Dong-Nhat Nguyen, Stanislav Zvanovec, Zabih Ghassemlooy, Optik – International Journal for Light and Electron Optics 196: 163154 (2019)

Transmission of a 25 Gbps non-return to zero signal over a hybrid link of 20 km standard single-mode fibre and 500m free-space optics under weak-to-moderate turbulence regimes is demonstrated via simulation to provide a practical solution for the last-mile access networks. Even though there are several complex mitigating methods to reduce the waveform distortions caused by both the fibre chromatic dispersion and atmospheric turbulence, we provide and discuss a simple approach using an electrical equalizer at the receiver. The simulation results demonstrate that, the proposed equalization technique offer about an order of magnitude improvement in the bit error rate at the received optical power of -20 dBm and a receiver sensitivity gain of 1.5 dB at the 7% forward error correction limit.