qammod.m

OFDM信道估计和均衡的仿真程序

%+----------------------------------------------------------------+
%|                                                                |
%|  Name: qammod.m                                                |
%|  Author: Mathew Liu, James Shen                                |
%|  Description: takes in a binary stream "in_binary" and maps    |
%|  them to a constellation defined by QAM symbols. The number    |
%|  of QAM symbols on this constellation is determined by M^2.    |
%|                                                                |
%+----------------------------------------------------------------+
function[symbols] = qammod(in_binary, carrier_count, M) 
% M^2 = number of points on constellation.
% in_binary(64,M) 64 derived from IFFT size
% in_binary is made from the S/P 

%=================== Generate QAM Alphabet =========================
temp_M = -(M-1):2:(M-1); 
for i=1:M
    for k = 1:M
        QAM(i,k) = temp_M(i) + j*temp_M(k);
    end
end
QAM = QAM(:).';

%================= Binary to Decimal and assign Symbol ==============
symbols = zeros(carrier_count, 1);
index = 1;
for row=1:carrier_count
   index = 1;
   for bit_position=1:M
      index = index + ((2^(bit_position-1)) * in_binary(row,bit_position));
      % index is a number from 1-16
   end
   symbols(row) = QAM(index);

end   

%====================== End File ====================================