A new improved-performance receiver for Single-Carrier-Decomposed Quadrature optical wireless communication systems

Single Carrier Decomposed-Quadrature Optical (SC-DQO) modulation has been suggested in the past, as a possible method for use in Optical Wireless (OW) Intensity Modulation with Direct Detection (IM-DD) communication systems. This method has lower peak-to-average power ratio (PAPR) when compared to Asymmetrically-Clipped Optical OFDM (ACO-OFDM). It was shown that its receiver utilizes only 50% of the signal power, while the other 50% is discarded. A new receiving method, based on an estimator which utilizes the discarded portion of the signal, is proposed in this paper, to generate an improved estimator for the transmitted signal. It is shown both theoretically and numerically that the new approach improves the receiver performance of the system by up to 3dB, achieving the efficiency of the latest ACO-OFDM methods, while preserving the PAPR advantage. With this approach, both the transmitter and the modulated signal are not changed while the additional receiver computational complexity is negligible.