ds-cdma系统的多用户检测matlab程序

%MMSE解相关多用户检测器和CD传统多用户检测器的误码率比较（八个用户） clear all; snr_indb=1:8; for k=1:length(snr_indb) snr=10^(snr_indb(k)/10); sgma=1; eb=2*(sgma^2)*snr; LC=31; echip=eb/LC; N=10000;%number of bits transmitted %creat PN codes fbconnection=[0 1 0 0 1]; mseq=m_sequence(fbconnection); fbconnection1=[0 0 1 0 1]; fbconnection2=[0 1 1 1 1]; goldseq=gold_seq(fbconnection1,fbconnection2); %N=2^length(fbconnection)-1; ind1=find(mseq==0); mseq(ind1)=-1; ind2=find(goldseq==0); goldseq(ind2)=-1; %creat 31*31 gold sequence temp=goldseq; pn_seq1=temp(3,:); pn_seq2=temp(4,:); pn_seq3=temp(7,:); pn_seq4=temp(10,:); pn_seq5=temp(15,:); pn_seq6=temp(20,:); pn_seq7=temp(26,:); pn_seq8=temp(31,:); % comput matrix R pp=[pn_seq1;pn_seq2;pn_seq3;pn_seq4;pn_seq5;pn_seq6;pn_seq7;pn_seq8]; RR=(1/LC)*pp*pp'; RR1=inv(eb*eye(8)); R=inv(RR+RR1); %generate codes for i=1:N temp1=rand; if(temp1<0.5),dsource1(i)=-1; else dsource1(i)=1; end; temp2=rand; if(temp2<0.5),dsource2(i)=-1; else dsource2(i)=1; end; temp3=rand; if(temp3<0.5),dsource3(i)=-1; else dsource3(i)=1; end; temp4=rand; if(temp4<0.5),dsource4(i)=-1; else dsource4(i)=1; end; temp5=rand; if(temp5<0.5),dsource5(i)=-1; else dsource5(i)=1; end; temp6=rand; if(temp6<0.5),dsource6(i)=-1; else dsource6(i)=1; end; temp7=rand; if(temp7<0.5),dsource7(i)=-1; else dsource7(i)=1; end; temp8=rand; if(temp8<0.5),dsource8(i)=-1; else dsource8(i)=1; end; end; number_of_err=0; number_of_err1=0; number_of_err2=0; for i=1:N %将每个bit repeat LC=31 times for j=1:LC repeatdata1(j)=dsource1(i); repeatdata2(j)=dsource2(i); repeatdata3(j)=dsource3(i); repeatdata4(j)=dsource4(i); repeatdata5(j)=dsource5(i); repeatdata6(j)=dsource6(i); repeatdata7(j)=dsource7(i); repeatdata8(j)=dsource8(i); end; for ii=0:2^8-1 j=1;aa=ii; while aa~=0 bk(j,ii+1)=rem(aa,2); aa=floor(aa/2); j=j+1; end end bk=bk*2-1; %tranmit signal is: trans_sig1=sqrt(echip)* repeatdata1.*pn_seq1; trans_sig2=sqrt(echip)* repeatdata2.*pn_seq2; trans_sig3=sqrt(echip)* repeatdata3.*pn_seq3; trans_sig4=sqrt(echip)* repeatdata4.*pn_seq4; trans_sig5=sqrt(echip)* repeatdata5.*pn_seq5; trans_sig6=sqrt(echip)* repeatdata6.*pn_seq6; trans_sig7=sqrt(echip)* repeatdata7.*pn_seq7; trans_sig8=sqrt(echip)* repeatdata8.*pn_seq8; %add AWGN noise noise=sgma*randn(1,LC); % receive signal for j=1:LC rtemp(j)=trans_sig1(j)+trans_sig2(j)+trans_sig3(j)+trans_sig4(j)+trans_sig5(j)+trans_sig6(j)+trans_sig7(j)+trans_sig8(j); end; r=rtemp+noise; r1=r;r2=r;r3=r;r4=r;r5=r;r6=r;r7=r;r8=r; %CD JUDGE I1=sum(r1.*pn_seq1); I2=sum(r2.*pn_seq2); I3=sum(r3.*pn_seq3); I4=sum(r4.*pn_seq4); I5=sum(r5.*pn_seq5); I6=sum(r6.*pn_seq6); I7=sum(r7.*pn_seq7); I8=sum(r8.