cp0803_ppmcorrmask_r.m

IEEEuwb仿真UWB信道冲击相应；rmsds仿真UWB信道的均方根时延扩展；PDP仿真UWB信道的功率延迟剖面 rakeselector仿真RAKE接收机的路径选择 PPMcorrmask_P仿真

%
% FUNCTION 8.12 :"cp0803_PPMcorrmask_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) that is produced by
% the 2PPM+TH transmitter
% 'fc' is the sampling frequency in Hertz 
% 'numpulses' is the number of transmitter pulses 
% 'dPPM' is the value of the PPM shift in seconds
% 'rake' represents the estimated discrete-type impulse response
%
function [mask]=cp0803_PPMcorrmask_R(ref,fc,numpulses,dPPM,rake)
%==================================================================
% Step One - Evaluation of the correlation mask
%==================================================================
dt=1/fc;
LR=length(ref);

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

% mask construction
PPMsamples=floor(dPPM./dt);
sref(1:PPMsamples)=mref(LR-PPMsamples+1:LR);
sref(PPMsamples+1:LR)=mref(1:LR-PPMsamples);
mask=mref-sref;