With the capability of reconfiguring the wireless electromagnetic environment, intelligent reflecting surface (IRS) is a new paradigm for designing future wireless communication systems. In this paper, we consider optical IRS for improving the performance of visible light communication (VLC) under a multiple-input and multiple-output (MIMO) setting. Specifically, we focus on the downlink communication of an indoor MIMO VLC system and aim to minimize the mean square error (MSE) of demodulated signals at the receiver. To this end, the MIMO channel gain of the IRS-aided VLC is first derived under the point source assumption, based on which the MSE minimization problem is then formulated subject to the emission power constraints. Next, we propose an alternating optimization algorithm, which decomposes the original problem into three subproblems, to iteratively optimize the IRS configuration, the precoding and detection matrices for minimizing the MSE. Moreover, theoretical analysis on the performance of the proposed algorithm in high and low signal-to-noise rate (SNR) regimes is provided, revealing that the joint optimization process can be simplified in such special cases, and the algorithm's convergence property and computational complexity are also discussed. Finally, numerical results show that IRS-aided schemes significantly reduce the MSE as compared to their counterparts without IRS, and the proposed algorithm outperforms other baseline schemes.
翻译:通过重新配置无线电磁环境的能力,智能反射表面(IRS)是设计未来无线通信系统的新范例。在本文件中,我们考虑光学IRS,在多投入和多输出(MIMO)设置下改进可见光通信(VLC)的性能;具体地说,我们侧重于室内IMO VLC系统下行连接通信,目的是尽量减少接收器降压信号的平均平方差错(MSE),为此,IMO频道获得IRS辅助VLC系统获得的光学反射光电路是首先在点源假设下产生的,然后根据点源假设在排放功率限制下制定MSE最小化问题。接下来,我们建议采用交替优化算法,将原始问题分为三个子问题,迭代优化IMO VLC系统配置,为最大限度地减少最低接收器降压信号的预编码和检测矩阵。此外,对高和低信号到新利率的拟议算法(SNRR)系统的性能分析分析分析,表明联合优化进程可以在排放力限制下制定最低通信系统最小化程序,最终将IMSA结果进行对比。