SRM University 2007 B.Tech Electronics and Communications Engineering Bank of EC306-Information Theory - Question Paper

b) A discrete memory less source has four symbols X1 X2 X3 and X4 with probabilities 0.4, 0.3, 0.2, 0.1 respectively. compute the entropy of the source and info content of message X1X2X2 X3

4. a) Consider a telegraph source having 2 symbols Dot and Dash. The Dot duration is 0.2seconds.The Dash duration is five times the Dot duration. The probability of the Dot occurring is twice that of the Dash. The time ranging from symbols is 0.2 seconds. compute the info rate of the source.

b). An analog signal is band limited to 3.4KHz and sampled at Nyquiest rate. The samples are quantized into four levels. every level represents 1 symbol. The probability of occurrence of these four levels are P(X1)=P(X4)=1/8 and P(X2)=P(X3)=3/8. find the info rate of the source.

5. discuss the Prefix codes, instantaneous codes and uniquely decipherable codes with examples.

6. The symbols of certain source is coded as follows. obtain the code efficiency and
redundancy.


Xi P(X) Code
X1 0.81 0
X2 0.09 10
X3 0.09 110
X4 0.01 111


7. Consider a DMS with symbols Xi, i=1, 2, 3, 4. and which is coded as follows. Show that Codes A and D are uniquely decodable but codes Band C are not uniquely decodable.

Xi Code A Code B Code C Code D
X1 00 0 0 0
X2 01 10 11 100
X3 10 11 100 110
X4 11 110 110 111





UNIT – III

DiscRETE AND ANALOG CODING

PART – A

1. Write the steps involved in Huffman coding algorithm.

2. provide the applications of Huffman’s coding algorithm.

3. describe optimum code.

4. describe discrete stationary source.

5. What is Lempel - ziv algorithm and provide its uses?

6. Differentiate Huffman coding algorithm and Lempel- ziv algorithm.

7. describe Quantization and provide its uses.

8. describe squared - fault distortion.

9. describe rate distortion function for memory less Gaussian source.

10. describe distortion – rate function for discrete – time, memory less Gaussian source.

11. provide the upper bound of rate of distortion.

12. What is scalar Quantization?

13. What is vector Quantization?

14. Draw the uniform and non-uniform tree for binary search vector Quantization.

15. elaborate the various encoding techniques applied to speech signals?

Earning:   Approval pending.