School of Electronics and Electrical Engineering, Lovely Professional University, Phagwara 144411, India.
Department of Electronics and Communication, Chandigarh University, Mohali 140413, India.
Sensors (Basel). 2023 Jan 10;23(2):786. doi: 10.3390/s23020786.
Twisted light beams such as optical angular momentum (OAM) with numerous possible orthogonal states have drawn the prodigious contemplation of researchers. OAM multiplexing is a futuristic multi-access technique that has not been scrutinized for optical satellite communication (OSC) systems thus far, and it opens up a new window for ultra-high-capacity systems. This paper presents the 4.8 Tbps (5 wavelengths × 3 OAM beams × 320 Gbps) ultra-high capacity OSC system by incorporating polarization division multiplexed (PDM) 256-Quadrature amplitude modulation (256-QAM) and OAM beams. To realize OAM multiplexing, Laguerre Gaussian (LG) transverse mode profiles such as LG00, LG140, and LG400 were used in the proposed study. The effects of the receiver's digital signal processing (DSP) module were also investigated, and performance improvement was observed using DSP for its potential to compensate for the effects of dispersion, phase errors, and nonlinear effects using the blind phase search (BPS), Viterbi phase estimation (VPE), and the constant modulus algorithm (CMA). The results revealed that the proposed OAM-OSC system successfully covered the 22,000 km OSC link distance and, out of three OAM beams, fundamental mode LG00 offered excellent performance. Further, a detailed comparison of the proposed system and reported state-of-the-art schemes was performed.
扭曲的光束，如具有众多可能正交状态的光学轨道角动量（OAM），引起了研究人员的极大关注。OAM 复用是一种未来的多址接入技术，迄今为止尚未在光卫星通信（OSC）系统中进行研究，它为超高容量系统开辟了新的窗口。本文通过结合偏振分复用（PDM）256 正交幅度调制（256-QAM）和 OAM 光束，提出了 4.8 Tbps（5 个波长×3 个 OAM 光束×320 Gbps）的超高容量 OSC 系统。为了实现 OAM 复用，在提出的研究中使用了拉盖尔高斯（LG）横模轮廓，如 LG00、LG140 和 LG400。还研究了接收器的数字信号处理（DSP）模块的影响，并观察到使用 DSP 可以改善性能，因为它有可能通过盲相位搜索（BPS）、维特比相位估计（VPE）和常数模算法（CMA）来补偿色散、相位误差和非线性效应的影响。结果表明，所提出的 OAM-OSC 系统成功覆盖了 22,000 公里的 OSC 链路距离，并且在三个 OAM 光束中，基模 LG00 提供了出色的性能。此外，还对所提出的系统与已报道的最新方案进行了详细比较。
