Time and wavelength division multiplexing passive optical network (TWDM‐PON) is adopted across the globe and is considered as the most remarkable trend of the next‐generation solution to serve exponential traffic growth for fifth‐generation (5G) network. In the interest of achieving 5G network requirements, we propose a mode division multiplexing (MDM) based bidirectional 40/40 Gbps hybrid TWDM‐PON and free‐space optics (FSO) system. The system performance is analyzed for bidirectional hybrid fiber/FSO channels incorporating four distinct Laguerre‐Gaussian (LG00, LG01, LG11, and LG21) spatial modes for variable fiber (10‐155 km)/FSO (10‐1000 m) link ranges and different receiver aperture diameters (20 μm‐60 cm). Based on Gamma‐Gamma (GG) modeled FSO channels using Laguerre Gaussian modes, bit error rate (BER) performance of the system is numerically investigated under the impact of dynamic atmospheric weather conditions, weak‐to‐strong turbulence conditions, pointing errors, and geometric loss (GL) at an acceptable BER of 10⁻⁹. In addition, to support the numerical analysis, the simulation results exhibit that the hybrid fiber/FSO LG00 signals over 1000 m FSO and 155 km fiber link ranges are successfully transmitted in the system with 40 μm spatial and 60 cm FSO receiver aperture diameters under the impact of strong turbulence, atmospheric attenuation of 0.2 dB/km and noise. Moreover, the performance comparison of the MDM‐based hybrid TWDM‐PON/FSO with the previous latest literature works reveals a superior system performance under practical environment conditions. The proposed work can be utilized to realize long‐reach, bandwidth‐efficient, high‐capacity, and high‐speed data transmission links.

中文翻译：

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使用Gamma-Gamma衰落模型在不同天气条件下使用指向误差的长距离40/40 Gbps模分复用混合时分和波分复用无源光网络/自由空间光学器件的性能分析

时分和波分复用无源光网络（TWDM-PON）在全球范围内被采用，被认为是为第五代（5G）网络提供指数流量增长的下一代解决方案的最显着趋势。为了达到5G网络要求，我们提出了一种基于模式分复用（MDM）的双向40/40 Gbps混合TWDM-PON和自由空间光学（FSO）系统。分析了双向混合光纤/ FSO信道的系统性能，该信道结合了四个不同的Laguerre-Gaussian（LG00，LG01，LG11和LG21）空间模式，用于可变光纤（10-155 km）/ FSO（10-1000 m）链路范围，以及不同的接收器孔径直径（20μm-60cm）。基于使用Laguerre高斯模式的Gamma-Gamma（GG）建模的FSO通道，^-9。此外，为支持数值分析，仿真结果表明，在光纤系统中，在40μm空间和60 cm FSO接收器孔径的情况下，在1000 m FSO和155 km光纤链路范围上的混合光纤/ FSO LG00信号已成功传输。强湍流，0.2 dB / km的大气衰减和噪声的影响。此外，将基于MDM的混合TWDM-PON / FSO与以前的最新文献进行的性能比较表明，在实际环境条件下，该系统具有出色的系统性能。拟议的工作可用于实现长距离，带宽有效，大容量和高速数据传输链路。