%
% FUNCTION 8.13 : "cp0803_PAMcorrmask_R"
%
% Evaluates the correlation mask ('mask') for a RAKE
% receiver in the case of binary PPM UWB signals.
% 'ref' is the reference signal (with no modulation)
%      which is produced by the 2PPM+TH transmitter
% 'fc' is the sampling frequency in Hertz
% 'numpulses' is the number of transmitted pulses
% 'rake' represents the estimated discrete-type impulse
%      response
%
% Programmed by Guerino Giancola
%

function [mask] = ...
   cp0803_PAMcorrmask_R(ref,fc,numpulses,rake)

% ---------------------------------------------
% Step One - Evaluation of the correlation mask
% ---------------------------------------------

dt = 1 / fc;
LR = length(ref);

% Energy normalization
Epulse = (sum((ref.^2).*dt))/numpulses;
nref = ref./sqrt(Epulse);

% Rake convolution

mref = conv(nref,rake);
mref = mref(1:LR);