JP2016220088A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system that can make it difficult to demodulate an authentication code transmitted from a mobile device to an on-vehicle unit and can improve an anticrime effect.SOLUTION: A radio communication system comprises: a mobile device 1 that can be carried around by a driver, modulate a specific authentication code, and transmit the modulated signal by radio; and an on-vehicle unit 2 that is mounted on a vehicle, receives the signal transmitted by the mobile device 1 by radio, and can demodulate the signal to obtain the authentication code. Only if the authentication code obtained by the on-vehicle unit 2 is a normal authentication code, the door lock of the vehicle or the start-up of the driving source of the vehicle can be permitted. The mobile device 1 can modulate the authentication code by a plurality of modulation schemes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless communication system capable of releasing a door lock of a vehicle or permitting start of a drive source of a vehicle only when an authentication code acquired by an in-vehicle unit is a regular authentication code.

  A portable device that can be carried by the driver and that can transmit a unique authentication code by radio wave, and an in-vehicle unit that can receive the transmitted authentication code. Wireless communication systems (so-called passive keyless entry devices) that can release the door lock of a vehicle or permit the start of a drive source of the vehicle only when the authentication code is used are widespread. As a conventional wireless communication system, the authentication code transmitted from the portable device is AM-modulated or FM-modulated, the signal is wirelessly transmitted, and the signal from the portable device is received and demodulated by the in-vehicle unit. The one that gets In addition, since this prior art is not related to the literature known invention, there is no prior art document information to be described.

  However, in the above-described conventional wireless communication system, it is impossible to take effective measures against a so-called relay attack action in which a third party illegally performs communication between the portable device and the in-vehicle unit with a repeater. There was a problem. In other words, in the communication between the portable device and the in-vehicle unit, a third party can easily demodulate the modulated signal, so that the legitimate authentication code from the portable device to the in-vehicle unit illegally using a repeater etc. The door lock can be released and the engine can be started.

  The present invention has been made in view of such circumstances, and provides a wireless communication system capable of making it difficult to demodulate an authentication code transmitted from a portable device to an in-vehicle unit and improving a crime prevention effect. There is to do.

  The invention according to claim 1 is a portable device that can be carried by a driver, modulates a unique authentication code, and can wirelessly transmit the modulated signal, and is mounted on a vehicle and wirelessly transmitted from the portable device. An in-vehicle unit capable of acquiring the authentication code by demodulating the signal, and only when the authentication code acquired by the in-vehicle unit is a regular authentication code. In the wireless communication system capable of releasing the door lock or permitting the start of the driving source of the vehicle, the portable device may modulate the authentication code by a plurality of modulation methods.

  According to a second aspect of the present invention, in the wireless communication system according to the first aspect, the portable device modulates the authentication code simultaneously with a plurality of modulation schemes or alternately modulates with a plurality of modulation schemes. .

  According to a third aspect of the present invention, in the wireless communication system according to the first or second aspect, the portable device modulates the authentication code by at least two modulation methods among AM, FM, and PM. To do.

  According to a fourth aspect of the present invention, in the wireless communication system according to any one of the first to third aspects, a predetermined signal is wirelessly transmitted from the in-vehicle unit when a predetermined operation is performed on the vehicle. The portable device is capable of wirelessly transmitting to the in-vehicle unit while modulating the authentication code on condition that the predetermined signal is received, and modulates the predetermined signal transmitted from the in-vehicle unit by a plurality of modulation methods. It is possible to do.

  According to the invention of claim 1, since the portable device can modulate the authentication code by a plurality of modulation methods, it is possible to make it difficult to demodulate the authentication code transmitted from the portable device to the vehicle-mounted unit. Can be improved.

  According to the invention of claim 2, since the portable device modulates the authentication code simultaneously with a plurality of modulation methods or alternately modulates with a plurality of modulation methods, the portable device demodulates the authentication code transmitted from the portable device to the in-vehicle unit. It can be made more difficult, and the crime prevention effect can be further improved.

  According to the invention of claim 3, since the portable device modulates the authentication code by at least two modulation methods among AM, FM, and PM, the authentication code transmitted from the portable device to the in-vehicle unit more easily and easily. Demodulation can be made difficult, and the crime prevention effect can be improved.

  According to the invention of claim 4, a predetermined signal is wirelessly transmitted from the in-vehicle unit by performing a predetermined operation on the vehicle, and the portable device modulates the authentication code on condition that the predetermined signal is received. However, since the predetermined signal transmitted from the in-vehicle unit can be modulated by a plurality of modulation methods, in addition to the signal transmitted from the portable device to the in-vehicle unit, The demodulation of the predetermined signal transmitted to the machine can be made difficult, and the crime prevention effect can be further improved.

