研究了水下湍流对轨道角动量(OAM)通信系统的性能影响,分析了不同环境参数和 传输距离下OAM通信系统信道容量的变化。结果表明,水下湍流环境中随着传输距离、湍流动 能耗散率和温度耗散率的增加, OAM态光束模式之间串扰加强,信道容量下降。当传输距离达 到7 m左右,信道容量下降为原来的一半;当湍流动能耗散率 为10－4m2/s3,容量下降 到理论最大值的75%; 当温度耗散率为10－8K2/s, 信道 容量下降到理论上最大值的一半;水下环境中盐度扰动比温度变化扰动对OAM通信系统性能的影响更大。

Influence of underwater turbulence on the performance of orbital angular momentum (OAM) communication system is investigated. The change of OAM communication system capacity with different environment parameters and transmission distances is presented. Results show that in underwater turbulence environment, the crosstalk between OAM beam modes is enhanced and channel capacity decreases with the increasing of transmission distance, dissipation rates of turbulent flow and temperature. When the transmission distance approaches 7 m, the channel capacity decreases to half of the original one. When the turbulence kinetic energy dissipation is close to 10－4m2/s3, the capacity decreases to 75% of the theoretical maximum. When the temperature dissipation rate is 10－8K2/s, the channel capacity reduces to half of the theoretical maximum. In underwater environment, salinity disturbance has a greater influence on the capacity performance than that of temperature disturbance.