Classical frequency estimation based on the classic Fourier analysis theoretically is a linear analysis method, while modern frequency estimation is non-linear analysis method, which has a higher resolution ratio and wider adaptability. 经典频率估计以经典傅里叶分析为主要理论依据,是一种线性的分析方法。现代频率估计是基于非线性变换的分析方法,比经典傅里叶分析法具有更高的分辨率和更广的适应性。