Method for synchronizing a receiver with a received ambiguous signal having a known number of at least two peaks
Method and receiver synchronizing receiver with received ambiguous signal having at least two peaks. Method includes providing information about known transmitted signal having a number of at least two peaks, the information including number of peaks and distances between at least two peaks, determining ratios between peaks of known transmitted signal and assigning determined ratio value to each peak, and deducing theoretical auto-correlation function from known transmitted signal. Auto-correlation function has number of correlations corresponding to number of peaks in known transmitted signal and correlators of the auto-correlation function are provided in same distance and have the same relative ratio as peaks in known transmitted signal. Further includes tracking received signal with auto-correlation function so that correlator pattern of auto-correlation function is aligned with peak pattern of received signal by assigning each peak of the received signal to a correlator of the auto-correlation function, and identifying each peak.
1. A method of synchronizing a receiver with a received ambiguous signal having a known number of at least two peaks, said method comprising:
a) providing information about a known transmitted signal having a given number of at least two peaks, and the information including the number of peaks and the distances between the at least two peaks;
b) determining ratios between the peaks of the known transmitted signal and assigning a determined ratio value to each peak;
c) deducing a theoretical auto-correlation function from said known transmitted signal, wherein the auto-correlation function has a number of correlations corresponding to the number of peaks in the known transmitted signal and wherein correlators of the auto-correlation function are provided in a same distance and have a same relative ratio as the peaks in the known transmitted signal;
d) tracking the received signal with the auto-correlation function so that a correlator pattern of the auto-correlation function is aligned with a peak pattern of the received signal by assigning each peak of the received signal to a correlator of the auto-correlation function; and
e) identifying each peak.
2. The method according to claim 1 , wherein the ratio of each peak is determined as a relation between a respective peak and a maximum peak.
3. The method according to claim 1 , wherein, in order to assign each peak of the received signal to a correlator of the auto-correlation function in step d), the method further comprises:
d1) determining the ratios between the peaks of the received signal; and
d2) assigning each peak of the received signal to the correlator of the auto-correlation function which has the same ratio value as the peak to be assigned or a ratio value which is closest to said peak.
4. The method according to claim 3 , wherein assigning a peak of the received signal to the correlator of the auto-correlation function in step d2) comprises comparing a matrix of the peak ratios of the auto-correlation function with a matrix of the peak ratios of the received signal.
5. A receiver for synchronizing with a received ambiguous signal having a known number of peaks, the receiver comprising:
a digital signal receiver for receiving an ambiguous signal;
a first plurality of correlators, comprising an early, a late, and a punctual correlator, receiving the ambiguous signal and a reference signal;
a second plurality of correlators receiving the ambiguous signal and the reference signal, each of the second plurality of correlators being respectively associated with a peak;
a comparison device to compare ratios of outputs of the second plurality of correlators to ratios of a theoretical signal,
wherein, when the comparison device determines that the ratios of the outputs are different from those of the theoretical signal, a corrector is arranged to correct the ratios to be inline with the theoretical signal.