SAT_QB

BHILAI INSTITUTE OF TECHNOLOGY,DURG ELECTRONICS AND TELECOMMUNICATION ENGINEERING SEVENTH SEMESTER SUBJECT--- SATELLITE COMMUNICATION

SATELLITE COMMUNICATIONUNIT-1 (TWO MARKS)

1. What is active satellite system?2. What is synchronous satellite?3. . State Advantages and Disadvantages of Multibeam Satellites4. What is INTELSAT?5. What is INMARSAT?6. What is Current Technology State Satellite communication?

7. What are Intersatellite Links8. Define Look angle9. What is difference between active and passive satellite.

UNIT-1 (SEVEN MARKS)1. What is meant by look angles? Explain them with reference to a geostationary satellite

and the earth station2. How can one determine the earth coverage and slant range for geostationary satellite?

What are the maximum values of the two parameters?3. Direct Broadcast Satellite Systems4. Orbital Mechanics and Orbital Elements5. Explain Azimuth and Elevation, Coverage Angle and Slant Range

6. Discuss placement of a satellite in a Geostationary Orbit7. Overview of Satellite System Engineering8. Define coverage angle of a satellite? Find the coverage angle of a satellite from

Which is visible at a minimum elevation angle of ten degree for geostationaryorbit. Derive the relationship used.

9. Explain the effect of eclipse on satellite .A satellite is in circular orbit at an Altitude of 10000 KM. finds the maximum eclipse time. Derive the relationship used.

10. State the Kepler’s Laws and find out distance between earth and satellite in case of synchronous satellite system.

11. An inter satellite relay allows messages to go from one satellite to another without passing through an intervening a station. Calculate path length and minimum distance between the radio path and the surface of the earth for a link between two geosynchronous satellite’s that are exactly 110 degree apart. Also determine the maximum possible separation between two geosynchronous satellite with a line of sight link between them

12. Give the details of frequencies used in satellite communication.

13. A satellite at a distance of 40000Km from a point on the earth surface radiates a power of 2W from an antenna gain of 17 db in the direction of observer .Find the flux density at

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the receiving point and power received by an antenna with an effective area of 10 m2 .If the operating frequency of satellite is 11GHz and receiving antenna has a gain of 52.3 db. Find the received power.

14. Give the frequency allocation & band spectrum used for satellite Communications.

15. Q Define the following terms with reference to satellite communication.i. Look angle

ii. Visibility iii. Geostationary orbitiv. Time of perigee

UNIT-2 (TWO MARKS)

1. What is Intermodulation Interference?2. Define Path Loss.3. Define EIRP.4. What is noise budget according to CCIR

UNIT-2 (SEVEN MARKS)

1. Explain Basic Radio Transmission Theory2. Derive general link equations. Find our expressions for C/N and G/T ratios. Explain

importance of these ratios on satellite link design.3. Explain the parameters that control the design of the earth station. What is the optimum

G/T ratio for a standard earth station?4. Explain analog television transmission through satellite. Write down the expressions for

S/N ratio calculations for satellite TV limits.5. Compare the performance of FM/FDM SCPC and CSSB systems.6. What is energy dispersal? Discuss its applications for satellite communication. Also

explain the dispersal signal.7. Give Classification of Different Analog and Digital Modulation Schemes as Used in

Satellite Communications and their Performance.8. Define path loss & EIRP. Hence comment on the choice of uplink & Downlink

frequencies as to their order9. Discuss various modulation techniques used for satellite communication.10. Write detail notes on

a. Interference effect on complete link design in satellite communication.b. SNR in FM satellite link.

11. Derive general link equation .Find out expression for C/N and G/Tratios. Explain the importance of these ratio on satellite link design.

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12. 36 MHz is the B.W. of transponder in satellite. The link can deliver overall CN

= 15dB

atreceiving earth station. The link is operated in FDM/FM/FDMA. Determine the maximum numbers telephone channel that the link can carry if the weighted worstchannel SNR is 51.0 dB.

