Kajian Dan Simulasi Prinsip Kerja Coded Orthogonal Frequency Division Multiplexing Untuk Sistem Transmisi Radio Over Fibe

Abstract

The fiber optics communication system is so far known to offer the highest information bandwidth, and has been intensively deployed world wide. This superior technological merit is fundamentally related to its use of high frequency optical carrier. However, optical fiber communication system requires the installation of fiber optics cable for the optical data transmission. This implied its restricted applications to user at fixed positions. On the other hand, the open air cellular communication technology has offered the high mobility and flexibility for the users. The obvious benefit of combining the two systems has led to the development of new technology that integrates optical fiber communication system with wireless communication system to provide great communication mobility with wide bandwidth. The integrated system (hybrid system) is known as the Radio over Fiber (RoF) system . In RoF system , traffic congestion problems between mobile phones via the Base Station (BS) and Remote Antenna Unit (RAU) can be reduced. In this final project, RoF communication system within the LAN network is considered. The realization of this model employs the Orthogonal Frequency Division Multiplexing (OFDM) method, which is equipped with convolution code technique, multi- mode optical fiber, Quadrature Amplitude Modulation (QAM) technique for digital modulation technique. In addition to that, the model also adopt Intensity Modulation-Direct Detection (IM–DD) technique for electro optic - opto electric conversion process. The system performance is analyzed and evaluated on the bases of Bit Error Rate (BER) variation versus the optical fiber’s transmission length for a selection of LD’s and PIN photodetectors as well as different multimode optical fibers.