Abstract: Binary Offset Carrier (BOC) modulation signal is a new type of satellite navigation signal with ingenious design. Eliminating the tracking ambiguity of signal is the premise of exploring its potentiality. Concerning the problem that the autocorrelation function of Cosine-phased BOC (CosBOC) signal is relatively more complex and difficult to express concisely and uniformly, as well as the lack of research on its tracking ambiguity, an unambiguous tracking method based on combined correlation function was proposed for CosBOC (10,5) signal in the E6 band of Galileo system. Firstly, a local reference signal of linear combination of as few local duplicated signals as possible and their shift weighted variants was designed, then through the code tracking loop, the reference signal was correlated with the received signal to obtain a correlation function without sub-peaks, eliminating the tracking ambiguity of code discriminator. Finally the code tracking error of the method was analyzed. The experimental results show that, compared with Binary Phase Shift Keying Like (BPSK Like) method, Bump Jump method and Pseudo Correlation Function (PCF) method, the proposed method has simple tracking loop structure, and it can suppress the tracking ambiguity completely and has better code tracking performance on the whole.

Key words: Cosine-phased Binary Offset Carrier (CosBOC), Galileo system, unambiguous tracking, combined correlation function, satellite navigation

摘要： 二进制偏移载波（BOC）调制信号是一种设计精妙的新型卫星导航信号，充分挖掘其性能的前提是解决好其跟踪模糊问题。余弦相位二进制偏移载波（CosBOC）信号的自相关函数相对更复杂且难以简洁统一地表示，其跟踪模糊问题的研究也相对薄弱，为此，以应用于伽利略系统的E6频段上的CosBOC（10，5）信号为研究对象，提出了一种基于组合相关函数的无模糊跟踪方法。该方法首先设计了由数目尽量少的本地复现信号及其移位加权来线性组合构成的本地参考信号；然后通过码跟踪环路该参考信号与接收信号相关后得到无副峰的相关函数，从而消除码鉴别器的跟踪模糊；最后分析了该方法的码跟踪误差。实验结果表明，该方法与类二进制相移键控法（BPSK Like）、峰跳法（Bump Jump）和伪相关函数法（PCF）相比，跟踪环路结构简单，完全抑制了跟踪模糊且整体上具有较好的码跟踪性能。

关键词: 余弦相位二进制偏移载波, 伽利略系统, 无模糊跟踪, 组合相关函数, 卫星导航