A combined PAPR-reduction technique for asymmetrically clipped optical OFDM system

•The proposed technique combines DFT-spread technique with peak-clipping technique.•10(−3)10(−3)A 6 dB of PAPR reduction can be obtained by the combined PAPR-reduction technique.•The combined technique can improve the BER performance of ACO-OFDM greatly.

In this paper, we propose a combined peak-to-average power ratio (PAPR) reduction technique for asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) system. The proposed PAPR-reduction technique combines discrete Fourier transform (DFT)-spread technique with peak-clipping technique. For a tradeoff between PAPR and BER performance, the clipping ratio (CR) in peak-clipping technique is set to 2.2. Under this CR, a 6 dB of PAPR reduction can be obtained by the combined PAPR-reduction technique at the probability of 10−3 and BER performance is barely affected by the clipping distortion. The transmission experiment over 100-km SSMF has been implemented to verify the feasibility of the proposed scheme. At the forward error correction (FEC) limit, ACO-OFDM with the combined PAPR-reduction technique has 1.8 dB improvement of received sensitivity compared to ACO-OFDM with DFT-spread technique and 3.8 dB improvement compared to conventional ACO-OFDM.