Presentation 2022-01-13
85.2-Tbit/s Coupled 4-Core Fiber Transmission over 3,120 km Using PS-16QAM Signals
Shohei Beppu, Daiki Soma, Hidenori Takahashi, Noboru Yoshikane, Itsuro Morita, Takehiro Tsuritani,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) In the optical submarine cable system, which is a global communication infrastructure, continuous and dramatic increase of the total cable capacity is required in order to meet the huge demand of communication traffic in the future. To maximize the total cable capacity under the average optical power limitation, the space-division multiplexing (SDM) technique has been attracting attention, in which multiple spatially channels are used to distribute the launch power. Because the capacity per channel decreases with the logarithm of the signal to noise ratio (SNR) according to Shannon's theorem, the total transmission capacity can be enlarged by increasing the number of SDM channels. In recent years, optical cables which accommodates a large number of fiber pairs (FPs) per cable and used them as SDM channels (namely, SDM1) has been considered a promising candidate. However, space limitation in conventional cable structures is a problem for further increasing the number of FPs. To further increase of the number of SDM channels, multi-core fibers (MCFs) and multimode fibers (MMFs) are attracting attention. In particular, MCFs with a standard cladding diameter of 125 um are considered as the first step toward the early development of SDM transmission systems using MCFs. Because standard cladding MCFs are expected to have the same mechanical strength and productivity as conventional SMFs, and conventional cable structures can also be applied. In this study, we focus on coupled MCFs, which can have larger number of cores than uncoupled MCFs. In addition to using the coupled MCFs, optimization of a modulation format according to the channel SNR is also important for maximizing the transmission capacity. In recent years, probabilistic shaping (PS), which can adjust the entropy, has been attracting attention as a modulation format optimization scheme. However, there is no report on the application of PS to coupled MCF transmission systems. In this work, the entropy of PS-16QAM signals was optimized for a 3,000-km optical submarine cable system with standard cladding diameter coupled core 4-core fibers. A transmission capacity of 85.2-Tbps was achieved after a 3,120-km coupled 4-core fiber transmission.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) Space division multiplexing / Multicore fiber / Probabilistic shaping
Paper # OCS2021-35
Date of Issue 2022-01-06 (OCS)

Conference Information
Committee OCS / CS
Conference Date 2022/1/13(2days)
Place (in Japanese) (See Japanese page)
Place (in English) Conference room 204A・B at KDDI Ishin-hall
Topics (in Japanese) (See Japanese page)
Topics (in English) Core and metro system, Submarine telecommunications system, Optical access system and next generation PON, Ethernet, Optical Transport Network (OTN), Transmission monitoring and control, Design and tool for optical transmission system, Co-operation between optical and mobile, etc.
Chair Takeshi Hoshida(Fujitsu) / Jun Terada(NTT)
Vice Chair / Daisuke Umehara(Kyoto Inst. of Tech.)
Secretary (NTT) / Daisuke Umehara(Fujikura)
Assistant / Takahiro Yamaura(Toshiba) / Yuta Ida(Yamaguchi Univ.)

Paper Information
Registration To Technical Committee on Optical Communication Systems / Technical Committee on Communication Systems
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) 85.2-Tbit/s Coupled 4-Core Fiber Transmission over 3,120 km Using PS-16QAM Signals
Sub Title (in English)
Keyword(1) Space division multiplexing
Keyword(2) Multicore fiber
Keyword(3) Probabilistic shaping
1st Author's Name Shohei Beppu
1st Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
2nd Author's Name Daiki Soma
2nd Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
3rd Author's Name Hidenori Takahashi
3rd Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
4th Author's Name Noboru Yoshikane
4th Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
5th Author's Name Itsuro Morita
5th Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
6th Author's Name Takehiro Tsuritani
6th Author's Affiliation KDDI Research, Inc.(KDDI Research, Inc.)
Date 2022-01-13
Paper # OCS2021-35
Volume (vol) vol.121
Number (no) OCS-320
Page pp.pp.11-15(OCS),
#Pages 5
Date of Issue 2022-01-06 (OCS)