On Shaping Gain of Multidimensional Constellation in Linear and Nonlinear Optical Fiber Channel
Journal article, 2025

Utilizing the multi-dimensional (MD) space for constellation shaping has been proven to be an effective approach for achieving shaping gains. Despite there exists a variety of MD modulation formats tailored for specific optical transmission scenarios, there remains a notable absence of a dependable comparison method for efficiently and promptly re-evaluating their performance in arbitrary transmission systems. In this paper, we introduce an analytical nonlinear interference (NLI) power model-based shaping gain estimation method to enable a fast performance evaluation of various MD modulation formats in coherent dual-polarization (DP) optical transmission system. In order to extend the applicability of this method to a broader set of modulation formats, we extend the established NLI model to take the 4D joint distribution into account and thus able to analyze the complex interactions of non-iid signaling in DP systems. With the help of the NLI model, we conduct a comprehensive analysis of the state-of-the-art modulation formats and investigate their actual shaping gains in two types of optical fiber communication scenarios (multi-span and single-span). The numerical simulation shows that for arbitrary modulation formats, the NLI power and relative shaping gains in terms of signal-to-noise ratio can be more accurately estimated by capturing the statistics of MD symbols. Furthermore, the proposed method further validates the effectiveness of the reported NLI-tolerant modulation format in the literature, which reveals that the linear shaping gains and modulation-dependent NLI should be jointly considered for nonlinearity mitigation.

multidimensional modulation format

constellation shaping

nonlinearity

Optical fiber communication

achievable information rates

Author

Bin Chen

Hefei University of Technology

Zhiwei Liang

Hefei University of Technology

Yi Lei

Hefei University of Technology

Jing Xin Deng

Hefei University of Technology

Shen Li

Centre d'Optique, Photonique et Laser

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

Gabriele Liga

Eindhoven University of Technology

IEEE Journal on Selected Areas in Communications

0733-8716 (ISSN) 15580008 (eISSN)

Vol. In Press

Subject Categories (SSIF 2025)

Communication Systems

Telecommunications

Signal Processing

DOI

10.1109/JSAC.2025.3543507

More information

Latest update

3/11/2025