支持终端晃动的多光源可见光通信系统有效容量研究

作为下一代网络的重点候选技术，可见光通信(VLC)以其超高的传输速率有望提供严格的时延服务质量(QoS)保障。现有VLC研究大多假设终端在接收信号过程中始终保持垂直向上。然而，在实际VLC系统中，终端晃动将对接收端入射角产生较大的影响，从而对VLC的信道增益与传输速率产生影响。该文针对统计时延QoS约束下多光源VLC系统晃动终端的可达传输速率展开研究。首先，基于3维离散时间马尔可夫链，提出VLC终端3自由度晃动模型，从时间相关性的角度刻画了VLC终端的随机晃动过程；其次，将终端晃动下多光源VLC系统的矢量传输过程映射为马尔可夫式服务过程，基于有效容量理论，研究支持终端晃动的VLC系统在统计时延QoS约束下的可达传输速率；最后，通过仿真实验说明了终端晃动对VLC系统容量的影响并验证了所推导有效容量的准确性。

Research on Effective Capacity of Multi-Source Visible Light Communication Systems Supporting Terminal Rotation

As one of the promising candidates of the next-generation network, Visible Light Communication (VLC) is expected to provide a strict delay QoS guarantee because of its high transmission rate. In the existing research of the VLC field, most of them assume that the direction of terminals is always vertically upward during the whole process of receiving signals. However, in a practical VLC system, the terminal rotation has considerable impacts on the angle of incidence and then affects the channel gain and transmission rate of VLC. In this paper, the achievable transmission rate of rotated terminals with the delay QoS constraint for the multi-source VLC system is investigated. Firstly, based on the three-dimension discrete-time Markov chain, a rotation model for the VLC terminal is proposed, which depicts the random rotation process of the VLC terminal from the perspective of temporal correlation. Secondly, the vectored transmission process of rotated terminals is mapped into Markov service process. Based on the effective capacity theory, the achievable transmission rate with the statistical delay QoS constraint for VLC system supporting terminal rotation is investigated. Finally, simulation results manifest significant rotation impacts on the VLC system capacity and the accuracy of the derived effective capacity.