mud.rar_ITS_Matched filter mud_mud_multiuser_multiuser detection

clear all; clc G=31; % Code length K=1; % Number of Codes or code sequences %.................Generation of first perferred PN sequence................ % First user's seed. PN1=[]; % Spreading code vector of user-1 sd1=[1 0 0 0 0 ]; sd11=sd1; for j=1:31 PN1=[PN1 sd1(5)]; if( sd1(2)==sd1(5)) temp1=0; else temp1=1; end sd1(2)=sd11(1); sd1(3)=sd11(2); sd1(4)=sd11(3); sd1(5)=sd11(4); sd1(1)=temp1; sd11=sd1; end %.......................................................................... %.................Generation of Second perferred PN sequence............... sd2=[1 0 0 0 0]; PN2=[]; sd22=sd2; for j=1:G PN2=[PN2 sd2(5)]; if sd2(5)==sd2(4) temp1=0; else temp1=1; end if sd2(2)==temp1 temp2=0; else temp2=1; end if sd2(1)==temp2 temp3=0; else temp3=1; end sd2(2)=sd22(1); sd2(3)=sd22(2); sd2(4)=sd22(3); sd2(5)=sd22(4); sd2(1)=temp3; sd22=sd2; end %.......................................................................... %.........................Generation of Gold Codes......................... Co_Mat=[]; for codes=1:K code=[]; % PN2(31)=PN2(1); for j=1:G code=[code xor(PN1(j),PN2(j))]; end Co_Mat=[Co_Mat code']; end for row=1:G for col=1:K if Co_Mat(row,col)==0; Co_Mat(row,col)=-1; end end end %.......................................................................... usr1=randsrc(1,10); ulen=length(usr1); test=Co_Mat*usr1; test1=test'; k=0; %------------------------------ for m=1:10 for n=1:31 mat(1,n+k)=test1(m,n); end k=k+31; end %-------------------------- M=2; modu=qammod(mat,M); snr=12; y=awgn(modu,snr); k=0; for m=1:1000 for n=1:31 y1(m,n)=y(1,n+k); end k=k+31; end rec=(y1*Co_Mat)/31; rec1=rec'; for j=1:1:1000 if rec1(j)<=-1; res(j)=0; else res(j)=1; end end err=0; for(i=1:1:ulen) if(usr1~=res(i)) err=err+1; end end BER=err/(1*ulen); hold; semilogy(snr,BER,'b.');