We experimentally demonstrate a highly filtering-tolerant multi-modulus equalization (MMEQ) process for very aggressively spectrum-shaped 9-ary quadrature-amplitude-modulation (9-QAM)-like polarization division multiplexing quadrature phase shift keying (PDM-QPSK) signal to achieve 400-Gb/s wavelength-division-multiplexing (WDM) channels on the 100-GHz grid for ultra-long-haul reach and high tolerance of the filter narrowing effect caused by reconfigurable optical add-drop multiplexers (ROADMs). We successfully transmitted 8 channels 480-Gb/s super-Nyquist (channel occupancy much less than signal baud rate) WDM signals at 100-GHz grid over 25 × 200 km conventional single-mode fiber-28 (SMF-28) with post Raman amplification and 25 ROADMs at a net spectral efficiency (SE) of 4b/s/Hz, after excluding the 20% soft-decision forward-error-correction (FEC) overhead. The system performance is significantly enhanced by the MMEQ based on 9-QAM-like constellations compared to the conventional 4 point QPSK constellation. A record transmission distance over conventional SMF-28 with a large number of ROADMs is firstly reported on the 400-Gb/s channels at 100-GHz grid.
© 2013 OSAFull Article | PDF Article
Pierpaolo Boffi, Paolo Martelli, Matteo Cirigliano, Maurizio Magarini, Mario Martinelli, Marco Bertolini, Marianna Pepe, Domenico Di Mola, and Giancarlo Gavioli
Opt. Express 19(22) 21898-21903 (2011)
Markus Nölle, Johannes Karl Fischer, Lutz Molle, Carsten Schmidt-Langhorst, David Peckham, and Colja Schubert
Opt. Express 19(24) 24370-24375 (2011)
Xinying Li, Jianjun Yu, Ze Dong, Hung-Chang Chien, Zhensheng Jia, and Nan Chi
Opt. Express 20(26) B217-B222 (2012)