GPS signal fine acquisition algorithm

In the applications of high sensitivity Global Position System (GPS) receiver, signals need to be processed are becoming weaker, so how to exactly estimate the signal parameter and smoothly transfer from acquisition to tracking in the high sensitivity is so important in the receivers´ solution. This paper develops a method called fine acquisition to estimate the carrier frequency, which can make the final frequency error decreased to less than 1Hz. When increasing the coherent integration time, appropriate curve fitting function can make the frequency error even smaller. This fine acquisition algorithm can make the acquisition of the satellite signals more precise, in the same time decrease the time cost in signal pull-inning, and increase the sensitivity of signal pull-inning, which maybe the bottle-neck of the high sensitivity GPS receivers.