Nama Mahasiswa : Suwadi Nrp : 2207301801 Pembimbing : Prof. Ir. Gamantyo Hendrantoro, M.Eng., Ph.D. Dr. Ir. Wirawan, DEA

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21 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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TRANSMISSION STRATEGY
IN MILLIMETER-WAVE FIXED WIRELESS COMMUNICATION
SYSTEMS TO MITIGATE THE EFFECT OF
TROPICAL RAIN ATTENUATION

Nama Mahasiswa : Suwadi
Nrp : 2207301801
Pembimbing : Prof. Ir. Gamantyo Hendrantoro, M.Eng., Ph.D.
Dr. Ir. Wirawan, DEA

ABSRACT


The demand for broadband communication for high-speed high-quality
multimedia transmission is driving the use of higher radio frequency spectrum.
One of the systems that make use of such a high spectrum is the local multipoint
distribution services (LMDS) which is a line of sight (LOS) point-to-multipoint
wireless access system operating at millimeter-wave frequency. In this band, rain
attenuation is the most influential propagation factor to determine the system
performance.
This dissertation research proposes the two strategies to achieve near-
uniform coverage in terms of availability and spectral efficiency in a 30-GHz
fixed cellular system with square cells in a tropical rain climate. The first strategy
is implemented by segmenting the area surrounding a base terminal station (BTS)
into rings, in each of which a certain combination of adaptive modulation, coding,
and cell-site diversity is used. The strategy is designed following the results of
simulation study evaluating link availability and average spectral efficiency using
fixed 64 QAM, AM (adaptive modulation), ACM (adaptive coded modulation),
joint AM-SC(selection combining) and joint ACM-SC. The second strategy is
implemented by using regenerative relay. The evaluation is done by applying the
synthetic storm technique (SST) based on rainfall intensities measurement in
Surabaya, Indonesia (7
o
13’ S, 112
o
43’ E) and adopting ITU-R P.838-3
recommendation for calculating rain attenuation.
Based on simulation results, this dissertation has recommended two
strategies to achieve high quality performance almost uniformly across the
coverage area of a broadband fixed wireless communication system. They are
adaptive transmission technique and regenerative relay application. In adaptive
transmission technique, minimum link availability of 99.95% and average spectral
efficiency of 5.995 bps/Hz can be achieved for maximum bit error rate of 10
-6
in
tropical regions by using one of four possible adaptive schemes in each of the
outer rings. It also can be achieved by using regenerative relay, but average
spectral efficiency about only 2.763 bps/Hz can be achieved for customers who
are served relays. The first strategy is suitable for large cell size with high density
customers and high traffic while second strategy is suitable for low density
customers and low traffic but the second strategy has lower complexity than first
strategy.
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Key words: Adaptive transmission, regenerative relay, broadband fixed wireless
communication systems, millimeter-wave, rain attenuation.