Patent ID: 7848397

Claim:
A method of generating frequency coherence between a received reference positioning signal carrier component and a unique positioning signal carrier component, said received reference positioning signal carrier component being transmitted by at least one reference transmitter and said unique positioning signal carrier component being generated by a positioning-unit device, said positioning-unit device comprising a receiver, a frequency steerable clock connected to a transmitter and a common oscillator, said common oscillator being common to said receiver frequency steerable clock within said positioning-unit device, said method comprising the steps of: a) receiving said reference positioning signal carrier component at said receiver within said positioning-unit device; b) measuring a frequency offset of said received reference positioning signal carrier component relative to said common oscillator; c) adjusting said frequency steerable clock by an amount derived from said measured frequency offset; d) further adjusting said frequency steerable clock by applying an additional frequency offset for a predetermined time period to time slew said unique positioning signal; e) generating said unique positioning signal carrier component at an aligned frequency with said reference positioning signal carrier component, wherein said unique positioning signal carrier component is aligned with said frequency steerable clock; f) continuously adjusting said unique positioning signal carrier component by applying said measured frequency offset to said frequency steerable clock, said frequency steerable clock referenced to said common oscillator, such that the frequency of said adjusted unique positioning signal carrier component is aligned with the frequency of said reference positioning signal carrier component.