25 Tb/s transmission over 5,530 km using 16QAM at 5.2 bits/s/Hz spectral efficiency

We transmit 250×100G PDM RZ 16QAM channels with 5.2 bits/s/Hz spectral efficiency over 5,530 km using single stage C-band EDFAs equalized to 40 nm. We use coded modulation and all channels are decoded with no errors after iterative decoding between a MAP and an LDPC based FEC decoder.