0195136047.pdf

14.1 SIGNALS AND SPECTRAL ANALYSIS 631

xr(t)

t

xi(t)

t

|x(t)|

t

∠x(t)

t

(b)

24

1

− 4 − 2 0

u− 1 (t)

(c)

1

1

2

t

x[n]

(d)

2.5

2

1

1.5

0

0.5

− 1

− 2

−2.5

−0.5

−1.5

n

Figure E14.1.1Continued