During free-space quantum key distribution, the rotation and fluctuation of reference frame degrades the performance of quantum key distribution (QKD). Reference-frame-independent QKD (RFI-QKD) overcomes this issue effectively. To date, much theoretical and experimental research has been conducted on the performance of free-space RFI-QKD. However, these studies are all based on free-space air and satellite ground, and none have investigated the performance of RFI-QKD in an underwater channel. Therefore, this paper constructed a channel model that considered both scattering and optical attenuation to obtain an RFI-QKD secret key rate in an underwater channel. The simulation results confirm that even in a relatively harsh underwater scenario, RFI-QKD maintains good performance.

中文翻译：

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水下信道中与参考帧无关的量子密钥分配性能

在自由空间量子密钥分发过程中，参考帧的旋转和波动会降低量子密钥分发（QKD）的性能。与参考系无关的 QKD (RFI-QKD) 有效地克服了这个问题。迄今为止，已经对自由空间RFI-QKD的性能进行了大量的理论和实验研究。然而，这些研究都是基于自由空间空中和卫星地面，没有研究过RFI-QKD在水下信道中的性能。因此，本文构建了一个同时考虑散射和光衰减的信道模型，以获得水下信道中的 RFI-QKD 密钥速率。仿真结果证实，即使在相对恶劣的水下场景中，RFI-QKD也能保持良好的性能。