Joint PAPR reduction and channel estimation in low-complexity VLC systems.

In recent times, there has been a surge in interest surrounding visible light communication (VLC) as a compelling adjunct to radio frequency (RF) technology. This enthusiasm stems from deployments showcasing its efficacy in high-speed data transmission, characterized by low complexity, robust security, and high reliability. Among the variants of orthogonal frequency division multiplexing (OFDM), direct current-biased optical OFDM (DCO-OFDM) stands out in the realm of VLC systems, owing to its ability to furnish rapid data provisioning. However, a significant drawback of selective mapping (SLM) based DCO-OFDM transceivers lies in its computational complexity and practical implementation challenges. To address this limitation, this paper presents a modified SLM technique termed selective phase modulation (SPM) aimed at mitigating the peak-to-average power ratio (PAPR) in the transmitter section while simplifying the data decoding process at the receiver end. The SPM method utilizes a phase modulation and demodulation process based on clusters and assisted by pilot signals, streamlining the transceiver architecture. The SPM methodology offers reduced computational complexity at the transmitter by selectively applying phase sequences to data, circumventing the necessity for side information (SI) transmission and SI estimation at the receiver with a known pilot symbol inserted in the data. This dual-functionality mechanism not only achieves complexity reduction but also facilitates channel estimation at the receiver for proper data recovery. Based on complexity analysis and simulation outcomes, the computational complexity reduction strategy outperforms the conventional selective mapping (CSLM) technique, VLC-based pilot-assisted PAPR reduction systems, and embedded coded modulation (ECM). This allows for smooth incorporation of this technology into future VLC systems. [Display omitted] • Innovative SLM Scheme : The research introduces a novel selected mapping (SLM) scheme to simplify visible light communication (VLC) systems, enhancing overall efficiency by reducing system complexity. • Clustered Symbol Approach : The method segments DCO-OFDM symbols, separates even and odd ones, and inserts pilot symbols to enhance adaptability. • Selective phase modulation (SPM) : Unlike traditional SLM, odd subcarriers are selectively multiplied, optimizing computational resources. • Dual-Purpose Technique : Inserts pilot symbols, reducing complexity and ensuring accurate channel estimation, eliminating SI transmission. [ABSTRACT FROM AUTHOR]