Differential Joint Channels Combination Techniquesfor GNSS Signal Acquisition

New composite Global Navigation Satellite System(GNSS)signals are usuallycharacterized by the presence of data and pilot channels and the adoption of a tiered codestructure.The problem of acquiring composite GNSS signals of the next generation systems(such as European Galileo,and U.S.s GPS modernization)is addressed.Several joint data/pilot channel combination strategies have been proposed to effectively deal with data and pilotchannel combinations in order to make full use of the transmitted signal power available inboth channels.These channel combination strategies were further updated with a differentialdetection scheme to improve the robustness of the acquisition process of GNSS receivers,particularly in weak signal environments.The statistical properties of differential channelscombination strategies are presented in detail.The performance of the proposed techniqueswas evaluated using Monte Carlo simulations on simulated Galileo E1Open Service(OS)sig-nals.The results reveal that differential channel combination techniques provide improvedperformance in comparison to the state-of-the-art single channel acquisition methodology.