中文说明： FIR(Finite Impulse Response)滤波器：有限长单位冲激响应滤波器，又称为非递归型滤波器，是数字信号处理系统中最基本的器件，它可以在保证任意幅频特性的同时具有严格的线性相频特性，同时其单位抽样响应是有限长的，因而滤波器是稳定的系统。因此，FIR滤波器在通信、图像处理、模式识别等领域都有着广泛的应用。 matlab 代码，生成时域和频域波形，可用于FIR滤波器仿真。
English Description：
Fir (fine impulse response) filter: finite length unit impulse response filter, also known as non recursive filter, is the most basic device in digital signal processing system. It can guarantee any amplitude frequency characteristics and has strict linear phase frequency characteristics. At the same time, its unit sampling response is finite length, so the filter is a stable system. Therefore, FIR filter is widely used in communication, image processing, pattern recognition and other fields.