Fast GNSS acquisition algorithm based on SFFT with high noise immunity

Abstract

The Global Navigation Satellite System(GNSS) has been widely used in various fields. To achieve positioning, the receiver must first lock the satellite signal. This is a complicated and expensive process that consumes a lot of resources of the receiver. For this reason, this paper proposes a new fast acquisition algorithm with High Signal-to-noise ratio(SNR) performance based on sparse fast Fourier transform(HSFFT). The algorithm first replaces the IFFT process of the traditional parallel code phase capture algorithm with inverse sparse fast Fourier transform (ISFFT) with better computing performance, and then uses linear search combined with code phase discrimination to replace the positioning loop and the estimation loop with poor noise immunity in ISFFT. Theoretical analysis and simulation results show that, compared with the existing SFFT parallel code phase capture algorithm, the calculation amount of this algorithm is reduced by 19%, and the SNR performance is improved by about 5dB. Compared with the classic FFT parallel code phase capture algorithm, the calculation amount of the algorithm in this paper is reduced by 43%, and when the capture probability is greater than 95%, the SNR performance of the two is approximately the same.