1.5-Tb/s Guard-Banded Superchannel Transmission over 56× 100-km (5600-km) ULAF Using 30-Gbaud Pilot-Free OFDM-16QAM Signals with 5.75-b/s/Hz Net Spectral Efficiency

We transmit a 1.5-Tb/s guard-banded superchannel, consisting of eight all-electronically-generated 30-Gbaud pilot-free PDM-OFDM-16QAM signals spaced at 32.8 GHz, over 5600-km ULAF, achieving the highest spectral-efficiency-distance product of over 32,000 km⋅b/s/Hz for Tb/s-class superchannel transmission with >5 b/s/Hz net spectral efficiency.