Up-sampling and cross-correlation for time of arrival determinations in passive entry/passive start systems

Patent metadata

Field	Value
Publication number	US-12270894-B2
Application number	US-202318214562-A
Country	US
Kind code	B2
Filing date	Jun 27, 2023
Priority date	Oct 12, 2018
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

A system is provided and includes a receiver and an access module. The receiver is configured to receive a signal transmitted from a portable access device to a vehicle. The access module is configured to generate a differentiated signal based on the received signal, up-sample the differentiated signal to generate a first up-sampled signal, up-sample an expected signal to generate a second up-sampled signal, cross-correlate the first up-sampled signal and the second up-sampled signal to generate a cross-correlation signal, determine, based on the cross-correlation signal, a phase difference between the first up-sampled signal and the second up-sampled signal, determine a round trip time of the signal received by the receiver based on the phase difference, and permit access to the vehicle based on the round trip time.

First claim

What is claimed is:

1. An access system for a vehicle, the access system comprising:
a transmitter configured to transmit a first wireless signal from the vehicle to a portable access device via one or more antennas;
a receiver configured to receive a second wireless signal transmitted from the portable access device to the vehicle via the one or more antennas; and
a control module configured to determine a phase based on the first wireless signal and the second wireless signal, and to determine a location of the portable access device relative to the vehicle based on the phase,
wherein
the second wireless signal indicates a phase delay of the first wireless signal, and
the control module is configured to determine the location of the portable access device based on the phase delay.

2. The access system of claim 1 , wherein the control module is configured to determine the location of the portable access device based on the phase.

3. The access system of claim 1 , wherein the control module is configured to determine a distance of the portable access device based on the phase.

4. The access system of claim 1 , wherein:
the transmitter is configured to transmit the first wireless signal from the vehicle at each of a plurality of frequencies;
the receiver is configured to receive at the vehicle the second wireless signal at each of the plurality of frequencies; and
the control module is configured to determine a plurality of phases respectively for the plurality of frequencies, and to determine the location of the portable access device relative to the vehicle based on the plurality of phases.

5. The access system of claim 4 , wherein the control module is configured to determine a distance of the portable access device based on the plurality of phases.

6. The access system of claim 4 , wherein the control module is configured to determine i) a first phase for a first one of the plurality of frequencies, ii) a second phase for a second one of the plurality of frequencies, iii) a distance of the portable access device based on the first phase, and iv) the distance of the portable access device based on the second phase.

7. The access system of claim 1 , wherein:
the first wireless signal includes a first continuous wave tone;
the second wireless signal includes a second continuous wave tone; and
the control module is configured to determine the phase based on the first continuous wave tone and the second continuous wave tone.

8. The access system of claim 7 , wherein the first continuous wave tone and the second continuous wave tone are unmodulated wave tones.

9. The access system of claim 1 , wherein the control module is configured to determine a phase difference between the first wireless signal and the second wireless signal, and to determine the location of the portable access device based on the phase difference.

10. The access system of claim 1 , further comprising the one or more antennas.

11. The access system of claim 1 , further comprising:
low-frequency antenna modules; and
radio frequency antenna modules configured to provide polarization diversity between each antenna of the portable access device and antennas of the radio frequency antenna modules including the one or more antennas,
the control module is configured to wirelessly communicate with the portable access device via at least one of i) the low-frequency antenna modules and ii) the radio frequency antenna modules, the wireless communication including the transmission of the first wireless signal and reception of the second wireless signal.

12. An access method for a vehicle, the method comprising:
transmitting a first wireless signal from the vehicle to a portable access device via one or more antennas;
receiving a second wireless signal transmitted from the portable access device to the vehicle via the one or more antennas;
determining a phase via a control module based on the first wireless signal and the second wireless signal, wherein the second wireless signal indicates a phase delay of the first wireless signal;
determining a location via the control module of the portable access device relative to the vehicle based on the phase; and
determining the location of the portable access device based on the phase delay.

13. The method of claim 12 , further comprising:
transmitting the first wireless signal from the vehicle at each of a plurality of frequencies;
receiving at the vehicle the second wireless signal at each of the plurality of frequencies;
determining a plurality of phases respectively for the plurality of frequencies; and
determining at least one of the location or a distance of the portable access device relative to the vehicle based on the plurality of phases.

14. The method of claim 13 , comprising determining the distance of the portable access device based on the plurality of phases.

15. The method of claim 13 , further comprising:
determining a first phase for a first one of the plurality of frequencies;
determining a second phase for a second one of the plurality of frequencies;
determining the distance of the portable access device based on the first phase; and
determining the distance of the portable access device based on the second phase.

16. The method of claim 12 , wherein:
the first wireless signal includes a first continuous wave tone;
the second wireless signal includes a second continuous wave tone; and
the phase is determined based on the first continuous wave tone and the second continuous wave tone.

17. The method of claim 16 , wherein the first continuous wave tone and the second continuous wave tone are unmodulated wave tones.

18. The method of claim 12 , further comprising:
determining a phase difference between the first wireless signal and the second wireless signal; and
determining the at least one of the location or a distance of the portable access device based on the phase difference.

19. An access system for a vehicle, the access system comprising:
a transmitter configured to transmit a first signal at each of a plurality of frequencies from the vehicle to a portable access device;
a receiver configured to receive a second signal transmitted from the portable access device to the vehicle, and receive at the vehicle the second signal at each of the plurality of frequencies; and
a control module configured to
determine a first phase for a first one of the plurality of frequencies based on the first signal and the second signal,
determine a second phase for a second one of the plurality of frequencies based on the first signal and the second signal, and
determine at least one of a location or a distance of the portable access device relative to the vehicle based on the first phase and the second phase.

20. An access system for a vehicle, the access system comprising:
a transmitter configured to transmit a first signal from the vehicle to a portable access device;
a receiver configured to receive a second signal transmitted from the portable access device to the vehicle; and
a control module configured to determine a phase based on the first signal and the second signal, and to determine at least one of a location or a distance of the portable access device relative to the vehicle based on the phase,
wherein
the first signal includes a first continuous wave tone,
the second signal includes a second continuous wave tone, and
the control module is configured to determine the phase based on the first continuous wave tone and the second conti

Assignees

• Denso Int America Inc
• Denso Corp

Inventors

• Stitt Raymond Michael
• Videtich John

Classifications

• G07C2209/63

  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 title

• G07C9/00309

  operated with bidirectional data transmission between data carrier and locks · CPC title

• B60R25/248

  Electronic key extraction prevention · CPC title

• B60R25/241

  whereby access privileges are related to the identifiers · CPC title

• B60R2325/205

  Mobile phones · CPC title