A SINS-aided two-step fast acquisition method for GNSS signal based on compressive sensing

摘要

The Global navigation satellite system(GNSS)multi-mode compatible andmulti-frequency informationnot only improves information redundancy but also eliminates errors such as ionosphericdelays to improve positioning performance. However, multi-mode and multi-frequency observationinformation increases the hardware overhead and computational complexity, especiallythe signal acquisition. In this contribution, according to the strong complementarity betweenGNSS and Strapdown inertial navigation system (SINS) and the sparsity of the GNSS signalspreading code in the autocorrelation domain, a SINS-aided fast acquisition method for GNSSsignals based on Compressive sensing (CS) is proposed. First, the inertia information of SINS narrowsthe Doppler frequency search range; then, the CS is applied to measure compressively theGNSS signal in two steps, ie, the first step is to narrow down the code phase search range, andthe second step is to determine the code phase of the half chip accuracy. Finally, the proposedmethod and the other two typical acquisition methods are compared by the detection probabilityand the Mean acquisition time (MAT). Theoretical analysis and experimental results showthat the proposed method can not only reduce the number of correlators and computationalcomplexity but also improve the detection probability and reduce the MAT.