Determining distance between two transmitter-receiver stations, e.g. for vehicle keyless entry, involves determining coincidence time points in stations corresponding to times at which transmitted, received microwave pulses coincide

摘要

The method involves generating first and second transmission signals (S1,S2) in the first and second stations (1,2), sending them to the other station as series of microwave pulses of defined repetition rates with a defined difference, determining first and second coincidence time points in the first and second stations corresponding to the times at which transmitted and received pulses coincide and deriving the distance from the intervals between coincidence time points