应用自适应时频分布的瞬时频率估计

Estimation of the Instantaneous Frequency Using Adaptive Time-Frequency Distribution

估计信号的瞬时频率常用解析信号的相位差分或Cohen类时频分布的时间一阶条件矩 ,但这些方法在信噪比较低时存在较大的方差。提出了一种新的瞬时频率估计方法 ,它把被分析的信号自适应地扩展到一组有限的 ,具有较好的时频局部化特征的基函数集上 ,用相应的自适应时频分布的谱峰检测来估计信号瞬时频率。仿真结果表明 ,该方法具有较好的抗噪声能力 ,且能够灵活地应用于估计多分量信号的瞬时频率 ,可以取得比其它方法更好的效果。

The central finite difference of the analytic signal and the first moment of Cohen time-frequency distribution have been commonly used to estimate the instantaneous frequency, however, they exhibit a high variance for noise signals with lower SNR. This paper introduces a new method for estimating the instantaneous frequency. In this method, signal is adaptively decomposed into a set of waveforms which are of good local behavior, and the peak detection of the related adaptive time-frequency distribution is used to estimate the instantaneous frequency. Simulation results have shown that this method is efficient at reducing noise and flexible in processing multicomponent signals, It can yield a more accurate estimation of the instantaneous frequency than other methods.;