WDM Transmission of Single-Carrier 120-GBd ETDM PDM-16QAM Signals Over 1200-km Terrestrial Fiber Links

We demonstrate the generation and wavelength-division multiplexing (WDM) transmission of single-carrier 120-GBd electronic time-division multiplexing (ETDM) polarization division multiplexed 16-ary quadrature amplitude modulation (16 QAM) optical signals. Both transmitter-side optical preemphasis and receiver-side maximum likelihood sequence estimation are utilized to mitigate the impairments caused by bandwidth limitation of the optoelectronic components. Thanks to the preemphasis and post equalization, we have successfully transmitted 12 WDM channels on 150-GHz grid, each loaded with 960-Gb/s (800 Gb/s data signals + 20% FEC emulated overhead bits) over 1200-km link based on 100 km/span TeraWave terrestrial optical fiber. The achieved data rate interface ensured spectral efficiency of 5.33 b/s/Hz. To the best of our knowledge, this is the first experiment with the highest symbol rate reported for ETDM-based 16 QAM signals.