Patent ID: 11899091
Assignee: CONTINENTAL AUTOMOTIVE FRANCE
Field: Measurement (Instruments)
Classification: CPC G  B  H | IPC B  G  H

Claim 0:
1. A method for estimating the distance between a vehicle and an authentication device, said vehicle comprising a computer and a plurality of communication modules each capable of communicating with said device over a wireless communication link, each communication module comprising an electronic clock that defines the sampling frequency of the signals received from the device, said method comprising:
transmission, by at least one of the communication modules, of a request signal destined for the device at a first instant,
reception of said request signal by the device,
transmission, by the device, of a response signal destined for at least one of the communication modules of the vehicle,
reception, by at least one of the communication modules, of said response signal,
addition of noise to the received response signal,
sampling of the noisy response signal,
detection, at a second instant, of the noisy response signal when the amplitude of said noisy response signal exceeds a predetermined detection threshold,
calculation of the time that has elapsed between the first instant and the second instant, and
estimation of the distance between the vehicle and the device based on the calculated time.