Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD Systems

In this paper, three forms of orthogonal frequency division multiplexing (OFDM) designed for intensity modulated/direct detection (IM/DD) optical systems are compared. These are asymmetrically clipped optical OFDM (ACO-OFDM), DC biased optical OFDM (DCO-OFDM) and asymmetrically clipped DC biased optical OFDM (ADO-OFDM). ADO-OFDM is a new technique that combines aspects of ACO-OFDM and DCO-OFDM by simultaneously transmitting ACO-OFDM on the odd subcarriers and DCO-OFDM on the even subcarriers. The odd subcarriers are demodulated as in a conventional ACO-OFDM receiver and the even subcarriers are demodulated using a form of interference cancellation. ADO-OFDM is shown to be more optically power efficient than…