Quadrature diversity combining for pulse-amplitude modulated DMT in IM/DD channels

PAM-DMT is a transmission technique for IM/DD channels that can be effectively employed without a DC bias, by using only the quadrature component of QAM constellations. In this contribution, and based on an algorithm previously employed for AC-DMT [8], we show that the non-linear distortion that falls onto the in-phase component of the received signal also contains useful information, and can be adequately combined with the quadrature component to improve the detection performance.