基于Hilbert变换的脉冲信号FRI采样及其参数估计

摘要

为了降低信号的采样速率,减少采集数据量,针对非严格有限新息率(Finite Rate of Innovation,FRI)信号,提出了一种基于 Hilbert变换的超声脉冲信号 FRI 采样方法。将脉冲超声检测信号通过 Hilbert变换解包络,形成具有有限新息率的脉冲信号,利用低速采样系统实现了脉冲超声检测信号的低速采样。通过零化滤波器方法从低速采样信号中解算出了脉冲超声检测信号的峰值时刻点,实现了对检测信号的参数估计。通过加入加性高斯白噪声验证了该采样方法对噪声的适应能力。试验结果表明,该低速采样方法可减少信号的采集数据量,并准确估计出峰值到达时刻点。%For the purpose of lowering the signal sampling rate and reducing the amount of testing data,a sampling method of ultrasonic pulse signal with non-restrict finite rate of innovation (FRI)is proposed based on Hilbert transform.The pulse signal with FRI is obtained by solving the envelope of the tested ultrasonic signal using Hilbert transform.Then,low rate sampling has been accomplished on pulse signal.The adaptive capacity of the low-rate sampling technique is verified by putting additional Gaussian white noise in the signal.The experimental results show that this method can not only reduce the amount of sampling data,but also be used to estimate the arrival time of the echo peak accurately.