Question

5 (15pt) In Quadrature-Carrier Multiplexing, two baseband signals mi(t) and m2(t) can be modulated on one single carrier frequency by taking advantage of the in-phase component and the auadratiure component of the carrier signa! At receiver side, let's assume the received signal r(t) is r(t) Acmi (t) cos(2n fet) + Acm2 (t) sin(2r/et) Employing a coherent detector, the mi) and m2(t) can be extracted from the received signal. Assuming the signal generated from the local oscillator at the receiver is LO(t) A cos(2m fet+ 訇, and LO2(t) A'sin(2tht ), what isthe output of the product modulator ui(t)? what is the output after the low pass filter tog)?Ty(t) = r(t) . La (t))

Answer 1

ocal osallata

m,(k),MzE) au pats signals are

Sm gnal +0 LPF