JP2982486B2 - ID card communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ID card communication system for communicating between a portable small ID card in which personal information and the like are written and a control device thereof by radio waves.

[0002]

2. Description of the Prior Art In a conventional portable ID card communication system, as shown in FIG.
1 is output to the modulator 102, and the local signal 108 of the local oscillator 108 is modulated. Modulator output 2
Is amplified by the transmission amplifier 103, and the antenna duplexer 10
4 from the antenna 105. On the other hand, ID
The received signal 5A from the card is amplified by the receiving amplifier 106 via the antenna 105 and the antenna duplexer 104, demodulated by the demodulator 107, and transmitted to the signal processing circuit 101. The ID card main body 200 receives the transmission signal 4A from the control device 100 by the receiving antenna 201, demodulates it by the demodulator 202, and sends out the control signal 11A to the signal processing circuit 205. In response, the signal processing circuit 205 sends the transmission signal 14A to the modulator 204, modulates the local oscillation signal 15A of the local oscillator 208, and sends the modulated signal to the control device 100 via the transmission antenna 206. Accordingly, the signal from the control device 100 is the frequency f1 of the local oscillation signal 108.
The transmission signal 5A from the ID card is a continuous signal having a frequency f2 of the local oscillation signal 15A and is transmitted at a different frequency to avoid interference between transmission and reception.

[0003]

In this conventional ID card communication system, the transmitting section of the ID card main body has a local oscillator 20.
8 is required, and because of its frequency stability, it is always energized to stabilize it. Therefore, considering the point of power consumption and application in the millimeter wave band, the configuration is complicated and the price is high. There were drawbacks such as becoming.

[0004]

SUMMARY OF THE INVENTION An ID card communication system according to the present invention comprises a control device for transmitting and receiving a carrier signal output as a radio wave , the control device, and a transmission using the carrier signal.
In an ID card communication including an ID card main body that performs reception, the control device generates one carrier signal and generates a carrier signal.
The carrier signal is divided into a first time slot section and a second time section.
The first time is divided into slots and arranged alternately.
Modulating a control signal of the control device in a slot section,
1st signal to be transmitted unmodulated in time slot section 2
The processing means and the ID card body generate the carrier signal by themselves.
And the second time
A second signal modulated as its own response signal in the lot section
Processing means.

[0005]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a first embodiment of the present invention. In the present invention, the received signal 4 is supplied as the local oscillation signal 13 of the modulator 204 by the control signal 14 from the signal processing circuit 205 instead of the local oscillator 208 in FIG. In the present invention, the transmission signal 4 of the control device 100 is controlled so that the control signal 1 is controlled in the section a and not controlled in the section b as shown in FIG. Is the unmodulated signal portion.

According to the present invention, the ID card main body 200 demodulates the received wave 4 by the demodulator 202 and outputs the signal processing circuit 205
Analyzes the control signal therein and sends a response signal 14 to the control device to the modulator 204. On the other hand, the received wave is supplied as it is to the modulator 204 as a carrier. At this time, the response signal 14 is output so that the modulation is just applied to the section b of the unmodulated signal portion of the received wave. As a result, the modulation output 5 is shown in FIG.
As shown in (1), the unmodulated signal portion of the received wave is modulated, and the control device 100 demodulates that portion to enable communication.

Here, the transmission signal from control device 100 and I
Since the received signal from the D card has the same frequency,
The transmission signal leaks into the reception by an amount corresponding to the isolation between the transmission and reception of the antenna shared circuit 104 in the control device 100. However, the portion of the received wave from the ID card body 200 overlaps with the unmodulated signal portion, and is actually the carrier of the transmitted wave. Therefore, the receiving demodulator 107 is multiplied with the carrier by a normal detector and demodulated. Will be realized. In addition, isolation between transmission and reception on the ID card body 200 side also poses a problem. However, if a sufficient power difference is provided between transmission and reception, the influence can be eliminated.

Next, a second embodiment of the present invention will be described with reference to FIG. This second embodiment is different from the conventional example shown in FIG. 5 in that a switch circuit for supplying and controlling a received signal 4 as a local oscillation signal 13 of a modulator 204 by a control signal 12 from a signal processing circuit 205 instead of a local oscillator 208. 208 are provided. In the second embodiment, the transmission signal 4 of the control device 100 is controlled so that the control signal 1 is controlled in the section a and not controlled in the section b as shown in FIG. In a, the modulated signal portion is used, and in section b, an unmodulated signal portion is used.

According to the present invention, the ID card body demodulates the received wave 4 by the demodulator 202, and the signal processing circuit 205 analyzes the control signal in the demodulated wave and determines the response within a non-modulated signal section in response to a response. And outputs the control signal 12 of the switch circuit 203 at random for a given period of time.
A response signal 14 to 00 is sent to the modulator 204. The output 13 of the switch circuit 203 supplies a carrier to the modulator 204 in such a manner that random access is performed for a certain time in the non-modulation part of the received wave. As a result, the modulated wave signal output 5 is shown in FIG.
As shown in (b), the control device 1 becomes an intermittent modulated wave.
At 00, the signal is demodulated, and signals from the individual ID card bodies are sent to the signal processing circuit 101. Regarding collision from a plurality of ID cards, retransmission is performed by a conventional random access technique.

Here, the transmission signal from control device 100 and I
Since the received signal from the D card body has the same frequency,
The transmission signal leaks into the reception for the isolation between the transmission and reception of the antenna shared circuit 104 in the control device. However, the portion of the received wave from the ID card overlaps with the unmodulated wave, and is actually the carrier of the transmitted wave, so that the receiving demodulator is multiplied with the carrier by a normal detector to realize demodulation. Will be. In addition, isolation between transmission and reception on the ID card side also poses a problem. However, if a sufficient power difference is provided between transmission and reception, the influence can be eliminated.

[0011]

As described above, according to the present invention, the local oscillation circuit of the ID card main body can be eliminated, so that the circuit configuration is simplified and communication at the same frequency of transmission and reception is possible. Therefore, the power consumption can be reduced, the size can be reduced, and by allocating the time slot of the non-modulation signal section to a plurality of ID cards, communication with many ID cards is possible and the frequency can be effectively used. effective.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of the first embodiment.

FIG. 3 is a configuration diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a second embodiment.

FIG. 5 is a configuration diagram of a conventional ID card communication system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Control device 101, 205 Signal processing circuit 102, 204 Modulator 103 Transmission amplifier 104 Antenna duplexer 105, 201, 206 Antenna 106 Receiving amplifier 107, 202 Demodulator 108 Local oscillator 203 Switch circuit 204 Modulator 205 Signal processing circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04Q 7/00-7/38 H04B 7/26

Claims (2)

(57) [Claims] To claim 1, wherein the carrier signal control device and the control device for transmitting and receiving a carrier signal which is output as a radio wave
In an ID card communication including an ID card main body that performs transmission and reception according to the control method , the control device generates one carrier wave signal.
The carrier signal is divided into a first time slot section and a second time slot section.
The first slot is arranged alternately in the time slot section.
Modulating the control signal of the control device during a time slot interval;
A first time slot for transmitting the second time slot section without any modulation;
Signal processing means and the ID card body is the carrier signal
Is used as its own transmission signal, and the second
The second that modulates as its own response signal in the time slot section
ID card communication system, characterized by a signal processing means. 2. The second time slot wherein the ID card main body is an unmodulated signal portion of a wave received from the control device.
2. The ID card communication system according to claim 1, wherein a predetermined period of time is randomly selected from the packets and used as a carrier of the ID card body.