Possible Channel Models for FSO

hi remo
1. log normal
2. gamma-gamma
3. negative exponetial
4. diffuce( indoor)
5. double genralized gamma -gamma

Hi Remo,

I agree with both praksh and rather… also the linlks posted by rather are quite helpful and informative… Thanks rather for your efforts…

Regards
Sahil Singh

Hi Rather,

You are welcome and no need for thanks…Since you have joined the forum recently..Keep discussing your queries on the forum.. It is really quite helpful…. All the best

Regards
Sahil Singh

Hi Remo,

Prakash had very clearly mentioned about the possible channel models that can be used for free space optics.. Thanks for the information..

Regards
Ankita

Hi Remo,

You are welcome.. matlab code for what ? can you please specify..

Regards
Ankita

Hi Remo,

Well I am not aware about it.. will try to see if I can be of help…

Regards
Ankita

Hi Remo,

You are welcome… Hope your query gets resolved soon

Regards
Ankita

Hi Remo,

I too am unaware about the matlab code… Hope someone else on the forum helps you in resolving your query…

Regards
Sahil Singh

Hi Rather,

Thanks for your appreciation…

Regards
Sahil Singh

Hello Remo,

Hope your query gets resolved soon.

Regards
Sahil Singh

HI Remo,

You are welcome…

Regards
Sahil Singh

hello friends

i will post all of the matlab code of possible channel ( please post again when you do in optisytem so that everyone can get help)

1. kim model for oudoor condition(courtesy of w.o. popolla , rajbhandari sir) reference book.- woc with matlab
%****To evaluate attenuation coefficient as a function of
visibility
%***Using the Kim model
clear
clc
% Wavelength in nm
wavl=830;
% Visibility values in km
Visibility=0.1:0.1:50;
for i=1:length(Visibility)
V=Visibility(i);
if (V >= 50)
q=1.6;
elseif (V > =6) && (V < 50)
q=1.3;
elseif (V > =1)&&(V < 6)
q=0.16*V+0.34;
elseif (V > =0.5)&&(V < 1)
q=V−0.5;
else
q=0;
end
Att_coeff(i)=(3.91/V)*(wavl/550)ˆ-q;
Att_coeff_dB_km(i)=10*Att_coeff(i)/log(10);
end
% Plot function
semilogy(Visibility,Att_coeff_dB_km)
xlabel(‘Visibility in km’)
ylabel(‘Attenuation coefficient in dB/km’)

1. log normal model( refernce -Optical Wireless Communications: System and Channel Modelling with MATLAB®
Z. Ghassemlooy, W. Popoola, S. Rajbhandari)
%PDF of log normal distribution
clear
clc
% E[I] value
Io=1;
I=0:0.005:3;
%Log irradinace variance values
Var_l=[0.1,0.2,0.5,0.8];
for i=1:length(Var_l)
for j=1:length(I)
B=sqrt(2*pi*Var_l(i));
C(j)=log(I(j)/Io)+(Var_l(i)/2);
D=2*Var_l(i);
pdf(i,j)=(1/I(j))*(1/B)*exp(−((C(j))ˆ2)/D);
end
end
%plot function
plot((I./Io),pdf)
xlabel(‘Normalised Irradiance, I/E[I]’)
ylabel(‘p(I)’)

hi everyone

Hi remo,
Please visit following links for details on possible channel mode in FSO:
A very common used turbulence model assumes that the variations of the medium can be
understood as individual cells of air or eddies of different diameters and refractive indices.
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5457931
https://arxiv.org/ftp/arxiv/papers/1203/1203.3006.pdf
http://www.mecs-press.org/ijcnis/ijcnis-v4-n3/IJCNIS-V4-N3-3.pdf
https://www.osapublishing.org/jocn/abstract.cfm?uri=jocn-2-5-293
https://www.researchgate.net/publication/225005739_Simplified_Channel_Model_for_Simulation_of_Free-Space_Optical_Communications

Thanks and regards,
Rajguru

Hi All,
Thank you for the code prakash. I appreciate your efforts

regards
Shafeen

Hi Prakash,

Thanks for providing the code… Surely it will help remo…

Regards
Rahul Tiwari..

Hi REmo,
The Matlab code for Lognormal Distribution pdf
By taking an example :
Suppose the income of a family of four in the United States follows a lognormal distribution with mu = log(20,000) and sigma = 1.
Compute and plot the income density.

x = (10:1000:125010)’;
y = lognpdf(x,log(20000),1.0);

figure;
plot(x,y)
h = gca;
h.XTick = [0 30000 60000 90000 120000];
h.XTickLabel = {‘0′,’$30,000′,’$60,000’,…
‘$90,000′,’$120,000’};

Hi Remo,
Program to generate the exponential sequence

n=input(‘Enter the duration of the signal N = ‘);
a=input (‘Enter the scaling factor a = ‘);
t=0:.1:n-1;
y=exp(-a*t);
plot(t,y);
ylabel (‘Amplitude’);
xlabel (‘Time Index’);
TITLE (‘Exponential Signal’);

Thanks

HELLO RAJGURU..
Can you please tell me the source where you have got the code from..?

Regards