Patent ID: 8930045
Filing Date: 2015-01-06
Classification: B60R,G01S,G07C

Abstract:
1. A passive entry passive start (PEPS) vehicle security system configured to thwart a relay attack on the system, said system comprising: a first ultra wideband transceiver (UWBX) installed on a vehicle and configured to transmit a request pulse at a request time; a mobile UWBX installed in a nomadic device and configured to transmit a reply pulse in response to the request pulse; and a controller configured to determine a distance between the first UWBX and the mobile UWBX based on a first time interval between the request time and a first time that corresponds to when the reply pulse is received by the first UWBX, wherein the controller is further configured to unlock doors of the vehicle only if the distance is less than an unlock threshold.