Sampling and Reconstruction of Analog Signals

Example 6a
• Reconstruct the sample in example 2a using spline function
• Maximum error is lower due to nonideal interpolation and the
fact that x a (t) is nonband-limited
• The ideal interpolation suffers more from time-limitedness
• The plot is excellent
Ts = 0.0002; n = -25:1:25; nTs = n*Ts;
x = exp(-1000*abs(nTs));
% Analog Signal reconstruction
Dt = 0.00005;
t = -0.005:Dt:0.005;
xa = spline(nTs,x,t);
plot(t*1000,xa);
xlabel('t in msec.'); ylabel('xa(t)')
stem(n*Ts*1000,x); hold off
% check
error = max(abs(xa - exp(-1000*abs(t))))
error =
0.0317
xa(t)
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Reconstructed Signal from x1(n) using cubic spline function
0
-5 -4 -3 -2 -1 0 1 2 3 4 5
t in msec.