FIR数字滤波器设计。包括常用窗函数及其MATLAB实现、基于频率抽样法的FIR滤波器设计、基于切比雪夫逼近法的FIR滤波器设计。-FIR digital filter design. Including the common window function and its MATLAB, based on frequency sampling FIR filter design, based on Chebyshev approxim