WorksheetsInformation Theory
Total questions: 46
Worksheet time: 23mins
Self information should be
Positive
Negative
Positive & Negative
None of the mentioned
The unit of average mutual information is
Bits
Bytes
Bits per symbol
Bytes per symbol
Binary Huffman coding is a
Prefix condition code
Suffix condition code
Prefix & Suffix condition code
None of the mentioned
The method of converting a word to stream of bits is called as
Binary coding
Source coding
Bit coding
Cipher coding
When X and Y are statistically independent, then I (x,y) is
1
0
Ln 2
Cannot be determined
The self information of random variable is
0
1
Infinite
Cannot be determined
Entropy of a random variable is
0
1
Infinite
Cannot be determined
Xn + 1
Xn - 1
Xn/2
X2n/3
For a (6, 4) block code where n = 6, k = 4 and dmin = 3, how many errors can be corrected by this code?
0
1
2
3
In decoding of cyclic code, which of the following is also regarded as 'Syndrome Polynomial'?
Generator Polynomial
Received code word Polynomial
Quotient Polynomial
Remainder Polynomial
26. While representing the convolutional code by (n, k, m), what does 'm' signify or represent in it?
Coded bits
Message bits
Memory size
All of the above
A source produces 4 symbols with probability 1/2, 1/4, 1/8, and 1/8 for this source, a practical coding scheme has an 8 average codeword length of 2 bits/symbols. The efficiency of the code is
1
7/4
7/8
14/4
A source generates three symbols with probabilities 0.25, 0.25, 0.50 at a rate of 3000 symbols per second. Assuming independent generation of symbols, the most efficient source encoder would have average bit rate
6000 bits/sec
4500 bits/sec
3000 bits/sec
1500 bits/sec
For designing of (4, 1) cyclic repetition code, what would be the order of the generator polynomial g(x)?
1
2
3
4
The minimum distance of linear block code (dmin) is equal to the minimum number of rows or columns of HT, whose . is equal to zero vector
sum
product
division
difference
For a Gaussian channel of 1 MHz bandwidth with the signal power to spectral noise density ratio of about 104 Hz, what would be the maximum information rate?
12000 bits/sec
14400 bits/sec
28000 bits/sec
32500bits/sec
15.15 KHZ
30.12 KHZ
24.5 KHZ
52.18 KHZ
H = Mlog2 (M)
H = log2 (M)
H = -log2 (M)
H = -Mlog2 (M)
19/2 bits/sec
19/4 bits/sec
38/3 bits/sec
38/5 bits/sec
If the probability of a message is 1/4, then the information in bits is
8
4
2
1
If receiver knows the message being transmitted the amount of information carried is
1
0
infinity
undefined
A fair Dice is thrown, find the amount of information gained if
you are told that 4 will appear
1.58 bits
2.58 bits
3.58 bits
4.58 bits
A biased coin has p(Head)=0.3. Find the amount of information gained if you are told that a tail will appear
0.514 bits
1.514 bits
2.514 bits
3.514 bits
If some transmission scheme contains 4 messages, calculate the information rate if all messages are equally likely Knowing that the r= 1.875 messages/sec.
1.75 bits/sec
2 bits/sec
3.75 bits/sec
4.75 bits/sec
A source, produces dots "." and dashes "_" with p(dot)=0.65. If the time duration of a dot is 200ms and that for a dash is 800ms. Find the average source entropy rate.
1.278 bit/sec
2.278 bit/sec
3.278 bit/sec
4.278 bit/sec
Two unbiased coins are tossed. What is the probability of getting at most one head?
3⁄4
1⁄6
1⁄3
1⁄2
When rolling a fair six-sided die, what is the probability of obtaining an even number?
1/6
1/3
1/2
2/3
the amount of information if binary digit (binit) occur with
equal likelihood in binary PCM
0
1
2
3
The Binary Symmetric Channel has a probability of error of 0.2. What is its channel
capacity?
0.2 bits
0.8 bits
1 bit
0 bits
The capacity of Gaussian channel is
C = 2B(1+S/N) bits/s
C = B2(1+S/N) bits/s
C = B(1+S/N) bits/s
C = B(1+S/N)2 bits/s
The capacity of a binary symmetric channel, given H(P) is binary entropy function is
1 - H(P)
H(P) - 1
1 - H(P)2
H(P)2 - 1
Code rate r, k information bits and n as total bits, is defined as
a.
b.
c.
d.
r = k/n
k = n/r
r = k * n
n = r * k
Information rate is defined as
Information per unit time
Average number of bits of information per second
rH
All of the above
The relation between entropy and mutual information is
I(X;Y) = H(X) - H(X/Y)
I(X;Y) = H(X/Y) - H(Y/X)
I(X;Y) = H(X) - H(Y)
I(X;Y) = H(Y) - H(X)
The channel capacity of the following matrix is
0.8812 bits/symbol
0.1485 bits/symbol
0.4582 bits/symbol
0.1187 bits/symbol
For joint probability matrix given below find
H(X,Y)
2.46 bits/symbol
1.46 bits/symbol
0.46 bits/symbol
2.95 bits/symbol
The channel capacity for binary symmetric channel is
C= 1-k
C= 1+k
C= B*log2(1+SNR)
0
Which are uniquely decodable codes?
Fixed length codes
Variable length codes
Fixed & Variable length codes
None of the mentioned
For a (7, 4) block code, 7 is the total number of bits and 4 is the number of
Information bits
Redundant bits
Total bits- information bits
None of the above
The code in convolution coding is generated using
EX-OR logic
AND logic
OR logic
None of the above
If the constraint length of a (n, k, L) convolutional code is defined as the number of encoder output bits influenced by each message bit, then the constraint length is given by
L(n + 1)
n(L + 1)
n(L + k)
L(n + k)
The cyclic codes are designed using
Shift registers with feedback
Shift registers without feedback
Flipflops
None of the mentioned
A cyclic code can be generated using
Generator polynomial
Generator matrix
Generator polynomial & matrix
None of the mentioned
The received code contains an error if the syndrome vector is
Zero
Non zero
Infinity
None of the mentioned
Syndrome is calculated by
HT/r
rHT
rH
None of the mentioned
For the generation of a cyclic code, the generator polynomial should be the factor of _____
xn + 1
xn – 1
xn /2
x2n/3
