雷达系统仿真设计报告二 - 图文

雷达系统仿真设计报告

for i=1:length(s) s(i)=10*log10(s(i)); end

subplot(325);plot(f,s);title('真实功率谱');ylabel('幅度(取对数)');xlabel('f');grid on;

（2）非相干相关韦布尔杂波实现代码 clear all; close all; clc

azi_num=2000; fr=1000; lamda0=0.05; sigmav=0.7;

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;

coeff=zeros(1,coe_num+1); for n=0:coe_num

coeff(n+1)=2*sigmaf*sqrt(pi)*exp(-4*sigmaf^2*pi^2*n^2/fr^2)/fr; end

b=zeros(1,2*coe_num +1); for n=1:2*coe_num +1 if n<=coe_num+1

b(n)=1/2*coeff(coe_num+2-n); else

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雷达系统仿真设计报告

b(n)=1/2*coeff(n-coe_num); end end

%生成高斯谱杂波 xxi=conv(b,xi); xxq=conv(b,xq);

xxi=xxi(coe_num*2+1:azi_num+coe_num*2); xxq=xxq(coe_num*2+1:azi_num+coe_num*2); xisigmac=std(xxi); ximuc=mean(xxi); yyi=(xxi-ximuc)/xisigmac; xqsigmac=std(xxq); xqmuc=mean(xxq); yyq=(xxq-xqmuc)/xqsigmac; p=1.5; q=2;

sigmac=sqrt((q.^p)/2); %杂波的标准差 yyi=sigmac*yyi; yyq=sigmac*yyq;

xdata=(yyi.*yyi+yyq.*yyq).^(1/p);

subplot(311),plot(xdata);title('相关Weibull分布杂波时域波形'); num=100;

maxdata=max(abs(xdata)); mindata=min(abs(xdata)); NN=hist(abs(xdata),num);

xpdf1=num*NN/((sum(NN))*(maxdata-mindata));

xaxis1=mindata:(maxdata-mindata)/num:maxdata-(maxdata-mindata)/num; th_val=p*(xaxis1.^(p-1)).*exp(-(xaxis1/p).^p)./(q.^p); subplot(312),plot(xaxis1,xpdf1);hold on;

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雷达系统仿真设计报告

plot(xaxis1,th_val,':r');

title('杂波幅度分布');xlabel('幅度' );ylabel('概率密度'); Ns=400;

pxx1=abs(fft(xdata(1:400),Ns).^2)/Ns; pxx2=abs(fft(xdata(401:800),Ns).^2)/Ns; pxx3=abs(fft(xdata(801:1200),Ns).^2)/Ns; pxx4=abs(fft(xdata(1201:1600),Ns).^2)/Ns; pxx5=abs(fft(xdata(1601:2000),Ns).^2)/Ns; pxx=10*log10((pxx1+pxx2+pxx3+pxx4+pxx5)/5); f=(0:length(pxx)-1)/length(pxx);

subplot(313),plot(pxx);title('功率谱估计');ylabel('幅度(取对数)');xlabel('f');grid on;

（3）非相干相关对数正态杂波实现代码

clear all; close all azi_num=2000; fr=1000; lamda0=0.05; sigmav=1.0;

sigmaf=2*sigmav/lamda0; rand('state',7*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); coe_num=12;

coeff=zeros(1,coe_num+1); for n=0:coe_num

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雷达系统仿真设计报告

coeff(n+1)=2*sigmaf*sqrt(pi)*exp(-4*sigmaf^2*pi^2*n^2/fr^2)/fr; end

b=zeros(1,2*coe_num +1); 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

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=10; sigmac=0.6;

yyi=sigmac*yyi+log(muc); xdata=exp(yyi);

subplot(311),plot(xdata); title('对数正态杂波时域波形'); num=50;

maxdata=max(abs(xdata)); mindata=min(abs(xdata));

subplot(312),hist(abs(xdata),num);title('概率密度函数估计'); Xdata=fft(xdata);

%%%%%%%%用分段周期图法对相关对数正态杂波进行谱估计 Ns=400;

pxx1=abs(fft(xdata(1:400),Ns).^2)/Ns;

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