MATLAB: Compare each element of a vector with each element of another vector

Question

I want to compare each row of distance1 with each row of distance2. If a column in distance1 is less than the same row on distance2. Then s_decoded = -1 else s_decoded =+1.

When running this code, s_decoded is coming with a value of 1×1 instead of a 1×1000. As distacne1 and distance2 are both 1×1000.

 % Maximum Likelihood (ML) detection rule
       distance1 = abs( y - sqrt(spe_snr)*h*(-1) );
       distance2 = abs( y - sqrt(spe_snr)*h*(+1) );
       
       if distance1 < distance2
           s_decoded = -1; % sqrt(spe_snr)*h*(-1) is closest to y
       else
           s_decoded = +1; % sqrt(spe_snr)*h*(+1) is closest to y
       end

Answer 1

Replace the if else block with the following lines.

s_decoded = ones(size(distance1));
s_decoded(distance1 < distance2) = -1;