Energy content of modulated signals Cos(a) 1+cos(20 ∫ g()+」g(Co(4x)t e+ The cosine part is fast varying and integrates to O Modulated signal has 1 2 the energy as the baseband signal Slide 10() Energy content of modulated signals ∞ ∞ Em = ∫−∞ U2 t dt = ∫−∞ Amg2 m () ( ) 2 t Cos2 (2πfct)dt Cos2 α = 1 + cos(2α) 2 A A2 ∞ 2 ∞ 2 () + 2 m ∫−∞g t Cos2 (4πfc Em = t)dt 2 m ∫−∞g t 2 () A2 m Em = E + ≈ 0 2 g • The cosine part is fast varying and integrates to 0 • Modulated signal has 1/2 the energy as the baseband signal Eytan Modiano Slide 10