【杂波仿真】对数正态分布杂波仿真【含Matlab源码 2741期】.zip

clear all;close all; azi_num=2000; fr=1000; lamda0=0.05; sigmav=1.0; sigmaf=2*sigmav/lamda0; rand('state',sum(100*clock)); d1=rand(1,azi_num); rand('state',7*sum(100*clock)+3); d2=rand(1,azi_num); xi=1*(sqrt(-2*log(d1)).*cos(2*pi*d2)); xq=2*sqrt(-2*log(d1)).*sin(2*pi*d2); coe_num=12; for n=0:coe_num coeff(n+1)=2*sigmaf*sqrt(pi)*exp(-4*sigmaf^2*pi^2*n^2/fr^2)/fr; end for n=1:2*coe_num+1 if n<=coe_num+1 b(n)=1/2*coeff(coe_num+2-n); else b(n)=1/2*coeff(n-coe_num); end end %Gaussion clutter generation xxi=conv(b,xi); xxi=xxi(coe_num*2+1:azi_num+coe_num*2); xisigmac=std(xxi); ximuc=mean(xxi); yyi=(xxi-ximuc)/xisigmac; muc=1.5; sigmac=0.6; yyi=sigmac*yyi+log(muc); xdata=exp(yyi); figure,plot(xdata);xlabel('时间');ylabel('幅度');title('对数正态分布杂波时域波形'); num=100; maxdat=max(abs(xdata)); mindat=min(abs(xdata)); NN=hist(abs(xdata),num); xpdf1=num*NN/((sum(NN)*(maxdat-mindat))); xaxis1=mindat:(maxdat-mindat)/num:maxdat-(maxdat-mindat)/num; th_val=lognpdf(xaxis1,log(muc),sigmac); figure;plot(xaxis1,xpdf1); hold,plot(xaxis1,th_val,':r'); title('杂波幅度分布');xlabel('幅度');ylabel('概率密度'); signal=xdata; signal=signal-mean(signal); figure,M=128; psd_dat=pburg(real(signal),16,M,fr); psd_dat=psd_dat/(max(psd_dat)); freqx=0:0.5*M; freqx=freqx*fr/M; plot(freqx,psd_dat);title('杂波频谱');xlabel('频率(Hz)');ylabel('功率谱密度'); powerf=exp(-freqx.^2/(2*sigmaf.^2)); hold;plot(freqx,powerf,':r');