Publication Date: 4/8/2019
Event: SubOptic 2019
Reference: pp. 2-5, 2019
Authors: Kohei Nakamura, NEC Corporation; Takanori Inoue, NEC Corporation; Shaoliang Zhang, NEC Laboratories America, Inc.; Fatih Yaman, NEC Laboratories America, Inc.; Eduardo Mateo, NEC Corporation; Yoshihisa Inada, NEC Corporation
Abstract: Flexible wavelength-multiplexing technique in backbone submarine networks has been deployed to accommodate the trend of variable-rate modulation formats. In this paper, we propose a new design of flexible-rate transponders in the scenario of flexible multiplexing scheme to achieve near-Shannon performance. Probabilistic-shaped (PS) M-QAM is capable of adjusting the bit rate at very finer granularity by adapting the entropy of the distribution matcher. Instead of delivering variable bit rates at the fixed baud rate, various baud rates of 200Gb/s PS-16QAM is demonstrated to fit into the flexible grid multiple 3.125GHz bandwidth. This flexible baud rate saves the limited optical bandwidth assigned by the flexible multiplexing scheme to improve bandwidth utilization. The 200G PS-16QAM signals are experimentally demonstrated over 9000km straight-line testbed to achieve 3.05b/s/Hz~5.33 b/s/Hz spectral efficiency (SE) with up to 4dB Q margin. In addition, the high baud rate signals are used for lower SE while low baud rate signals are targeting at high SE transmission to reduce the implementation penalty.
Publication Link: https://suboptic2019.com/download/5192/