基于瞬时参数估计的信号分量提取

Signal Component Extraction Using Instantaneous Parameters Estimation

具有非线性时频关系的多分量信号频谱占有较宽的频带且相互交叠,针对此类信号分量提取难的问题,提出了一种基于瞬时参数估计的信号分量提取算法。首先,采用FMmlet变换将被分析信号在时频空间内展开;然后,根据时频面内能量峰脊与瞬时频率的对应关系,应用谱峰检测法估计出所需提取分量的瞬时频率;按照最小二乘法滤波原理估计该分量的瞬时幅值,继而按照信号瞬时模型恢复重构出对应的信号分量。理论分析和仿真试验表明,该方法能从时频相交或不相交的多分量复杂时变信号中提取出所需信号分量,且失真度小。

The multicomponent signal with nonlinear time-frequency(TF) structure occupies a wide frequency band,and its spectral contents usually overlap.Aimed at the difficulty of extracting the needed component from such complex signals,a novel method was proposed to extract components based on instantaneous parameters estimation.Firstly,FMmlet transform was adopted to determine TF distribution with high TF resolution and less cross-term interference.Then,according to the corresponding relation of energy ridges in TF plane and the IFs,the IF of needed component was estimated with the TF peak-detection method.And the instantaneous amplitude of needed component was estimated using least squares algorithm.Finally,combining the instantaneous frequency and amplitude,the needed component was reconstructed by using the signal model.A synthetic signal was analytically formulated and used as a tested signal for evaluating the method performance.Theoretical predictions and numerical experiment show the feasibility of the method which has good application prospects for in-depth feature extraction of non-stationary multi-component signals.