Information Theory and coding IT2302 Important questions for AU Nov/Dec 2012 examinations

Anna University,Chennai Nov/Dec 2012 Examinations Important Questions
Information Theory and coding IT2302 
1.     Encode the following messages with their respective probability using basic Huffman algorithm

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