Research on full duplex FSO access system with hybrid 16PSK/256QAM-OFDM downlink and duobinary uplink signals

作者：Shao, Yufeng^*; Yu, Ni; Wang, Anrong; Tian, Qing; Yi, Linfang; Yang, Qiming; Li, Yanlin; Liu, Shuanfan; Yuan, Jie; Zuo, Renjie; Chen, Peng; Li, Chong

来源：Optics Communications, 2024, 550: 129956.

DOI：10.1016/j.optcom.2023.129956

• FSO
• Full -duplex
• 16PSK/256QAM-OFDM
• Duobinary
• BER

a 100Gbit/s novel full duplex free space optical (FSO) access system scheme is proposed and demonstrated. Using the downlink hybrid 16phase shift keying (PSK)/256quadrature amplitude modulation (QAM)-orthogonal fre-quency division multiplexing (OFDM) and duobinary uplink signals. In downlink branch, in-phase/quadrature-phase (I/Q) modulation based on Mach-Zehnder modulator (MZM) and coherent detection technology are adopted. Meanwhile, 0.1Terahertz (THz) wave signal generated by two independent optical sidebands beating frequency at positive intrinsic-negative photodiodes (PIN PDs) for hybrid downlink 16PSK/256QM-OFDM sig-nals. In uplink branch, intensity modulation and direct detection (IM/DD) can achieve reduced the communi-cation budget cost and simplified the system configuration Simulation results show that the value of bit error ratio (BER) less than hardware decision forward error correction (HD-FEC) threshold after 300 m FSO channel transmission under the different weather conditions (such as sunny, rainy and snow).