Prady, Amaludin Ibnu (2015) Analisis Efek Near Far Terhadap Interferensi Pada Sistem Komunikasi HF TRDMA. Undergraduate thesis, Institut Technology Sepuluh Nopember.
Preview |
Text
2211100176-Undergrdaute Thesis.pdf - Published Version Download (2MB) | Preview |
Abstract
Sistem komunikasi radio High Frequency (HF) memiliki
kelebihan yakni dapat memberikan transmisi jarak jauh, biaya relatif
murah serta fleksibel. Namun, karena bandwidth kanal yang digunakan
pada sistem komunikasi HF terbatas yaitu pada frekuensi 3-30 MHz,
diperlukan suatu metode akses jamak yang mampu meningkatkan
efisiensi penggunaan kanal. Salah satunya adalah dengan menggunakan
metode Time-Reversal Division Multiple Access (TRDMA) pada
komunikasi HF. Salah satu permasalahan yang perlu diatasi dalam
mengimplementasikan TRDMA pada komunikasi HF adalah efek nearfar.
Efek near-far adalah fenomena saat terdapat dua pemancar (atau
lebih) yang memancarkan sinyal ke satu penerima yang sama, dalam
konteks uplink pada proses multiple-access, yang bekerja dengan
frekuensi yang sama. Karena bekerja di frekuensi yang sama, tentu akan
ada efek interferensi antara keduanya, sehingga mempengaruhi kualitas
sinyal pemancar utama, yang diukur menggunakan parameter signal to
interference ratio (SIR). Pengaruh jarak setiap pemancar terhadap
kualitas sinyal dari masing-masing pemancar tersebut itulah yang disebut
sebagai efek near-far. Pada penelitian ini digunakan data dari
rekomendasi ITU-R P.533 untuk mendapatkan kinerja komunikasi pada
band HF. Dilakukan mekanisme kontrol daya pancar untuk mendapat
hasil SIR ideal untuk semua user, dengan cara menyamakan daya di
penerima untuk setiap pemancar, mendekati -120 dBW. Lalu dilakukan
perhitungan SIR untuk pemancar utama Kupang dan Merauke, dengan
penerima di Surabaya. Didapatkan hasil kinerja SIR komunikasi HF
TRDMA, cukup baik hanya jika hanya ada 1 peng-interferensi.
Sedangkan lebih dari itu nilainya sudah dibawah 0 dB, sehingga perlu
digabungkan dengan teknik spread spectrum, dengan level yang rendah,
agar tidak boros dalam penggunaan bandwidth.
=========================================================================================================
High frequency (HF) radio communication systems has an
advantage, that it can provide a long distances transmission, relatively
cheap, and flexible. But consider that the channel bandwidth of HF
frequency band was limited, from 3-30 MHz, it is necessary to use an
multiple access method to increase channel usage efficiency. Once of it
was by apllied Time Reversal Division Multiple Access (TRDMA)
method for HF communication systems. One of the problem to be solved
to implements TRDMA on HF communications system is near far effect.
Near far effect is a phenomenon when there was two transmitter (or more)
that propagates a signal to a same receiver, in an uplink context of a
multiple access process, using a same frequency. Because of using a same
frequency, there was an interference effect between them, that affect to
signal quality of the main trasmitter, which caltulated by signal to
interference ratio (SIR) parameter. The affection of distances and signal
quality of each transmitter is named near far effect. In this research, is
using data from ITU-R P.533 to get information about communication
performance at high frequency band. We applied transmission power
control to get an ideal SIR performance for each user, by equate received
power for each user, approach -120 dBW for each user. Then SIR
performance was calculated, with the receiver in Surabaya, and two main
transmitter at Kupang and Merauke. So we get SIR performance of HF
communication systems. It found that SIR performance of HF TRDMA
communication systems is only have positive value in dB scale, when
only has 1 interference link. When the interference link was 2 or more,
the value was negative. So it need to be combined with other techniques
such as spread spectrum with a low sequence level, that enough to
increase SIR performance, but still efficient in using bandwidth.
| Item Type: | Thesis (Undergraduate) |
|---|---|
| Additional Information: | RSE 621.384 151 Pra a |
| Uncontrolled Keywords: | Komunikasi HF, TRDMA, Efek Near-Far, SIR |
| Subjects: | T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK5103.2 Wireless communication systems. Two way wireless communication |
| Divisions: | Faculty of Electrical Technology > Electrical Engineering > 20201-(S1) Undergraduate Thesis |
| Depositing User: | Mr. Tondo Indra Nyata |
| Date Deposited: | 14 Feb 2019 07:22 |
| Last Modified: | 14 Feb 2019 07:22 |
| URI: | http://repository.its.ac.id/id/eprint/62218 |
Actions (login required)
 |
View Item |