Galileo Primary Code Acquisition Based on Multi-hypothesis Secondary Code Ambiguity Elimination

This paper addresses the problem of primary code acquisition for the Galileo E1 signal in challenging environments. The detector sensitivity is augmented by extending the observation window up to several primary code periods. A novel solution is proposed to cope with the secondary code ambiguity, based on the enumeration of all possible secondary chips sign combinations and exploiting an optimized parallel architecture. Performance is presented in terms of Receiver Operating Characteristics (ROC) and Mean Acquisition Time (MAT), obtained through simulation and analytical results. The paper shows that the proposed scheme is able to introduce an interesting improvement, limiting at the same the complexity increase.