Patent ID: 7778311

Claim:
A method implemented in a satellite navigation receiver for navigation data bit synchronization in the signals received from navigational satellites, the method comprising: collecting correlation values over several consecutive data bits; calculating, for each of a plurality of pairs of adjacent correlation values having a common data bit position j within the several consecutive data bits, a function F(j), wherein the function F(j) is a normalized dot product of the adjacent correlation values having a common navigational data bit position j; adding the values of F(j) calculated for the plurality of pairs to produce a value SumF(j); repeating the calculating and adding for multiple values of the data bit position j to produce a collection of values {SumF(j)} corresponding to the multiple values of the data bit position j; comparing each value of SumF(j) to a lower threshold and a higher threshold; and using a soft decision approach based on SumF(j) to detect a navigational data bit edge, wherein the soft decision approach includes using a real value of F(j) varying between −1 and +1.