Experimental demonstration of 28 Gbaud QPSK and 16-QAM zero-guard-interval CO-OFDM transmissions

28 Gbaud QPSK and 16-QAM zero-guard-interval (ZGI) CO-OFDM transmission with only 1.34% overhead for OFDM processing is reported. The high tolerance of ZGI CO-OFDM to residual inter-symbol interference and imperfect frame synchronization is also demonstrated.