fig6_78.m

《最优阵列处理》一书第六章的MATLAB例程

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Example 6.8.3  Dm=3
% Dominant Mode Rejection: Array Gain vs. us/BWnn
% Lillian Xiaolan Xu
% updated 09/13/2000, 02/13/2001
% updated by K. Bell 1/18/08
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
clear all
close all

N=10;
BWnn=4/N;
INR1=10.^([30]/10);
INR2=10.^([30]/10);
SNR=10.^([-10:10:30]/10);

n=(-(N-1)/2:(N-1)/2)';
us=[0:0.002:0.25];
ui1=0.3;
ui2=-0.3;
vi1=exp(i*n*pi*ui1);
vi2=exp(i*n*pi*ui2);

vm=ones(N,1);
Dm=3;
e=1;
w1=ones(N,1)/N;
%............................ MPDR and DMR ..............................
Ri=INR1*vi1*vi1'+INR2*vi2*vi2'+eye(N);
for numsnr=1:size(SNR,2)
    for num=1:size(us,2)
        vs=exp(i*n*pi*us(num));
        Rs=SNR(numsnr)*vs*vs';
        Rx=Rs+Ri;
        %....................DMR.............
        [E,eigv]=eig(Rx);
        [Y,index]=sort(diag(real(eigv)));
        alpha=sum(Y(1:N-Dm))/(N-Dm);
        Rd=0;
        for numd=1:Dm
            Rd=Rd+e*(Y(N-numd+1)-alpha)*E(:,index(N-numd+1))*E(:,index(N-numd+1))';
        end
        Rd=Rd+alpha*eye(N);

        w3=inv(Rd)*vm/(vm'*inv(Rd)*vm);
        ArrayGain(numsnr,num)=real(w3'*Rs*w3/(w3'*Ri*w3))/(SNR(numsnr)/(INR1+INR2+1));
    end;
end
figure
x=us/BWnn;
y1=10*log10(ArrayGain(1,:));
y2=10*log10(ArrayGain(2,:));
y3=10*log10(ArrayGain(3,:));
y4=10*log10(ArrayGain(4,:));
y5=10*log10(ArrayGain(5,:));
plot(x,y1,x,y2,'--',x,y3,'-.',x,y4,':',x,y5,'-*');
grid on
axis([0 0.25 -30 50])
legend('{\itSNR} = -10 dB','{\itSNR} = 0 dB','{\itSNR} = 10 dB','{\itSNR} = 20 dB','{\itSNR} = 30 dB')
xlabel('{\itu}_{\ita}/{\itBW}_{\itNN}')
ylabel('Array Gain (dB)')