In space division multiplexing (SDM) transmission utilizing mode division multiplexing (MDM) technologies, transmission performance of each spatial channel is highly dependent on a spatial mode that delivers information symbols over few-mode fibers (FMFs) or multi-mode fibers (MMFs). This still remains as a dominant barrier to realize a future deployable long-haul MDM transport systems. In this article, we review the transmission issues we face when transmitting MDM signals over long distances. We also present the review of key techniques that we have recently developed to overcome mode-relevant linear phenomena. By developing the projection technique for a signal detection application in multiple-input multiple-output (MIMO) systems, a novel linear filtering adaptation technique is proposed to enhance the performance of our interference canceling scheme with decreased complexity. Experimental evaluation using dense SDM transmission results over multicore FMFs verifies a fast convergence property brought by the proposed projection technique.

中文翻译：

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基于快速MIMO仿射投影的干扰消除技术增强长距离模式复用传输

在使用模分复用 (MDM) 技术的空分复用 (SDM) 传输中，每个空间信道的传输性能高度依赖于通过少模光纤 (FMF) 或多模光纤 (MMF) 传送信息符号的空间模式. 这仍然是实现未来可部署的长途 MDM 传输系统的主要障碍。在本文中，我们回顾了长距离传输 MDM 信号时面临的传输问题。我们还回顾了我们最近开发的克服与模式相关的线性现象的关键技术。通过为多输入多输出 (MIMO) 系统中的信号检测应用开发投影技术，提出了一种新颖的线性滤波自适应技术，以提高我们的干扰消除方案的性能，同时降低复杂性。在多核 FMF 上使用密集 SDM 传输结果的实验​​评估验证了所提出的投影技术带来的快速收敛特性。