基于重叠的P码频域直接捕获法研究

Method of Direct Acquisition Search Technique for P Code in Frequency Domain Based on Extended Replica Refolding Acquisition Search Technique

P码可为GPS接收机提供目标精确测距,现有的P码频域直接捕获法主要有扩展复制重叠法XFAST(Extendedreplica folding acquisition search technique)和均值法。本文针对P码频域直接捕获的XFAST法的不足,提出再重叠的扩展复制重叠法─即首先对输入信号和本地扩展分段信号以一定长度分别重叠,然后对本地扩展分段信号再进行段重叠,最后重叠了的输入信号和扩展分段信号进行循环相关处理,以此进一步提高XFAST法频域中对P码的捕获效率,文中对结果进行了讨论。

The precise measurement distance for some object can be obtained by P code for GPS receiver.Now there are XFAST（extended replica folding acquisition search technique） and mean value method.According to the shortcoming of the XFAST to capture P code in frequency domain,the refolding XFAST is put forward to in the paper.The input signal and extended segmented signals are folded separatively by some length first.Then the extended segmented signals are folded by every segment.At last the cycle correlation is adopted to the folded input signal and extended segmented signals.The efficiency to capture P code in frequency domain is promoted further compared with the XFAST.The result is tested in the final.