High sensitivity GPS acquisition algorithm based on code doppler compensation

To extend the coherent integration time M, and to increase the non-coherent integration times N is an effective way for weak GPS signal acquisition. But with the increasing of the integration time, the phase sliding caused by code doppler is more obvious, and it will cause a lot of non-coherent integration loss, which affects acquisition performance. This paper presents a new algorithm based on code doppler picking points compensation. According to the prediction of phase slip time, new algorithm can make several times non-coherent integration results accumulate to the same code phase. The acquisition sensitivity is improved. Simulation results show that, when M =10, N = 20, new algorithm can capture signal whose C/N
₀
is as low as 20dB-Hz.