160 Gbit/s data transmission using combined subcarrier- polarization-mode division multiplexed OFDM-RoFSO system under different turbulence conditions.

An OFDM based radio over FSO (RoFSO) transmission system with 3-level multiplexing using RF subcarrier multiplexing (SCM), mode division multiplexing (MDM) and polarization division multiplexing (PDM) is proposed. Eight information channels, each having 20 Gbps data rate are combined through multiplexing at SCM level with subcarrier frequency i.e. 40 GHz and 60 GHz, MDM level with optical modes i.e. HG00 and LG10 and PDM level via horizontal and vertical polarization before being transmitted through RoFSO link. Thus, a total of 160 Gbps data is transmitted through RoFSO link. The proposed system is simulated and its performance is analysed for receiver parameters such as total received power, SNR, bit error rate (BER), Q-factor, and channel crosstalk under different atmospheric turbulence conditions. It has been observed that the proposed system is bandwidth efficient and achieves higher transmission capacity in comparison to 1-level (SCM) and 2-level (SCM-MDM) multiplexing. Further, no significant interference from adjacent channels is observed as the channel crosstalk is within the specified limits. [ABSTRACT FROM AUTHOR]