a plurality of attenuators, for example, 5 dB, 10 dB, and 15 dB are used, and switching is performed can be similarly implemented.

In the above description, an example using PSK modulation has been described. However, a 0-degree phase shifter, a 90-degree phase shifter,
The present invention can be similarly implemented by using QPSK modulation using a degree phase shifter and a 270 degree phase shifter.

In the above description, the 0-degree phase shifter 412
a, the example using the 180-degree phase shifter 412b has been described.
The present invention can be similarly implemented by using another phase shifter, for example, a 170-degree phase shifter to switch the phase shift change amount together with the attenuation amount.

(Embodiment 5) FIG. 5 shows a communication system of a mobile object identification system according to Embodiment 5 of the present invention. The data string is composed of a solid recognition data string and an information data string. The difference from the first embodiment is that ASK modulation with a different modulation factor is performed according to communication data.

The transponder 5 which has sequentially entered the communication area
01a, 501b, 501c and 501d are interrogators 510
The transmitted microwave signal is converted into a solid-state recognition data sequence 5
A response signal is returned by reflecting at a modulation factor of 20 dB in the ON-OFF ratio at the time of transmission 02, and at a modulation factor of 10 dB at the time of transmission of the information data sequence 503. Solid recognition data string 502
Is smaller than the information data sequence 503. For example, the solid recognition data sequence 502 is 4 bytes, and the information data sequence 503 is 128 bytes. The information data sequence 503a and the solid recognition data sequence 502b are transmitted to the interrogator 510 at the same time.
b is separated and demodulated, and the data of the transponder 501b is read.

Thereafter, a transmission stop command 504 is transmitted to the transponder 501b to stop the transmission of the response signal. Similarly, the information data string 503c and the solid recognition data string 50
5a, information data string 506c and solid recognition data string 502
Although d is transmitted at the same time, the interrogator 510 separates and demodulates only the solid-state recognition data strings 505a and 502d having a large modulation factor, and reads the data of the responders 501a and 501d. Interrogator 510 receives received solid recognition data sequence 50
2 and 505, and the responder 501 that has not read the information data strings 503 and 506 (the responder 501 in FIG. 5).
Continue reading as long as c) is present.

As described above, each transponder 501a, 501
b, 501c, and 501d have the small data amount and the communication time of the solid-state recognition data string having a short communication time.
By changing the modulation factor of the response signal at the time of communication of the information data sequence having a long communication time, the interrogator 510 can change the plurality of transponders 501.
Since the solid-state recognition data strings a, 501b, 501c, and 501d can be separated and recognized based on the difference in modulation degree and the transponders in the area can be managed, a plurality of transponders 501a, 501b, 501c, and Even if 501d simultaneously sends response signals, the interrogator 510 sets the multiple responders 501
A mobile object identification system capable of reading the data of a, 501b, 501c, and 501d in a short time without any remaining reading can be realized.

In the above description, the responders 501a to 501a
Although the description has been made of the example in which the transponder 501d includes four transponders, the present invention can be similarly implemented even when there are five or more transponders.

In the above description, the responders 501a,
Although the description has been given of the example of the configuration in which the 501b, 501c, and 501d perform ASK modulation, the PSs using the phase shifters having different modulation degrees are used.
Even if it is configured to perform K modulation, it can be similarly implemented.

In the above description, an example of a configuration in which only a response signal with a high modulation factor is demodulated has been described. However, a configuration in which a response signal with a low modulation factor is also separated and demodulated can be similarly implemented. It is.

In the above description, the responders 501a, 501b, 501c, 501 for which data reading has been completed.
d, the transmission stop command is transmitted to the transponders 501a, 501b, 501c, and 501d that have not completed data reading.
The present invention can be similarly implemented by transmitting a retransmission command for retransmitting data at a specific timing.

[0082]

As described above, according to the present invention, there is obtained an advantageous effect that a compact and inexpensive mobile object identification system capable of reading a plurality of transponders in the same area can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a moving object identification system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a moving object identification system according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a moving object identification system according to a third embodiment of the present invention;

FIG. 4 is a block diagram showing a moving object identification system according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a communication system of a mobile object identification system according to a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a communication method of a conventional contactless IC card system.

