A novel PAPR reduction method for ADO-OFDM VLC systems

摘要

Asymmetrically clipped DC-biased optical frequency division multiplexing (ADO-OFDM) technology is developed in visible light communication (VLC) systems. Peak to average power ratio is the major problem in the optical OFDM signal, which reduces the performance of VLC due to the light-emitting diode non-linearity. This paper illustrates the uses of the signal clipping method, and different companding approaches for PAPR reduction, such as the μ-law, logarithmic, and novel proposed scheme. The proposed model is a nonlinear companding technique which is a modified version of the μ-law and logarithmic models placed at the front end of the VLC transmitter. De-companding is placed before the ADO-OFDM modulator, which reconstructs the OFDM signal. Simulation results denote that the proposed model in companding and de-companding is a better choice. The advantage of this technique is a tradeoff between the bit error rate and PAPR. It reaches over 70% reduction of the original PAPR signal and can boost the BER from 0.03 up to 4.9 ×10~(-6) when signal-to-noise =26 dB. So, according to these results, the proposed system is considered a performance enhancement model for the ADO-OFDM based on VLC.