This code generate a Gamma-Gamma distribution (as a function of weather turbulence conditions alpha and beta (this is an example of weak turbulence)) with pointing error (zeta):

Alpha= 21.6; Beta= 19.8 (weak turbulence conditions); Zeta= 0.5 (severe pointing error );

Sigma = 1;

a=1;

we = 2*Sigma*Zeta;

Ao = 1;

g1_AB = gamrnd(Alpha,1/Alpha);

g2_AB = gamrnd(Beta,1/Beta);

hg_AB = g1_AB*g2_AB;

hp_AB = Ao*exp(-2*a*a/(we^2));

Accordingly, the overall Gamma-Gamma FSO channel with pointing error is given by:

g_AB = hp_AB * hg_AB.

Have you tried:

http://www.mathworks.co.uk/help/stats/gamrnd.html

This code generate a Gamma-Gamma distribution (as a function of weather turbulence conditions alpha and beta (this is an example of weak turbulence)) with pointing error (zeta):

Alpha= 21.6; Beta= 19.8 (weak turbulence conditions); Zeta= 0.5 (severe pointing error );

Sigma = 1;

a=1;

we = 2*Sigma*Zeta;

Ao = 1;

g1_AB = gamrnd(Alpha,1/Alpha);

g2_AB = gamrnd(Beta,1/Beta);

hg_AB = g1_AB*g2_AB;

hp_AB = Ao*exp(-2*a*a/(we^2));

Accordingly, the overall Gamma-Gamma FSO channel with pointing error is given by:

g_AB = hp_AB * hg_AB.

is it nessesary to include pointing error line as

hp_AB = Ao*exp(-2*a*a/(we^2));

what is the overall channel ?