Radar Detection - MATLAB Simulations for Radar Systems Design - page 118

betan_1 = 0.;
D1 = dn;
n = 0;
ratio = 2.0 / (a * b);
r1 = 0.0;
betan = 0.0;
alphan = 0.0;
while betan < 1000.,
n = n + 1;
alphan = dn + ratio * n * alphan0 + alphan;
betan = 1.0 + ratio * n * betan0 + betan;
alphan_1 = alphan0;
alphan0 = alphan;
betan_1 = betan0;
betan0 = betan;
dn = dn * D1;
end
PD = (alphan0 / (2.0 * betan0)) * exp( -(a-b)^2 / 2.0);
if ( a >= b)
PD = 1.0 - PD;
end
return
Listing 2.5. MATLAB Program Ðprob_snr1.mÑ
% This program is used to produce Fig. 2.4
close all
clear all
for nfa = 2:2:12
b = sqrt(-2.0 * log(10^(-nfa)));
index = 0;
hold on
for snr = 0:.1:18
index = index +1;
a = sqrt(2.0 * 10^(.1*snr));
pro(index) = marcumsq(a,b);
end
x = 0:.1:18;
set(gca,'ytick',[.1 .2 .3 .4 .5 .6 .7 .75 .8 .85 .9 ...
.95 .9999])
set(gca,'xtick',[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18])
loglog(x, pro,'k');
end