K Ishida, K Shimizu, T Mizuochi… - Optical Fiber …, 2004 - opg.optica.org
Transmission of 20 x 20 Gb/s RZ-DQPSK signals over 5090 km with 0.53 b/s/Hz spectral
efficiency Page 1 Transmission of 20 x 20 Gb/s RZ-DQPSK signals over 5090 km with 0.53 b/s/Hz …