cp0801_ppmcorrmask.m

cp0801_PPMcorrmask为PPM-TH-UWB信号的相关模板信号计算函数

%
%FUNCTION 8.4 :"cp0801_PPMcorrmask"
%
% Evaluates the correlation mask of 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
% 'numpulses' is the number of transmitted pulses
% 'dPPM' is the value of the PPM shift
%
function [mask]=cp0801_PPMcorrmask(ref,fc,numpulses,dPPM)
%--------------------------------------------------------
% Step One - Evaluation of the correlation mask
%--------------------------------------------------------
dt=1/fc;
% energy normalization
Epulse=(sum((ref.^2).*dt))/numpulses;
ref=ref./sqrt(Epulse);

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