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CO-OFDM and DP-QPSK Based DWDM Optical Wireless Communication System

Abstract The 5 G technology provides a promising solution for future broadband networks. It requires access to high-speed wireless services for systems at anytime and anywhere. For adapting the 5 G services, this paper proposes an optical wireless system with hybrid scheme of dual polarized Gbps dense wavelength division multiplexed (DWDM) system. The multi-carrier transmission technique such as coherent optical orthogonal frequency division multiplexing (CO-OFDM) has also been incorporated into the system. The frequency spacing for the DWDM system is taken 25, 50 and 100 GHz according to the ITU-T standard. Here the subcarriers of each channel are modulated with the dual polarized-quadrature phase shift keying (DP-QPSK) sequence. The information is transmitted with an overall data rate of 0.32 Tbps. The system is successfully demonstrated at different turbulence regime from clear weather to severe turbulence weather under Gamma-Gamma atmospheric turbulence channel model. Due to the high optical signal-to-noise ratio (OSNR) tolerance and high spectrum efficiency of the dual polarized multi-channel and multicarrier transmission technique, the link distance achieved is 2.9 km in clear weather, 2.6 km in moderate turbulence regime, 2.3 km in high turbulence regime and 0.9 km in severe turbulence regime. A comparison study with related works has been carried out. Mathematical modeling is also incorporated for detail analysis of the proposed system.