A novel PAPR reduction scheme for VLC DCO-OFDM systems

In this study, we aim to reduce the peak-to-average power ratio (PAPR) for indoor visible light communication (VLC) orthogonal frequency division multiplexing (OFDM) systems and improve the system performance. By utilizing the spatial multiplexing (SMP) technique, we propose a subcarrier spatial grouping (SSG) scheme to address the high PAPR and LED restricted linear range problems. In this scheme, the high-PAPR wideband OFDM signals are partitioned into several low-PAPR narrowband independent signals that are simultaneously transmitted from multiple LED light sources. At the receiver, zero forcing (ZF) is used to reverse the impairments of the channel transform. The computer simulation results demonstrate that the proposed approach achieves lower PAPR and more robustness to LED nonlinearities leading to better bit error rate performance for the same spectral efficiency than that of the conventional DCO-OFDM scheme does in the whole signal-to-noise ratios range.