function fadingcoeff=genh(I,v,Dop,tb)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%                                                                        %
%%     Archivo: canalSUI.m                                                %
%%                                                                        %
%%     Descripci髇: Generamos un 鷑ico coeficiente de desvanecimiento     %
%%      con la 'suma de sinusoides' del modelo de Jakes.                  %
%%                                                                        %
%%     Par醡etros:                                                        %
%%          I = Longitud de la trama                                      %
%%          v = Velocidad del terminal (m/s)                              %
%%          Dop = M醲ima frecuencia del efecto Doppler                    %
%%          tb = Duraci髇 del simbolo                                     %
%%                                                                        %
%%     Autores: Bertrand Muquet, Sebastien Simoens, Shengli Zhou          %
%%      Octubre 2000                                                      %
%%                                                                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

  fc = 2.3e9; 			% Frecuencia portadora en Herz (2.5GHz 3.2GHz)
  fdmax = Dop;        
  
  N = 100;                      % N鷐eros de ondas incidentes
  t = tb:tb:tb*I;               % La variable 'tiempo'

  len = length(t);
  theta = rand(1,N)*2*pi;              % Generando las fases uniformes
  fd = cos(2*pi*((1:N)/N))*fdmax;      % Generando frecuencias equiespaciadas desde
                                       %  "-fdmax" a +fdmax"
 
  E = exp(j.*(2*pi*fd(:)*t(:)'+repmat(theta(:),1,len)));
  E = E/sqrt(N);
  fadingcoeff = sum(E);
  %plot(t,abs(fadingcoeff))
  %xlabel('time (second)');ylabel('Envelope of the fading coefficient');