MEÜ.EÖ.FR-212/01
Sayfa 1/1
Yayın Tarihi : 08.04.2011
T.C.
MERSİN ÜNİVERSİTESİ
MÜHENDİSLİK FAKÜLTESİ EEM BÖLÜMÜ
2019-2020 EĞİTİM-ÖĞRETİM YILI GÜZ DÖNEMİ
EEM 364 TELECOMMUNICATION SYSTEMS MIDTERM
SINAV SORULARI
Sınav Tarihi: 25 / 04 / 2020 Saati: :
1) [20 points] If ℎ(𝑡)= 𝑓(𝑡)∗ 𝑔(𝑡), find 𝑓(𝑡 − 2)∗ 𝑔(𝑡 + 2) in terms of ℎ(𝑡) by the help of Fourier
transform.
2) [20 points] Find the Fourier transforms of below signals:
(a) 𝑔(𝑡)= 3𝛿(3𝑡)+ 𝑟𝑒𝑐𝑡 (2𝑡
3)sin(10𝜋𝑡)+ 8 + 𝑒−5|𝑡|.
(b)
3) [30 points] The spectrum of a message signal 𝑔(𝑡) is given as 𝐺(𝑓) = 5𝑒−| 𝑓
2∙106|.
(a) Calculate the total energy of 𝑔(𝑡).
(b) Find the %95 bandwidth of the signal.
4) [30 points] Power spectral density (PSD); 𝑆𝑚(𝑓) of a message signal; 𝑚(𝑡) is given below. The
signal is fed to a system that takes the derivative of the input signal. Then it is passed thru a Low
Pass Filter (LPF) with a cut-off frequency of 𝑓𝑐=10𝐾𝐻𝑧.
(a) Draw the PSD of 𝑥(𝑡), 𝑆𝑥(𝑓)
(b) Draw the PSD of 𝑦(𝑡), 𝑆𝑦(𝑓)
(c) Calculate the total power of the output signal of 𝑦(𝑡); 𝑃𝑦.
PS: Submit your answers via http://ue.mersin.edu.tr/ portal with your OWN HANDWRITING.
* GOOD LUCK *
Prof. Dr. Caner Özdemir
t,sn
y(t)
-2 2
4
f
S (f)
30 KHz
10
-30 KHz
m
m(t) x(t) y(t)
d/dt LPF