Analisis Performansi Fso Dengan Teknik Ofdm Pada Kanal Kim Dan Kruse Menggunakan Modulasi Qpsk (performance Analysis Of Fso With Ofdm Technique In Kim And Kruse Channel Using Qpsk Modulation)

Abstract

Abstrak Sistem Optical Wireless Communication (OWC) salah satu alternatif teknologi indoor dan outdoor yang tepat, dimana teknologi Free Space Optics (FSO) salah satu pengembangan teknologi komunikasi optik, praktiknya digabungkan dengan teknologi Orthogonal Frequency Division Multiplexing (OFDM) memiliki keunggulan kecepatan data kirim dengan kapasitas bandwidth yang besar. Tugas Akhir ini melakukan simulasi dan analisis performansi sistem OFDM pada FSO menggunakan modulasi QPSK dengan kanal Kim dan Kruse pada pengaruh variasi panjang gelombang, daya kirim terhadap performansi sistem dikondisi visibility atmosfir serta jarak dari pengirim ke penerima dengan acuan Bit Error Rate (BER)<10-4 . Hasil simulasi dan analisis didapatkan peningkatan panjang gelombang dari 850 nm sampai 1550 nm meningkatkan performansi sistem pada kanal Kim dikondisi visibility atmosfer 0.02 km dan Kruse 0.1 km. Peningkatan daya kirim 2 watt dapat menghasilkan peningkatan performansi sistem dikondisi visibility atmosfer 0.02 km. Peningkatan panjang gelombang dapat menambah jarak pada kanal Kim di clear air 0.43 km, light fog 0.53 km, dense fog 0,02 km dan Kruse di clear air 0.38 km, light fog 0.47 km, namun dikondisi dense fog tidak memenuhi standar BER, hanya panjang gelombang 1550 nm yang memenuhi standar BER. Penambahan nilai FFT dapat memperbanyak jumlah subcarrier sehingga performansi sistem meningkat dan mengurangi bit error sehingga nilai BERnya semakin kecil. Kata Kunci : FSO, OFDM, QPSK, BER, Kim, Kruse Abstract The Optical Wireless Communication (OWC) system is an alternative for indoor and outdoor technology, where Free Space Optics (FSO) technology is one of the developments in optical communication technology, in practice combined with Orthogonal Frequency Division Multiplexing (OFDM) technology has the advantage of data speeds with large bandwidth capacity. This final project simulation and analysis of OFDM performance system at FSO using QPSK modulation with Kim and Kruse channels on the effect of wavelength variations, transmitted power on performance system in atmospheric visibility conditions and distance from transmitter to receiver with reference to Bit Error Rate (BER) <10-4 . The results obtained an increasing of wavelength from 850 nm to 1550 nm to increase the performance system in Kim channel is 0.02 km and 0.1 km in Kruse at atmospheric visibility conditions. An increasing transmitted power 2 watts can result increasing performance system at atmospheric visibility condition by 0.02 km. The increase in wavelength can increase the distance to the Kim channel at clear air 0.43 km, light fog 0.53 km, dense fog 0.02 km and Kruse at clear air 0.38 km, light fog 0.47 km, but in conditions dense fog doesn’t reach BER standards, only 1550 nm reach BER standards. The increasing of FFT value can increase the number of subcarriers so that system performance increases and reduces bit error so that the BER value is getting lower. Keywords: FSO, OFDM, QPSK, BER, Kim, Kruse