*pn_seq8); % DD JUDGE I=R*[I1,I2,I3,I4,I5,I6,I7,I8]'; y=[I1,I2,I3,I4,I5,I6,I7,I8]'; for ii=1:2^8 c(ii)=2*(bk(:,ii))'*y-(bk(:,ii))'*R*bk(:,ii); end [m,mm]=max(c); bb=bk(:,mm); if(bb(1)~=dsource1(i)),number_of_err2=number_of_err2+1;end; if(bb(2)~=dsource2(i)),number_of_err2=number_of_err2+1;end; if(bb(3)~=dsource3(i)),number_of_err2=number_of_err2+1;end; if(bb(4)~=dsource4(i)),number_of_err2=number_of_err2+1;end; if(bb(5)~=dsource5(i)),number_of_err2=number_of_err2+1;end; if(bb(6)~=dsource6(i)),number_of_err2=number_of_err2+1;end; if(bb(7)~=dsource7(i)),number_of_err2=number_of_err2+1;end; if(bb(8)~=dsource8(i)),number_of_err2=number_of_err2+1;end; % DD make decision if(I(1)<0), desion1=-1; else desion1=1; end; if(I(2)<0), desion2=-1; else desion2=1; end; if(I(3)<0), desion3=-1; else desion3=1; end; if(I(4)<0), desion4=-1; else desion4=1; end; if(I(5)<0), desion5=-1; else desion5=1; end; if(I(6)<0), desion6=-1; else desion6=1; end; if(I(7)<0), desion7=-1; else desion7=1; end; if(I(8)<0), desion8=-1; else desion8=1; end; if(desion1~=dsource1(i)),number_of_err=number_of_err+1;end; if(desion2~=dsource2(i)),number_of_err=number_of_err+1;end; if(desion3~=dsource3(i)),number_of_err=number_of_err+1;end; if(desion4~=dsource4(i)),number_of_err=number_of_err+1;end; if(desion5~=dsource5(i)),number_of_err=number_of_err+1;end; if(desion6~=dsource6(i)),number_of_err=number_of_err+1;end; if(desion7~=dsource7(i)),number_of_err=number_of_err+1;end; if(desion8~=dsource8(i)),number_of_err=number_of_err+1;end; %CD MAKE DECISION % CD make decision if(I1<0), desion11=-1; else desion11=1; end; if(I2<0), desion21=-1; else desion21=1; end; if(I3<0), desion31=-1; else desion31=1; end; if(I4<0), desion41=-1; else desion41=1; end; if(I5<0), desion51=-1; else desion51=1; end; if(I6<0), desion61=-1; else desion61=1; end; if(I7<0), desion71=-1; else desion71=1; end; if(I8<0), desion81=-1; else desion81=1; end; if(desion11~=dsource1(i)),number_of_err1=number_of_err1+1;end; if(desion21~=dsource2(i)),number_of_err1=number_of_err1+1;end; if(desion31~=dsource3(i)),number_of_err1=number_of_err1+1;end; if(desion41~=dsource4(i)),number_of_err1=number_of_err1+1;end; if(desion51~=dsource5(i)),number_of_err1=number_of_err1+1;end; if(desion61~=dsource6(i)),number_of_err1=number_of_err1+1;end; if(desion71~=dsource7(i)),number_of_err1=number_of_err1+1;end; if(desion81~=dsource8(i)),number_of_err1=number_of_err1+1;end; end err(k)=number_of_err/(3*N)%MMSE ber err1(k)=number_of_err1/(3*N)%CD ber err2(k)=number_of_err2/(3*N) end %plot(snr_indb,err); semilogy(snr_indb,err,'k');%MMSE ber grid on; hold on; semilogy(snr_indb,err1,'r');%CD ber hold on semilogy(snr_indb,err2,'^-')