Unambiguous Tracking Method for Cosine-BOC Signals Based on an Optimizing Combined Correlation Functions

Abstract

This paper proposes an unambiguous tracking method based on the optimized combined autocorrelation function (ACF) for the cosine-phased binary offset carrier (cosine-BOC) modulated signals, which are applied in global navigation satellite system (GNSS). The main idea is to generate a specially constructed local reference waveform for cosine-BOC modulated signals, which is equivalent to get a group of samples of the ACF, then the unambiguous combined correlation function is obtained by weighting and adding these samples. Simulations show that the proposed method not only eliminate the ambiguity completely, but also maintains a narrow main-peak to obtain outstanding tracking accuracy performance of the cosine-BOC modulation. Additionally, the proposed method is proven to be with good performance in moderate and long multipath interferences mitigation.