Abstract: For the weak GPS satellite signal,it requires longer coherent integration duration to improve the receiver’s sensitivity．Unfortunately,the influence of navigation data bit-flip limits integral duration to 20ms．It’s difficult for the traditional methods to balance sensitivity and computation complexity．In this paper,a rapid weak signal acquisition algorithm based on transition detection was proposed．Firstly,the possible position of bit-flip is detected in 1ms through the comparison of the coherent integration results of the several groups of signal blocks,and the rest signal which is at intervals of 20ms with the flip bit is removed．Then coherent integration is applied to its subblock signal in 19ms and its results operate non-coherent integration to overcome its bit-flip．The theoretical analysis and simulation results show the algorithm’s performance,and it can capture the weak signal under -47dB SNR with higher computation efficiency．The proposed algorithm will improve the sensitivity and the computation complexity of GPS receiver.

Key words: Weak signal acquisition,Acquisition,Bit-flip,GPS