clear all; samplerate = 1600e3; nyqistrate = samplerate/2; Wp1 = 160e3/nyqistrate; Ws1 = 200e3/nyqistrate; Rp = 1; Rs = 40; [n, Wc] = buttord(Wp1, Ws1, Rp, Rs); [b] = fir1(n, Wc); x = 1:22; y = filter(b,1,x); y = y(2:2:end); phase_channels = 2; b_poly = buffer(b, phase_channels); y1 = filter(b_poly(2,:), 1, x(1:2:end)); y2 = filter(b_poly(1,:), 1, x(2:2:end)); y_poly = y1 + y2; y_err = y - y_poly; print_ppf_filter_coef(b, phase_channels);