Pulse Compression - MATLAB Simulations for Radar Systems Design - page 262

if( winid == 2.)
win = kaiser(n,pi);
else
if(winid == 3.)
win = chebwin(n,60);
end
end
end
end
deltar = c / 2. / b;
max_rrec = deltar * nfft / 2.;
maxr = max(scat_range);
if(rrec > max_rrec | maxr >= rrec )
'Error. Receive window is too large; or scatterers fall outside window'
return
end
t = linspace(0,taup,n);
for j = 1:1:nscat
range = scat_range(j);% + rmin;
psi1 = 4. * pi * range * f0 / c - ...
4. * pi * b * range * range / c / c/ taup;
psi2 = (2*4. * pi * b * range / c / taup) .* t;
x(j,:) = scat_rcs(j) .* exp(i * psi1 + i .* psi2);
y = y + x(j,:);
end
figure(1)
plot(t,real(y),'k')
xlabel ('Relative delay - seconds')
ylabel ('Uncompressed echo')
ywin = y .* win';
yfft = fft(y,n) ./ n;
out= fftshift(abs(yfft));
figure(2)
delinc = rrec/ n;
%dist = linspace(-delinc-rrec/2,rrec/2,n);
dist = linspace((-rrec/2), rrec/2,n);
plot(dist,out,'k')
xlabel ('Relative range in meters')
ylabel ('Compressed echo')
axis auto
grid