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One of the major design concerns in designing a Ka-band
Satellite communication system is the deep rain fades often
encountered at frequencies above 20 GHz. In order to maintain
reliable transmissions, certain rain compensation method must
be employed. Solutions for alleviating the rain fade include
adaptive forward error control, resource sharing, uplink power
control, and site diversity. Oftentimes one may have to use
more than one of these techniques to compensate for a large
rain attenuation. The first part of this thesis dwells on the
issue of uplink power control. Attenuation level estimated from
a downlink beacon is used for uplink power control. Using a
highly sensitive switched radiometer with a narrowband pre-
filter, we propose algorithms to estimate the downlink power
based on the sampled radiometer outputs. Multipath fading and
shadowing effect usually exist in a mobile satellite channel.
These effects become more noticeable when an omnidirectional
antenna is used by a ground receiver. In this case, noncoherent
signalings like MFSK and DPSK are more practical and robust
than other coherent signals. The second part of this thesis
analyzes cutoff rate performance of multichannel MFSK and DPSK
signals in various mobile satellite environments. System design
issues like the diversity combining, the choice of binary or M-
ary codes, the metric conversion and quantization losses, and
the deinterleaving order are all investigated.
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