中文摘要：

针对在小波和小波包分解中最大分解层的确定多凭借经验，同时为避免过度分解造成的假频，提出一个确定最大分解层的实用方法。该方法不仅利用数据长度和小波阶数，还进一步利用数据的振幅谱以及尺度函数和小波函数的中心频率，从而使得该方法能有效避免小波和小波包过度分解产生的假频。实例应用表明了该方法的有效性和实用性。

英文摘要：

In view of the fact that the maximum wavelet and wavelet packet decomposition level is usually obtained through experience and pseudo-frequencies may result due to over-decomposition, a practical method of determining maximum decomposition level is proposed, which not only makes use of data length and wavelet-order but also of data amplitude spectrum and central frequencies of scaling and wavelet functions. So the pseudo-frequencies caused by scaling and wavelet functions can be avoided efficiently. Example shows that the proposed method is effective and practical.