Low-complexity peak-to-average power ratio reduction scheme for flip-orthogonal frequency division multiplexing visible light communication system based on μ-law mapping

An orthogonal frequency division multiplexing (OFDM) technique called flipped OFDM (flip-OFDM) is apposite for a visible light communication system that needs the transmitted signal to be real and positive. Flip-OFDM uses two consecutive OFDM subframes to transmit the positive and negative parts of the signal. However, peak-to-average power ratio (PAPR) for flip-OFDM is increased tremendously due to the low value of total average power that arises from many zero values in both the positive and flipped frames. We first analyze the performance of flip-OFDM and perform a comparison with the conventional DC-biased OFDM (DCO-OFDM); then we propose a flip-OFDM scheme combined with μ-law mapping to reduce the high PAPR. The simulation results show that the PAPR of the system is reduced about 17.2 and 5.9 dB when compared with the normal flip-OFDM and DCO-OFDM signals, respectively.