Engineering BE Electronics and Telecommunication Sem 5 May 2019 2019 Digital Communication Question Paper - Mumbai University | munotes

Questions asked in this paper

1. Q2 Attempt any three out of remaining five questions
2. Q2 Figures to right indicate full marks
3. Q3 Assume data wherever required and state it clearly
   • a) Stating the relationship between PDF and CDF, give the properties of PDF
   • b) Define Entropy of an information source? When is the entropy maximum?
   • c) Over a long transmission line draw the following data format for the binary sequence Select the best and justify the answer
   • d) Explain the role of Hamming distance in error detection & correction?
   • e) For impulse responses g'={1 ,1,1} design the state diagram
   • a) A discrete memoryless source has an alphabet of six symbol with their probabilities as
4. Q1 Determine the Minimum Variance Huffman code-words and average code-word length and hence find Entropy of the system li) Verify the average code-word length using Shannon Fano
   • iii) Compare and comment on the results of both
   • b) encoder has a constraint length of 3 and code rate of 1/3. The impulses for each are g'=100 11. Draw 10
   • a) State and prove the Conditional Probability. 10 Draw the signal space diagram for 16-PSK and 16-QAM and find their error probability. Also draw their PSD and determine bandwidth. 10 check matrix of a (7,4) Hamming code is given as follows: 10
   • i) Find Generator matrix, using which find out the code-words of 1100 , li) Determine the error detecting and correcting capability of system, iil) Draw the encoder for the above block code
   • b) Sketch the encoder and syndrome calculator for the generator polynomial 10 and obtain the syndrome for the received code-word 1101011
   • a) Discuss the problem of inter symbol interference (ISI). Explain the measures to 10 be taken to reduce ISI. How to study ISI using eye pattern?
   • b) Consider a convolution encoder with the constraint length K=3 and g'= {1,0,1} 10 and ,1}. Find the code vector for the message stream 11010 using time domain approach. Verify the code vector using transform approach Explain with the required diagrams (Any Three): 20
   • b) Shannon Hartley Theorem for Channel Capacity
   • c) Need for error control codes
   • d) Define the following terms and give their significance

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