qpsk_modulate.asv

来自「PFDM 仿真程序」· ASV 代码 · 共 16 行

function mod_symbols = QPSK_modulate(x)
% function y = modulate(x,b,e)
%
%    mod_symbols - modulated output, in the form of a row vector
%    x - a vector of input bits, for all the subcarriers (row vector)

mod_symbols=[];


 % Angle [pi/4 3*pi/4 -3*pi/4 -pi/4] corresponds to 
 % Gray code vector [00 10 11 01], respectively.
   table=exp(j*[-3/4*pi 3/4*pi 1/4*pi -1/4*pi]);  % generates QPSK symbols
   table=table([0 1 3 2]+1); % Gray code mapping pattern for QPSK symbols
   inp=reshape(bits_in,2,full_len/2);
   mod_symbols=table([2 1]*inp+1);  % maps transmitted bits into QPSK symbols