Title :
16
125 Gb/s Quasi-Nyquist DAC-Generated PM-16QAM Transmission Over 3590 km of PSCF
Author :
Cigliutti, Roberto ; Nespola, Antonino ; Zeolla, Dario ; Bosco, Gabriella ; Carena, Andrea ; Curri, Vittorio ; Forghieri, Fabrizio ; Yamamoto, Yoshinori ; Sasaki, Takashi ; Poggiolini, Pierluigi
Author_Institution :
Dipt. di Elettron. e Telecomun., Politec. di Torino, Turin, Italy
Abstract :
We report on a transmission experiment over high-performance pure silica core fiber (PSCF) of 16 Nyquist wavelength-division-multiplexed (Nyquist-WDM) channels at a symbol rate of 15.625 GBaud, using polarization-multiplexed (PM) 16 symbols quadrature amplitude modulation (16QAM), resulting in a per-channel raw bit rate of 125 Gb/s. The channel spacing is 16 GHz, corresponding to 1.024 times the symbol rate. The interchannel crosstalk penalty is drastically reduced through the confinement of the signal spectrum within a near-Nyquist bandwidth, achieved with digital filtering and digital-to-analog converters (DACs) operating at 1.5 samples/symbol. The optical line is a recirculating loop composed of two spans of high-performance PSCF with erbium-doped fiber amplifiers only. The transmission distance of 3590 km at a target line bit-error rate (BER) of 1.5 10-2 is achieved at a raw spectral efficiency (SE) of 7.81 b/s/Hz. Assuming a commercial hard forward error correction with 20.5% redundancy, capable of handling the target BER, the net SE is 6.48 b/s/Hz, the highest so far reported for multithousand kilometer transmission of PM-16QAM at ≥ 100 Gb/s per channel. These results demonstrate the feasibility of very high SE DAC-enabled ultra-long-haul quasi-Nyquist-WDM transmission using PM-16QAM with current technologies and manageable digital signal processing complexity.
Keywords :
channel spacing; digital-analogue conversion; error statistics; forward error correction; optical crosstalk; optical fibre amplifiers; optical fibre communication; optical modulation; quadrature amplitude modulation; silicon compounds; wavelength division multiplexing; BER; Nyquist-WDM channels; PM-16QAM transmission; PSCF; bit rate 125 Gbit/s; bit rate 2000 Gbit/s; channel spacing; digital filtering; digital signal processing complexity; digital-to-analog converters; distance 3590 km; erbium-doped fiber amplifiers; frequency 16 GHz; hard forward error correction; interchannel crosstalk penalty; optical line; polarization multiplexing; pure silica core fiber; quadrature amplitude modulation; quasiNyquist DAC; raw spectral efficiency; redundancy; target BER; target line bit-error rate; wavelength-division-multiplexing; Bit error rate; Channel spacing; Digital signal processing; Nonlinear optics; Optical receivers; Optical transmitters; Wavelength division multiplexing; Coherent detection; Nyquist-WDM; optical communications; quadrature amplitude modulation (QAM); wavelength division multiplexing (WDM);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2223551