Multiple Access Techniques for Bipolar Optical Code Division in Wireless Optical Communications
Multiple Access Techniques for Bipolar Optical Code Division in Wireless Optical Communications
复制标题
无线光通信中双极光码分多址技术
DOI：
10.1109/access.2020.2991071
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
S. Tseng
中科院分区：
文献类型：
--
作者：
Hsu;Eddy Wijanto;Tzu;Po;S. Tseng
本文提出了双极光码分多址技术在无线光通信中的应用。首先，使用多个光纤布拉格光栅（FBG）和光环行器对光信号进行编码。然后，可以使用双极数据来控制水平或垂直偏振状态。使用两个设备进行了实验，以确定在自由空间光通信中使用多址技术进行双极光码分的可行性。第一个实验测试了第一种架构，其中每个用户通过切换数据位来操作机械光开关，通过自由空间通道中的准直器生成具有特定偏振状态的光信号。作为解码部件，主要使用多个FBG和光环行器。解码信号被发送到平衡光电探测器，该探测器可以从编码器重建原始数据。第二个实验涉及第二种架构，其中使用带有掺铒光纤放大器的编码器和带有衰减器的解码器来提高系统稳定性。第三个实验旨在测试所提出的架构是否可以减轻多址干扰。在最后的实验中，使用超快光开关代替原来的光开关来选择特定偏振态的光信号，以提高整体传输速率。实验结果表明该方案可以在自由空间光通信系统中成功实现。所提出方案的架构通过简单且具有成本效益的设计减轻了多址干扰。
In this paper, multiple access techniques for bipolar optical code division are proposed for application in wireless optical communications. First, several fiber Bragg gratings (FBGs) and optical circulators are used to encode optical signals. Then, the horizontal or vertical polarization state can be controlled using bipolar data. Experiments were conducted using two devices to determine the feasibility of using multiple access techniques for bipolar optical code division in free-space optical communication. The first experiment tested the first architecture, in which each user operates a mechanical optical switch by switching data bits to generate optical signals with specific polarization states through a collimator in a free-space channel. As the decoding components, several FBGs and optical circulators are used as primary devices. Decoded signals are sent to a balanced photodetector, which can reconstruct original data from the encoder. The second experiment involved a second architecture, in which an encoder with an erbium-doped fiber amplifier and a decoder with an attenuator are used to improve system stability. The third experiment was designed to test whether multiple access interference can be alleviated with the proposed architectures. In the final experiment, an ultrafast optical switch was used instead of the original optical switch for selecting optical signals with a specific polarization state to improve the overall transmission rate. The experimental results indicate that the proposed scheme could be successfully implemented in free-space optical communication systems. The architectures of the proposed scheme mitigate multiple access interference with a simple and cost-effective design.