un_pam.m

基于Matlab

function s = un_pam(M,z)

 % check if valid M 
 if M/2 ~= floor(M/2),
   error('M must be an even integer'); 
 end

 % generate constellation points at +/-{1,3,5,7,etc.}
 C=2*[0:M-1]-M+1;  
 C=C/sqrt(mean(abs(C).^2));

 [d,I]=min(abs(z-C)); 
 s=C(I(1));