Performance evaluation of high-speed integrated fiber-free space optics transmission enabled by DP-32-QAM signals for last mile access networks

We model and evaluate an integrated fiber-FSO transmission technique for access networks. 100 Gbps information is transmitted over a single wavelength channel by employing in-phase quadrature modulation with DP-32-QAM signals. Further, a digital-signal-processing (DSP) module is employed to compensate for the channel losses. The performance of the proposed transmission has been evaluated for 50 km fiber length (fixed) and FSO range varying from 510 m–4.2 km. We have analyzed the transmission scheme for clear weather and for varying levels of rain, fog, and haze (low, medium, and heavy). Furthermore, transmission scheme is investigated for densely populated Chandigarh city and the results demonstrate reliable 100 Gbps transmission along 2500 m range with acceptable performance levels i.e., Log(BER) ∼ −2.46 and $\text{EVM} < 12\%$ .