Performance analysis of a 448 Gbps PDM/WDM/16-QAM hybrid SMF/FSO system for last mile connectivity

A combined wavelength division multiplexing (WDM)-polarization division multiplexing dual polarization (DP) in-phase quadrature modulation is proposed in hybrid single mode fiber (SMF)/free space optics (FSO) communication system to be used for last mile connectivity. Four WDM channels are used; each carries 112 Gbps information data. Additionally, 16-quadrature amplitude modulation signals are used in a DP in-phase quadrature modulation. Also, for SMF nonlinear losses and dispersion loss, digital signal processing algorithms are used to compensate nonlinear fiber losses, dispersion, and FSO channel losses. Furthermore, we assumed constant SMF length of 50 km with various ranges for the FSO link. External climate changes like clear air (CA), hazy, rainy, and foggy weather conditions are considered for evaluating the system performance. Both the bit error rate (BER) and percentage of error vector magnitude (EVM%) are used as performance metrics. The simulation results assure the longest transmission distance of 50 km SMF + 3.5 km FSO under CA and the shortest transmission distance of 50 km SMF + 0.675 km FSO under heavy fog with an overall capacity of 448 Gbps. At BER < 3.8 x 10(-3) and EVM% < 15%, these transmission ranges are conducted. Consequently, the proposed SMF/FSO system is suggested to be used in the fifth generation last-mile wide-area networks.

Automated summary

This paper proposes a combined wavelength division multiplexing (WDM)-polarization division multiplexing dual polarization (DP) in-phase quadrature modulation method in a hybrid single mode fiber (SMF)/free space optics (FSO) communication system for last mile connectivity. Four WDM channels carrying 112 Gbps data are used, along with 16-quadrature amplitude modulation signals. Digital signal processing algorithms are applied to compensate for SMF nonlinear losses, dispersion, and FSO channel losses. The simulation results demonstrate that the proposed SMF/FSO system can achieve transmission distances up to 50 km SMF + 3.5 km FSO under clear air conditions and down to 50 km SMF + 0.675 km FSO under heavy fog, with a total capacity of 448 Gbps at BER < 3.8 x 10(-3) and EVM% < 15%. Therefore, it is suggested to be used in the fifth generation last-mile wide-area networks.