통신이론 Principles of Communication 5판 솔루션 지은이 Zeimer

Principles of Communication 5Ed R. E. Zeimer, William H Tranter Solutions Manual

Chapter 2

Signal and Linear System Theory
2.1 Problem Solutions

Problem 2.1 For the single-sided spectra, write the signal in terms of cosines: x(t) = 10 cos(4πt + π/8) + 6 sin(8πt + 3π/4) = 10 cos(4πt + π/8) + 6 cos(8πt + 3π/4 ? π/2) = 10 cos(4πt + π/8) + 6 cos(8πt + π/4) For the double-sided spectra, write the signal in terms of complex exponentials using Euler’s theorem: x(t) = 5 exp[(4πt + π/8)] + 5 exp[?j(4πt + π/8)] +3 exp[j(8πt + 3π/4)] + 3 exp[?j(8πt + 3π/4)] The two sets of spectra are plotted in Figures 2.1 and 2.2. Problem 2.2 The result is x(t) = 4ej(8πt+π/2) + 4e?j(8πt+π/2) + 2ej(4πt?π/4) + 2e?j(4πt?π/4) = 8 cos (8πt + π/2) + 4 cos (4πt ? π/4) = ?8 sin (8πt) + 4 cos (4πt ? π/4)

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CHAPTER 2. SIGNAL AND LINEAR SYSTEM THEORY

Single-sided amplitude 10 5 f, Hz 0 2 4 6 0 π/4 π/8

Single-sided phase, rad.

f, Hz 2 4 6

Figure 2.1: P…(생략)