Experimental study of non-binary LDPC coding for long-haul coherent optical QPSK transmissions

Shaoliang Zhang, Murat Arabaci, Fatih Yaman, Ivan B. Djordjevic, Lei Xu, Ting Wang, Yoshihisa Inada, Takaaki Ogata, Yasuhiro Aoki
2011 Optics Express  
The performance of rate-0.8 4-ary LDPC code has been studied in a 50GHz-spaced 40Gb/s DWDM system with PDM-QPSK modulation. The net effective coding gain of 10dB is obtained at BER of 10 −6 . With the aid of time-interleaving polarization multiplexing and MAP detection, 10,560km transmission over legacy dispersion managed fiber is achieved without any countable errors. The proposed nonbinary quasi-cyclic LDPC code achieves an uncoded BER threshold at 4×10 −2 . Potential issues like phase
more » ... s like phase ambiguity and coding length are also discussed when implementing LDPC in current coherent optical systems.
doi:10.1364/oe.19.019042 pmid:21996844 fatcat:ivx57urkjfhrdbmiq3fdnufb5y