Joint data-pilot acquisition of GPS L1 civil signal

Global navigation satellite systems (GNSSs), such as the modernized GPS, the European Galileo and the Chinese Compass, are developing rapidly. The modernized GPS introduces a new composite signal called L1 civil (L1C) signal, which consists of two different components, the data and pilot channels. The presence of two components allows the use of special techniques specifically tailored to acquire the new signal. In this paper, the authors analyze the performance of four different implementation strategies, namely, i.Data-only, ii.Pilot-only, iii.Noncoherent joint data-pilot, and iv.Coherent joint data-pilot, for two different unambiguous acquisition methods, i.e., the BPSK-like technique and sub carrier phase cancellation (SCPC) technique. Monte Carlo simulations are carried out to assess the performance of the four different strategies, and results indicate that joint data-pilot channel strategy outperforms any other individual channel strategy. Moreover, coherent combining can provide up to 1 dB-Hz improvement than noncoherent combining at equal value of detection probability for joint datapilot strategy.