On Companding Transform Techniques for OFDM Visible Light Communication over Indoor Dispersive Channels

摘要

The μ-law companding transform (CT) is proposed for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing visible light communication (VLC-OFDM) systems. The proposed PAPR reduction technique based on the μ-law CT can minimize nonlinear signal distortions and LED chip overheating problems that occur due to nonlinear characteristics of the transmitter LEDs. The performance of the proposed PAPR reduction is studied via simulations. It is verified that the proposed μ-law CT outperforms the previously proposed DFT spread (DFTS) method in VLC-OFDM systems in terms of PAPR reduction capability. The bit error rate (BER) performance of the VLC-OFDM system with the μ-law CT is also analyzed over an indoor dispersive VLC channel model.