A SINS-Assisted Fast Acquisition Method for GNSS Signals Based on Compressed Sensing

Abstract

Providing observations at multiple frequencies and compatibility of multiple systems have become the development trend of global navigation satellite systems (GNSS), and multi-frequency and multiple systems will inevitably lead to a large increase in data volume. The traditional GNSS acquisition algorithm based on Nyquist theorem has the disadvantages of slow acquisition speed and complicated hardware. In this contribution, a Strapdown Inertial Navigation System (SINS)-assisted GNSS fast acquisition algorithm based on compressed sensing (CS) is proposed. First, the SINS speed information is used to estimate the GNSS Doppler frequency to reduce the frequency search range; Then, according to the sparse nature of the GNSS signal, a CS model is built, which is sparsified and compressed to reduce the sampling rate and reduce the computational complexity; Finally, compare the modulus of the correlation operation with the threshold to determine whether the satellite signal was acquired and obtain the Doppler shift value and code phase of the acquired signal, and reconstruct the signal. Theoretical analysis and experimental simulation results show that the proposed algorithm based on CS can significantly improve the GNSS signal acquisition speed and reduce the calculation amount and sampling rate, which can effectively solve the traditional acquisition algorithm with large data volume and slow speed.