SATELLITE COMMUNICATIONS STUDY

Satellite communication systems have become an essential part of the world's
telecommunication infrastructure, serving billions of people with telephone, data and
video services. Despite the growth of fiber optic links, which have much greater capacity
than satellite systems and a lower cost per bit, satellite systems continue to thrive and
investment in new systems, continues. Satellite services have shifted away from
telephony toward video and data delivery, with television broadcasting directly to the
home emerging as oneof themost powerful applications.
The objective of this project is to study satellite communications study through
experiments and MATLAB simulation for QPSK as satellite modulation techniques. The
experiments carried out were on TVRO board and weather satellites. Factors involved in
determining actual signals from a broadcast television signal and tuning foreign
television channels. Satellite footprints prediction is also has been carried on weather
satellite experiments. It also shows the location of satellite within a certain time interval
and indicates the area covered by asatellite. Besides that, the study on Global Positioning
Systems (GPS) using Earth.Google also been conducted. It shows satellite images
combined with maps and aerial photographs depends on medium or high resolution
terrain data. In satellite modulation techniques which are QPSK, aMATLAB coding has
been developed and the study on demodulator and modulator has also been considered.
Geostationary Earth Orbit (GEO) satellites carry the majority services, because
the use of high gain fixed antennas at earth stations maximizes the capacity of the
satellites. Over the years, there has been atrend away from trunk communications using
very large earth station antennas toward delivery from more powerful satellites to
individual users using much smaller antennas. Low Earth orbit (LEO) and Medium Earth
Orbit (MEO) satellites are used for mobile communications and navigation system and,
as the need for Geographic Information Systems grows with a variety of applications,
LEO earth imaging satellites have the potential to provide strong revenue streams.