Fast Acquisition Algorithm with High Anti-Noise Performance Based on SFFT-DT

Aiming at the problem of poor anti-noise performance of Sparse Fast Fourier Transform parallel code phase capture algorithm， a new fast capture algorithm with high noise immunity is proposed. Based on the feature that the pseudo-code correlation function has only one large value point， the algorithm uses Downsampling Fast Fourier Transform（DFFT） to replace the positioning loop and the estimation loop process in the SFFT parallel code phase capture algorithm， which are less tolerant to noise. The algorithm parameters are optimized. Theoretical analysis and simulation results show that， compared with the existing SFFT capture algorithm， the calculation speed of the SFFT-DT capture algorithm is increased by about 19%， the anti-noise performance is improved by about 5 dB. Compared with the classic FFT capture algorithm， when the two anti-noise performances are approximately the same （under the premise that the capture probability is greater than 95%）， the calculation amount of the algorithm in this paper is reduced by about 43%.