FAQ EC6004-SATELLITE COMMUNICATION

Transcription

1 BHARATHIDASAN ENGINEERING COLLEGE DEPARTMENT OF ECE Year / Sem : IV/ VII Sub.Code / Name : EC6004: SATELLITE COMMUNICATION FAQ PREPARED BY: S.RAJALAKSHMI

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19 Unit-I PART- A 1. State kepler s first and third law.(n/d-2016) (A/M-2017) 2. What is the limit of visibility?.(n/d-2016) 3. Define orbital period.(a/m-2017) PART-B 1. I) Illustrate the orbital parameters used for positioning a satellite.(8) (N/D-2016) ii) Estimate the suitable equations fo look angles and the ange fo geostationary satellite.(8) (N/D-2016) 2. I) categorize the frequency allocations and draw the frequency spectrum for satellite services.(12) (N/D-2016) ii) Illustrate the effects of non-spherical earth.(4) (N/D-2016) 3. Derive the equation for a satellite orbit.(16) (A/M-2017) 4. I) Derive the equations which permit the elevation angle to be calculated.(8)(a/m-2017) ii) Tabulate the various types of obits with their merits and demerits.(8) (A/M-2017) Unit- II PART- A 1. Examine why noise temperature is a useful concept in communication receivers.(n/d- 2016) 2. Formulate uplink and downlink equation of a satellite access.(n/d-2016) 3. How do you characterize uplink and downlink?.(a/m-2017) 4. What are the effects to which the displacement in association with tacking feeds gives rise?.(a/m-2017) PART-B 1. I) Justify the reasons behind why the transponders are connected in the communication channel with a neat diagrams.(4) (N/D-2016) ii) Analyze the wideband receivers and input de-multiplexer with appropriate diagrams.(12) (N/D-2016) 2. Examine how the attitude and orbit control system (AOCS ) is achieved though spin stabilization systems?. Give necessary diagrams. (N/D-2016) 3. I) Consider a dual up converter with the following specifications: Uplink frequency spectrum=14 to 14.5 GHz First intermediate frequency=140mhz Carrier bandwidth =72MHz BPF-1 center frequency =1.19GHz

20 Determine first local oscillator frequency, range of second local oscillator frequency, frequency, frequency spectrum of unwanted sideband bandwidths of BPF-1 AND BPF-2. (8) (A/M-2017) ii) With suitable mathematics explain the design aspects of uplink. (A/M-2017) 4. What are the three main systems for tracking satellites?. How can tracking systems be affected?. What are the main functions of TTC sub-system? Explain.(16)(A/M-2017) Unit- III PART- A 1. Write the features of MATV. (N/D-2016) 2. A satellite downlink at 12 GHz operates with a transmit power of 6W and an antenna gain of 48.2 db. Calculate the EIP in dbw. (N/D-2016) 3. Draw the schematic for a rain rate measuring device.(a/m-2017) 4. What are the factors contributing to noise in an earth station receiving channel?.(a/m-2017) PART-B 1. I) point out the calculation of link power budget equation.(4)(n/d-2016) ii) list the various types of system noise. Explain it in detail. (12)(N/D-2016) 2. I) Derive the expression of output back-off, satellite TWTA output for the downlink communication. (8)(N/D-2016) ii) Calculate the carrier-to-noise ratio for the combined uplink and downlink communication.(8) (N/D-2016) 3. I) From the calculation of system noise temperature prove that C/N ratio directly proportional to G/T ratio.(10)(a/m-2017) ii) Consider the receive side of an earth station. The antenna gain is 6dB and its noise contribution is 60K.the waveguide loss is 0.5dB.Determine the equivalent noise temperature of LNA assuming that the noise contribution by the down converter is negligible and earth station G/T is 40 db/k.(to=300k).(6)(a/m-2017) 4. With test set-up explain the procedure of EIP and antenna gain measurement.(a/m- 2017) PART- A Unit-IV 1. Point out the pre-assigned TDMA satellite access.(n/d-2016) 2. How does the spread spectrum system differ from conventional communication system?(n/d-2016) 3. Draw the curve for the transfer characteristics of TDM.(A/M-2017)

21 4. Draw the spectrum of a baseband voice signal. (A/M-2017) PART-B 1. I) Express FDMA in detail and also enumerate the interference in FDMA. (8)(N/D-2016) ii) Explain the direct sequence spread spectrum communication in detail.(8)(n/d-2016) 2. I) Identify the band limited and power limited TWT amplifier operation.(10)(n/d-2016) ii) Explain the operation of digital TASI in TDMA operation.(6)(n/d-2016) 3. Write the design aspects and explain the technical features of TDMA frame structure.(16)(a/m-2017) 4. I) Draw the schematic for on board signal processing system for FDMA/TDM operation and explain.(8) (A/M-2017) ii) With mathematics briefly discuss on capacity of spread spectrum systems.(8)(a/m- 2017) Unit-V PART- A 1. What do you infer about GAMSAT?(N/D-2016) 2. Outline the three regions to allocate the frequency for satellite services.(n/d-2016) 3. Draw a typical set up of international telephone service via satellite.(a/m-2017) 4. List the frequency bands assigned fo DTH systems. (A/M-2017) PART- B 1. Elaborate the main features, and services offered by mobile satellite systems.(16)(n/d- 2016) 2. Discuss the sevices of the following system with its usage. (N/D-2016) i) INTELSAT. ii) . iii) BTV iv) DTH 3. What is meant by INMARSAT? What are the objectives of the GARMSAT program? What are the applications seen for DAB. (16)(A/M-2017) 4. I) With block diagram explain the working principle of DBS-TV receiving system.(8) (A/M-2017) ii) Write an overview on VSAT systems. (A/M-2017)