一种基于Chirplet分解的时频分析快速算法

针对信号自适应chirplet分解未知参数多、实现起来比较困难的特点,提出了一种新的chirplet分解快速算法．该算法利用计算信号的二次相位函数,得到其能量分布集中于信号的调频率曲线上的结论,此时通过谱峰检测可同时获得chirplet调频率、时间中心和幅度的估计;然后通过解线性调频技术获得其初始频率和宽度的估计．仿真结果验证了本文算法的有效性．

A FAST IMPLEMENTATION OF TIME- FREQUENCY ANALYSIS BASED ON ADAPTIVE CHIRPLET DECOMPOSITION

The adaptive chirpiet decomposition contains a lot of unknown parameters and has much difficulty in its implementation. In this condition, a fast implementation of adaptive chirpiet decomposition is presented in this paper. By computing the quadratic phase (QP) function of the signal, it is shown that the QP function is concenlrated along the frequency rate law of the signal, and the peak of the QP function yields the estimates of the chirpiet rate, time center and the amplitude. Then the initial frequency and the time extent can be obtained by the dechirp technique. The simulation results demonstrate the validity of the method proposed.