reception diversity maximum ratio combining

I'm writing about the reception diversity maximum ratio combining of the program now. but I don't know about the idea of the weight. please tell me someone. ------------------------------------------------------------------

   %---Selection combing---
   if diversity == 0 || diversity == 2
   for data = 1 : datanumber
       for i=1 : K
           if Z_k(1,i,data) == 1
               PSin(3,1+(i-1)*Dsub:Dsub*i,data) = PSin(1,1+(i-1)*Dsub:Dsub*i,data);
           else 
               PSin(3,1+(i-1)*Dsub:Dsub*i,data) = PSin(2,1+(i-1)*Dsub:Dsub*i,data);
           end
       end
   end
   end
   %---Equal gain combing------- 
    if diversity == 1 || diversity == 3 
        PSin(3+ooo,:,:) = PSin(1,:,:)+PSin(2,:,:);  
          if M == 16 
        PSin(3+ooo,:,:) = PSin(3+ooo,:,:)/2; 
          end 
    end 
 %---------------maximum ratio combing------------- 
     if diversity == 2 || diversity == 3 

     end