noiseAM&FM.rar_FM 干扰_matlab 噪声调频_噪声调幅干扰_干扰仿真_调幅噪声

%噪声调频干扰 function y=noiseFM(uj,mf,wpp); if nargin==0 uj=1; mf=0.6; wpp=6; end fj=35e6; fs=4*fj; Tr=520e-6; bj=10e6; t1=0:1/fs:3*Tr-1/fs; N=length(t1); u=wgn(1,N,wpp); df1=fs/N; n=0:N/2; f=n*df1; wp=10e6; ws=13e6; rp=1; rs=60; [Nn,wn]=buttord(wp/(30e6/2),ws/(30e6/2),rp,rs); [b,a]=butter(Nn,wn); u1=filter(b,a,u); figure subplot(2,2,1), plot(t1,u1), title('调制噪声波形'); axis([0,0.05e-4,-6,6]) subplot(2,2,2), j2=fft(u1); plot(f,10*log10(abs(j2(n+1)*2/N))) title('调制噪声功率谱'); i=1:N-1; ss=cumsum([0 u1(i)]) ss=ss*Tr/N; y=uj*cos(2*pi*fj*t1+2*pi*mf*bj*ss+100); p=(1/N)*sum(y.^2) subplot(2,2,3), plot(t1,y), title('噪声调频干扰时域波形') axis([0,0.05e-4,-1.5,1.5]) subplot(2,2,4), J=fft(y); plot(f,(abs(J(n+1)))) title('噪声调频干扰已调波功率谱')