[1] Winzer P J. Modulation and multiplexing in optical communication systems. IEEE LEOS Newsletter, 2009, 23(1): 4–10

[2] Fukuchi K, Kasamatsu T, Morie M, Ohhira R, Ito T, Sekiya K, Ogasawara D, Ono T. 10.92-Tb/s (273 40-Gb/s) triple-band/ultradense WDM optical-repeatered transmission experi-ment. In Proceedings of Optical Fiber Communication Conference (OFC)2001.2001, Paper PD24

[3] Gnauck A H, Charlet G, Tran P, Winzer P J, Doerr C R, Centanni J C, Burrows E C, Kawanishi T, Sakamoto T, Higuma K. 25.6-Tb/s C + L band transmission of polarization-multiplexed RZ-DQPSK signals. In: Proceedings of Optical Fiber Communication Conference (OFC) 2007.2007, PD19

[4] Zhou X, Yu J, Huang M F, Shao Y, Wang T, Nelson L, Magill P, Birk M, Borel P I, Peckham D W, Lingle R Jr. 64-Tb/s (640 ×107- Gb/s) PDM-36 QAM transmission over 320 km using both pre- and post-transmission digital equalization. In: Proceedings of Optical Fiber Communication Conference (OFC) 2010.2010, PDP B9

[5] Qian D, Huang M, Ip E, Huang Y K, Shao Y, Hu J, Wang T. High capacity/spectral efficiency 101.7-Tb/s WDM transmission using PDM-128QAM-OFDM over 165-km SSMF within C- and L-bands. Journal of Lightwave Technology, 2012, 30(10): 1540–1548

[6] Sano1 A, Kobayashi T, Yamanaka S, Matsuura A, Kawakami H, Miyamoto Y, Ishihara K, Masuda H. 102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone. In: Proceedings of Optical Fiber Communication Conference (OFC) 2012.2012, PDP B5C.3

[7] Luo M, Li C, Yang Q, He Z, Xu J, Zhang Z, Yu S. 100.3-Tb/s (375×267.27-Gb/s) C- and L-band transmission over 80-km SSMF using DFT-S OFDM 128-QAM. In: Proceedings of Asia-Pacific Communications and Photonics Conference (ACP) 2014.2014, PDP AF4B.1

[8] Richardson D J, Fini J M, Nelson L E. Space-division multiplexing in optical fibers. Nature Photonics, 2013, 7(5): 354–362

[9] Krummrich P M, Petermann K. Evaluation of potential optical amplifier concepts for coherent mode multiplexing. In: Proceedings of Optical Fiber Communication Conference (OFC) 2012.2012, Paper OMH5

[10] Ip E, Bai N, Huang Y K, Mateo E, Yaman F, LiMJ. 88×3×112-Gb/ s WDM transmission over 50 km of three-mode fiber with inline few-mode fiber amplifier. In: Proceedings of 37th European Conference and Exhibition on Optical Communication (ECOC), 2011.2011, Paper Th.13.C.2

[11] Sleiffer V, Jung Y, Veljanovski V, Uden R, Kuschnerov M, Kang Q, Grüner-Nielsen L, Sun Y, Richardson D, Alam S, Poletti F, Sahu J, Dhar A, Chen H, Inan B, Koonen T, Corbett B, Winfield R, Ellis A, Waardt H. 73.7 Tb/s (96×3×256-Gb/s) mode-division-multiplexed DP-16QAM transmission with inline MM-EDFA. In: Proceedings of European Conference and Exhibition on Optical Communication (ECOC) 2012.2012, Th.3.C.4

[12] Ryf R, Randel S, Fontaine N K, Montoliu M, Burrows E, Chandrasekhar S, Gnauck A H, Xie C, Essiambre R, Winzer P, Delbue R, Pupalaikis P, Sureka A, Sun Y, Gruner-Nielsen L, Jensen R V, Lingle R. 32-bit/s/Hz spectral efficiency WDM transmission over 177-km few-mode fiber. In: Proceedings of Optical Optical Fiber Communication Conference (OFC) 2013.2013, PDP5A.1

[13] Ip E, Li M J, Huang Y K, Tanaka A, Mateo E, Wood W, Hu J Q, Yano Y, Koreshkov K. 146l×6×19-Gbaud wavelength- and modedivision multiplexed transmission over 10×50-km spans of fewmode fiber with a gain-equalized few-mode EDFA. In: Proceedings of Optical Fiber Communication Conference (OFC) 2013.2013, PDP5A.2

[14] Yang Q, He Z, Yang Z, Yu S, Yi X, Shieh W. Coherent optical DFTspread OFDM transmission using orthogonal band multiplexing. Optics Express, 2012, 20(3): 2379–2385

[15] Li C, Yang Q, Jiang T, He Z, Luo M, Li C, Xiao X, Xue D, Yi X, Yu S. Investigation of coherent optical multi-band DFT-S OFDM in long haul transmission. IEEE Photonics Technology Letters, 2012, 24(19): 1704–1707

[16] Randel S, Ryf R, Sierra A, Winzer P J, Gnauck A H, Bolle C A, Essiambre R J, Peckham DW, McCurdy A, Lingle R Jr. 6×56-Gb/s mode-division multiplexed transmission over 33-km few-mode fiber enabled by 6×6 MIMO equalization. Optics Express, 2011, 19(17): 16697–16707

[17] Liu X, Buchali F, Tkach R W. Improving the nonlinear tolerance of polarization-division-multiplexed CO-OFDM in long-haul fiber transmission. Journal of Lightwave Technology, 2009, 27(16): 3632–3640