%發(fā)射分集,選擇性合并
clear;
for SNR=[1 sqrt(10) 10 sqrt(1000) 100 sqrt(100000) 1000]    %信噪比
    C=zeros(1,8);
    i=1;
    for Nr=[1 3 5 7 9 24 48 64]   %發(fā)射天線的數(shù)目
        ronglian=zeros(1,200);
        for n=1:200                         %重復(fù)次數(shù)
            H=(randn(Nr,1)+j*randn(Nr,1))/sqrt(2);     %瑞利信道，零均值復(fù)高斯隨機(jī)變量，方差為0.5
            G=(abs(H)).^2;                             %選擇性合并
            K=max(G);                                  %選擇性合并
            ronglian(1,n)=log2(1+SNR*K);               %求容量
        end
        C(1,i)=sum(ronglian)/200;                      %求算術(shù)平均
        i=i+1;
    end
    Nr=[1 3 5 7 9 24 48 64];
    plot(Nr,C,'-*');
    grid on;
    hold on;
    axis([0,70,0,14]);
end
xlabel('接收天線Nr');
ylabel('容量/(bit/s/Hz)');
text(40,2.7,'SNR=0dB');
text(40,4.4,'SNR=5dB');
text(40,6.5,'SNR=10dB');
text(40,7.4,'SNR=15dB');
text(40,9.0,'SNR=20dB');
text(40,10.7,'SNR=25dB');
text(40,12.5,'SNR=30dB');