1 is a block diagram showing a wireless communication system according to an embodiment of the present invention. Schematic diagram showing an FM modulated signal in the same wireless communication system Schematic diagram showing an AM carrier that carries an FM modulated signal in the same wireless communication system The schematic diagram which shows the transmission signal which was simultaneously modulated by FM modulation system and AM modulation system in the same radio | wireless communications system The schematic diagram which shows the transmission signal which was modulated by the FM modulation system and AM modulation system alternately in the radio | wireless communications system which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
As shown in FIG. 1, the wireless communication system according to this embodiment performs communication between a portable device 1 (electronic key) carried by a driver and an in-vehicle unit 2 mounted on a vehicle such as an automobile, Only when the authentication code acquired by the in-vehicle unit 2 is a regular authentication code, it is composed of a so-called passive keyless entry device that can release the door lock of the vehicle or permit the start of the drive source of the vehicle.

  The portable device 1 can be carried by the driver, modulates a unique authentication code, and wirelessly transmits the modulated signal. The authentication code generation unit 4 and the modulation / demodulation unit 5 are formed. The control unit 3 and the transmission / reception means 6 are provided. The authentication code generation means 4 can generate or hold a unique authentication code (such as a unique ID code corresponding to the vehicle), and is configured to be able to modulate the authentication code by the modulation / demodulation means 5. .

  The modulation / demodulation unit 5 can modulate the unique authentication code generated or held by the authentication code generation unit 4 or demodulate a predetermined signal received by the transmission / reception unit 6. Each means 6 is electrically connected. The modulation / demodulation means 5 according to this embodiment includes an analog modulation unit that can perform analog modulation (AM, FM, PM, etc.) and a digital modulation unit that can perform digital modulation (PSK, FSK, ASK, etc.). Configured.

  The transmission / reception means 6 is composed of an antenna of the portable device 1 and can wirelessly transmit the signal modulated by the modulation / demodulation means 5 from the in-vehicle unit 2 and can receive a radio signal from the in-vehicle unit 2. It is. The transmission / reception means 6 can transmit and receive high frequency (RF) and low frequency (LF). In this embodiment, the signal from the portable device 1 to the in-vehicle unit 2 is from the high frequency (RF) and from the in-vehicle unit 2. The signal for the portable device 1 is set to be low frequency (LF).

  On the other hand, the in-vehicle unit 2 is mounted on a vehicle (a vehicle body in the present embodiment), receives a signal wirelessly transmitted from the portable device 1, and demodulates the signal to obtain an authentication code. The control unit 7 in which the authentication code acquisition unit 8, the determination unit 9, and the modulation / demodulation unit 10 are formed, and the transmission / reception unit 11 are configured. The transmission / reception means 11 is composed of an antenna of the in-vehicle unit 2 and is electrically connected to the modulation / demodulation means 10, similarly to the transmission / reception means 6 of the portable device 1.

  The modulation / demodulation means 10 can demodulate a signal received by the transmission / reception means 11 or modulate a predetermined signal to be transmitted from the in-vehicle unit 2 to the portable device 1, similar to the modulation / demodulation means 5 of the portable device 1. Yes, it is electrically connected to the authentication code acquisition means 8. The authentication code acquisition means 8 can acquire a unique authentication code based on the signal from the portable device 1 demodulated by the modulation / demodulation means 10 and is electrically connected to the determination means 9.

  The determination means 9 can determine whether or not the authentication code acquired by the authentication code acquisition means 8 (that is, the authentication code wirelessly transmitted from the portable device 1) is a regular authentication code. Only when it is determined to be the code, the vehicle door lock can be released or the start of the vehicle drive source (engine or the like) can be permitted. Therefore, when the driver carrying the regular portable device 1 approaches the vehicle, the door lock of the vehicle is released and the door can be opened and closed, and the starting operation of the drive source such as the engine can be performed. is there.

  Specifically, a predetermined signal (LF signal) is wirelessly transmitted from the transmission / reception means 11 of the in-vehicle unit 2 by performing a predetermined operation (for example, unlocking the door) on the vehicle, and the portable device 1 On the condition that the predetermined signal is received by the transmission / reception means 6, the authentication code of the authentication code generation means 4 is modulated and can be wirelessly transmitted to the in-vehicle unit 2 as an RF signal. The vehicle door lock can be released or the drive source of the vehicle can be permitted to start only when the authentication code is a proper authentication code.

