说明：  基于FFT谱连续细化算法的高精度频率估计，这种算法可以精确到小数点后两位，这种算法与MUSIC法和ESPRIT法相比，计算量大大降低，而且精度非常高。
(This procedure is based on the FFT spectrum continual refinement algorithm s high accuracy frequency， this algorithm may precisely to decimal point latter two, compared the MUSIC algorithm and the ESPRIT algorithm, the computation complexity reduces greatly, moreover the precision is high.)