基于分数阶Fourier变换的瞬时频率估计方法

A method of instantaneous frequency estimation based on fractional Fourier tansformation

通过分析分数阶Fourier变换功率谱与信号相位微分的关系,提出了根据信号密度分布和分数阶Fourier谱估计信号瞬时频率的方法。并对含噪声和不含噪声的两种信号进行了计算机仿真,仿真结果表明了该方法的有效性,实验表明该方法适用于信噪比大于3dB的信号。采用非递归算法,不需要进行时频平面上的投影和峰值搜索,运算量低。

The relationship between the fractional Fourier power spectrum and signal's phase differentiation operation are considered.A novel method for solving the instantaneous frequency estimation problem from only intensity distributions and the fractional Fourier spectrum is proposed.The efficiency of the method is demonstrated on two examples including signals with and without noise.It is shown that the proposed method works well for signal-to-noise ratios (SNRs) higher than about 3 dB.The proposed method is noniterative and doesn't need projection or peak-searching,thus it takes low computiong cost.