Anna University,Chennai Nov/Dec 2012
Examinations
Important Questions
Information Theory and
coding IT2302
UNIT I-V
1.
Encode the
following messages with their respective probability using basic Huffman
algorithm
|
M1
|
M2
|
M3
|
M4
|
M5
|
M6
|
M7
|
M8
|
|
1/2
|
1/8
|
1/8
|
1/16
|
1/16
|
1/16
|
1/32
|
1/32
|
calculate the efficiency of coding and
comment on the result
2.
Find the
channel matrix of the resultant channel. Find P(z1) if P(x1)= 0.6 and P(x2)=
0.4
3.
State and
prove the source coding theorem
4.
State and
prove the properties of mutual information
5.
A discrete memory less source has an alphabet
of seven symbols whose probabilities of occurrence are as described below
Symbol: s0
s1 s2
s3 s4
s5 s6
Prob : 0.25
0.25 0.0625
0.0625 0.125 0.125
0.125
Compute the Huffman code for this source
moving combined symbols as high as possible
6.
Explain the
LPC model of analysis and synthesis of speech signal. State the advantages of
coding speech at low bit rates.
7.
Explain in
detail about Adaptive Huffman Coding
8.
With a
block diagram explain psychoacoustic model
9.
Explain the
compression principles of P and B frames
10.explain the working of JPEG encoder
11.
Explain in
detail about H.261
12.Consider the (7, 4) Hamming code defined by
the generator polynomial g(x) = 1+x+x3.
The code word 1000101 is sent over a noisy channel, producing the received
word 0000101 that has a single error. Determine the syndrome polynomial s(x) for this received word. Find its
corresponding message vector m and
express m in polynomial m(x).
13.
Consider a
(7, 4) cyclic code with generator polynomial g(x) = 1+x+x3. Let data d= (1010). Find the corresponding systematic code word
14.Determine the encoded message for the
following 8- bit data codes using the CRC generating polynomial g(x) = x4+x3+x0. (a) 11001100(b) 01011111
15.Construct a convolutional encoder for the following
specifications: rate efficiency ½, constraint length 3, the connections from
the shift register to modulo – 2 adder are described by the following
equations, g1(x)
=1+x+x2, g2(x)=1+x2.Determine the output
codeword for the message [10011]
16.
Explain the Turbo
Decoding in detail
17.A convolution encoder has a single shift register with 2
stages, 3 mod-2 adders and an output Mux. The generator sequence of the encoder
as follows: g(1)=(1,0,1), g(2)=(1,1,0) g(3)=(1,1,1). Draw the block
diagram and encode the message sequence (1110) and also draw the state diagram
