cp0201_waveform.m

利用压缩包内的5和函数产生PPM调制的UWB信号

%FUNCTION 2.5:"cp0201_waveform"
%
%Generates the energy-normalized pulse waveform
%Special case of the second derivative Gaussian pulse:SCHOLTZ'S MONOCYCLE
%**********************************************************************
% ref:
% Scholtz R.A."Multiple Access with Time-Hopping Impulse Modulation"
% in Proceedings of MILCOM '93,1993,PP.679-691
%**********************************************************************
%'fc' is the sampling frequency
%'Tm' is the pulse duration
%'tau' is the shaping parameter
function [w0]=cp0201_waveform(fc,Tm,tau)
%-------------------------------------------------------
%Step One - Pulse waveform generation
%-------------------------------------------------------
dt=1/fc;
OVER=floor(Tm/dt);

e=mod(OVER,2);
kbk=floor(OVER/2);
tmp=linspace(dt,Tm/2,kbk);
s=(1-4.*pi.*((tmp./tau).^2)).*exp(-2.*pi.*((tmp./tau).^2));
if e
    for k=1:length(s)
        y(kbk+1)=1;
        y(kbk+1+k)=s(k);
        y(kbk+1-k)=s(k);
    end
else
    for k=1:length(s)
        y(kbk+k)=s(k);
        y(kbk+1-k)=s(k);
    end
end
E=sum((y.^2).*dt);
w0=y./(E^0.5);