Communications
Analog Communication Systems
Marks 1Marks 2
Digital Communication Systems
Marks 1Marks 2Marks 8Marks 10
Random Signals and Noise
Marks 1Marks 2Marks 4
Fundamentals of Information Theory
Marks 1Marks 2
Noise In Digital Communication
Marks 1Marks 2
1
GATE ECE 2005
MCQ (Single Correct Answer)
+2
-0.6
A carrier is phase modulated (PM) with frequency deviation of 10 kHz by a single tone frequency of 1 kHz. If the single tone frequency is increased to 2 kHz, assuming that phase deviation remains unchanged, the bandwidth of the PM signal is
A
21 kHz
B
22 kHz
C
42 kHz
D
44 kHz
2
GATE ECE 2004
MCQ (Single Correct Answer)
+2
-0.6
Two sinusoidal signals of same amplitude and frequencies 10 kHz and 10.1 kHz are added together. The combined signal is given to an ideal frequency detector. The output of the detector is
A
0.1 kHz sinusoid
B
20.1 kHz sinusoid
C
a linear function of time
D
a constant
3
GATE ECE 2003
MCQ (Single Correct Answer)
+2
-0.6
A DSB-SC signal is to be generated with a carrier frequency fc = 1MHz using a nonlinear device with the input-output characteristic $$v_0=a_0v_i\;+\;a_1v_i^3$$.where a0 and a1 are constants. The output of the nonlinear device can be filtered by an appropriate band-pass filter. Let $$v_0=A_c'\;\cos\left(2{\mathrm{Ï€f}}_\mathrm c'\mathrm t\right)\;+\;m\left(t\right)$$ where m(t) is the message signal. Then the value of $$f_c'$$ (in MHz) is
A
1.0
B
0.333
C
0.5
D
3.0
4
GATE ECE 2003
MCQ (Single Correct Answer)
+2
-0.6
Let $$m\left(t\right)\;=\cos\left[\left(4\mathrm\pi\times10^3\right)t\right]$$ be the message signal and $$c\left(t\right)\;=5\cos\left[2\mathrm\pi\times10^6t\right]$$ be the carrier.

c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM signal is three times the transmission bandwidth of the AM singal, then the coefficient of the term $$\cos\left[2\mathrm\pi\left(1008\times10^3\right)t\right]$$ in the FM signal (in terms of the Bessel coefficients) is

A
$$5\;J_4\left(3\right)$$
B
$$\left(5/2\right)\;J_8\left(3\right)$$
C
$$\left(5/2\right)\;J_8\left(4\right)$$
D
$$5\;J_4\left(6\right)$$
GATE ECE Subjects
Signals and Systems
Network Theory
Control Systems
Digital Circuits
General Aptitude
Electronic Devices and VLSI
Analog Circuits
Engineering Mathematics
Microprocessors
Communications
Electromagnetics