发表机构
Indian Institute of Technology Kanpur; Indian Institute of Technology Jodhpur; University of Southampton（坎普尔印度理工学院; 焦特普尔印度理工学院; 南安普顿大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对LD驱动VLC O-OFDM系统，提出统计推断框架估计信道，推导多种估计器及BCRLB，仿真表明MMSE性能最优。
AI 中文摘要
基于激光二极管（LD）的照明灯具在汽车应用中日益受到关注，并有望扩展到住宅和商业环境，为高带宽可见光通信（VLC）系统创造机会。然而，实际的LD基VLC链路受到输入信号相关散粒噪声（ISDSN）、相对强度噪声（RIN）和热噪声的损害，这些噪声影响了可靠的信道估计（CE）。本研究在统计随机信道模型下，探讨了这些噪声对单输入单输出（SISO）光正交频分复用（OOFDM）VLC系统接收端信道估计的联合影响。本文开发了一个统计推断框架，其中接收机利用观测到的信号变化来在光学损伤下估计信道。推导了最小二乘（LS）、最大似然（ML）、最大后验概率（MAP）、最小均方误差（MMSE）和线性MMSE（LMMSE）估计器的闭式表达式。此外，推导了贝叶斯克拉美-罗下界（BCRLB）以基准均方误差（MSE）性能。针对直流偏置光O-OFDM（DCO-OFDM）和非对称限幅光O-OFDM（ACO-OFDM）的蒙特卡洛仿真验证了分析。结果表明，在ISDSN和RIN联合存在下，信道估计性能显著下降，而MMSE估计器始终实现最低的MSE，展示了在实际VLC系统中实现稳健和自适应接收机运行的强大潜力。
英文摘要
Laser diode (LD)-based luminaires are gaining increasing attention in automotive applications and are expected to extend to residential and commercial environments, creating opportunities for high-bandwidth visible light communication (VLC) systems. However, practical LD-based VLC links are impaired by input-signal-dependent shot noise (ISDSN), relative intensity noise (RIN), and thermal noise, which affect reliable channel estimation (CE). This work investigates their joint impact on receiver-side CE in a single-input single-output (SISO) optical orthogonal frequency division multiplexing (OOFDM) VLC system under a statistically random channel model. A statistical inference framework is developed in which the receiver exploits observed signal variations to estimate the channel under optical impairments. Closed-form expressions are derived for least squares (LS), maximum likelihood (ML), maximum a posteriori probability (MAP), minimum mean square error (MMSE), and linear MMSE (LMMSE) estimators. In addition, the Bayesian Cramer-Rao lower bound (BCRLB) is derived to benchmark mean square error (MSE) performance. Monte Carlo simulations for direct current-biased O-OFDM (DCO-OFDM) and asymmetrically clipped O-OFDM (ACO-OFDM) validate the analysis. Results show substantial CE degradation under the joint presence of ISDSN and RIN, while the MMSE estimator consistently achieves the lowest MSE, demonstrating strong potential for robust and adaptive receiver operation in practical VLC systems.
