Identification system for confirming authorization for access to an object or the use of an object, in particular of a motor vehicle

• US 6,873,248 B2
• Filed: 10/15/2002
• Issued: 03/29/2005
• Est. Priority Date: 02/15/2001
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Ott, Albert
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): NGUYEN, NAM V
• Application Number:
  US10/270,955
• Publication Number:
  US 20030052539A1
• Time in Patent Office: 896 Days
• Field of Search: 340/5.61, 340/5.33, 340/5.5, 340/5.64, 340 101- 106, 340/572.1, 340/572.7, 340/7.2, 341/176, 4551711-1811, 375/141, 375/332
• US Class Current: 340/5.72
• CPC Class Codes: B60R 2325/105 Radio frequency identification data [RFID]
• CPC Class Codes: B60R 25/246 characterised by the challenge triggering
• CPC Class Codes: G07C 2009/00388 code verification carried out according to the challenge/response method
• CPC Class Codes: G07C 2009/00555 comprising means to detect or avoid relay attacks
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

An identification system in which a trigger signal, emitted on an object side and received by a portable code generator, is provided. The trigger signal is used on the object side to phase code a reference signal. The code generator encodes a response signal using the trigger signal in a phase-coded manner and retransmits the response signal. The received response signal is compared with the generated reference signal in an object-side evaluation unit using an autocorrelation function. If the value of the autocorrelation function is larger than a threshold value, an enabling signal is generated.

Claims

1. An identification system for confirming authorization for access to an object or the use of an object comprising:

a transceiver unit which is arranged at the object and which generates and emits a trigger signal, wherein a phase-encoded reference signal is generated using the trigger signal and a defined code,

a mobile code transmitter which receives the trigger signal and generates a phase-encoded response signal using the received trigger signal and a code which corresponds to the code of the transceiver unit, and transmits the response signal back, and

an object-end evaluation unit which has a correlation unit which calculates a correlation value of a correlation function using the received response signal and the reference signal and which generates an enable signal for controlling a security assembly only if the correlation value is greater than a predefined threshold value.

2. The identification system as claimed in claim 1, wherein the transceiver unit and/or the evaluation unit each have a memory in which the reference signal and the code are stored.

3. The identification system as claimed in claim 1, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency in the frequency range greater than 100 kHz.

4. The identification system as claimed in claim 1, wherein the evaluation unit predefines the threshold value with which the calculated value of the correlation is compared.

5. The identification system as claimed in claim 3, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 433 MHz.

6. The identification system as claimed in claim 3, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 868 MHz.

7. The identification system as claimed in claim 1, wherein the object is a motor vehicle.

8. A method for confirming authorization for access to an object or the use of an object comprising the steps of:

generating and emitting a trigger signal at the object;

generating a phase-encoded reference signal using the trigger signal and a defined code at the object,

receiving the trigger signal at a mobile code transmitter;

generating a phase-encoded response signal using the received trigger signal and a code which corresponds to the code of the transceiver unit;

transmitting the response signal back to the object;

calculating a correlation value of a correlation function using the received response signal and the reference signal; and

generating an enable signal for controlling a security assembly only if the correlation value is greater than a predefined threshold value.

9. The method as in claim 8, further comprising the step of storing the reference signal and the code.

10. The method as in claim 8, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency in the frequency range greater than 100 kHz.

11. The method as in claim 8, further comprising the step of predefining the threshold value with which the calculated value of the correlation is compared.

12. The method as in claim 10, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 433 MHz.

13. The method as in claim 10, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 868 MHz.

14. A motor vehicle having an identification system for confirming authorization for access to the motor vehicle comprising:

a transceiver unit which is arranged at the motor vehicle and which generates and emits a trigger signal, wherein a phase-encoded reference signal is generated using the trigger signal and a defined code,

a mobile code transmitter which receives the trigger signal and generates a phase-encoded response signal using the received trigger signal and a code which corresponds to the code of the transceiver unit, and transmits the response signal back, and

an evaluation unit arranged in the motor vehicle which has a correlation unit which calculates a correlation value of a correlation function using the received response signal and the reference signal and which generates an enable signal for controlling a security assembly only if the correlation value is greater than a predefined threshold value.

15. The motor vehicle as claimed in claim 14, wherein the transceiver unit and/or the evaluation unit each have a memory in which the reference signal and the code are stored.

16. The motor vehicle as claimed in claim 14, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency in the frequency range greater than 100 kHz.

17. The motor vehicle as claimed in claim 14, wherein the evaluation unit predefines the threshold value with which the calculated value of the correlation is compared.

18. The motor vehicle as claimed in claim 16, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 433 MHz.

19. The motor vehicle as claimed in claim 16, wherein the response signal is transmitted in a phase-modulated fashion with a carrier frequency of approximately 868 MHz.