13. Find out the expression for the received power.14. Derive the expression for SNR in case of FM detection.15. Explain analog television transmission through satellite. Derive expression for signal to

noise ratio for satellite TV link.16. Briefly describe the transmission of FDM telephone signal via satellite and state

the bandwidth requirement. What is the value of S/N.17. Under what condition a link is said to be Noise dominant & Inference

dominant

UNIT-3 (TWO MARKS)

1. State different Multiple Access Techniques as used in satellite2. What is CSMA?3. What is TDMA?4. What is Carrier recovery?5. What is DAMA?


1. What is the difference between multiplexing and multiple access techniques? Are FDM and TDM similar to corresponding FDMA/TDMA respectively? If not why? Explain the relative advantages and disadvantages of FDMA and TDMA.

2. Comment on FDMA and CDMA.3. What is the difference between multiplexing and multiple access techniques?4. Write shorts notes on Beam Hopping TDMA.5. Explain the TDMA technique used for satellite communication.6. Write detail notes on

i. TDMA vs FDMA.ii. CDMA vs FDMA

7. Compare different multiple access technique used for satellite communication.8. Discuss the concept of spread spectrum. How does it provide security against

unauthorized tapping and jamming?9. Draw the Block scheme of CDMA and explain its working10. The 5 earth station all operate in TDMA mode. Transponder BW 36 MHz The original

speech signals are sampled at 8KHz rate using 8 bits per sample. System uses QPSKFind the bit rate for each PCM signal. What is the frame time for time for each PCMsignal? What is the max rate of transmission that can be used and how many telephonicchannels can be transmitted.

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UNIT-4 (TWO MARKS)

1. General comments on satellite communication system performance.2. What do you understand by satellite system availability?3. What is telemetry?


1. Draw the block diagram of satellite explain it in brief.

2. What is the telemetry, tracking and command (TTC) sub-system? Explain its functioning.

3. What kind of antennas is used for TTC signal transmission during transfer orbit and on orbit?

4. Explain the construction of a repeater telling the difference between a repeater and atransponder?

5. Explain the construction and working of a transponder.6. Explain types of Antennas in Satellite Communications7. Explain satellite sub systems reliability.8. Write detail notes on Satellite transponder9. Draw the block schematic of communication satellite.10. Explain TTC and control sub system.11. Give a brief discussion on a satellite subsystem.

UNIT-5 (TWO MARKS)

1. What is Fixed Point Satellite Network?2. What is Mobile Satellite Network, 3. Absorptive Attenuation Noise by Atmospheric Gases.4. What is Low Earth Orbit Satellite Systems5. What is Medium Earth Orbit Satellite Systems?6. What are Very Small Aperture Terminal (VSAT) Network7. What is VSAT?8. What is TVRO?

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1. What are the equipments that an earth station requires? Discuss their design requirements.

2. Explain with suitable diagram the working of various antenna systems to be used in earthstations? Give antenna requirements for long and small earth stations.

3. Write shorts notes on TVRO system

4. .Explain the parameters that control the design of the earth station. What is the optimum

G/T ratio for a standard earth station?

5. What are the equipments that an earth station requires?

Discuss their design requirements

6. Explain with suitable diagram the working of various antenna systems to be used in earth

stations? Give antenna requirements for long and small earth stations..

7. Explain Tropospheric Multipath and Scintillation Effects8. Explain Rain Attenuation, Noise due to Rain, Rain Depolarization9. Discuss earth station design requirements.10. Discuss earth station design requirements.11. For an earth station having an antenna of diameter 30 m and overall efficiency

of 68%, the working signal frequency is 4150 Mhz .At this frequency the system Noise temperature is 79 K when the antenna points at the satellite at an 28 K.Calculate G/T ratio of the earth .In case the sky noise temperature rises to 88 K. What will be the new G/T ratio?

12. What is TVRO system .Discuss its operation.

13. Explain the parameters that control the design of ES. What is the optimum G/T ratio for a standard earth station.

14. Briefly describe a VSAT system.

15. What are the various types of interference signals encountered in microwave

satellite communication? Enumerate the effect of interferences in link design.

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