[Explanation of symbols]

101, 201, 301, 401, 501 Interrogator antenna 102, 202, 302, 402, 510 Interrogator 103, 203, 303, 403 Transponder 104, 204, 304, 404 Transponder antenna 105, 205, 305, 405 signal source 106, 206, 306, 406 distribution circuit 107, 207, 307, 407 duplexer 108, 208, 308, 408 control unit 109, 209 ASK modulation unit 110, 210, 310, 410 reception demodulation unit 111, 211 , 311, 411 Data processing unit 112, 212 Absorber 113, 213, 313, 413 Switch 114, 214, 314, 414 Control unit 115, 215, 315, 415 Modulation unit 116, 416 Demodulation unit 117 Random number generation unit 309, 409 PSK modulator 312, 412 shift Phaser 417 Attenuator 502 Solid recognition data sequence 503 Information data sequence 504 Transmission stop instruction 505 Solid recognition data sequence 506 Information data sequence 507 Transmission stop instruction 508 Transmission stop instruction

Claims (20)

[Claims] 1. A signal source for generating an output signal, a modulator for modulating an output signal from the signal source, an antenna for transmitting an output signal modulated by the modulator, and a response signal received by the antenna. A demultiplexer for demultiplexing the reflected wave from the output signal, a demodulation unit for demodulating the response signal, a data processing unit for processing a signal from the demodulation unit, and control for controlling an interrogator based on data of the processing unit An interrogator having a unit, a transponder antenna for receiving a signal transmitted from the interrogator and transmitting a response signal to an antenna of the interrogator, a demodulation unit for demodulating a received signal, and data of the demodulation unit And a first, second, and third absorber having different absorption amounts from the switching unit, and amplitude-modulate a signal from the interrogator into a reflected wave as a response signal. Modulation section A mobile object identification system comprising a transponder having: 2. The apparatus according to claim 1, wherein the modulator of the transponder performs amplitude modulation of a signal from the interrogator into a reflected wave as a response signal by switching any two absorbers during communication. Mobile object identification system. 3. A signal from the interrogator is amplitude-modulated into a reflected wave as a response signal by switching between the first and second absorbers at the time of the first communication. 2. The moving object identification system according to claim 1, wherein the amplitude is modulated by switching the first and third absorbers. 4. The absorption amount of the first absorber is 0 dB, the absorption amount of the second absorber is 10 dB, and the absorption amount of the third absorber is 2 dB.
The mobile object identification system according to claim 1, wherein the mobile object identification system is set to 0 dB. 5. A response signal of the transponder is composed of a data string including a solid-state recognition data string and an information data string. When the solid-state recognition data string is transmitted, the first and third absorbers are switched to transmit a response signal from the interrogator. 2. The moving object identification system according to claim 1, wherein the signal is amplitude-modulated to a reflected wave as a response signal, and the amplitude modulation is performed by switching the first and second absorbers when transmitting the information data sequence. 6. A signal source for generating an output signal, a modulator for modulating an output signal from the signal source, an antenna for transmitting an output signal modulated by the modulator, and a response signal received by the antenna. A demultiplexer for demultiplexing the reflected wave from the output signal, a demodulation unit for demodulating the response signal, a data processing unit for processing a signal from the demodulation unit, and control for controlling an interrogator based on data of the processing unit An interrogator having a unit, a transponder antenna for receiving a signal transmitted from the interrogator and transmitting a response signal to an antenna of the interrogator, a demodulation unit for demodulating a received signal, and data of the demodulation unit And a first, second, and third phase shifters having different phase amounts from the switcher, and phase-modulate a signal from the interrogator into a reflected wave as a response signal. Modulation section A mobile object identification system comprising a transponder having: 7. The mobile object identification system according to claim 6, wherein a signal from the interrogator is phase-modulated into a reflected wave as a response signal by switching any two phase shifters during communication. 8. During the first communication, the signal from the interrogator is phase-modulated into a reflected wave as a response signal by switching the first and second phase shifters. The mobile object identification system according to claim 6, wherein phase modulation is performed by switching the first and third phase shifters. 9. The phase amount of the first phase shifter is 0 degrees, the phase amount of the second phase shifter is 170 degrees, and the phase amount of the third phase shifter is 18 degrees.
