Experimental comparison of 28 Gb/s NRZ and EDB schemes for faster-than-Nyquist PON

摘要

In this paper, we experimentally demonstrate 28 Gb/s non-return-to-zero (NRZ) and electrical duo-binary (EDB) schemes over 25-km standard single-mode fiber transmission for faster-than-Nyquist passive optical network (FTN-PON). FTN signaling is a promising technology in the bandwidth-limited PON system. In order to improve the transmission performance, a combination of feed-forward equalization, post-filter and maximum likelihood sequence detection (FFE-MLSD) need to be employed for FTN-NRZ scheme, while only a simple 3-level FFE is needed for FTN-EDB scheme. The simulation results reveal that EDB scheme with 3-level FFE can transmit further fiber length compared with NRZ scheme at same receiver sensitivity. The experimental results show that EDB scheme achieves a power budget of 37.5 dB for 25-km fiber transmission with a pre-amplifier at the receiver, which is similar to 1.7 dB better than the best performance achieved by NRZ scheme. Meanwhile, the computational complexity of EDB scheme with 3-level FFE is 33.3 lower than that of NRZ scheme based on FFE-MLSD. The EDB scheme with 3-level FFE shows the potential for the future FTN-PON.