  Here, the portable device 1 according to the present embodiment is configured so that the authentication code can be modulated by the modulation / demodulation means 5 by a plurality of modulation schemes, and AM (amplitude modulation), FM (frequency modulation), and PM. The authentication code is modulated by at least two modulation methods in (phase modulation). For example, the FM modulation signal (see FIG. 2) obtained by FM-modulating the authentication code is modulated by the AM carrier wave (FIG. 3) (that is, the authentication code is simultaneously modulated by a plurality of FM and AM modulation schemes). Since the transmission signal as shown in FIG. 4 can be obtained, the transmission signal is wirelessly transmitted to the in-vehicle unit 2 as an RF signal.

  Further, as shown in FIG. 5, the authentication code is alternately modulated by a plurality of FM and AM modulation schemes (alternately temporally modulated) as shown in FIG. And those that alternately modulate with a predetermined signal as a trigger). In this embodiment, AM and FM modulation schemes are used, but PM modulation schemes (such as PM instead of either AM or FM, or those in which PM is added to AM and FM, etc.) Included).

  According to this embodiment, since the portable device 1 can modulate the authentication code by a plurality of modulation schemes, it is possible to make it difficult to demodulate the authentication code transmitted from the portable device 1 to the in-vehicle unit 2, and to prevent crimes. Can be improved. In particular, since the portable device 1 according to the present embodiment simultaneously modulates the authentication code using a plurality of modulation methods or alternately modulates the authentication code using a plurality of modulation methods, demodulation of the authentication code transmitted from the portable device 1 to the in-vehicle unit 2 is performed. Can be made more difficult, and the crime prevention effect can be further improved. Further, since the portable device 1 according to the present embodiment modulates the authentication code by at least two modulation methods among AM, FM, and PM, authentication transmitted from the portable device 1 to the in-vehicle unit 2 is simpler and easier. The demodulation of the code can be made difficult, and the crime prevention effect can be improved.

  However, in this embodiment, a predetermined signal is wirelessly transmitted from the in-vehicle unit 2 by performing a predetermined operation on the vehicle, and the portable device 1 receives an authentication code on condition that the predetermined signal is received. It can be wirelessly transmitted to the in-vehicle unit 2 while being modulated, and the predetermined signal transmitted from the in-vehicle unit 2 may be modulated by a plurality of modulation methods as described above. In this case, in addition to the signal transmitted from the portable device 1 to the in-vehicle unit 2, it is also difficult to demodulate the predetermined signal transmitted from the in-vehicle unit 2 to the portable device 1, and the crime prevention effect can be further improved. it can.

  Although the present embodiment has been described above, the present invention is not limited to this, and other modulation schemes may be used instead of AM, FM, PM, for example. In the present embodiment, the determination unit 9 is provided in the in-vehicle unit 2 to determine whether or not the authentication code acquired by the in-vehicle unit 2 is a regular authentication code. The determination means may be formed in the part (for example, ECU or the like) to be determined. In addition, in this embodiment, although applied to the motor vehicle, you may make it apply to other vehicles, such as a two-wheeled vehicle.

  As long as the portable device is a wireless communication system that can modulate the authentication code by a plurality of modulation methods, the portable device may be one having a different external shape or one having other functions added.

DESCRIPTION OF SYMBOLS 1 Portable device 2 In-vehicle unit 3 Control part 4 Authentication code production | generation means 5 Modulation / demodulation means 6 Transmission / reception means 7 Control part 8 Authentication code acquisition means 9 Determination means 10 Modulation / demodulation means 11 Transmission / reception means

Claims (4)

A portable device that can be carried by the driver, modulates a unique authentication code, and wirelessly transmits the modulated signal;
A vehicle-mounted unit that is mounted on a vehicle and receives a signal wirelessly transmitted from the portable device, and that can demodulate the signal to obtain the authentication code;
In a wireless communication system that can release the door lock of the vehicle or permit the start of the drive source of the vehicle only when the authentication code acquired by the in-vehicle unit is a regular authentication code,
The wireless communication system, wherein the portable device can modulate the authentication code by a plurality of modulation schemes.   The wireless communication system according to claim 1, wherein the portable device modulates the authentication code simultaneously with a plurality of modulation schemes or alternately modulates with a plurality of modulation schemes.   The wireless communication system according to claim 1 or 2, wherein the portable device modulates the authentication code by at least two modulation methods among AM, FM, and PM.   When a predetermined operation is performed on the vehicle, a predetermined signal is wirelessly transmitted from the in-vehicle unit, and the portable device transmits to the in-vehicle unit while modulating the authentication code on condition that the predetermined signal is received. The wireless communication system according to any one of claims 1 to 3, wherein the wireless communication system is capable of wireless transmission and can modulate a predetermined signal transmitted from the in-vehicle unit by a plurality of modulation methods.

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