Free-space optical communication over strong atmospheric turbulence channels
Free-space optical communication over strong atmospheric turbulence channels
复制标题
强大气湍流信道上的自由空间光通信
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
I. Djordjevic
中科院分区：
文献类型：
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作者：
Z. Qu;I. Djordjevic
光通信可以部署在光纤链路或自由空间光(FSO)链路上。光纤链路基于封闭的两层波导层(芯和包层)，由护套保护，用于信号传输，具有低损耗、极大带宽、小失真的特点，代表着相对稳定的信道。FSO链路是众所周知的“免费”通信介质，已被广泛应用于短距离光传输系统。尽管FSO信道具有许多优点，但由于吸收、散射和大气湍流等大气效应的影响，FSO传输系统的性能可能会下降。大气湍流是引起信道起伏的主要原因，因此接收光束会受到强度闪烁和空间位相失真的影响。当空间模式复用用于FSO通信时，模式串扰可能成为限制系统容量的因素。在这一章中，我们首先分析了大气湍流，并建立了一个模型来仿真大气湍流信道。然后将介绍轨道角动量(OAM)多路复用/多路分解，然后描述缓解湍流效应的方法。
Optical communication can be deployed over a fiber-optic link or a free-space optical (FSO) link. Fiber-optic links are based on a closed two waveguide layers (core and cladding), protected by the jacket, for signal transmission, which are characterized by low-loss, extremely large bandwidth, small distortions, and represent relatively stable channels. FSO links are known for the “free” communication media, and have been widely used in shot-reach optical transmission systems. Despite the advantages of FSO channels, the performance of FSO transmission systems may be degraded by the atmospheric effects such as absorption, scattering effects, and atmospheric turbulence. Atmospheric turbulence is the main reason for channel fluctuation, as a result, the received beam will be affected by the intensity scintillation and spatial phase distortion. When spatial-mode multiplexing is used for FSO communication, mode crosstalk may become the limiting factor for the system capacity. In this chapter, we first analyze the atmospheric turbulence, and build a model to emulate the atmospheric turbulence channel. Then orbital angular momentum (OAM) multiplexing/demultiplexing will be introduced, followed by the description of approaches to mitigate the turbulence effects.