PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

DTFT, DFT, ZT, and FFT 537

− 15

− 40 − 30 − 20 − 10 0 10 20 30 40

− 10

− 5

0

Amplitude

5

10

15

20

Auto-correlation plots

R11

R22

R1

FIGURE 5.49

(See color insert following page 374.) Autocorrelation plots of part c of Example 5.11.

abs[conj[fft(f1n)]*fft(f2n)] versus W

abs[fft(xcorr(f1(n),f2(n)))] versus W

0

0

100

200

Magnitude

300

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0

0

100

200

Magnitude

300

0.1 0.2 0.3 0.4 0.5

W

0.6 0.7 0.8 0.9 1

FIGURE 5.50

Plots of part d—abs[conj[fft(f1n)] * fft(f2n)] and abs[fft(xcorr(f1(n), f 2(n)))]—of Example 5.11.