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Replies: 0

 amit Posts: 2 Registered: 11/21/12
Posted: Nov 21, 2012 9:51 AM

hi, im new to matlab and not used it before and any help, i will be really thankful, im trying to get a graph of PF vs PD
this is my code, but something is wrong, especially for the outputs of y4, im not really sure anymore.

%monte carlo simulation
function [y1,y2,y3,y4]= ed(SNRL,SNRS,SNRH,n) %ed is the energy detection
g1= SNRL:SNRS:SNRH;
g=10.^(g1/10);
beta=0.01; % is the probability of flase alarm

pf1=zeros(1,length(g));
pd1=zeros(1,length(g));
pf2=zeros(1,length(g));
pd2=zeros(1,length(g));

for i=1 : length(g)
y0 = randn(n,1000000);
y1= randn(n,1000000)*sqrt(g(i))+y0;

Tgam = gaminv(1-beta,n/2,2/n*(1+g(i))); %threshold
pf1(i)= gamcdf(Tgam,n/2,2/n*(1+g(i)))
pd1 (i) = gamcdf(Tgam,n/2,2/n); % prob of detection
pf2(i)= length (find(sum(y1.^2)/n<Tgam))/1000000;
pd2 (i) = length (find(sum(y0.^2)/n<Tgam))/1000000;

end
y1=pf1; y2=pd1; y3=pf2; y4=pd2;