A novel dimming control scheme, termed as generalized dimming control (GDC), is proposed for visible light communication (VLC) systems. The basic idea of GDC is to exploit adaptively time, spatial and signal domain resources for enhancing communication performance under practical illumination constraints. In particular, to satisfy the illumination constraints, an incremental algorithm for index mapping is first proposed to achieve target optical power and uniform illumination. Next, GDC having the optimal activation pattern is investigated to improve the bit-error rate (BER) performance of VLC. In particular, the BER performance of GDC is analyzed using the union bound technique. Based on the analytical BER bound, the optimal activation pattern of GDC scheme having the minimum BER criterion (GDC-MBER) is obtained by exhaustively searching all conditional pairwise error probabilities. However, since GDC-MBER requires high search complexity, two low-complexity GDC schemes having the maximum free distance criterion (GDC-MFD) are proposed. The first low-complexity GDC-MFD scheme, termed as GDC-MFD1, is derived by a lower bound of the free distance using the Rayleigh-Ritz theorem. The second low-complexity GDC-MFD scheme, termed as GDC-MFD2, is proposed to reduce further the computation by exploiting the time-invariance characteristics of the VLC channel. Simulation and numerical results show that GDC-MBER, GDC-MFD1 and GDC-MFD2 have similar BER performance, and they can achieve more than 3 dB SNR gains compared with conventional dimming control schemes for a BER of ${10^{ - 4}}$ and a dimming level of 50%.

中文翻译：

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可见光通信的通用调光控制方案

针对可见光通信（VLC）系统，提出了一种新颖的调光控制方案，称为通用调光控制（GDC）。GDC的基本思想是在实际的照明约束下，自适应地利用时域，空间域和信号域资源来增强通信性能。特别是，为了满足照明约束，首先提出了一种用于索引映射的增量算法，以实现目标光功率和均匀照明。接下来，研究具有最佳激活模式的GDC以改善VLC的误码率（BER）性能。特别是，使用联合约束技术分析了GDC的BER性能。根据解析的BER界限，通过穷举搜索所有有条件的成对错误概率，可以获得具有最小BER准则（GDC-MBER）的GDC方案的最佳激活模式。然而，由于GDC-MBER需要高的搜索复杂度，因此提出了两种具有最大自由距离准则（GDC-MFD）的低复杂度的GDC方案。第一个低复杂度的GDC-MFD方案称为GDC-MFD1，它是使用Rayleigh-Ritz定理通过自由距离的下限导出的。提出了第二种低复杂度的GDC-MFD方案，称为GDC-MFD2，以通过利用VLC通道的时不变特性进一步减少计算量。仿真和数值结果表明，GDC-MBER，GDC-MFD1和GDC-MFD2具有相似的BER性能， $ {10 ^ {-4}} $ 和50％的调光水平。