BOC信号合成相关函数通用无模糊跟踪方法

Unitary Unambiguous Tracking Method Based on Combined Correlation Functions for BOC Modulated Signals

针对全球导航卫星系统(GNSS)所使用的二进制偏移载波(BOC)调制信号存在跟踪模糊的问题,提出了一种能够应用于多种BOC类型信号的通用无模糊跟踪方法。首先基于调制形状码向量的概念提出了BOC信号通用表示方式。然后,推导了BOC信号互相关函数的调制形状码向量表达式。最后,在BOC通用模型的基础上,基于合成相关函数思想,设计了一种通用无模糊跟踪方法。仿真结果表明,该方法可以适用于各种相位和阶数以及复合和包含复信号的BOC调制信号,得到无模糊的窄单峰相关函数。通过分析该方法的抗噪声性能和多径抑制性能,证明其相对于传统的BOC无模糊跟踪方法具有更好的抗噪声性能。

In order to solve the ambiguous tracking problem for binary offset carrier （BOC） modulated signals which are used in global navigation satellite system （GNSS）, a unitary unambiguous tracking method which is suitable for all kinds of BOC modulated signals is proposed to solve the ambiguous tracking problem. Firstly, the concept of step-shape bits vector is proposed to obtain a unified signal expression. Then, a formula of the cross-correlation function based on step-shape bits vector is derived. Finally, an unambiguous tracking method is proposed based on the idea of combined correlation functions. Simulation results indicate that the proposed method can deal with all kinds of BOC modulated signals including composite and complex ones with different phases or orders. An unambiguous correlated function with narrow single peak can be obtained by the proposed method. Furthermore, the anti-noise and multipath mitigation performance of proposed method are analyzed and the proposed method has better performance in anti-noise mitigation than the traditional unambiguous tracking methods.