Patent ID: 8160123

Claim:
A device for receiving radio-navigation signals by satellite, said received signals being transmitted at a first frequency or carrier frequency, said device comprising: at least means for generating a local signal at a second frequency or local frequency and a tracking device including a feedback loop, for phase-locking the local frequency on the carrier frequency, said feedback loop including a hardware portion and a software portion, said hardware portion comprising at least one integrator which performs the correlation between the local signal and the received signal, the signal deriving from the correlation being called correlated signal, said correlation being performed at high frequency, said software part performing functions of discriminating the phase of the correlated signal and filtering said phase, the software portion working at low frequency, the duration of a basic computation cycle being denoted T, each cycle being indexed by an integer number n so that the duration of a cycle is contained in the time interval [(n−1)T, nT], the correlated signal at the instant nT being denoted Zp(n), the signal θ(n) deriving from the discrimination being equal to the argument of the product of Zp(n) multiplied by a complex exponential function Z R (n), the argument of which is a compensation term that is a function of n and of T, wherein, if C(n) is used to denote the linear variation coefficient of the phase of the local frequency φ local between the instants nT and (n+1)T such that [φ local ((n+1)T)−φ local (nT)]/T is equal to C(n), C(n) being calculated previously from data available respectively at the instant (n−1)T and concerning the value of the received phase, its position and its acceleration, then said compensation term depends at least on C(n) and C(n−1).