Pre-Distorted ADO-OFDM for Mutual Interference Eliminating with Low Complexity and Low Latency

Although the conventional asymmetrically clipped direct current biased optical OFDM (ADO-OFDM) scheme shows a tradeoff of the optical power efficiency and spectrum efficiency compared with the asymmetrically clipped optical OFDM (ACO-OFDM) and DC biased optical OFDM (DCO-OFDM) schemes, it will face the problem of mutual interference, leading to the high complexity, extra latency, and error propagation issues. Thus, in this paper, a pre-distorted ADO-OFDM (PADO-OFDM) scheme is proposed to eliminate the mutual interference between ACO-OFDM and DCO-OFDM signals, which means the demodulation of ACO-OFDM and DCO-OFDM signals can be processed simultaneously, and the conventional error propagation from the previous subtraction method can be avoided. Moreover, the corresponding characteristic of PADO-OFDM is also derived, while the formula of probability density function is investigated. Through the complexity analysis, the computational complexity of PADO-OFDM at the receiver is much lower than that of the conventional ADO-OFDM. Moreover, simulation results show that compared with the conventional ADO-OFDM scheme, the proposed PADO-OFDM scheme has the advantages of low process latency.