qpskencoder.m

simulation module for visual wireless sensor network

% ------------------------------------------------------------------------------- %
% QPSKEncoder(..) Module 
% -----------------------
% This module does QPSK Encoding. The constellation points will be kept at (1,1)
% (1,-1),(-1,1) and (-1,-1). (i.e, at 45,135,-135,-45 degrees) respectively.
%
% Inputs : Two bit streams that constitute the Input symbol stream.
% Outputs : The I and Q Modulated Symbol streams.
%
% Note :
% ------
% If you want the constellation points to be placed farther apart, you have to do
% the required scaling yourself outside the routine. In most simulation cases, this
% may not be required since generally, the noise variance and the fade power will 
% be adjusted to obtain the required Eb/No operating point.
%
% Written by,
% -----------
% Vijaya Chandran Ramasami,
% Radar Systems Lab,
% The University of Kansas, 
% Lawrence, KS 66044.
% E-Mail - [e-mail]
% ------------------------------------------------------------------------------- %
function [I_Symbols, Q_Symbols] = QPSKEncoder(BitStreamOne,BitStreamTwo)

I_Symbols = (2*BitStreamOne-1);
Q_Symbols = (2*BitStreamTwo-1);