Low-PAPR Asymmetrically Clipped Optical OFDM for Intensity-Modulation/Direct-Detection Systems

In this paper, we propose a discrete Hartley transform (DHT)-spread technique for peak-to-average power ratio (PAPR) reduction in a DHT-based asymmetrically clipped optical orthogonal frequency-division multiplexing (ACO-OFDM) system. At the complementary cumulative distribution function of 10^-3, the PAPR values of our proposed scheme are about 9.7 and 6.2 dB lower than those of conventional DHT-based ACO-OFDM without DHT-spread technique for 2-pulse-amplitude modulation (2-PAM) and 4-PAM, respectively. The transmission experiment over a 100-km standard singlemode fiber had been realized to verify the feasibility of the proposed scheme. When the overall link rate was about 10 Gb/s, the proposed scheme had an approximately 7-dB improvement of received sensitivity at forward error correction limit compared with the conventional scheme. The proposed scheme has better transmission performance than the conventional scheme due to its low PAPR and effective equalization.