数字信号课程设计报告

figure(2); subplot(3,1,1)

plot(f,abs(X(1:(N+1)/2)));title('原信号频域图') figure(1);

subplot(3,1,2);

plot(t,y1);title('加白噪后的时域图'); figure(2);

subplot(3,1,2);

plot(f,abs(Y1(1:(N+1)/2)));title('加白噪后的频域图'); figure(1);

subplot(3,1,3);

plot(t,yl);title('滤波后信号时域图') figure(2)

subplot(3,1,3);

plot(f,abs(Yl(1:(N+1)/2)));%plot(f,abs(Yl)); title('滤波后信号频域图') figure(3)

[h2,w2]=freqz(bl,1);

plot(w2/(2*pi)*fs,20*log10(abs(h2)));title('blackman低通滤波器频率响应图');