1
GATE ECE 2012
MCQ (Single Correct Answer)
+1
-0.3
A source alphabet consists of N symbols with the probability of the first two symbols being the same. A source encoder increases the probability of the first symbol by a small amount $$\varepsilon $$ and decreases that of the second by $$\varepsilon $$. After encoding, the entropy of the source
A
increases
B
remains the same
C
increases only if N = 2
D
decreases
2
GATE ECE 2012
MCQ (Single Correct Answer)
+1
-0.3
The power spectral density of a real process X(t) for positive frequencies is shown below. The value of $$E\,\left[ {{X^2}\,(t)} \right]$$ and $$E\,\left[ {X\,(t)} \right]$$, respectively, are GATE ECE 2012 Communications - Random Signals and Noise Question 21 English
A
$$6000/\,\pi ,\,0$$
B
$$6400/\,\pi ,\,0$$
C
$$\,6400/\,\pi ,\,\,20\,\left( {\pi \sqrt 2 } \right)$$
D
$$\,6000/\,\pi ,\,\,20\,\left( {\pi \sqrt 2 } \right)$$
3
GATE ECE 2012
MCQ (Single Correct Answer)
+1
-0.3
In a base band communications link, frequencies up to 3500 Hz are used for signaling. Using a raised cosine pulse with 75% excess bandwidth and for no inter-symbol interference, the maximum possible signaling rate in symbols per second is
A
1750
B
2625
C
4000
D
5250
4
GATE ECE 2012
MCQ (Single Correct Answer)
+2
-0.6
A binary symmetric channel (BSC) has a transition probability of 1/8. If the binary transmit symbol X is such that P(X =0) = 9/10, then the probability of error for an optimum receiver will be
A
7/80
B
63/80
C
9/10
D
1/10