Combined discrete Fourier transform precoding and clipping using direct detection optical OFDM

We propose and demonstrate experimentally the bit error rate (BER) performance of intensity modulation with direct detection (IM/DD) optical orthogonal frequency division multiplexing (OFDM) system by combining discrete Fourier transform (DFT) precoding with clipping. The experimental results show that the received sensitivity at a BER of 10−4 for a 12 Gs/s DFT-precoded and clipped OFDM signal and after 100-km standard single-mode fiber transmission has been improved by 3.5 dB when compared with the original OFDM systems in the SMF link, and by 2.5 dB when compared with compared with the DFT-precoded OFDM signals. When compared with the DFT-precoded QPSK OFDM signal, the DFT-precoded and clipped OFDM QPSK signal can achieve approximately 4.5 dB of peak-to-average power ratio (PAPR) reduction at a complementary cumulative distribution functional value of 10−3.