www.pudn.com > WiMAX_Downlink_802.16e_Matlab.zip > rayleighnew.m, change:2004-12-06,size:1758b

function ray_chann=rayleighnew(nsamp,tstp,fd,counter) 
 
%****************** variables ************************* 
% idata  : input Ich data      
% qdata  : input Qch data      
% iout   : output Ich data 
% qout   : output Qch data 
% ramp   : Amplitude contaminated by fading 
% rcos   : Cosine value contaminated by fading 
% rsin   : Cosine value contaminated by fading 
% nsamp  : Number of samples to be simulated        
% tstp   : Minimum time resolution                     
% fd     : maximum doppler frequency                
% no     : number of waves in order to generate fading    
% counter  : fading counter                           
% flat     : flat fading or not  
% (1->flat (only amplitude is fluctuated),0->nomal(phase and amplitude are fluctutated)     
%****************************************************** 
no=25; 
if fd ~= 0.0   
    ac0 = sqrt(1.0 ./ (2.0.*(no + 1)));   % power normalized constant(ich) 
    as0 = sqrt(1.0 ./ (2.0.*no));         % power normalized constant(qch) 
    %ic0 = counter;                        % fading counter 
  
    pai = 3.14159265;    
    wm = 2.0.*pai.*fd; 
    n = 4.*no + 2; 
    ts = tstp; 
    wmts = wm.*ts; 
    paino = pai./no;                         
 
    xc=zeros(1,nsamp); 
    xs=zeros(1,nsamp); 
    ic=[1:nsamp]+counter; 
 
  for nn = 1: no 
	  cwn = cos( cos(2.0.*pai.*nn./n).*ic.*wmts ); 
	  xc = xc + cos(paino.*nn).*cwn; 
	  xs = xs + sin(paino.*nn).*cwn; 
  end 
 
  cwmt = sqrt(2.0).*cos(ic.*wmts); 
  xc = (2.0.*xc + cwmt).*ac0; 
  xs = 2.0.*xs.*as0; 
 
  %ramp=sqrt(xc.^2+xs.^2);    
  %rcos=xc./ramp; 
  %rsin=xs./ramp; 
  ray_chann=xc+j*xs; 
 
   
 
else   
 ray_chann=ones(1,nsamp); 
end 
 
% ************************end of file***********************************