i am referring to a book titled " MIMO - OFDM wireless comm with matlab". In this i understood the mathematics but unable to understand the code for rayleigh and rician fading channels. Pls if some one can share his views on this will be very helpful

% plot_Ray_Ric_channel.m
clear, clf
N=200000; level=30; K_dB=[-40 15];
gss=[’k-s’; ’b-o’; ’r-^’];
% Rayleigh model
Rayleigh_ch=Ray_model(N);
[temp,x]=hist(abs(Rayleigh_ch(1,:)),level);
plot(x,temp,gss(1,:)), hold on
% Rician model
for i=1:length(K_dB);
  Rician_ch(i,:) = Ric_model(K_dB(i),N);
  [temp x] = hist(abs(Rician_ch(i,:)),level);
  plot(x,temp,gss(i+1,:))
end
xlabel(’x’), ylabel(’Occurrence’)
legend(’Rayleigh’,’Rician, K=-40dB’,’Rician, K=15dB’)

%%%% functions 1
function H=Ray_model(L)
% Rayleigh channel model
% Input : L = Number of channel realizations
% Output: H = Channel vector
  H = (randn(1,L)+j*randn(1,L))/sqrt(2);

%%%% functions 2
function H=Ric_model(K_dB,L)
% Rician channel model
% Input : K_dB = K factor[dB]
% Output: H = Channel vector
  K = 10^(K_dB/10);
  H = sqrt(K/(K+1)) + sqrt(1/(K+1))*Ray_model(L);  %%%%% didnt understand this line.

[dpb]

What specifically didn't you understand?

The second model is just a constant plus a scaled magnitude of the first. This should be related to the mathematics in the reference, but I haven't tried to find it..

[TUSHAR MURATKAR]

@dbp

But in the refernce nothing is given like that.