Abstract:

Based on the influence analysis of weak GPS signals on acquisition under high dynamic environment, a fast acquisition algorithm is developed. The involvement of the inertial navigation system is applied to estimate the GPS carrier Doppler frequency so as to decrease the range of frequency uncertainty. By improving the acquisition method of coherent and non-coherent integration based on fast Fourier transform (FFT), it overcomes the energy diffusion caused by the data bit sync and Doppler rate. In addition, the acquisition time is reduced and its sensitivity is enhanced. Simulation results illustrate that the proposed algorithm is valid to 24 dB-Hz carrier tonoise (CNR) GPS signal acquisition within 300 ms.