Performance analysis of modified Asymmetrically-Clipped Optical Orthogonal Frequency-Division Multiplexing systems

•A modification to the ACO-OFDM technique is proposed through unipolar encoding.•A mathematical model for the (BER) performance is carried out to the proposed system and verified by Monte Carlo simulations.•The BER performance of the MACO-OFDM and that of conventional ACO-OFDM are compared.•Both the MACO-OFDM and conventional ACO-OFDM are applied in atmospheric turbulent channel.

A modification to the Asymmetrically-Clipped Optical Orthogonal Frequency-Division Multiplexing (ACO-OFDM) technique is proposed through unipolar encoding. A performance analysis of the Bit Error Rate (BER) is developed and Monte Carlo simulations are carried out to verify the analysis. Results are compared to that of the corresponding ACO-OFDM system under the same bit energy and transmission rate; an improvement of 1 dB is obtained at a BER of 10−4 . In addition, the performance of the proposed system in the presence of atmospheric turbulence is investigated using single-input multiple-output (SIMO) configuration and its performance under that environment is compared to that of ACO-OFDM. Energy improvements of 4 dB and 2.2 dB are obtained at a BER of 10−4 for SIMO systems of 1 and 2 photodetectors at the receiver for the case of strong turbulence, respectively.