demodulate256.m

幅度相位调制解调代码

function y = demodulate256(x,s256,c256);
% function y = demodulate(x, b, e, s2,s4,s16,s64,s256, c2,c4,c16,c64,c256);
%
% Finds minimum distance estimate of each received signal and returns the
% corresponding binary codeword.  Use a Zero-Forcing approach for convenience
%
%    y - modulated output, in the form of a row vector
%    x - a vector of input symbols, for all the subcarriers (row vector)
%    h - channel value (in frequency) for all subcarriers (64 elements)
%    b - subcarrier bit allocation (64 elements in this matrix, each one
%        corresponding to the number of bits to be allocated to the subcarrier
%        having the same index)
%    e - energy allocation (64 elements in this matrix)
%    s_ - the encoder for a given constellation size
%    c_ - the codewords as vectors of bits for the indices
e=32;
y=[];
for i = 1:length(x)
        [tmp, index] = min(abs(s256-x(i)/sqrt(e)));
        y = [y c256(index,:)];
   end
end