针对二进制偏移载波(BOC)调制信号自相关多峰特性引起的信号捕获模糊性问题,提出了一种子相关相乘边峰消除技术(CMSCT)。根据BOC子相关函数的特性,通过将不同子相关函数相乘获得边峰消除能力,并且为了充分利用接收信号,进一步提高捕获性能,提出了相应的优化算法。分析对比了提出算法的实现复杂度和基于恒虚警率准则的峰值发现概率,对Galileo E1C中频采样信号的处理结果表明:提出的边峰消除方法有效解决了捕获模糊性问题。
Multiple peaks of autocorrelation function of binary offset carrier(BOC)modulated signal can lead to ambiguity of signal acquisition.To solve the problem,a correlation multiplication side-peak cancellation technique(CMSCT)is proposed.Based on the special property of sub-correlation function of BOC signal,side peaks can be removed by multiplying different sub-correlation functions.Corresponding modified algorithm is presented for the purpose of taking full advantage of all received data to improve the acquisition performance.The complexity of the proposed algorithm as well as its detection probability based on the constant false alarm rate criterion are analyzed and compared with other algorithms.The result of using CMSCT for intermediate frequency sampling signal of Galileo E1 Cshows that the presented technique can effectively solve the problem of ambiguous acquisition.