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 2023
Numerical
+2
-0

Let X(t) be a white Gaussian noise with power spectral density $$\frac{1}{2}$$W/Hz. If X(t) is input to an LTI system with impulse response $$e^{-t}u(t)$$. The average power of the system output is ____________ W (rounded off to two decimal places).

Your input ____
2
GATE ECE 2022
Numerical
+2
-0

Consider a real valued source whose samples are independent and identically distributed random variables with the probability density function, f(x), as shown in the figure.

GATE ECE 2022 Communications - Random Signals and Noise Question 8 English

Consider a 1 bit quantizer that maps positive samples to value $$\alpha$$ and others to value $$\beta$$. If $$\alpha$$* and $$\beta$$* are the respective choices for $$\alpha$$ and $$\beta$$ that minimize the mean square quantization error, then ($$\alpha$$* $$-$$ $$\beta$$*) = ___________ (rounded off to two decimal places).

Your input ____
3
GATE ECE 2017 Set 1
MCQ (Single Correct Answer)
+2
-0.6
Let $$X(t)$$ be a wide sense stationary random process with the power spectral density $${S_x}\left( f \right)$$ as shown in figure (a), where $$f$$ is in Hertz $$(Hz)$$. The random process $$X(t)$$ is input to an ideal low pass filter with the frequency response $$$H\left( f \right) = \left\{ {\matrix{ {1,} & {\left| f \right| \le {1 \over 2}Hz} \cr {0,} & {\left| f \right| > {1 \over 2}Hz} \cr } } \right.$$$

As shown in Figure (b). The output of the low pass filter is $$y(t)$$.

GATE ECE 2017 Set 1 Communications - Random Signals and Noise Question 29 English 1 GATE ECE 2017 Set 1 Communications - Random Signals and Noise Question 29 English 2

Let $$E$$ be the expectation operator and consider the following statements :
$$\left( {\rm I} \right)$$ $$E\left( {X\left( t \right)} \right) = E\left( {Y\left( t \right)} \right)$$
$$\left( {{\rm I}{\rm I}} \right)$$ $$\,\,\,\,\,\,\,\,E\left( {{X^2}\left( t \right)} \right) = E\left( {{Y^2}\left( t \right)} \right)$$
$$\left( {{\rm I}{\rm I}{\rm I}} \right)\,$$ $$\,\,\,\,\,\,E\left( {{Y^2}\left( t \right)} \right) = 2$$

Select the correct option:

A
only $${\rm I}$$ is true
B
only $${\rm I}$$$${\rm I}$$ and $${\rm I}$$$${\rm I}$$$${\rm I}$$ are true
C
only $${\rm I}$$ and $${\rm I}$$$${\rm I}$$ are true
D
only $${\rm I}$$ and $${\rm I}$$$${\rm I}$$$${\rm I}$$ are true
4
GATE ECE 2016 Set 3
MCQ (Single Correct Answer)
+2
-0.6
A wide sense stationary random process $$X(t)$$ passes through the $$LTI$$ system shown in the figure. If the autocorrelation function of $$X(t)$$ is $${R_x}\left( \tau \right),$$ then the autocorrelation function $${R_x}\left( \tau \right),$$ of the output $$Y(t)$$ is equal to GATE ECE 2016 Set 3 Communications - Random Signals and Noise Question 30 English
A
$$2{R_X}\left( \tau \right) + {R_X}\left( {\tau - {T_0}} \right) + {R_X}\left( {\tau + {T_0}} \right)$$
B
$$2{R_X}\left( \tau \right) - {R_X}\left( {\tau - {T_0}} \right) - {R_X}\left( {\tau + {T_0}} \right)$$
C
$$2{R_X}\left( \tau \right) + 2{R_X}\left( {\tau - 2{T_0}} \right)$$
D
$$2{R_X}\left( \tau \right) - 2{R_X}\left( {\tau - 2{T_0}} \right)$$
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