The moving object identification system according to claim 6, wherein the angle is set to 0 degree. 10. A response signal of the transponder is composed of a data string including a solid-state recognition data string and an information data string. When the solid-state recognition data string is transmitted, by switching between the first and third phase shifters, the interrogator receives the response signal from the interrogator. 7. The mobile object identification system according to claim 6, wherein said signal is phase-modulated into a reflected wave as a response signal, and at the time of transmitting the information data sequence, the phase is modulated by switching between the first and second phase shifters. . 11. A signal source for generating an output signal, a modulator for modulating an output signal from the signal source, an antenna for transmitting an output signal modulated by the modulator, and a response signal received by the antenna. A demultiplexer for demultiplexing the reflected wave from the output signal, a demodulation unit for demodulating the response signal, a data processing unit for processing a signal from the demodulation unit, and control for controlling an interrogator based on data of the processing unit An interrogator having a unit, a transponder antenna for receiving a signal transmitted from the interrogator and transmitting a response signal to an antenna of the interrogator, a demodulation unit for demodulating a received signal, and data of the demodulation unit A control unit for controlling a transponder based on the signal, a switcher, an attenuator, and first, second, and third phase shifters having different phase amounts, and a reflected wave as a response signal using a signal from the interrogator as a response signal Phase modulation A moving object identification system comprising a transponder having a modulating unit. 12. The moving object identification system according to claim 11, wherein a signal from the interrogator is phase-modulated to a reflected wave as a response signal by switching any two phase shifters during communication. 13. During communication, an arbitrary attenuator is used, and an arbitrary two phase shifters are switched.
The mobile object identification system according to claim 11, wherein a signal from the interrogator is phase-modulated to a reflected wave as a response signal. 14. During the first communication, the signal from the interrogator is attenuated by the attenuator, and the first and second phase shifters are switched to phase-modulate the reflected wave as a response signal. In the second communication, no attenuator is used.
The phase modulation is performed by switching the phase shifter, and the phase modulation is performed by switching the first and third phase shifters without using the attenuator at the time of the third communication. Mobile object identification system. 15. The phase amount of the first phase shifter is 0 degree, the phase amount of the second phase shifter is 170 degrees, and the phase amount of the third phase shifter is 1 degree.
The moving object identification system according to claim 11, wherein the angle is set to 80 degrees. 16. The moving object identification system according to claim 11, wherein the attenuation of the attenuator is set to 10 dB. 17. A response signal of the transponder is composed of a data string including a solid-state recognition data string and an information data string, and switches between the first and third phase shifters without using an attenuator when transmitting the solid-state recognition data string. 12. The method according to claim 11, wherein phase modulation is performed on a reflected wave as a response signal, attenuated by an attenuator when transmitting an information data sequence, and phase modulation is performed by switching between a first and a third phase shifter. Mobile object identification system. 18. A response signal of the transponder is composed of a data string including a solid-state recognition data string and an information data string. At the first transmission of the solid-state recognition data string, a signal from the interrogator is attenuated by an attenuator. By switching the first and third phase shifters, phase modulation is performed on a reflected wave as a response signal, and a signal from the interrogator is attenuated by the attenuator at the time of the first transmission of the information data sequence. The phase modulation is performed by switching the phase shifter, and the first and third phase shifters are switched without using the attenuator at the time of transmitting the solid-state recognition data sequence from the second time onward. Phase modulated,
12. The mobile object identification system according to claim 11, wherein a phase modulation is performed by switching between the first and second phase shifters without using an attenuator at the time of transmitting the information data sequence from the second time. 19. Recognizing a transmission stop command from the interrogator,
The mobile object identification system according to any one of claims 1, 6 and 11, wherein the transmission of a response signal from the transponder is stopped. 20. An interrogator having an antenna for transmitting an output signal and a receiving antenna for receiving a response signal, and a transponder for communicating with the interrogator. The mobile object identification system according to any one of the above.