基于空间光调制器的MIMO大气传输特性研究

大气湍流对无线光通信系统的影响不可忽视，为了更准确地反映实验室模拟多输入、多输出(MIMO)大气湍流信道的实际特征，提出了一种利用相位屏来模拟MIMO大气湍流信道的方法，并针对基于液晶空间光调制器（LC-SLM）的液晶调制法展开研究，通过实验验证该方法的可行性。实验结果表明:通过相位屏模拟MIMO大气湍流信道的激光光斑发生不同程度的畸变，湍流环境下两路激光发射系统比单路发射激光系统功率稳定性好，在前向纠错误差极限（3.8×10?3）下，单个发射单个接收系统的链路代价为10.5 dB，2个发射2个接收的MIMO系统的链路代价为9.3 dB。该项研究对于实验室模拟MIMO大气湍流信道实验方法提供一种新思路。

MIMO atmospheric transmission characteristics based on spatial light modulator

The influence of atmospheric turbulence on wireless optical communication systems cannot be ignored. In order to accurately reflect the actual features of laboratory-simulated multiple-input multiple-output (MIMO) atmospheric turbulence channels, a method using phase screens to simulate MIMO atmospheric turbulence channels was proposed. The liquid crystal modulation method based on liquid crystal spatial light modulator (LC-SLM) was studied, and the feasibility of the method was verified by experiments. The experimental results show that the laser spot of MIMO atmospheric turbulence channels simulated by phase screen has different degrees of distortion. In the turbulent environment, the power stability of the two-channel laser emission system is better than that of the single-channel laser emission system. Under the forward error correction error limit (3.8×10?3), the link penalty of the single-emission single-receiving system is 10.5 dB, and the link penalty of the two-emission two-receiving MIMO system is 9.3 dB. This research provides a new idea for the experimental method of simulating MIMO atmospheric turbulent channels in laboratory.