The present invention relates to a method of determining a distance or location of a remote device or reflector, the method comprising: receiving a signal from a remote signal transmitter associated with or contained in or attached to the remote device; estimating a first propagation delay associated with the received signal, wherein the first propagation delay represents a first candidate for a correct propagation delay; deriving a relationship between the first candidate and one or more other candidates for a correct propagation delay from the received signal; determining a plurality of other candidates for a correct propagation delay based on said relationship; generating a likelihood histogram based on said candidates for a correct propagation delay; selecting a propagation delay from said candidates based on the likelihood histogram; and determining a distance or location of the remote device or reflector using the selected propagation delay.