代码很简单:
N = 40;
fs = 20 * 10 ^ 9;
freq = [0, 1 * 10 ^ 9, 2 * 10 ^ 9, 3 * 10 ^ 9, 5 * 10 ^ 9, 7.5 * 10 ^ 9, 10 * 10 ^ 9]
mag = [1, 1, 1, 0.3, 0.1, 0.005, 0.001]
d = fdesign.arbmag('N,F,A', N, freq, mag, fs);
W = [1, 1, 1, 1, 1, 1, 1];
fir = design(d, 'equiripple', 'weights', W, 'SystemObject', true);
sents = ones(1, 300) * amplitude;
rcvds = fir(sents);
% plot
figure(1)
stem(sents_downsampled)
hold on
stem(rcvds)
legend('sents', 'received')
通过查看
freqz
,过滤器似乎设计正确: