Projets
Master's degree Project
Master's degree Project
Performance study of an optical DWDM-FSO communication system using SIM-OFDM technique
Performance study of an optical DWDM-FSO communication system using SIM-OFDM technique
Abstract
Abstract
In this study, we used the SIM-OFDM (Subcarrier Index Modulation-Orthogonal Frequency Division Multiplexing)/ESIM-OFDM (Enhanced SIM-OFDM) technique to provide robustness to the FSO (Free Space Optics) systems with low PAPR (Peak to Average Power Ratio) and best transmission throughput. Since OFDM does not provide a suitable signal (real and unipolar), we have implemented DCO-OFDM (Direct Current biased Optical OFDM) and U-OFDM (Unipolar OFDM), which are types of unipolar OFDM, while applying Hermitian Symmetry to them to provide a purely real signal. The thresholding problem at reception for SIM-OFDM brought us to its enhanced version which is ESIM-OFDM. This latter allowed us to earn a minimum of 3 dB compared to OFDM with a reduced PAPR for any QAM under an AWGN (Additive White Gaussian Noise) channel. We showed that it is possible to achieve 10 Gbit/s DWDM (Dense Wavelength Division Multiplexing) for a range of 2 km with ESIM-OFDM technique under a realistic FSO channel.
In this study, we used the SIM-OFDM (Subcarrier Index Modulation-Orthogonal Frequency Division Multiplexing)/ESIM-OFDM (Enhanced SIM-OFDM) technique to provide robustness to the FSO (Free Space Optics) systems with low PAPR (Peak to Average Power Ratio) and best transmission throughput. Since OFDM does not provide a suitable signal (real and unipolar), we have implemented DCO-OFDM (Direct Current biased Optical OFDM) and U-OFDM (Unipolar OFDM), which are types of unipolar OFDM, while applying Hermitian Symmetry to them to provide a purely real signal. The thresholding problem at reception for SIM-OFDM brought us to its enhanced version which is ESIM-OFDM. This latter allowed us to earn a minimum of 3 dB compared to OFDM with a reduced PAPR for any QAM under an AWGN (Additive White Gaussian Noise) channel. We showed that it is possible to achieve 10 Gbit/s DWDM (Dense Wavelength Division Multiplexing) for a range of 2 km with ESIM-OFDM technique under a realistic FSO channel.
Memoire_Fifa_version_corrigée.pdf