DIGITAL COMMUNICATION LAB VIVA Questions :-
2. What are different types of multiplexing?
5. What is Amplitude shift Keying (ASK) ?
6. What are different types of digital modulation?
7. What is Phase shift keying ( PSK)?
8. What is Frequency shift keying (FSK) ?
9. What is Binary Phase shift Keying (BPSK) ?
10. What is bandwidth of BPSK signal?
11. What do you mean by Differential Phase Shift Keying (DPSK)?
12. What is Bandwidth of DPSK?
13. Show the phase change in DPSK at the digital input 10111101.
15. Why JK flip-flop is being used in this type if Keying?
16. What are the advantages over other types of keying?
19. What is the used formula to find out the bending loss for an optical fiber?
20.Differentiate ASK and FSK.?
23. Define pre-emphasis & de-emphasis?
24. Why is ASK called as ON-OFF keying?
25. What are the advantages of digital transmission?
26. What is meant by frequency synthesizer?
27. Applications of frequency synthesizer?
28. What is meant by line coding?
32. Define Manchester encoding?
33. What are the two function of fast frequency hopping?
34. What are the features of code Division multiple Accesses?
35. What is called multipath Interference?
40. How to avoid aliasing effect ?
44. How many digital television terrestrial broadcasting standards (DTTB) are used?
45. Difference in HDTV and SDTV?
47. How aperture effect can be corrected?
49. Explain nysquist criterion and interval?
50. Which kind of multiplexing used in digital communication?
51. Define Aperture effect . How it can be avoided
52. Why is Sample & Hold circuit used?
53. An Analog signal is given as
X(t) = 3cos 50pt + 10 sin 300 pt + cos 100pt
Calculate Nyquist rate
54. The spectrum of a signal g(t) has bandwidth 0.8KHZ and centered around 10 KHZ. Find Nyquist Rate
55. why pm is better than fm ?
56. Difference in digital and discrete signals?
58. A PCM system uses a uniform quantizer followed by a 7 bit encoder,with bit rate 50Mbps.What is the message bandwidth for system to operate satisfactorially?
59. Properties of Matched filter?
60. Difference between CDMA & TDMA
61. What is Pulse code modulation(PCM)?
62. How the performance of a PCM is corrupted?
63. What are the two types of Spread spectrum technique?
64. We need to send 3 bits at a time at a bit rate of 3Mbps.The carrier frequency is 10MHz.Calculate No of levels and Bandwidth
65. What is a Constellation Diagram?
66. Which modulation is a combination of other 2 schemes
67. Name two principles by which spread spectrum achieves its goal
68. Which of the 3 multiplexing techniques is common for fibre optic links
69. What is the minimum number of bits in a PN sequence if we use FHSS with a channel bandwidth of 5kHz and Bss=120kHz?
70. Which theorm gives Maximum Data Rate of a channel