Performance Analysis of Mode Division Multiplexing (MDM) Based Hybrid PON FSO System Under Fog Weather Conditions

The evolution of data hungry services will have a serious impact on existing radio based architecture which has already begun to feel the heat of bandwidth starvation. Thus, in order to deliver seamless and high-speed data connectivity to the end-users, we propose an all optical hybrid optical link by integrating passive optical network (PON) with free-space optical (FSO) links. Additionally, we have also incorporated Laguerre-Gaussian (LG) based mode division multiplexing (MDM) to enhance data capacity of the proposed link. The proposed link can achieve data transfer rate of 20 Gbps using LG modes of the order of 00 and 01. Despite adverse link conditions due to fog attenuation, it is observed that the required signal-to-noise ratio (SNR) of the proposed link for delivering forward error correction (FEC) compatible bit error rate (BER) of 10
⁻³
increases only by 19.3% as severity of fog conditions changes from light to heavy. The proposed link exhibits reasonable performance stability as no significant deviations are observed even when the data rate is doubled.