Fast GNSS satellite signal acquisition method based on multiple resamplings

Abstract

A fast Global Navigation Satellite System (GNSS) satellite signal acquisition method based on resampling is presented. In contrast to traditional approaches, which perform a single-round search with a high data rate, the proposed method introduces a signal acquisition mechanism that uses data resampling. Starting from a resampled data rate slightly above the Nyquist frequency, the proposed method conducts multiple rounds of searches with an increasing sampling rate. After each round of searching, the satellites are sorted according to their relative signal strengths. By removing satellites at the bottom of each sorted list, the search space for satellite acquisition is continuously pruned. If a sufficient number of satellites are not acquired when the original data rate is reached, the method will switch to the weak-signal detection mode and use non-coherent integration for the satellites at the top on the list. The non-coherent integration process continues until either a sufficient number of satellites are acquired or the maximum number of steps is reached. The experimental results show that the proposed method can acquire the same set of satellites as traditional methods but with a considerably lower computational cost. The proposed method was implemented in a software-based GNSS receiver and can also be used in hardware-based receivers.

Research on multi-constellation GNSS compatible acquisition strategy based on GPU high-performance operation

“…The purpose of signal acquisition is to determine the satellite that can be observed and to estimate the rough code phase and carrier Doppler shift [21,22]. The essence of the capture is to use the strong auto-correlation of the pseudo random noise (PRN) code in the navigation signal to identify the navigation signal from the noise [23].…”