matlab ssb 调幅 程序 求 高人 解释

% ch5example7prog1.m

clear

fs=10000

t=1/fs:1/fs:1

m_t(fs*1)=0

for F=150:400

m_t=m_t+0.003*sin(2*pi*F*t)*(400-F)

end

m_t90shift=imag(hilbert(m_t))

carriercos=cos(2*pi*1000*t)

carriersin=sin(2*pi*1000*t)

s_ssb1=m_t.*carriercos-m_t90shift.*carriersin

s_ssb2=m_t.*carriercos+m_t90shift.*carriersin

%下面租键中做出各波形以及频谱

figure(1)

subplot(4,2,1)plot(t(1:100),carriercos(1:100),...

t(1:100),carriersin(1:100),'--r')

subplot(4,2,2)plot([0:9999],abs(fft(carriercos)))

axis([0 2000 500 6000])

subplot(4,2,2)plot(t(1:100),m_t(1:100))

subplot(4,2,3)plot([0:9999],abs(fft(m_t)))

axis([0 2000 500 6000])

subplot(4,2,4)plot([0:9999],abs(fft(s_ssb1)))

axis([0 2000 500 6000])

subplot(4,2,5)plot(t(1:100),s_ssb2(1:100))

subplot(4,2,6)plot([0:9999],abs(fft(s_ssb2)))

axis([0 2000 500 6000])

好了，弊山你看亮租一下，对不对

用希御培尔伯特变换可以实现包络检波!

clear allclose all

t=0:200

x1=sin(8*pi*t/100)+1

subplot(411)plot(t,x1)title('信号')

x2=4*sin(40*pi*t/100)

subplot(412)plot(t,x2)title('载波')

x3=(1+x1).*x2

subplot(413)plot(t,x3)title('调幅信号')

x4=abs(hilbert(x3))

subplot(414)plot(t,x4)title('解调信号'闹拆或液伍)

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