MATLAB Program for Signal Analysis Using Wavelet Packet Transform

In this program, we implement wavelet packet transform (WPT) to analyze signal characteristics. Wavelet packet transform is a powerful mathematical tool that decomposes signals into sub-signals at different frequency bands, enabling detailed analysis of signal frequency properties. The implementation includes key MATLAB functions such as wpdec() for wavelet packet decomposition, wprcoef() for reconstruction of specific frequency components, and besttree() for optimal tree structure selection. The algorithm involves multi-level decomposition where signals are split into approximation and detail coefficients at each level, providing fine-grained frequency resolution. Through this program, users will learn how to perform signal preprocessing, select appropriate wavelet bases (like db4 or sym8), configure decomposition levels, and visualize the resulting wavelet packet coefficients using MATLAB's plotting functions. This practical implementation helps understand key signal processing concepts including frequency-domain analysis, time-frequency localization, and feature extraction techniques.