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 2007
MCQ (Single Correct Answer)
+2
-0.6
Two 4-ray signal constellations are shown. It is given that $${\phi _1}$$ and $${\phi _2}$$ constitute an orthonormal basis for the two constellations. Assume that the four symbols in both the constellations are equiprobable. Let $${{{N_0}} \over 2}$$ denote the power spectral density of white Gaussian noise. GATE ECE 2007 Communications - Noise In Digital Communication Question 21 English

The ratio of the average energy of Constellation 1 to the average energy of Constellation 2 is

A
$$4{a^2}$$
B
$$4$$
C
$$2$$
D
$$8$$
2
GATE ECE 2007
MCQ (Single Correct Answer)
+2
-0.6
Two 4-ray signal constellations are shown. It is given that $${\phi _1}$$ and $${\phi _2}$$ constitute an orthonormal basis for the two constellations. Assume that the four symbols in both the constellations are equiprobable. Let $${{{N_0}} \over 2}$$ denote the power spectral density of white Gaussian noise. GATE ECE 2007 Communications - Noise In Digital Communication Question 20 English

If these constellations are used for digital communications over an AWGN channel, then which of the following statements is true?

A
Probability of symbol error for Constellation 1 is lower
B
Probability of symbol error for Constellation 1 is higher
C
Probability of symbol error is equal for both the constellations
D
The value of N0 will determine which of the two constellations has a lower probability of symbol error.
3
GATE ECE 2006
MCQ (Single Correct Answer)
+2
-0.6
Let $$g\left( t \right){\mkern 1mu} {\mkern 1mu} \,\,\,\,\,{\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} p\left( t \right){}^ * p\left( t \right)$$ where $$ * $$ denotes convolution and $$p(t) = u(t) - u(t-1)$$ with $$u(t)$$ being the unit step function

The impulse response of filter matched to the signal $$s(t) = g(t)$$ $$ - \delta {\left( {t - 2} \right)^ * }\,\,g\left( t \right)$$ is given as:

A
$$s\left( {1 - t} \right)$$
B
$$ - s\left( {1 - t} \right)$$
C
$$ - s\left( t \right)$$
D
$$ s\left( t \right)$$
4
GATE ECE 2006
MCQ (Single Correct Answer)
+2
-0.6
In the following figure the minimum value of the constant “C”, which is to be added to y1(t) such that y1(t) and y2(t) are different, is GATE ECE 2006 Communications - Noise In Digital Communication Question 26 English
A
$$\Delta $$
B
$${\Delta \over 2}$$
C
$${{{\Delta ^2}} \over {12}}$$
D
$${\Delta \over L}$$
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