Radar Detection - MATLAB Simulations for Radar Systems Design - page 136

% pfa = 1e-7;
% np = 1;
% R_1st_frame = 61e3; % Range for first frame
% R0 = 55e3; % range to last frame
% SNR0 = 9; % SNR at R0
% frame = 0.3e3; % frame size
nfa = log(2) / pfa;
range_frame = R_1st_frame:-frame:R0; % Range to each frame
% implement Eq. (2.98)
SNRi = SNR0 + 40 .* log10((R0 ./ range_frame));
% calculate the Swerling 5 Pd at each frame
b = sqrt(-2.0 * log(pfa));
if np ==1
for frame = 1:1:size(SNRi,2)
a = sqrt(2.0 * 10^(.1*SNRi(frame)));
pd5(frame) = marcumsq(a,b);
end
else
[pd5] = pd_swerling5(pfa, 1, np, SNRi);
end
% compute additional SNR needed due to fluctuation
for frame = 1:1:size(SNRi,2)
[Lf(frame),Pd_Sw5] = fluct_loss(pd5(frame), pfa, np, swid);
end
% adjust SNR at each frame
SNRi = SNRi - Lf;
% compute the frame Pd
for frame = 1:1:size(SNRi,2)
if(swid==1)
Pdi(frame) = pd_swerling1 (nfa, np, SNRi(frame));
end
if(swid==2)
Pdi(frame) = pd_swerling2 (nfa, np, SNRi(frame));
end
if(swid==3)
Pdi(frame) = pd_swerling3 (nfa, np, SNRi(frame));
end
if(swid==4)
Pdi(frame) = pd_swerling4 (nfa, np, SNRi(frame));
end
if(swid==5)
Pdi(frame) = pd5(frame);
end
end