中文说明：采用PBFDAF算法进行回声消除，代码逻辑清晰，简单易懂，对初学自适应滤波器，回声消除算法等能够起到很好的学习作用。
English Description：
Using pbfdaf algorithm for echo cancellation, the code logic is clear, simple and easy to understand. It can play a good role in learning adaptive filter and echo cancellation algorithm for beginners.