function metric = brmet(sig,q_test,ch_coefs);%BRMET User defined branch metric.%   RHO = BRMET(R,Q,ALPHA) evaluates branch metric and returns the%   result as a column vector for all testing channel symbols Q. The%   entries of RHO variable correspond to the squared Euclidean distance%   of received signal R and testing channel symbols Q. ALPHA simply%   contains the complex path fadings of the MIMO channel.%%   See also DETECT, CHANNEL.%   Copyright 2001-2003 Kamil Anis, anisk@feld.cvut.cz%   Dept. of Radioelectronics, %   Faculty of Electrical Engineering%   Czech Technical University in Prague%   $Revision: 2.1 $  $Date: 2003/1/16 17:33:28 $%   --%   <additional stuff goes here>[m,n] = size(ch_coefs);[q_dim,foo] = size(q_test);sig = repmat(sig,q_dim,1);outsum = 0;for j=1:n % outer sum  insum = 0;  	for i=1:m % inner sum      insum1 = ch_coefs(i,j) .* q_test(:,i);      insum = insum + insum1;	end    outsum1 = abs(sig(:,j) - insum) .^ 2;  outsum = outsum + outsum1;end  metric = outsum;