This paper reviews the performance of optimized modulation formats in two, four, and eight
dimensions. We present performance (lower bounds) for higher dimensions by exploiting …

Nowadays, public demands high capacity global internet traffic in terms of cloud computing,
video gaming, fiber to the home and mobile networks, etc. To fulfill such huge traffic …

We propose a RF-pilot aided modulation format identification (MFI) technique to enable a
hitless flexible coherent transceiver with fast format switching. For the MFI, modulation format …

Constellation shaping has been widely used in optical communication systems. We review
recent advances in two-dimensional constellation shaping technologies for fiber-optic …

Four-dimensional signal constellations based on the checkerboard lattice D 4 offer a
packing gain over conventional QAM constellations per polarization. Due to the increased …

We investigate the rate adaptability of quadrature amplitude modulation (QAM)-based
probabilistic constellation shaping (PCS) using a fixed forward error correction (FEC) …

We propose a hitless flexible coherent transceiver enabled by a novel modulation format
identification (MFI) scheme for dynamic agile optical networks. The modulation format …

Multidimensional optical modulation (MOM) is one of the promising techniques for spectrally
efficient optical access network transmissions. However, inter-dimensional interference (IDI) …

We propose the combination of log-likelihood ratio (LLR) table and min-sum algorithm-
based LLR updates for simple, precise, and flexible soft-demapping of multi-dimensional …

This chapter overviews the relatively large body of work (experimental and theoretical) on
modulation formats for optical coherent links. It first gives basic definitions and performance …