如何提高卫星导航定位P码的捕获速度和精度是军用接收技术研究的热点问题之一。在GPS P码扩展复制重叠(XFAST)捕获算法和均值捕获算法的基础上, 提出一种基于时频融合的捕获算法, 通过对本地序列进行XFAST处理, 在不影响相关度的基础上扩大搜索范围,并对处理后的本地序列和接收序列进行均值处理, 相当于减少之后相关的码元个数, 也即减少了运算量, 从而达到提高捕获速度的目的。对所提算法的可行性进行了分析, 给出了算法的具体处理过程, 仿真实验验证了该方法的有效性。

How to improve the acquisition speed and precision of satellite navigation positioning P-code is one of the hot issues in military receiving technology research. Based on the GPS P-code extended replication overlap (XFAST) acquisition algorithm and the mean acquisition algorithm, an acquisition algorithm based on time-frequency fusion is proposed.Through XFAST processing to the local sequence, the search area is expanded without affecting the degree of correlation. Then averaging is made to the processed local sequence and the received sequence, thus to reduce the amount of computation, and to achieve the purpose of improving the capture speed. The feasibility of the algorithm is analyzed, and the specific process of the algorithm is presented. The simulation results verify the effectiveness of the proposed method.