Patent ID: 7786931
Filing Date: 2010-08-31
Classification: G01S

Abstract:
1. Method of determining the position of a mobile terminal (UE), including a step of said terminal (UE) acquiring pseudo-random codes modulating signals received from satellites (SN) in view belonging to a constellation (CS) of positioning satellites and related to a reference time by comparison with signal replicas resulting from hypotheses, and a step of determining the position of said terminal (UE) from said acquired codes and from navigation data contained in said signals, which method is characterized in that, in the acquisition step, i) assistance data is transmitted to said terminal (UE) representing an approximate reference time and its approximate position, ii) estimated positions of said constellation (CS) of satellites (SN), estimated distances between said terminal (UE) and each of said satellites (SN) in view and associated Doppler effects are determined as a function of pairs of hypotheses relating to said approximate reference time and said approximate position, iii) a signal replica is determined for each pair of hypotheses corresponding to said estimated positions and distances and to said associated Doppler effects over a selected time interval, and iv) the pair of hypotheses corresponding to the signal replica having a maximum correlation with the signal received during said time interval is selected in order to determine said pseudo-random codes modulating said received signals.