双模噪声背景下多阈值小波包在信号消噪中的应用

针对一类非高斯噪声——双模噪声信号进行消噪时,传统小波变换和小波包变换在选取恰当阈值准则及阈值量化时存在困难,通过详细分析双模噪声信号结构及频率分布特征,在将小波包分解频带按照频率顺序排列且通过比较最底层子空间节点能量大小的基础上,提出一种将频带进行多分段的多阈值小波包消噪方法.实验结果表明:在双模噪声且信噪比相同情况下,该方法比传统的多尺度小波软阈值、小波包自适应阈值消噪效果都优越,是一种非常有效的信号消噪方法.

The Signal De-Noising Based on Multi-Threshold Wavelet Packet under Dual-Mode Noise

For a class of non-Gaussian noise-dual-mode noise de-noising,traditional wavelet transform and wavelet packet transform had difficulty in selecting the appropriate threshold criteria and thresholds to quantify.Through detailed analysis of the structure and frequency distribution characteristics of the dual-mode noise signal,and based on wavelet packet decomposition frequency band according to the order and comparing the lowest level of energy subspace node,a band of multi segment and multi threshold wavelet packet de-noising method has been proposed.Simulation results show that in the background of the dual-mode noise and signal to noise ratio under the same situation,this method which is a very effective method of signal de-noising is better than the traditional multi-scale wavelet soft threshold and wavelet packet adaptive threshold de-noising effect.