Vehicle Access System

摘要

The invention relates to an access unit for communicating with a further access unit to control access to a vehicle. The access unit comprises at least a first transmitter for transmitting a polling signal; and at least a first receiver for receiving an authentication signal from the further access unit in response to the polling signal. At least the first transmitter is a first ultra-wideband transmitter and at least the first receiver is a first ultra-wideband receiver. The invention also relates to a vehicle access system which is a combination of the access and further access units. The invention also relates to methods of operating a vehicle access system and a vehicle access unit.

主权项

1. An access unit configured to control access to a vehicle via communication with a further access unit, the access unit comprising:
a first transmitter configured to transmit a polling signal; and a first receiver configured to receive an authentication signal from the further access unit in response to said polling signal; wherein the first transmitter is a first ultra-wideband transmitter and the first receiver is a first ultra-wideband receiver; wherein the first transmitter is configured to pulse the polling signal with a time interval between transmissions; and wherein the first transmitter is configured to modify a length of the time interval between transmissions of the polling signal in response to a distance between the access unit and the further access unit, wherein the distance between the access unit and the further access unit is determined based on a time of flight of communications between the access unit and the further access unit, the first transmitter being configured to set the length of the time interval in dependence on the determined distance.