Radar Detection - MATLAB Simulations for Radar Systems Design - page 126

vt = vt0 + (num / (deno+eps));
delta = abs(vt - vt0) * 10000.0;
vt0 = vt;
end
if (np == 1)
temp = -vt / (1.0 + snrbar);
pd = exp(temp);
return
end
temp1 = 1.0 + np * snrbar;
temp2 = 1.0 / (np *snrbar);
temp = 1.0 + temp2;
val1 = temp^(np-1.);
igf1 = incomplete_gamma(vt,np-1);
igf2 = incomplete_gamma(vt/temp,np-1);
pd = 1.0 - igf1 + val1 * igf2 * exp(-vt/temp1);
Listing 2.17. MATLAB Program Ðfig2_10.mÑ
% This program is used to reproduce Fig. 2.10
close all
clear all
pfa = 1e-9;
nfa = log(2) / pfa;
b = sqrt(-2.0 * log(pfa));
index = 0;
for snr = 0:.1:22
index = index +1;
a = sqrt(2.0 * 10^(.1*snr));
pro(index) = marcumsq(a,b);
prob(index) = pd_swerling1 (nfa, 1, snr);
end
x = 0:.1:22;
plot(x, pro,'k',x,prob,'k:');
axis([2 22 0 1])
xlabel ('SNR - dB')
ylabel ('Probability of detection')
legend('Swerling V','Swerling I')
grid