weibulltest.m

对雷达杂波分布为weibull功率谱为高斯谱的杂波模型进行仿真.

clear all; close all;
azi_num = 2000;
fr = 1000;
lamda0 = 0.05;
sigmav = 1.0;
sigmaf = 2*sigmav/lamda0;

randRes1=spRand(0,1,azi_num);%生成两组互相独立的高斯随机数
randRes2=spRand(0,2,azi_num);
%求滤波器系数
BT = .3; 
OF = 6;   
NT = 2;  
b = gaussfir(BT,NT,OF);
%生成高斯谱杂波
xxi = conv(b,randRes1(1,:));
xxq = conv(b,randRes2(2,:));
%去掉暂态响应
yyi=disZ(xxi,NT,OF,azi_num);
yyq=disZ(xxq,NT,OF,azi_num);

p=1.5;
q=1.2;
sigmac=sqrt((q.^p)/2);
yyi=sigmac*yyi;
yyq=sigmac*yyq;

ydata=(yyi.^2+yyq.^2).^(1/p);
figure,plot(ydata);
%仿真结果的概率密度
pdfRes=pdfPlot(abs(ydata),100);
%概率密度函数理论值
th_val=(p/q)*(pdfRes(1,:)./q).^(p-1).*exp(-(pdfRes(1,:)./q).^p);

%作出仿真结果和理论的概率密度函数曲线.
figure(2)
plot(pdfRes(1,:),pdfRes(2,:),pdfRes(1,:),th_val,'r:');
title('杂波幅度分布');xlabel('幅度');ylabel('概率密度');

%求功率谱密度
signal = ydata;
signal = signal-mean(signal);%去直充分量
[psd_dat,freqx]=pburg(real(signal),32,256,fr);  %%%用Burg法估计功率谱密度
psd_dat=psd_dat/(max(psd_dat));      %归一化处理
powerf=exp(-freqx.^2/(2*sigmaf.^2)); %理想高斯谱曲线
figure(3)
plot(freqx,psd_dat,freqx,powerf,':r');
title('杂波频谱');xlabel('频率(Hz)');ylabel('功率谱密度');