Abstract: In order to perform carrier phase tracking better, compared with the GPS signal, Galileo L1F signal increases navigation data without pilot channel. Then the data channel can use the discriminator unlimited in navigation data. The traditional combination of discriminators in Galileo L1F signal carrier phase tracking loop can still be improved. In this paper, a new combination of discriminators is proposed, because the discriminator for pilot channel-only has better performances than the discriminator for data channel-only. Through the simulation experiment under different thermal noise environments, the performances of both new and traditional combinations of discriminators are tested at the objective of improving the carrier phase tracking accuracy. The results show that the new combination of discriminators has great advantage over traditional combination of discriminators in restraining signal noise and preventing loss of lock.

Key words: Galileo L1F, Combination of phase discriminators, PLL, Carrier tracking loop, Thermal noise