Analisa Kinerja Teknik Modulasi Digital pada Kanal Optik Nirkabel

Abstract

AbstrakTransmisi optik nirkabel dengan kecepatan tinggi memiliki berbagai potensi untuk aplikasi jarak pendek terutama untuk komunikasi di dalam ruangan. Tulisan ini memaparkan perbandingan kinerja transmisi FSO menggunakan beberapa variasi skema modulasi. Pengamatan unjuk kinerja terutama dilakukan menggunakan bit error rate (BER). Gangguan turbulensi atmorferik menjadi bagian dari pemodelan kanal log normal yang digunakan dalam simulasi. Modulasi dasar spasial yang digunakan adalah on-off keying sebagai teknik klasik FSO, beserta pulse position modulation yang merupakan variasi spasialnya. Menelaah penggunaan modulasi baseband untuk sistem optik, disimulasikan PSK 2, 4, 8, 16, serta QAM 4 da n 16. Simulasi dengan data ukuran kecil menghasilkan bahwa BPSK dan 4 QAM menunjukkan unjuk kerja terbaik dengan BER rata-rata sekitar 10 -3 pada kondisi gangguan sedang sampai tinggi. Sementara tingkat error pada OOK dan PPM masih di atas 10 -0.5 . Kata kunci: FSO, OOK, PPM, PSK, QAM Abstract Free space optical transmission with its data speed has many potential in close range especially indoor communication. This paper compared the performance of FSO transmission on a number of modulation schemes. The observations are mainly

Bidirectional Network in Hybrid Coarse Wavelength Division Multiplexing/Time Division Multiplexing (CWDM/TDM) on NG-PON2 for 40 Gbps

“…Low pass filter (LPF) is used to carry signals from the modulation results. The transmitter can produce sequences data from NRZ which is passed from two stages of Dynamic Y Select which functions as a time slot because in the uplink section the data is transmitted at the time slot using the same wavelength [7]. Equation ( 5) is the formula for Dynamic Y Select 1 for 16 time slots.…”

“…Paper [7] describes NG-PON2 on standard section for new challenges. Several points show NG-PON2 has new scheme and technique to improve the communications network access.…”

Software-based simulation to analyze the variation of digital modulation and atmospheric condition on the free space optic (FSO) link performance

“…The following research compared the performance of FSO transmission employing BPSK and Quadrature Phase Shift Keying (QPSK) modulation. This investigation performed a BER value of 10 −3 at 17 dB SNR and QPSK modulation better than BPSK [6]- [8]. The BER of the OOK and PPM modulations was greater than 10 −0.5 , indicating that both were very susceptible to atmospheric disturbance conditions.…”

“…An effective FSO communication system has properties such as functioning at higher power for longer distances and being reliable at highspeed modulation to attain optimal performance. FSO communication systems must operate over a wide temperature range and slightly degrade performance due to air disturbance [3]- [6].…”