1
GATE ECE 2013
MCQ (Single Correct Answer)
+2
-0.6
Bits 1 and 0 are transmitted with equal probability. At the receiver, the pdf of the respective received signals for both bits are as shown below. GATE ECE 2013 Communications - Random Signals and Noise Question 40 English

The optimum threshold to achieve minimum bit error rate (BER) is

A
$${1 \over 2}$$
B
$${4 \over 5}$$
C
1
D
$${3 \over 2}$$
2
GATE ECE 2011
MCQ (Single Correct Answer)
+2
-0.6
X(t) is a stationary random process with autocorrelation function Rx$$\left( \tau \right)$$= exp$$\left( { - \pi {\tau ^2}} \right)$$. This process is passed through the system shown below. The power spectral density of the output process Y(t) is GATE ECE 2011 Communications - Random Signals and Noise Question 42 English
A
$$\left( {4\,{\pi ^2}{f^2} + 1} \right)\,\exp \left( { - \pi {f^2}} \right)$$
B
$$\left( {4\,{\pi ^2}{f^2} - 1} \right)\,\exp \left( { - \pi {f^2}} \right)$$
C
$$\left( {4\,{\pi ^2}{f^2} + 1} \right)\,\exp \left( { - \pi f} \right)$$
D
$$\left( {4\,{\pi ^2}{f^2} - 1} \right)\,\exp \left( { - \pi f} \right)$$
3
GATE ECE 2010
MCQ (Single Correct Answer)
+2
-0.6
X(t) is a stationary process with the power spectral density Sx(f) > 0 for all f. The process is passed through a system shown below. GATE ECE 2010 Communications - Random Signals and Noise Question 43 English

Let Sy(f) be the power spectral density of Y(t). Which one of the following statements is correct?

A
Sy(f) > 0 for all f
B
Sy(f) > 0 for $$\left| f \right|$$ > 1 kH
C
Sy(f) > 0 for f = nf0, f0 = 2kHz, n any integer
D
Sy(f) > 0 for f = (2n + 1)f0, f0 = 1 kHz, n any integer
4
GATE ECE 2008
MCQ (Single Correct Answer)
+2
-0.6
Noise with double-sided power spectral density of K over all frequencies is passed through a RC low pass filter with 3-dB cut-off frequency of fc. The noise power at the filter output is
A
K
B
K fc
C
K $$\pi $$ fc
D
$$\infty $$
GATE ECE Subjects
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
CBSE
Class 12