# GTU previous question papers -BE- VII Sem -Satellite Communication -May/June -2012

GTU previous question papers

GUJARAT TECHNOLOGICAL UNIVERSITY

BE- VIIth SEMESTER–EXAMINATION – MAY/JUNE- 2012

Subject code: 1710

Subject Name: Satellite Communication

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) Give Comparison of LEO, MEO and GEO satellite orbits and gives application also.

(b) List the orbital elements and explain each of them in detail. Also give their significance in orbital maintenance.

Q.2 (a) List various types of control required to maintain the satellite in space and explain attitude and orbital control system in detail.

(b) What is uplink? Draw and Explain Uplink block-diagram. Also explain all the steps to followed for Uplink power budget preparation.

OR

(b) Give the list of all Multiple Access System used for satellite communication. Explain any one of them in detail and give comparison of any three

Q.3 (a) What is XPD ? properly explain. How XPD are predicted ? Also Draw and Explain properly The Canting Angle and Tilt Angle with required equations.

(b) Determine the visibility of a earth station situated at mean sea level at latitude of 48.420 north and longitude 89.260 west. Assume a minimum angle of elevation of 50.

OR

Q.3 (a) What is VSAT ? List the application of VSAT. Also Draw and explain the architecture of VSAT system.

(b) A earth station have equivalent noise temperature of 2000 K, noise bandwidth of 18 MHz, antenna gain of 50dB and carrier frequency of 12 GHz Determine, Gain to Equivalent Noise temperature ratio, Noise density, and Total Noise Power.

Q.4 (a) List Five major types of orbits and explain any two of them in detail.

(b) The uplink C/N0 ratio is 88dBHz and downlink value is 78dBHz. Calculate overall C/N0.

OR

Q.4 (a) List all seven operational NGSO constellation design and explain any two of them in detail.

(b) In a TDMA system transmission rate is 60 Mbps, Voice channel bit rate is 64 Mbps Number of burst/ frame are 10, number of bits in a preamble are 150. frame time 750 μsec. Find Noise channel capacity.

Q.5 (a) What is GPS ? Explain principle of GPS position location. Also explain signal generation in GPS.

(b) Draw and Explain the block diagram of satellite transponder in detail

OR

Q.5 (a) List all propagation effects which are not associated with hydrometer and explain them

(b) Give all the steps to launch the satellite vehicles for geostationary orbits and explain it with required figure and equations.