100 Practical MATLAB® Applications for Engineers
Write a program that returns
a. The plots of f 1 (t) versus t and f 2 (t) versus t, over the range − 2 π ≤ t ≤ 2 π, using the
sinc function
b. The plots of the amplitude modulated (AM) signals for f 1 (t) and f 2 (t) versus t,
over the range 0 ≤ t ≤ 3 , if the carrier signal is fc(t) = 10 cos(20πt)
c. Repeat part b for the case of angular modulation (FM or PM)P. 1. 4 1 L e t f(t) = A cos(2πwot + φ) be a continuous time function.
How many samples are then required to uniquely determine A, wo, and φ.
Is it always possible to solve for A, wo, and φ?
P. 1. 4 2 L e t A = 5, wo = 2 rad/s, and φ = 30 °, for the signal defi ned in P.1.41.
Write a program that returns the following plots:
a. f(t) versus t
b. f(nT) versus nT, for T = 0.1
c. Reconstruct f(t) from f(nT) using the summation of sinc functions (by applying
the sampling theorem)
P.1.43 Create the symbolic expression for f(t) defi ned in P.1.42 and obtain the following
plots:
a. f(t) versus t, using ezplot.
b. Let A = 7, wo = 3 rad/s, and φ = 45 ° by redefi ning the symbolic expression of
part a, by using the subs symbolic function.
c. AM and FM/PM signals using the symbolic approach, if the carrier is fc(t) =
10 cos(20πt) and the information is f(t).