基于频域搜索的GPS信号P码直接捕获改进算法

Improved algorithm for direct GPS signal P-Code acquisition based on frequency domain search

为减少由峰值模糊造成的载波频偏误判概率,提出一种改进算法,通过计算Q路信号的相关值提高了对载波频率偏移的分辨能力,并利用相关值的重叠相加改进了目标码段的相关峰值.仿真结果表明,改进算法在不损失捕获速度和不增加资源消耗的前提下,有效地提高了检测概率、降低了载波频偏误判概率,是一种快速高效的GPS信号P码直接捕获算法.

An improved algorithm is proposed to reduce the wrong judgment probability of carrier frequency due to ambiguous peak. It enhances the resolving power of carrier frequency offset by extracting the Q branch＇ s spectrum to calculate the correlation and improves the correlation peak value of target sequence by using the overlap-add effect of correlation. Simulations are made to analyze the acquisition performance of the algorithm and the results show that the algorithm presented is a fast and effective direct acquisition algorithm for GPS signal P code, which improves acquisition performance without loss of acquisition speed and increase of hardware consumption.