A BOC Signal Synchronization Algorithm Based on TK Operator

Abstract

The binary phase shift keying (BPSK) modulation method is generally utilized for the traditional navigation satellite systems; however, the new generation of GNSS, such as modernized GPS, European Galileo, Chinese Compass, etc., will apply binary offset carrier (BOC) modulation technique, which can efficiently split the spectrums of navigation signals using the same frequency so as to reduce the interferences among different systems. But the autocorrelation function of BOC modulated signals has the drawback of multimodality, so it’s very hard to synchronize to the right peak when acquiring and tracking signals, especially under low SNR circumstances, which can decrease the positioning accuracy and even lead to wrong positioning results. A BOC modulated signal synchronization algorithm based on TK (Teager-Kaiser) operator is proposed in this article, which could eliminate all the other peaks in autocorrelation function of BOC modulated signals, and create an ideal curve with only one right peak. As a result, this method could avoid the false lock of code phase and guarantee the high precision fix results.