신호 및 시스템 3판 솔루션 (저자 Pillips , 3rd ed)

CHAPTER 1
1.1 to 1.41 - part of text

1.42

(a) Periodic: Fundamental period 〓 0.5s (b) Nonperiodic (c) Periodic Fundamental period 〓 3s (d) Periodic Fundamental period 〓 2 samples (e) Nonperiodic (f) Periodic: Fundamental period 〓 10 samples (g) Nonperiodic (h) Nonperiodic (i) Periodic: Fundamental period 〓 1 sample

l.43

π 2 y ( t ) 〓 ? 3 cos ? 200t + ? ? ? ? 6? ?
2 π 〓 9 cos ? 200t + ? ? 6?

9 π 〓 cos ? 400t + ? 1 ? 2 3? 9 (a) DC component 〓 -2 9 π (b) Sinusoidal component 〓 cos ? 400t + ? ? 2 3? 9 Amplitude 〓 -2

1

200 Fundamental frequency 〓 Hz π

1.44

The RMS value of sinusoidal x(t) is A ? 2 . Hence, the average power of x(t) in a 1-ohm resistor is ( A ? 2 ) 〓 A2/2.
2

1.45

Let N denote the fundamental period of x[N]. which is de?ned by 2π N 〓 Ω The average power of x[n] is therefore 1 2 P 〓 - ∑ x [ n ] N 1 〓 N
n〓0 N -1 N -1

∑A
n〓0

2

A 〓 N

n〓0 2 N -1

2 2πn cos ? - + φ? ? N ? 2