qammod.m

上传的是一个16Qam预失真处理的程序

% Program 3-23
% qammod.m
%
% This function is used for Gray coding of 16QAM modulation
%
% programmed by R. Funada and H. Harada
%

function [iout,qout] = qammod (paradata,para,nd,m1)

%******************** variables *************************************

% paradata  : input data (para-by-nd matrix)
% iout      : output Ich data
% qout      : output Qch data
% para      : Number of parallel channels
% nd        : Number of data
% m1        : Number of modulation levels
% ( QPSK-2  16QAM-4)

%********************************************************************

% The constellation power

k = sqrt(10);
iv = [-3 -1 3 1];

m2 = m1/2;
count2 = 0;

for ii =1:nd
    isi = zeros(para,1);
    isq = zeros(para,1);
    
    for jj = 1:m1
        
        if jj <= m2
           isi = isi+2.^(m2-jj).*paradata((1:para),count2+jj);
       else
           isq = isq+2.^(m1-jj).*paradata((1:para),count2+jj);
       end
   end
   
   iout((1:para),ii) = iv(isi+1)./k;
   qout((1:para),ii) = iv(isq+1)./k;
   
   count2 = count2 + m1;
end

%******************** end of file ***********************************