In the BeiDou Navigation Satellite System (BDS) B1 band, a single‐sideband complex binary offset carrier (SCBOC) modulation is employed to combine the legacy and the modernized B1 signals into an asymmetric‐wideband composite signal for the backward compatibility. However, SCBOC modulation has only been regarded as a means to achieve the co‐existance between B1I and B1C signals, whose high‐precision ranging potential is not fully understood or exploited. In this paper, a new pathway for BDS B1 receivers to further enhance their ranging precision is established for the first time, by proposing an unambiguous cross‐assisted tracking (CAT) loop, which fully exploits the ranging performance of the SCBOC subcarrier and the inherent coherence between components in the composite signal. Simulation and experiment using live BDS‐3 signals show that compared to the traditional tracking processing for independent components, the CAT loop can significantly improve ranging performance precision, thus providing a high‐precision processing mode for the BDS B1 composite signal.

中文翻译：

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BDS B1宽带复合信号的高精度无歧义跟踪技术

在北斗导航卫星系统（BDS）的B1频段，采用单边带复二进制偏移载波（SCBOC）调制将旧的和现代化的B1信号组合成非对称宽带复合信号，以实现向后兼容性。但是，SCBOC调制仅被视为实现B1I和B1C信号共存的一种手段，其高精度测距潜力尚未得到充分理解或利用。本文通过提出明确的交叉辅助跟踪（CAT）环路，首次建立了BDS B1接收机进一步提高其测距精度的新途径，该环路充分利用了SCBOC子载波的测距性能和其固有特性。复合信号中各分量之间的相干性。