结合具体应用，以2倍抽取为例，简要分析了多相滤波的基本原理及具体实现方法，并附带了matlab代码，从实验结果可以看出多相滤波可以实现与传统FIR滤波相同的功能。-Combine concrete application, take 200　extracts as an example, the synopsis analyzes the radical principle that the polyphase filters and concretely carries out a method, and supplementary matlab code, can discover polyphase to filter as a result to carry out to filter same function with traditional FIR from the experiment.