A tracking method for GPS L2C signal based on the joint using of data and pilot channels

GPS L2C signal is one of the modernized GPS civilian signals. With respect to GPS L1 C/A signal, L2C signal is more robust in harsh environment, since its tracking threshold would be lower by taking the advantage of new designed pilot channel. Up to now, some of current tracking methods are only based on the pilot channel or data channel of L2C signal and discard the other, which results in 50% power loss. Other methods are based on the joint tracking of the outputs of data and pilot channels' discriminators, which needs more additional computation resources and the integration time of tracking is limited by data. In this paper, a new method based on joint tracking of data and pilot channels but not discriminators is proposed. We know the navigation data of GPS signal, mainly consisted of ephemeris and almanac, are continuously and repeatedly broadcast. So the navigation data of GPS signal are predicable. Based on this, the proposed method removes the navigation data of data channel through a new designed navigation data predication module, before coherently combines the integration results of data and pilot channel. Then, the coherent integration result has both the energy of data channel and pilot channel. Compared with the previous methods, the proposed method has no power loss and it doesn't need additional computation resource. Furthermore, the integration time will not be limited by navigation data since they have been predictably removed and much better tracking performance is expected. Theoretical and simulation results demonstrated the results.