MIMO信道容量仿真matlab代码

clc; clear all; close all; mt=3; mr=3; for n=1:3 %n=1对应SISO,n=2对应等功率算法，n=3对应注水算法 ESNO=-5:5:30; for m=1:length(ESNO) esno=ESNO(m); esno=10^(esno/10); sum1=0; sum2=0; sum3=0; for z=1:1000 if(n==1) H=randn/sqrt(2)+sqrt(-1)*randn/sqrt(2); sum1=sum1+log2(1+esno*((abs(H))^2)); else hr=randn(mr,mt)/sqrt(2); hi=randn(mr,mt)/sqrt(2); h=hr+j*hi; a=eig(h*(h')); % 特征值 a=real(a); a=a(find(a>0)); r=length(a); if(n==2) cx=0; for g=1:r c1=log2(1+esno*a(g)/mt); cx=cx+c1; end sum2=sum2+cx; %等功率核心算法结束 else %注水算法 a=sort(a); %升序 for p=1:r sum=0; for x=p:r sum=sum+1/(a(x)); end aver=mt/(r-p+1)*(1+sum/esno); %求水平线 y=aver-mt/(esno*a(p)); if(y>0) break; end end for x=p:r y(x)=aver-mt/(esno*a(x)); end c=0; for x=p:r c=c+log2(1+a(x)*y(x)*esno/mt); end sum3=sum3+c; %注水核心算法结束 end end end cequ1(m)=sum1/1000; cequ2(m)=sum2/1000; cequ3(m)=sum3/1000; end if(n==1) plot(ESNO,cequ1,'s-.','Color','r'); hold on; end if(n==2) plot(ESNO,cequ2,'s-.','Color','k'); hold on; end if(n==3) plot(ESNO,cequ3,'s-.','Color','m'); hold on; end end legend('SISO 1X1','MIMO_(power) 3X3','MIMO_(water) 3X3',4); xlabel('信噪比(dB)'); ylabel('平均信道容量'); title('等功率与注水算法的对比');