Passive keyless entry system

• US 6,747,545 B2
• Filed: 03/16/2001
• Issued: 06/08/2004
• Est. Priority Date: 03/20/2000
• Status: Expired due to Term

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Boeh, Frank, Nowottnick, Juergen
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): Nguyen, Nam V
• Application Number:
  US09/810,143
• Publication Number:
  US 20010033222A1
• Time in Patent Office: 1,180 Days
• Field of Search: 340/5.6, 340/5-1-, 340/5.7, 340/5-1-, 340/825.69, 340/825.72, 340/825.73, 340/825.76
• US Class Current: 340/5.61
• CPC Class Codes: G07C 2009/00396 starting with prompting the keyless data carrier
• CPC Class Codes: G07C 2009/00412 the transmitted data signal being encrypted
• 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 2209/63 Comprising locating means for detecting the position of the data carrier, i.e. within the vehicle or within a certain distance from the vehicle
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/122 Counter-measures against attacks; Protection against rogue devices
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds

Abstract

An arrangement for a passive keyless entry system is disclosed, comprising a base station and a portable data carrier, wherein the data carrier and the base station are configured to determine authorized access of the base station, wherein first and second position information of the relative position of the data carrier with respect to the antenna coils and UHF receiver stages of the base station is gained from measurements of the low-frequency, magnetic alternating fields transmitted by LF transmitter stages of the base station to the data carrier, and the UHF signal transmitted by a UHF transmitter stage of the data carrier to the base station, wherein a signal representing authorized access is generated by the base station when both position information components differ by less than a predetermined extent.

Claims

1. An arrangement for a passive keyless entry system comprising:

a base station arranged on an object to be secured against unauthorized access and a portable data carrier wherein the data carrier and the base station are configured to determine authorized access of the base station

wherein the data carrier includes a plurality of orthogonally aligned antenna coils each being coupled to a LF receiver stage, and a UHF transmitter stage,

wherein the base station includes a plurality of LF transmitter stages, an antenna coil associated with each LF transmitter stage a plurality of UHF receiver stages for receiving an UHF signal from the data carrier,

wherein first position information of the relative position of the data carrier with respect to the antenna coils of the base station is gained from a measurement of the low-frequency, magnetic alternating fields transmitted by the LF transmitter stages of the base station to the data carrier, which information is transmitted in the UHF signal from the data carrier to the base station,

wherein second position information of the relative position of the data carrier with respect to the UHF receiver stages of the base station is gained from a subsequent measurement of the UHF signal transmitted by the UHF transmitter stage of the data carrier to the base station,

wherein a signal representing authorized access is generated by the base station when both position information components differ by less than a predetermined extent.

2. An arrangement as claimed in claim 1, wherein the two position information components are determined by measuring the field strengths and/or the phase differences of the magnetic alternating fields at the locations of the antenna coils of the data carrier coupled to the respective LF receiver stages, or by measuring the UHF signal at the locations of the UHF receiver stages of the base station.

3. The arrangement as claimed in claim 1, wherein the data carrier is a chip card.

4. A base station for an arrangement in a passive keyless entry system with a data carrier, the base station comprising:

a plurality of LF transmitter stages;

an antenna coil associated with each LF transmitter stage;

a plurality of UHF receiver stages for receiving an UHF signal from the data carrier; and

a processor configured to generate a signal representing authorized access when a first and second position information components differ by less than a predetermined extent, wherein the first position information of the relative position of the data carrier with respect to the base station is determined from a measurement of the low-freguency, magnetic alternating fields transmitted by the LF transmitter stages of the base station to the data carrier, which information is transmitted in the UHF signal from the data carrier to the base station, and wherein the second position information of the relative position of the data carrier with respect to the UHF receiver stages of the base station is determined from a subsequent measurement of the UHF signal transmitted by the UHF transmitter stage of the data carrier to the base station.

5. A data carrier for an arrangement in a passive keyless entry system with the base station as claimed in claim 4, the data carrier comprising:

a plurality of orthogonally aligned antenna coils each being coupled to a LF receiver stage, and a UHF transmitter stage.