CAJ | 학술논문

为了解决传统 GPS 接收机对弱信号频率牵引速度比较慢、成功率较低的问题，该文提出基于 FFT 的频率估计方法。为了克服导航数据比特反转带来的影响，用平方法和差分法分别构造的新变量作为FFT运算的输入。实验结果显示，没有比特边沿先验信息的情况下，差分构造变量的方法在21 dBHz弱信号时正确估计频率概率在95%以上，有比特边沿先验信息的情况下，平方构造变量的方法在19 dBHz弱信号下正确检测频率概率仍能达到95%。
위료해결전통 GPS 접수궤대약신호빈솔견인속도비교만、성공솔교저적문제，해문제출기우 FFT 적빈솔고계방법。위료극복도항수거비특반전대래적영향，용평방법화차분법분별구조적신변량작위FFT운산적수입。실험결과현시，몰유비특변연선험신식적정황하，차분구조변량적방법재21 dBHz약신호시정학고계빈솔개솔재95%이상，유비특변연선험신식적정황하，평방구조변량적방법재19 dBHz약신호하정학검측빈솔개솔잉능체도95%。
The frequency pull-in process of traditional GPS receiver is time-consuming and its success rate is low under weak GPS signal environments. In order to solve this problem, FFT-based fine frequency estimation methods are presented. To overcome data bit phase transition, new input variables of FFT are constructed by using the squaring or differential algorithm. The experimental results show that the frequency detection probability is above 95% using differential algorithm whenC/N0=21 dBHz if prior information of the navigation data is unknown. The frequency detection probability is above 95% using squaring algorithm whenC/N0=19 dBHz if prior information of the navigation data is known.