基于相关移位BOC(n,n)无模糊度捕获算法

GPS现代化过程中，为避免导航信号频段间的互相干扰，采用了BOC调制技术来实现频带资源的合理利用.但是经过BOC调制的信号的自相关函数会存在多个副峰，这将会使捕获存在模糊性.针对这一问题提出了一种新的无模糊度捕获算法，根据BOC单元相关函数的特性，通过与移位半个码片取反后的新函数相乘，最终实现消除边峰的能力.仿真分析表明，本文提出的算法可以削弱副峰的干扰，使主峰跨度减小到半码片宽度，捕获灵敏度同ASPeCT方法，但均峰比比ASPeCT方法提高约10%，计算量也减少了40%. 

An Unambiguous Acquisition Algorithm Based on Correlation Shift for BOC(n,n)

In the course of GPS modernization, in order to avoid mutual interference between navigation signal frequency bands, the BOC modulation technology is adopted to realize rational utilization of frequency band resources. However, there are multiple side peaks in the auto-correlation function of the BOC modulated signal, which will make the acquisition ambiguous. In this paper, a new unambiguous acquisition algorithm was proposed to solve this problem. According to the characteristics of the correlation function of BOC unit, the side-peak cancellation was finally achieved by multiplying a new function after the half-chip shift and the code with polarity reversed. Simulation results show that the algorithm proposed in this paper can mitigate the interference of the side peak, reduce the main peak span to half-chip width, and acquire the same sensitivity as the ASPeCT method.However, the peak-to-average ratio is increased by about 10% and the computational complexity is reduced by 40%.