小波变换中的信号边界延拓方法研究

Research on Signal Extended Methods in Wavelet Transform

研究了小波变换中的离散信号边界延拓问题,由离散小波变换后信号长度的变化引出信号边界处理问题,给出了各种边界延拓方法及其数学表达式。利用正弦信号分析各种边界延拓方法对信号进行小波变换产生的不同结果和对信号极值检测的影响,给出了相应仿真实验和重要结论。

Discrete signal boundary extended methods in wavelet transform are studied. The length of signal in discrete wavelet transform varies with different signal filter bank. All＇ kinds of extended method and its mathematic expression are detailedly described. Based on sine signal, different extended methods have different results after wavelet transform. This paper discusses these results and analyzes detecting the local extremum of signal. A series of experimental results and some important conclusions are1 acquired.