卫星导航MSK扩频调制及跟踪技术研究

Study on MSK Modulation and Tracking Technique for Satellite Navigation Systems

针对基于最小频移键控(MSK)扩频调制的卫星导航信号的跟踪问题,建立了通用的MSK调制的信号功率谱密度模型,分析了基于MSK调制的二进制偏移载波(MSK-BOC)信号的跟踪模糊现象,提出了一种基于本地码余弦脉冲成形的稳定的MSK-BOC(n,n)卫星导航信号无模糊跟踪方法,仿真并论证了使用该方法的MSK-BOC(n,n)信号的无模糊码跟踪误差和多径误差包络.分析结果表明,该方法可以完全消除MSK-BOC(n,n)信号的跟踪模糊现象,简化跟踪环路的软硬件设计,并保证较好的跟踪精度.

In order to investigate the applications of the signals based on the spread-spectrum minimum shift keying （MSK） modulation for satellite navigation systems, the general mathematical model of the MSK modulated signals was established and the biased tracking for the minimum shift keying-binary offset carrier （MSK-BOC） signals was demonstrated. Then, a novel algorithm was proposed to remove the threat of potentially giving biased measurements of MSK-BOC（n, n） signals. The performance in terms of tracking accuracy was theoretically analyzed and the architecture of the code tracking loop in accordance with this algorithm was presented. The results indicate that this unambiguous tracking algorithm can reduce the complexity of the required hardware and software blocks and have an acceptable tracking performance.