Analysis of Companding Reduction of PAPR in Optical Wireless OFDM System in the Presence of LED Nonlinearity

This paper studied the companding reduction of peak to average power ratio (PAPR) in optical wireless communication (OWC) system. The companding was evaluated by the reduction of PAPR and the system bit error rate (BER). The BER of companded asymmetrically clipped optical orthogonal frequency division multiplexing (ACOOFDM) signal under additive white gaussion noise (AWGN) channel was simulated. The nonlinearity of light emitting diode (LED), which was used as optical front end, was also considered in the simulation. The simulation results show that BER is degraded by not only companding noise but also the noise caused by LED nonlinearity. The companding noise is dominant when the signal to noise ratio (SNR) is lower than about 13dB. However, the BER is mainly affected by LED nonlinearity when the SNR is higher than about 15.8dB.