| 摘要 |
In a remote keyless entry (RKE) system, the distance from a transmitter fob to a vehicle is determined by iteratively attenuating (308) the sensitivity of a receiver on the vehicle in response to receiving a control signal segment (302), until a predetermined number of iterations have been counted (310, 312), or the signal cannot be successfully decoded (304, 306). The RKE system can thereby determine that the transmitter is close - if the signal is still received and successfully decoded (304, 306) even though the receiver sensitivity is attenuated by a predetermined amount, or distant - if the received signal can no longer be successfully decoded. A vehicle function can be activated (314) e.g. locking / unlocking in addition to a transmitter fob distance determination (316) being performed. |
