www.gusucode.com > ZBLAST算法仿真源码程序 > ZBLAST算法仿真源码程序/131014135Pro/vblastpic11.m

    % vblastpic11.m
%比较MMSE-PIC和MMSE-OSIC的性能
tx=2;rx=2;L=30000;Modulation='BPSK';
SNR=[0:2:20];
A=randint(tx*L,1);
X=zeros(tx,L);
for k=1:tx
X(k,:)=(-1).^(A(k:tx:end)+1);
end
H=sqrt(1/2)*(randn(rx,tx,L)+i*randn(rx,tx,L));
n=sqrt(1/2)*(randn(rx,L)+i*randn(rx,L));
R=zeros(rx,L);
for k=1:L
    R(:,k)=sqrt(1/tx)*H(:,:,k)*X(:,k);
end
%MMSE-PIC===================================================================
bermp11=[];
bermp22=[];
  for m=SNR
      m
      snr=10^(m/10);
      R_noised=R+sqrt(1/snr)*n;
      x=[];
      a=zeros(tx*L,1);
      %第一遍检测
      for t=1:L
          r=R_noised(:,t);
          HH=H(:,:,t);
          xtemp=zeros(tx,1);
          w=inv(HH'*HH+(1/snr)*eye(tx))*HH';
          y=w*r;
          xtemp=(y>=0)-(y<0)+0;
          x=[x,xtemp];
      end
   for k=1:tx
          a(k:tx:end)=(x(k:tx:end)+1)/2;
      end
      [errbit,temp_ber]=biterr(A,a);
      bermp11=[bermp11,temp_ber];   
      %第二遍PIC检测
      xx=[];
      for t=1:L
          r=R_noised(:,t);
          G=pinv(H(:,:,t));
          for k=1:tx
          y(k)=H(:,k,t)'*(r-sqrt(1/2)*H(:,:,t)*x(:,t)+sqrt(1/2)*x(k,t)*H(:,k,t));
          end
          xxtemp=(y>=0)-(y<0)+0;
          xx=[xx xxtemp];
      end
      for k=1:tx
          a(k:tx:end)=(xx(k:tx:end)+1)/2;
      end
      [errbit,temp_ber]=biterr(A,a);
      bermp22=[bermp22,temp_ber];
  end
  %MMSE-SIC=================================================================
   bermss=[];
  for m=SNR
      m
      snr=10^(m/10);
      R_noised=R+sqrt(1/snr)*n;
      x=[];
      a=zeros(tx*L,1);
      for t=1:L
          r=R_noised(:,t);
          HH=H(:,:,t);
          G=pinv(HH);
          S=[1:tx];
          xtemp=zeros(tx,1);
           for k=1:tx
              [wki,ki]=minnorm(G);
              w=inv(HH'*HH+(1/snr)*eye(tx-k+1))*HH';
              y=w(ki,:)*r;
              xtemp(S(ki))=(y>=0)-(y<0)+0;
              r=r-sqrt(1/tx)*xtemp(S(ki))*H(:,S(ki),t);
              HH(:,ki)=[];
              S(ki)=[];
              G=pinv(HH);
          end
          x=[x,xtemp];
      end
      for k=1:tx
          a(k:tx:end)=(x(k:tx:end)+1)/2;
      end
      [errbit,temp_ber]=biterr(A,a);
      bermss=[bermss,temp_ber];
  end
  %==========================================================
  figure
  semilogy(SNR,bermp11,'o- b'),hold on
  semilogy(SNR,bermp22,'s- r')
  semilogy(SNR,bermss,'p- g'),grid on
  legend('MMSE','MMSE-PIC','MMSE-SIC')
  xlabel('SNR(dB)');
  ylabel('误比特率');
  title('tx=2,rx=2,MMSE-PIC,MMSE-OSIC检测性能')