Sun Zheng-Guo, Yu Hongyi, Zhu Yi-Jun
Appl Opt. 2017 Nov 10;56(32):8959-8968. doi: 10.1364/AO.56.008959.
In this paper, we investigate visible light communication (VLC) attocell systems in which any two neighboring attocells overlap. An efficient signal design for VLC called time superposition reuse (TSR) is proposed to mitigate interference and improve spectral efficiency. In the scheme, two neighboring cells are allocated with two time slots that have superposition in the time domain. By adjusting superposition between time slots, the system can achieve a flexible spectral efficiency and system performance. Further, we develop an optimal power allocation strategy for TSR in the system. The strategy is given according to the position of the user and the level of superposition, and then the corresponding optimal Euclidean distance is derived. In addition, we analyze the system performance and prove that the optimal Euclidean distance is an increasing function of the delay between signals and a decreasing function of the sampling period. Simulation results demonstrate that the optimal power allocation has a better performance than uniform power allocation and TSR outperforms time division multiple access significantly for the user in VLC attocell systems.
在本文中，我们研究了任意两个相邻微微小区相互重叠的可见光通信（VLC）微微小区系统。提出了一种名为时间叠加复用（TSR）的VLC高效信号设计，以减轻干扰并提高频谱效率。在该方案中，为两个相邻小区分配在时域中具有叠加的两个时隙。通过调整时隙之间的叠加，系统可以实现灵活的频谱效率和系统性能。此外，我们为系统中的TSR开发了一种最优功率分配策略。该策略根据用户位置和叠加水平给出，然后推导出相应的最优欧几里得距离。此外，我们分析了系统性能，并证明最优欧几里得距离是信号之间延迟的增函数和采样周期的减函数。仿真结果表明，对于VLC微微小区系统中的用户，最优功率分配比均匀功率分配具有更好的性能，并且TSR明显优于时分多址接入。
