PAPR Reduction for OFDM in VLC Systems

Orthogonal frequency-division multiplexing (OFDM) has been widely studied and adopted in visible-light communication (VLC) systems because of its advantages including high spectral efficiency and low-complexity implementation. However, OFDM-based VLC systems suffer from a high peak-to-average power ratio (PAPR), along with the nonlinear transfer characteristics of light-emitting diodes (LEDs). In this paper, discusses a subcarrier grouping scheme for an OFDM-based VLC system. This scheme exploits the property that one LED lamp usually contains multiple independent LED chips and here all OFDM signal subcarriers are divided into groups, and each group is transmitted by an individual LED chip while the same receiver structure is maintained. Since only some of the subcarriers are located on each LED chip, PAPR can be reduced significantly. Hence, the achievable input power can be increased, which leads to a higher signal-to-noise ratio (SNR) and a lower bit error rate (BER). This paper can be considered as a literature survey or a case study to analyze PAPR reduction in OFDM based VLC systems.