Problem 1 [ ] Given a signal m(t) and its spectrum M( f ) M ( f ) f XXXXXXXXXXW W XXXXXXXXXXFigure 1 The process of the double-sideband modulation can be described by the following diagram XXXXXXXXXXFigure 2 Write the expressions of , and . Sketch and Problem 2 [] An AM modulator operates with a message signal mt=9 cos20pt-7 cos?(60pt) The unmodulated carrier is given by 100 cos?(200pt) and the added dc bias A=2. Please give the modulator output xc(t). Problem 3 [] Let the input to a phase modulator be mt=u(t). Assume the unmodulated carrier is Accos?(?ct). Write and sketch phase modulater output xc(t) for kp=p. Problem 4 [] If the message signal mt is sinusoidal signal sin(20pt) and the unmodulated carrier is 2cos?(2000t). Find the frequency output and draw the output. Problem 5 [] Figure 3 describes the generation of lower-sideband SSB. Redraw this figure to illustrate the generation of upper-sideband SSB. Give the equation defining the upper-sideband filter. Figure 3 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Problem 1 [20 points ] Given a signal m(t) and its spectrum M( f ) M ( f ) f XXXXXXXXXX20 20 The process of the double-sideband modulation can be described by the following diagram ×× ×× m(t)m(t) Lowpass FilterLowpass Filter ModulatorModulator DemodulatorDemodulator Write the expressions of , and . Sketch and Problem 2 [20 points] Let the input to a phase modulator be QUOTE . Assume the unmodulated carrier is . Write and sketch phase modulator output for QUOTE . Problem 3 [20 points] If the message signal is...
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