Weak global navigation satellite system signal acquisition with bit transition

This study analyses the bit transition and integration over multiple code periods in weak global navigation satellite system signal acquisition. Bit transition must be considered in weak signal environments as it causes a correlation peak splitting reducing the correlation gain. In this study, a modified time parallel acquisition (MTPA) scheme is designed to solve the bit transition problem, and different accumulation schemes over multiple code periods are proposed to detect weak signals. Especially, a fast Fourier transform-based symbol combination for bit transition algorithm, which is suitable for the MTPA scheme, is presented in order to accelerate the coherent accumulation. Simulation results, along with the receiver operative characteristic curves, are presented to verify the performance of the MTPA and accumulation algorithms.