G.H.Raisoni College of Engineering
Department Of Information Technology
Class:V Sem
Subject:- Information Theory & Data
Communication
Session - 2009-10
Question Bank
1. Compare the Merits & Demerits of digital & analog communication.
2. Describe the following digital modulation methods with help of waveform
a) FSK
b) PSK
c) QAM
3. Write short note on
a) M-ary encoding
b) Bit rate & baud
4. Draw & Explain block schematic of BPSK transmitter & Receiver with help of Truth
Table, Phase diagram & output waveform.
5. Write short note on DPSK transmitter.
6. What is difference between PSK and QAM?
7. Explain the significance of the I and Q channel in a QPSK modulation.
8. What is a constellation diagram, and how is it used with PSK?
9. What is difference between Standard FSK and MSK ? What is the advantage of
MSK?
10. Why does the receive clock for UART operate 16 times faster than the receive bit
rate?
11. Why did the EIA establish the RS-232 interface?
12. Draw and explain the block diagram of simplified data communication model.
13. Draw & Explain block schematic of BPSK transmitter & receiver with help of truth
table &output wave from.
14. Briefly explain return-to-zero and non-return-to-zero transmission.
15. Write short note on Rs-232 & UART.
16. Explain Super frame-format & Extended Super-frame format.
17. What are Hamming codes? What are their properties?
18. Explain different Topologies used in Data Communication.
19. Explain different Error correction method with example.
20. Explain how generator and parity check matrices are obtain for cyclic code.
21. What is the use of syndromes? Explain syndrome decoding.
22. Give the properties of auto correlation function of periodic signal.
23. Explain following error detecting techniques
a) Exact count encoding
b) VRC and LRC.
24. State and explain error detection and correction capabilities of hamming code.
25. What is the purpose of the sample and hold circuit?
26. Explain the relation between dynamic range, resolution, and the number of bits in a
PCM code.
27. Discuss the basic layer of formation in OSI model ,Draw the neat sketch of model and
explain function of each layer in brief.
28. What is frame synchronization? How is it achieved in a PCM-TDM system?
29. Explain PCM system in detail .also explain the process of quantization with diagram.
30. Write technical note on
a) Cyclic Redundancy check ckt (CRC)
b) Convolution Code
c) Linear Block Code.
31. For BPSK modulator with carrier frequency of 70 MHz & input bit rate of 10mbps
determine
(I) upper & lower side frequency
(II)Nyquist band width
(III)Draw output spectrum
(IV)Baud rate.
32. Following probabilities are given for a binary communication channel
P(A0)=0.7,P(A1)=0.3,P(B0/A0)=0.9,P(B1/A0)=0.1,P(B0/A1)=0.4/P(B1/A1)=0.6.Ap
ply optimum receiver algorithm to find the message if Bo and B1 is received.
33. Consider a generator matrix G for non-systematic (6,3) code is
G=
1 0 0 1 0 1
0 1 0 0 1 1
0 0 1 1 1 0
(i) Construct the code for this generator matrix G
(ii) Show that Dmin, is 3 & consequently this can correct at least one error
34. Determine the encoded message for the following 8-bit data codes using the
following CRC Generating polynomial P(x)=11001
(I)11001100
(II)01011111
35. Determine the BCS for the following data- and CRC generating polynomials
G(x)=10010101
P(x)=110011
36. For a tri-bit input of Q=0,I=0,and C=0(000).determine the output amplitude and
phase for the 8-QAM transmitter shown in2-32(a) (Ref page 78wayne tomsi AECS
5th edition)
37. For a16-QAM modulator with an input bit rate (fb) equal to 20MBPS and carrier
frequency of 100MHz, Determine the minimum double-sided Nyquist bandwidth
(fn)and the baud, sketch the output spectrum.
38. Determine the 12-bit linear code, the 8-bit compressed code ,and the recovered 12-bit
code for resolution of 0.02v and analog sample voltages of (a)0.05v,(b)0.32(c)10.23v.
39. determine the dynamic range in db for the following n-bit linear sign-magnitude PCM
codes n=7,8,12and 14.
40. for a 12-bit data string of 101100010010, determine the number of hamming bits
required, arbitrarily place the Hamming bit into the data string, determine the
condition of each hamming bit ,assume an arbitrary single-bit transmission error ,and
prove that the Hamming code will direct the error.