Simulation and experimental investigation of nonlinear effects in 5G fronthaul transmission system based on WDM-PON architecture.

• The nonlinear effects are investigated in 5G fronthaul system based on WDM-PON architecture. • In the 12-channel case, the FWM effect is studied in O-band whilst the XPM effect is discussed in C-band by simulation. • The results show that all channels cannot achieve the BER threshold of 1.0 × 10 - 3 except for the first and last channels in O-band, and the sensitivity penalty of probe channel caused by the XPM effect is 3.6 dB in C-band. Wavelength-division multiplexing passive optical network (WDM-PON) is considered as a mainstream solution for 5G fronthaul transmission system to cope with the rapidly increasing bandwidth demand. In such a multi-wavelength system, nonlinear effects limit the achievable transmission distance and channel capacity. Therefore, in this paper, the impact of nonlinear effects on a multi-wavelength transmission system with 25 Gb/s/λ non-return-to-zero (NRZ) and a 200-GHz channel spacing over 25 km standard single-mode fiber (SSMF) is investigated through experiment and simulation. The effects of four-wavelength mixing (FWM) in O-band as well as cross-phase modulation (XPM) in C-band are both studied and discussed. Experiments are performed for 3- and 4-channel transmission cases, while 12-channel transmission is performed by simulation. The results show that in the O-band scenario, the FWM effect severely affects the performance of the channels near the zero-dispersion wavelength. Besides, the XPM products overlap the signal in the C-band, which also degrades the sensitivity. Based on these analyses, the nonlinear effects should be fully considered when planning wavelengths for 5G fronthaul transmission, including wavelength distribution and channel spacing selection. [ABSTRACT FROM AUTHOR]