qpsk.asv

mc-cdma matlab下的性能仿真

% qpsk.m
%
% Function to perform QPSK modulation
%
% Programmed by SP.Feng
%

function [iout,qout]=qpsk(inputdata,num_user,num_data,mod_level)

%****************** variables *************************
% inputdata : input data (para-by-nd matrix)
% iout :output Ich data
% qout :output Qch data
% num_user : Number of paralell users
% num_data : Number of data
% mod_level : Number of modulation levels
% *****************************************************

level2=mod_level./2;
num_odata=num_data/mod_level;

inputdata2=inputdata.*2-1;
count=0;

for j=1:num_odata

	isi = zeros(num_user,1);
	isq = zeros(num_user,1);

	for i = 1 : level2 
  		isi = isi + 2.^( level2 - i ) .* inputdata2((1:num_user),i+count);
  		isq = isq + 2.^( level2 - i ) .* inputdata2((1:num_user),level2+i+count);
	end

	iout((1:num_user),j)=isi;
	qout((1:num_user),j)=isq;

	count=count+mod_level;

end

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