www.pudn.com > SpacetimeMatlabCode.rar > est.m, change:2004-03-21,size:1097b

function [est_coefs,signal]=est(signal,ch_coefs,frames,sim_options) 
 
%************************************************************************** 
%This file carriers out channel estimation based on MMSE technique. It 
%outputs the signal stripped of its preamble and the channel estimates. 
%************************************************************************** 
 
pilots=[0 0 0 0 0 0 0 0 0 0 1 -1 -1  1 -1 -1  1 -1  1  1;1 -1 -1 -1  1 -1 -1  1 -1  1 0 0 0 0 0 0 0 0 0 0]; 
pilots=pilots.'; 
 
tr_symbols=signal(1:20,:,:); 
signal=signal(21:end,:,:); 
for k=1:frames 
    if sim_options.RxDiv==2 
        h11=mean(tr_symbols(11:20,1,k).*conj(pilots(11:20,1))); 
        h12=mean(tr_symbols(1:10,1,k).*conj(pilots(1:10,2))); 
        h21=mean(tr_symbols(11:20,2,k).*conj(pilots(11:20,1))); 
        h22=mean(tr_symbols(1:10,2,k).*conj(pilots(1:10,2))); 
        est_coefs(:,:,k)=[[h11;h12]  [h21; h22]]; 
    else 
       h11=mean(tr_symbols(11:20,1,k).*conj(pilots(11:20,1))); 
       h21=mean(tr_symbols(1:10,1,k).*conj(pilots(1:10,2))); 
       est_coefs(:,:,k)=[h11;h21]; 
    end 
end