Pulse Compression - MATLAB Simulations for Radar Systems Design - page 260

win = hamming(n);
else
if( winid == 2.)
win = kaiser(n,pi);
else
if(winid == 3.)
win = chebwin(n,60);
end
end
end
end
% check to ensure that scatterers are within receive window
index = find(scat_range > rrec);
if (index ~= 0)
'Error. Receive window is too large; or scatterers fall outside window'
return
end
% calculate sampling interval
t = linspace(-taup/2,taup/2,n);
replica = exp(i * pi * (b/taup) .* t.^2);
figure(1)
subplot(2,1,1)
plot(t,real(replica))
ylabel('Real (part) of replica')
xlabel('time in seconds')
grid
subplot(2,1,2)
sampling_interval = taup / n;
freqlimit = 0.5/ sampling_interval;
freq = linspace(-freqlimit,freqlimit,n);
plot(freq,fftshift(abs(fft(replica))));
ylabel('Spectrum of replica')
xlabel('Frequency in Hz')
grid
for j = 1:1:nscat
range = scat_range(j) ;;
x(j,:) = scat_rcs(j) .* exp(i * pi * (b/taup) .* (t +(2*range/c)).^2) ;
y = x(j,:) + y;
end
figure(2)
plot(t,real(y),'k')
xlabel ('Relative delay - seconds')
ylabel ('Uncompressed echo')
grid