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Name of the College : SREE CHAITANYA COLLEGE OF ENGINEERING
University : JNTUH
Department : Electronics And Communication Engineering
Subject Code/Name : 07A70405/SATELLITE COMMUNICATIONS
Year/Sem : IV/I
Website : scce.ac.in
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/scce.ac.in/4936-07A70405-SATELLITECOMMUNICATIONS.pdf

Satellite Communications Question Paper :

Code No: 07A70405
R07 Set No. 2
IV B.Tech I Semester Examinations,December 2011

Related : Sree Chaitanya College Of Engineering 07A70410 Optical Communications B.Tech Question Paper : www.pdfquestion.in/4931.html

Common to Electronics And Telematics, Electronics And Communication Engineering
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions :
All Questions carry equal marks :
1. (a) What is meant by dierential GPS? What are its uses?
(b) Explain the GPS TIME. [6+10]
2. (a) Discuss the noise model of receiver.
(b) Derive the system temperature in terms of Tin,TRF ,Tm,TIF GRF , and Gm. [8+8]

3. Discuss the origin of Satellite Communications in detail. [16]
4. (a) Describe the various function to be carried out by satellite launching earth station when launching the satellite.
(b) Explain the operation on deriving mechanism of Antenna employed in the earth station. [8+8]

5. Explain the orbital consideration and constellation size of NGSO. [16]
6. (a) Explain dierent types of redundancy connections to complete subsystem reliability of a Satellite System.
(b) Write short notes on \Spacecraft Subsystems.” [8+8]

7. (a) Prove that the smallest value that the inclination angle can have is equal to latitude of the launch site in the plane of the orbit.
(b) A Satellite is in circular equatorial orbit at an altitude of 10,000 Km from the Earth’s surface. Determine the Maximum Eclipse time in a day during the full Eclipse period. [8+8]

8. (a) A TDMA system operates at 300 Mbits/s with a 5 ms frame time. Assume that all slots are of equal length and that a guard time of 2ms is required between slots. Compute the eciency of the communications resource (CR) for the case of 5, 10, 50 and 100 slots per frame.
(b) What is meant by the SPADE system? [10+6]

Code No: 07A70405
R07 Set No. 4
1. Describe the General Structure of Satellite Communication. [16]
2. (a) Define Kepler’s laws of orbiting bodies and derive an equation to show that the third law is true for any orbiting satellite.

(b) A Satellite is orbiting round the earth at 42124 Km.The earth station is looking at this satellite at an elevation angle of 350. Calculate the slant range. Make suitable assumptions and give reasons for making such an assumption. [8+8]

3. (a) What is meant by GPS Navigation message?
(b) Write sub frame details of GPS navigation message. [8+8]
4. Explain in detail the losses that occur during propagation of EM wave from earth station to satellite and vice versa. In what way they help in satellite communication link design. [16]

5. (a) On what factor the electrical power requirement in satellite depends and explains the electrical power distribution in a satellite.
(b) List out the power failure factors in satellite and how to avoid them. [8+8]

6. (a) Define Bits, Symbols and channels in TDMA.
(b) Explain TDMA frame structure. [3+13]
7. Explain the connectivity of LEO satellites to MCS via geostationary satellite. [16]

8. Explain the following sensors that are used to sense the altitude of a satellite:
(a) Sun Sensor
(b) Dual Cone Sensor
(c) Infrared Sensor. [5+5+6]

IV B.Tech I Semester Examinations,December 2011 :
Satellite Communications :
1. (a) What do you understand by G/T of an earth station?
(b) In a satellite communication system, the satellite is at height of 36,000Km above earth the frequency used is 4GHz and the transmitting antenna gain is 75 dB and the receiving antenna gain is 45 dB.

Calculate :
i. The free space transmission loss
ii. The received power, when the transmitter power is 200watts. [8+8]

2. (a) Explain the Basic Dierences between an Active and Passive Satellites.
(b) Give Brief Idea about Mobile Satellite Communication. [8+8]

3. Discuss the phenomena of eclipse as applied to geostationary satellite and solar interference experienced at an earth station. How do these factors influence the system design. [16]
4. Illustrate the scan angle of an individual beam width within instaneous coverage. [16]

5. What is meant by TDMA frame acquisition and frame synchronization? What is frame delay? How does it help in carrying out TDMA frame acquisition and frame synchronization techniques? [16]