8.5. 1 High spectral-efficiency long-haul transmission YearModulation FormatData Rate2009QPSK CO-OFDM1.2 Tb/s2010QPSK NGI-CO-OFDM1.2 Tb/s201016-QAM CO-OFDM520.8 Gb/s2012256-IPM CO-OFDM231.5 Gb/sHigher Order Modulation – an overview | ScienceDirect Topics www.sciencedirect.com › topics › engineering › higher-order-modulation