水下光通信系统在非Kolmogorov湍流中的传输特性

湍流效应是限制水下无线光通信(underwater wireless optical communication,UWOC)系统性能的关键因素之一。在强海洋非Kolmogorov湍流中,首先以平面波和球面波为光源,研究了采用孔径接收的差分相移键控(differential phase-shift-keying,DPSK)调制的UWOC系统性能。接着,基于Gamma-Gamma信道模型,利用Whittaker函数推导出了平均误码率(average bit error rate,ABER)的解析表达式。最后研究了不同光束形状、调制方式、孔径尺寸以及非Kolmogorov湍流参数即内尺寸和幂率对ABER的影响规律。结果表明,UWOC系统采用球面波传输、DPSK调制在比较小的内尺寸和较大的幂率湍流下传输经孔径接收可以提升ABER性能。

Properties of underwater optical communication system in non-Kolmogorov turbulence

Underwater turbulence is one of the significant phenomena that degrade the underwater wireless optical communication system performance.In strong oceanic non-Kolmogorov turbulence,performance of UWOC systems exercising differential phase-shift-keying(DPSK)with an aperture receiver is evaluated when plane wave and spherical wave is used as the excitation.The analytical expressions for average bit error rate(ABER)are derived based on Gamma-Gamma channel model by the help of the Whittaker function,and the results are presented versus the source,modulation,aperture diameter as well as the non-Kolmogorov oceanic turbulence parameters,namely,inner scale and power law exponent.The results show that a UWOC system using DPSK modulated spherical wave over a smaller inner scale and larger power law exponent with a larger aperture receiver can improve the ABER performance.