Polarization and frequency division multiplexed 1Gsymbol/s, 64 QAM coherent optical transmission with 8.6bit/s/Hz spectral efficiency over 160km. - Hiroki Goto; Masato Yoshida; Tatsunori Omiya; Keisuke Kasai; Masataka Nakazawa (IEICE Electron. Express, 2008)

60Gbit/s 64 QAM-OFDM coherent optical transmission with a 5.3GHz bandwidth. - Tatsunori Omiya; Seiji Okamoto; Keisuke Kasai; Masato Yoshida; Masataka Nakazawa (IEICE Electron. Express, 2010)

256 QAM Digital Coherent Optical Transmission Using Raman Amplifiers. - Masato Yoshida; Seiji Okamoto; Tatsunori Omiya; Keisuke Kasai; Masataka Nakazawa (IEICE Trans. Commun., 2011)

400 Gbit/s 256 QAM-OFDM transmission over 720 km with a 14 bit/s/Hz spectral efficiency using an improved FDE technique. - Tatsunori Omiya; Masato Yoshida; Masataka Nakazawa (OFC/NFOEC, 2013)