clear all
close all
clc

% Create signal
param.N      = 1000;                        % length of the data
param.f      = [pi/8 , pi/30 ,pi/40];       % frequencies 
param.a      = [1.5, 1.2,2]   ;             % amplitudes
param.alpha  = [-0.05 -0.02 -0.01];         % amplitudes

n = [0:param.N-1];
y(1,:)    = param.a(1)*sin(param.f(1)*n).*exp(param.alpha(1)*n);
y(2,:)    = param.a(2)*sin(param.f(2)*n).*exp(param.alpha(2)*n);
y(3,:)    = param.a(3)*sin(param.f(3)*n).*exp(param.alpha(3)*n);
y = sum(y,1)  ;