BOC（n，n）类信号的无模糊抗多径跟踪算法

摘要

Binary Offset Carrier (BOC) modulation has separate power spectrum and large Gabor bandwidth,but the multi-peak auto-correlation function makes the tracking algorithms difficult to balance the multipath mitigation and ambiguity resolution perform-ance.BOC(n,n) signals are the BOC signals of which the spreading code frequency is equal with the sub-carrier frequency.The TMBOC and CBOC signals derived from BOC(n,n) signals are widely used in modern GNSS systems.A BOC(n,n) tracking algorithm is pro-posed.The algorithm first adopts the local shaping technique based on gating function to construct an anti-multipath s-curve,and then a non-match prompt tracking code is introduced to eliminate the ambiguity at half of the chip duration.The algorithm successfully remove the ambiguity while still keeps the tracking accuracy and multipath performance.Different tracking algorithm for derived BOC(n,n) sig-nals are discussed.The simulation results show that the multipath performance achieves the theoretical limitation for specified bandwidth with no tracking ambiguity.%二进制偏移载波（Binary Offset Carrier， BOC）调制具有分裂的功率谱和大 Gabor 带宽，但 BOC 信号相关峰的多峰特性使跟踪算法难以兼顾多径抑制和解模糊性能。 BOC（n，n）信号是子载波频率与主扩频码频率相同的 BOC 调制，衍生出的 TMBOC 和 CBOC 信号在卫星导航系统中有着广泛的应用。提出了一种 BOC（n，n）类信号的跟踪算法，该算法首先利用基于门函数的本地赋形技术形成利于抗多径的鉴别曲线，再构造一路非匹配的准时跟踪码，消除鉴别曲线在超前半个码片处的跟踪模糊。与传统抗多径算法相比，在不降低跟踪精度和抗多径性能的同时，解决了 BOC（n，n）信号的跟踪模糊。对不同的 BOC（n，n）衍生信号分别给出了跟踪方案，仿真结果表明，算法可达到 BOC（n，n）类信号给定带宽下的多径抑制极限，且不存在跟踪模糊。