Patent ID: 7486657

Claim:
A method f or retrieving time information from a time signal ( 89 ) transmitted by a time signal transmitter, wherein said time information is present in said time signal in the form of data bits ( 83 - 85 ), said method comprising the following steps: a) forming said time signal ( 89 ) of a multitude of time frames ( 80 - 82 ), each said time frame having a constant time frame duration, b) allocating to each said time frame ( 80 - 82 ) at least one said data bit ( 83 - 85 ) representing said time information in said time signal, c) determining a logic value of said at least one data bit ( 83 - 85 ) on the basis of a time duration (T 1 , T 2 ) of an amplitude change of an amplitude of said time signal ( 89 ), d) allocating a first said logic value to a first said data bit ( 83 , 85 ), said first logic value representing a first said time duration (T 1 ) of a first said amplitude change of said time signal ( 89 ), e) allocating a second said logic value to a second said data bit ( 84 ), said second logic value representing a second said time duration (T 2 ) of a second said amplitude change, said first and second amplitude changes providing at least two amplitude changes, f) determining a first instant (t 0 , t 2 , t 4 ) respectively of said first and second amplitude changes g) determining a second instant (t 1 , t 5 ) relative to the first instant (t 0 , t 2 , t 4 ) and with reference to said first time duration (T 1 ), h) determining a third instant (t 3 ) relative to the first instant (t 0 , t 2 , t 4 ) and with reference to the second time duration (T 2 ), i) examining a first time window ( 86 ) encompassing said second instant (t 1 , t 5 ) to determine whether the amplitude of the time signal ( 89 ) returns to an original amplitude value, and j) allocating said first logic value to one of said at least one data bit ( 83 ) as said first data bit if said amplitude returns within said first time window ( 86 ) to the original amplitude value.