GNSS Signals Acquisition and Tracking in Unfavorable Environment

Anotace: In this paper, we propose a method based on applying specific transformations to the Global Navigation Satellite System (GNSS) signals received in unfavorable environment. As a result, one simple classical receiver including these adjustments becomes sensitive to several Multi-Constellation and Multi-Frequency (MC/MF) GNSS signals and achieves efficiently their collective acquisition. The proposed method consists of three variants each dedicated to a particular type of Binary Offset Carrier (BOC) family signals; the primary is based on undersampling process, the second is founded on time expansion and the last one permits the acquisition of more than five different GNSS signals by a single local Composite Binary Coded Symbols (CBCS) waveform replica. Hence, the proposed scheme, by avoiding the use of multiple demodulators in the baseband, allows less receiver complexity and accordingly better realization cost. The simulation results showed that the proposed method presents an effective solution for the reception of MC/MF signals in unfavorable environments.