B.TECH - Semester 8 satellite and mobile communication Question Paper 2019 (nov)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- What is the difference between geostationary and low earth orbiting satellite? Can a low earth orbiting satellite be used for communication purpose? Give reasons.
- State Kepler's laws of planetary motion.
- A satellite is rotating at a distance of $20,000 \mathrm{~km}$ from a point on the earth surface. If the operating frequency of satellite is 4 Gz and receiving antenna gain is 61.4 dB . Determine the power received given that EIRP $=26.02 \mathrm{~dB...
- What is meant by station keeping of satellite? Explain its significance and also methods to achieve it.
- Illustrate a coverage area consisting of three cellular clusters, each cluster contain 7cells explain the advantages of frequency reuse.
- Differentiate soft hardoff and hard hardoff.
- State the factors affecting small scale fading? What do you mean by fading?
- State four advantages of direct sequence modulation.
- What is meant by near for problem in CDMA? State a method to overcome it.
- Define (a) voice activation (b) cell sectorisation. How does the sectorisation improve the capacity (can 1 when $60^{\circ}$ sectory is used (c) $120^{\circ}$ sectoring is used). ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{4} \boldsymbol{=} \mathbf{4...
- List various satellite subsystems (atleast 6). Briefly explain subsystems and state their important functions.
- Derive the $\mathrm{C} / \mathrm{N}$ at the earth station and at the satellite. The following parameters apply to a satellite down life : EIRP $=22.5 \mathrm{dBW}$, Free space losses $=195 \mathrm{~dB}$, other losses $=1.5 \mathrm{~dB}$. Earth state...
- (a) Discuss the various typess of antenna used (i) space craft (ii) earth station.
- (b) Calculate the gain of a 3 m parabolical antenna operating at a frequency of 12 GHz . Assume aperture efficiency of 0.5 .
- (a) Explain the Okamura's propagation model.
- (b) Find the median path loss using Okamura model for $d=5 k m, h_{t e}=100 m$, $h_{r e}=10 \mathrm{~m}$. If base station transmitter EIRP $=1 \mathrm{kw}$ at carrier frequency of 900 MHz . Find the received power let receiving antenna gain in unity....
- Explain in detail the four techniques used for improving the coverage and capacity in cellular system.
- Explain the various multiple access technique stating advantages and disadvantages of each.
- What is the average number of users allowed per cell in a CDMA system if the following datas are given: Other interference $/$ metre $=0.55$ SINR at the receiver $=8 \mathrm{~dB}$ Total spread factors = 125 No/lo = 0.25 If the cell uses a directiona...
- State and explain any three spreading codes and their advantages. What should be the ideal - cross correlation between the spreading codes.
- (a) How does a MIMO system provides high spectral efficiency in a Rayleigh scattering environment?
- (b) Briefly describe smart antenna. ( $\mathbf{6} \boldsymbol{\times} \mathbf{1 0} \boldsymbol{=} \mathbf{6 0}$ Marks)