Science Publishing Group
In this paper, the authors proposes a novel symbol mapping that uses signal shaping to alleviate the BER problem in constellation sharing with the use of phase information. This mapping solves one of the most critical problems; the small Euclid distance of the PSK symbols in the constellation sharing of OOK and PSK in Passive Optical Networks (PONs). Constellation sharing enables next generation PONs to overlay existing PONs with the use of an advanced modulation format based on the Digital Signal Processing (DSP) technology that well supports migration of the access network. The modulation format of Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), and Quadrature Amplitude Modulation (QAM) can co-exist with the existing PONs, which utilize On-Off Keying (OOK).