- 2 Suppose M T A B C Where Rect T Is Defined As In Problem 1 If We Have An Am Communications System That Sends 1 (75.95 KiB) Viewed 29 times
2. Suppose m(t) (a) (b) (c) where rect(t) is defined as in Problem 1. If we have an AM communications system that sends a signal [A+m(t)]]cos(2 fet), sketch the AM signal when we have a modulation index of 0.25. Please label key points on both axes. Now suppose our new message signal is mnew (t) = 2m(t) + 0.5 and we send an AM signal that is [A+mnew(t)]cos(2 ft). At what value of A will this AM signal be just on the edge of overmodulation? Justify your answer. Now suppose we have an FM communications system where m(t) is the same as in the AM case described above in Part a. Assuming f = 1kHz and kf = 27, what are the minimum and maximum instantaneous frequencies of the FM signal FM (t) for the modulating signal m(t)? Suppose you now transform the message signal m(t) by doubling its period, and we call this message signal mnew-FM(t). Assuming the same feand kf from Part c, what are the minimum and maximum instantaneous frequencies of the FM signal for the modulating signal mnew-FM(t)? (d) ==-(-1)"rect(tn),