由于硬件已经固定，但是出现较大的尖波干扰，需要从软件上进行滤波，去除干扰并取得了不错的效果

% [db,mag,pha,grd,w] = freqz_m(b,a); % db = Relative magnitude in dB computed over 0 to pi radians % mag = absolute magnitude computed over 0 to pi radians % pha = Phase response in radians over 0 to pi radians % grd = Group delay over 0 to pi

主要包括各种滤波去噪的方法，比如FIR滤波器、IIR滤波器、自适应滤波器等