Dixit Vipul, Kumar Atul
Appl Opt. 2022 Feb 1;61(4):858-867. doi: 10.1364/AO.440511.
By offering a wide license-free spectrum, visible light communication (VLC) has emerged as a game-changing technology for networks beyond 5G. In this study, the multiple-input multiple-output (MIMO) technology is combined with a non-orthogonal multiple access VLC (NOMA-VLC) system to provide a reliable error-free high data rate network for multi-user scenarios. A generalized -PPM modulated MIMO based multi-user NOMA-VLC system with × line-of-sight connections for each user is presented. Considering a practical scenario of imperfect successive interference cancellation, a novel closed form formulation of error probability for the proposed system is obtained. This study also includes a comprehensive analysis of two-user and three-user -PPM modulated 2×2 MIMO-NOMA-VLC systems, and exact error probability expressions are derived. With the identical set of parameters, the -PPM modulated MIMO-NOMA-VLC system totally outperforms the on-off keying modulated MIMO-NOMA-VLC system. As the number of photodetectors per user increases, the error probability of the considered system decreases. An -PPM modulated 2×2 MIMO based three-user NOMA-VLC system offers the best performance at a power allocation co-efficient of 0.3. The simulation results validate the derived error probability expressions.
通过提供广泛的免许可频谱，可见光通信（VLC）已成为一种改变5G以上网络格局的技术。在本研究中，多输入多输出（MIMO）技术与非正交多址VLC（NOMA-VLC）系统相结合，为多用户场景提供可靠的无差错高数据速率网络。提出了一种基于广义脉冲位置调制（PPM）的多用户NOMA-VLC系统，每个用户具有×视距连接。考虑到不完全连续干扰消除的实际场景，得到了该系统误码率的一种新的闭式表达式。本研究还对两用户和三用户PPM调制的2×2 MIMO-NOMA-VLC系统进行了全面分析，并推导了精确的误码率表达式。在相同的参数设置下，PPM调制的MIMO-NOMA-VLC系统完全优于开关键控调制的MIMO-NOMA-VLC系统。随着每个用户光电探测器数量的增加，所考虑系统的误码率降低。一个基于PPM调制的2×2 MIMO三用户NOMA-VLC系统在功率分配系数为0.3时性能最佳。仿真结果验证了推导的误码率表达式。
