EE4440 HW#1 Solution
January 20, 2011
1. Given a signal the signal x(t) shown below in (a), plot or sketch(b-e):
x(t)
1
(a)
0
2
t
(b) x(t 4)
(c) x(4t)
(d) x(t)
(e) x(2 2t)
Solution: The following MATLAB program solves:
function hw1prob1sol ()
dur =10;
t =
EE4440 HW#2 Solution
February 2, 2011
1. Answer the following:
(a) What kind of spectrum does a periodic signal have?
Solution: Line or discrete.
(b) What is the procedure (give it step by step with equations) for nding the spectrum of a periodic
signal?
EE4440 HW#3 Solution
February 27, 2011
1. For what class of signals can a Fourier Series be computed?
Solution: Periodic!
2. The block diagram below is a very rudimentary scrambling system for analog communications. In
ancient times it was used to secure
EE4440 HW#4
February 27, 2011
1. Design a direct conversion DSB-SC receiver that uses a PLL for local oscillator sync. Assume that
the message signal does not have a pilot carrier embedded, and that you must use signal squaring as
discussed in class to pr
EE440 HW#5 Solution
March 8, 2011
1. In class we discussed narrow band angle modulated signals (NBFM/NBPM) as the truncation of an
innite series. We justied the truncation by saying that kp a(t) was small, so the higher order terms
are negligible. The ban
EE4440 HW#6 Solution
April 13, 2011
1. Implement dierential PCM in MATLAB, write a function that DPCM encodes a data stream, a
function that DPCM decodes a data stream, and a script which tests the two.
(a) Assume that you have some mechanism of letting t
EE4440 HW#7 Solution
April 13, 2011
1. Draw the waveform for the binary sequence 0100 1011 using each of the
following line codes:
(a) Unipolar On-O RZ
(b) Unipolar On-O NRZ
(c) Polar RZ
(d) Polar NRZ
(e) Bipolar RZ
(f) Manchester
Solution:
a.)
b.)
c.)
d.
EE4440 HW#8 Solution
April 13, 2011
1. What frequency must be used for basis symbols 1 = sin(c t) and 2 =
cos(c t) with a symbol period of 1/(9600Hz) to contain 6 cycles of the sin
and cos?
Solution: The frequency is 6 times the frequency of the symbol fr