想做CIC插值抽取滤波器,五级级联。若插值比例为4,则单级滤波器的系数是h1 = [1 1 1 1];那么五级级联滤波器的系数就是h2=conv(h1,h1);h4 = conv(h2,h2);h5 = conb(h4,h1);然后要滤波器系数归一化吗?h_cic = impz(h5/(5^5,1)吗?