中文说明：
变采样和多相滤波器的实现。本程序实现了一个变采样程序，中间设计滤波器设计和插值抽取。其中滤波器设计用的是窗函数法，根据要求设计窗函数，得到窗函数的长度。接着是插值，滤波，抽取，得到最后变采样之后的波形文件、另外对比了用直接卷积和多相分解卷积两种方法最后的结果。
English Description：
The realization of variable sampling and polyphase filter. This program implements a variable sampling program, middle design, filter design and interpolation decimation. The filter design uses the window function method, according to the requirements of the design window function, get the length of the window function. Then, interpolation, filtering and extraction are used to get the waveform file after the final variable sampling. In addition, the results of direct convolution and polyphase deconvolution are compared