% fade2.m
% Get Rayleigh fading result

function [r, iout, qout] = fade2(idata, qdata, nsamp, tstp, fm, N1, counter, flat)

%******************* variables *******************************
% idata         input Ich data
% qdata         input Qch data
% nsamp         Number of samples to be simulated
% tstp          Minimum time resolution
% fm            Maximum doppler frequency (Hz)
% N1            Number of waves in order to generate fading
% counter       fading counter
% flat          flat fading or not
% r             envelope of fading channel complex impulse response
% iout          output Ich data
% qout          output Qch data
%***************************************************************

if fm == 0.0 
    iout = idata;
    qout = qdata;
else
    [theta, ramp, xc, xs] = fade( nsamp, tstp, fm, N1, counter, flat);       
    
    if flat==1
        iout = ramp.*idata(1:nsamp); % output signal(ich)
        qout = ramp.*qdata(1:nsamp); % output signal(qch)
    else
        iout = xc.*idata(1:nsamp)-xs.*qdata(1:nsamp); % output signal(ich)
        qout = xs.*idata(1:nsamp)+xc.*qdata(1:nsamp); % output signal(qch)
    end
end

r = sqrt(iout.^2+qout.^2);
%******************* end of file **********************************