Improved Companding Transform for PAPR Reduction in ACO-OFDM-Based VLC Systems

In this letter, an improved linear nonsymmetrical transform (ILNST) is proposed to reduce the peak-to-average power ratio (PAPR) for asymmetric clipping optical orthogonal frequency division multiplexing-based visible light communication (VLC) systems. The emission power conservation criteria are implemented to calculate the enlarge coefficient with a given compression coefficient. The transfer characteristic of a 5 mm commercial light-emitting diodes is introduced to estimate the VLC systems performance. Bit error ratio (BER) and complementary cumulative distribution function simulation results show that the proposed ILNST outperforms the classical linear nonsymmetrical transform method in PAPR reduction and BER enhancement.