Passive approach detection system and method using a unidirectional FOB

摘要

A system and method of passive approach detection is provided. The method comprises: transmitting a plurality of data signals corresponding to multiple power levels respectively from a fob device based on motion detected in the fob device; each of the plurality of data signals includes initial bytes encoded with a power level and transmitter identification (ID); receiving one or more of the plurality of data signals at a receiver based on the distance between the fob device and the receiver; filtering out signals at a secondary processor by comparing one or more of the plurality of data signals received to a predetermined list of signals valid for reception; and transmitting a wake-up signal to a primary processor based on the comparison, the wake-up signal enabling the primary processor to transition from a sleep mode to a wake-up mode.