基于合成相关函数的sin-BOC/MBOC无模糊捕获方法

Synthesized correlation function based unambiguous acquisition technique for sin-BOC/MBOC modulated signals

为了有效消除正弦相位二进制偏移载波(binary offset carrier,BOC)调制信号捕获过程中存在的多相关峰模糊性问题,提出了一种针对正弦相位BOC调制的无模糊捕获方法。该方法通过构建两路本地辅助信号,利用本地信号与接收信号的互相关函数的非线性组合构建无模糊的合成相关函数,从而实现正弦相位BOC调制信号的无模糊捕获。同时,该方法同样适用于复杂BOC(multiplexed-BOC,MBOC)调制信号,并且本地辅助信号的二级码片波形取代了传统方法中MBOC本地复制信号的多级码片波形,极大地简化了接收机的电路结构。理论分析与仿真结果表明,该方法在以牺牲一定的捕获灵敏度为代价的前提下,成功实现了正弦相位BOC调制信号的无模糊捕获,并且在无数据调制的导航通道中表现出更高的捕获灵敏度。

An unambiguous acquisition technique for sine phased binary offset carrier （BOC） modulated sig- nal is proposed to eliminate the ambiguity threat in sin-BOC modulated signals acquisition process. Two local auxiliary signals are proposed in this method, and the nonlinearly combination of the two cross-correlation func tions between the received signal and the two local auxiliary signals constitute an unambiguous synthesized cor- relation function. This technique is also suitable for multiplexed BOC （MBOC） modulated signals simultaneous ly, and the two-lever local code symbols in the proposed method supersedes multi-lever local replica MBOC code symbols in traditional method, which simplifies the structure of circuits in the receiver. Theoretical and simula tion results demonstrate that the proposed technique completely removes ambiguity threat in sin-BOC/MBOC modulated signals acquisition process with slightly acquisition sensitivity degradation, and it is more suitable to be used in data-less channels.