基于因子图的Gold码迭代捕获算法研究

为了降低Gold码捕获的捕获时间与复杂度，本文提出将基于因子图的迭代m序列捕获算法应用于Gold码捕获。以GPS信号的C/A码为例首先根据Gold码的生成多项式确定一组具有稀疏结构的校验关系，然后为了降低迭代计算的复杂度，提出了不同校验关系顺次校验与混合校验的迭代捕获算法，最后通过仿真研究比较了不同的校验关系和校验方法对迭代捕获算法性能的影响。仿真结果表明顺次迭代且迭代次数递减的校验方法最优，该方法能够在不损失检测概率的情况下降低Gold码捕获的复杂度，同时降低其捕获时间。

Iterative Acquisition Algorithm of Gold Codes Based on Factor Graphs

To decrease the acquisition time and complexity of Gold code acquisition, m-sequence iterative acquisition algorithm was applied to Gold code. Take GPS C/A code an example, firstly, a group of sparse check relations were found according to creating polynomials of Gold code. Then for the purpose of decreasing the complexity of iterative computation, ordinal check and mixed check method were proposed. Finally, the influences on iterative acquisition performance made by different check relations and different check method were researched by simulation. Simulation results show that ordinal check with degressive iterative number is optimal, which can effectively decrease the complexity and acquisition time.