On the Method of GPS Navigation Message Synchronization Based on FFT

The most important steps for navigation data extraction are bit synchronization and frame synchronization. The traditional algorithms are complicated which are implemented with frame synchronization followed by bit synchronization. A new algorithm is proposed in this paper, which is based on FFT and could obtain bit synchronization and frame synchronization simultaneously. The traditional algorithms and the new algorithm are developed by using real intermediate frequency samples of GPS signal based on MATLAB software. Theoretical analysis and numerical results show that both of these two algorithms could obtain navigation data effectively and reliably, and the new algorithm is better than traditional algorithm.