% This matlab script simulates the MIMO channel estimation% Based on the paper by Jaiganesh, Markus, Harish% titled 'optimal Channel training for multiple antenna systems% The matrix required on the receiver is developed here and dumped as txt% fileclear allseq =  [0,1,1,0,0,1,-1,0,-1,0,0,-1,-1,0,0,-1, ...  %MC CDMA midamble sequence  0,-1,1,0,0,-1,-1,0,-1,0,0,1,-1,0,0,-1,...  0,1,1,0,0,1,1,0,1,0,0,-1,-1,0,0,1,...  0,1,-1,0,0,1,-1,0,-1,0,0,-1,1,0,0,-1,...  0,-1,-1,0,0,1,-1,0,-1,0,0,-1,-1,0,0,-1,...  0,-1,-1,0,0,-1,-1,0,-1,0,0,1,1,0,0,-1,...  0,1,-1,0,0,1,1,0,1,0,0,-1,1,0,0,1,...  0,1,1,0,0,-1,-1,0,-1,0,0,-1,1,0,0,-1,...  0,1,1,0,0,-1,1,0,1,0,0,1,-1,0,0,1,...  0,-1,1,0,0,-1,1,0,1,0,0,1,-1,0,0,-1,...  0,1,1,0,0,-1,1,0,1,0,0,-1,-1,0,0,1,...  0,-1,-1,0,0,1,-1,0,-1,0,0,-1,-1,0,0,1,...  0,-1,1,0,0,1,-1,0,-1,0,0,-1,1,0,0,1,...  0,-1,-1,0,0,1,-1,0,-1,0,0,-1,-1,0,0,-1,...  0,1,-1,0,0,-1,-1,0,-1,0,0,1,1,0,0,1,...  0,1,-1,0,0,-1,-1,0,-1,0,0,-1,-1,0,0,-1]';cseq = complex( seq(1:2:end), seq(2:2:end));Nt   = length(cseq); %Length of the midamblesL    = 16; %Length of the tapsM    = 4; %Number of Antennasuser = zeros( length(cseq), M );for i=1:Muser(:,i) = circshift( cseq, 16*(i-1));end% S is of dimension (Nt - L + 1 x ML)   S = zeros( Nt - L + 1, M*L);j = 0;k = 0; for i = 1:M*L       if ( mod(i,L) == 1)          k = k + 1;          j = 0;      end  S(:,i) = user(end - j:-1:end - (Nt - L) - j,k);        j = j + 1;  end  cpar = inv(S'*S)*S';     isir1 = filter([0.8,0.6],1,user(:,1)); isir2 = filter([0.6,0.8],1,user(:,2)); isir  = isir1 + isir2; r   = 2000 * isir(end:-1:end-(Nt - L),1);  h   = cpar*r;  rpar = real(cpar); ipar = imag(cpar);   rparl = reshape( rpar', size(rpar,1) * size( rpar,2 ), 1 );  iparl = reshape( ipar', size(ipar,1) * size( ipar,2 ), 1 );   par = zeros( length(rparl) * 2 , 1 ); par(1:2:end) = rparl; par(2:2:end) = iparl;  return; fp = fopen( '~selvan/Work/Matlab/mccdma_par.txt','w');   col  = 8; for i = 1: length(par) / col    for j = 1:col     fprintf(fp, '%f,',par( (i-1) *col + j));    end    fprintf(fp,'\n');end