基于合成相关函数的Cosine-BOC信号无模糊跟踪方法

Combined-correlation-function-based unambiguous tracking method for Cosine-BOC signals

二进制偏移载波(binary offset carrier,BOC)调制信号的自相关函数具有多峰性,导致全球导航卫星系统(global navigation satellite systems,GNSS)接收机同步阶段容易产生误捕和模糊跟踪。针对此问题,提出了一种基于合成相关函数的Cosine-BOC信号无模糊跟踪方法。该方法通过设计两路本地辅助信号的波形,与接收BOC信号进行相关运算,构造出无边峰的合成相关函数,实现无模糊跟踪。理论分析与仿真结果表明,该方法能够完全消除BOC自相关函数边峰,保持主峰的宽度,有效地提高了码跟踪的可靠性,同时具有较好的多径抑制能力,且适用于任意阶数的Cosine-BOC调制信号。

Due to multiple side-peaks in the binary offset carrier （BOC） autocorrelation function （ACF）, false lock and ambiguous tracking will be generated with high probability in the synchronous process for the global navigation satellite system （GNSS） receivers. An unambiguous tracking method based on a combined correlation function for Cosine-BOC signals is proposed. This new method is implemented to create a no-side- peak combined correlation function by designing the modulated symbols of two local signals, which are cross correlation with the received BOC signal. The theoretical analysis and simulation results indicate that the pro- posed method can remove the side-peaks of BOC ACF completely while maintaining the shape of the main peak, thus the tacking reliability is improved effectively, and it exhibits an average multipath performance. This method is also suitable for arbitrary order Cosine-BOC signals.