cp0302_ppm_periodic.m

此文件收集了《超宽带无线电基础》一书中的所有关于UWB的matlab代码。是进行UWB仿真开发的好工具。

%
% FUNCTION 3.3 : "cp0302_PPM_periodic"
%
% Generation of a PPM-UWB signal in the case of a generic
% periodic modulating signal and rectangular pulses
% Modulating signal is chosen to be characterized by
% an exponential decay exp(-t)
%
% Transmitted power is fixed at 'Pow'
% The signal is sampled with frequency 'fc'
% 'np' is the number of generated pulses
% 'Ts' is the average pulse repetition period
% Each rectangular pulse has time duration 'Tr'
% The periodic signal is characterized by
% shape parameters 'A' and 'B', and period 'Tp'
%
% The function returns the generated signal 'Stx'
% and the corresponding sampling frequency 'fc'
%
% Programmed by Guerino Giancola
%

function [Stx,fc]=cp0302_PPM_periodic;

% ----------------------------
% Step Zero - Input parameters
% ----------------------------

Pow = -30;    % average transmitted power (dBm)

fc = 1e11;    % sampling frequency

np = 10000;   % number of pulses

Tr = 0.5e-9;  % time duration of the rectangular pulse [s]

Ts = 2e-9;    % average pulse repetition period [s]

A = 1e-9;     % first shape parameter
B = 10;       % second shape parameter 
Tp = 20e-9;   % period of the modulating signal [s]

% ----------------------------------------
% Step One - Simulating transmission chain
% ----------------------------------------

dt = 1 / fc;        % sampling period
sTs = floor(Ts/dt); % number of samples per frame 
sTot = sTs * np;    % total number of samples
Stx = zeros(1,sTot);% output vector

% PPM
j = (0:1:np-1);
M0 = A.*exp(-(B/Tp).*mod(j*Ts,Tp));
M1 = j.*Ts;
Mtot = M0 + M1;
for k = 1 : np
  Stx(1+floor(Mtot(k)/dt))=1;
end