In the optical domain, it has been shown that probabilistic shaping is a very effective method of closing the so called ‘Shaping Gap’. The corresponding algorithms work in blocks and to be most efficient in terms of net data rate when shaping sequences with a very long block length. This comes however, at the cost of these algorithms being more complex. Enumerative Sphere Shaping is capable achieving comparable gains as other algorithms at much lower block length and thus reduced complexity. For the optical channel, this reduction in block length comes with another advantage. Optical fiber nonlinearities distort the signal at high optical powers and this provides a limit on how much information can be sent. In recent times, it has been shown that long shaping blocklengths have a negative impact on tolerance against these nonlinearities, while the opposite is true for short blocklengths. As a result of this effect, a tradeoff exists between rate loss and tolerance against fiber nonlinearities. Enumerative Sphere Shaping is shown to have an optimum with a much shorter blocklength than other algorithms, resulting in overall better performance.
In the project history, Abdelkerim first introduced ESS for the optical communication society with a (to appear) JLT paper. Then, he employed ESS to obtain rate adaptation and reach increase, reported in an ECOC paper. Subsequently, Sebastiaan provided the first experimental demonstration of ESS in optical fiber communications in an OECC/PSC post-deadline paper.
Results and Publications
S. Goossens et al., “First Experimental Demonstration of Probabilistic Enumerative Sphere Shaping in Optical Fiber Communications” in Proceedings of the 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC), Fukuoka, Japan, 2019, pp. 1-3.
A. Amari et al., “Enumerative Sphere Shaping for Rate Adaptation and Reach Increase in WDM Transmission Systems”, 2019, arXiv:1907.01881
A. Amari et al., “Introducing Enumerative Sphere Shaping for Optical Communication Systems with Short Blocklengths” 2019, arXiv:1904.06601