Dept. of Electrical Engineering
University of Toronto
Communication Systems
ECE316
Problems 1
2 + 2j
1. Simplify the expression - + 5 j and put it in both polar and rectangular form.
1 2j
2. Consider the expression x ( t ) = e j 4 t + cos ( 4 t ) . This i
Dept. of Electrical Engineering
University of Toronto
Communication Systems
ECE316
Problems 3
1. Consider the signal x ( t ) = cos ( 2 f m t ) , where f m = 1 KHz. This signal is multiplied by a
square wave with minimum value 0, maximum value equal to 1,
University of Toronto
Department of Electrical and Computer Engineering
Communication Systems
ECE316
Elvino S. Sousa (Fall - 2013)
Block Diagram of a Communication System
Interference
Input
message
Input
Transducer
Transmitter
message
signal
transmitted
s
ECE316
Communication Systems
E. S. Sousa
Problems 6 - FM
11. Consider a message signal that is a pulse ( t ) = 2 if 0 t - ms. Consider a carrier
10
4 cos ( 2 f c t ) , where f c = 100 KHz. If k f = 5 KHz/V plot the modulated signal assuming
FM modulation.
Dept. of Electrical Engineering
University of Toronto
Communication Systems
ECE316
Problems 2
1. Find the Fourier transform of the following signal. Simplify the expression as much as possible.
2
1
3
1
t
5
10
2. Find the energy spectral density for the ab
Dept. of Electrical Engineering
University of Toronto
Communication Systems
ECE316
Problems 4
1. The signal x ( t ) =
( t kT ) is input to an ideal band-pass filter with center frequency 2
k =
MHz and bandwidth 500 KHz. If T = 10 s, give the output of th