Constrained Turbo Block Convolutional Codes for 100 G and Beyond Optical Transmissions

Constrained turbo block convolutional (CTBC) codes are developed for 100 G and beyond optical transmissions. The CTBC codes developed herein each fit within one optical transport network (OTN) frame. The CTBC codes involve a simple outer block code that is serially concatenated with a simple inner recursive convolutional code using a constrained interleaver that simultaneously delivers a high interleaver gain and a high minimum Hamming distance. Codes with 11.1 dB net coding gain (NCG) at 12.5% overhead (OH), 11.3 dB NCG at 15% OH, 11.6 dB NCG at 20% OH, and 11.9 dB NCG at 23.4% OH are reported. Compared with other codes that have been previously proposed for OTN applications, CTBC codes have much lower encoding/decoding complexity, improved NCG/OH tradeoffs, and avoid negative error floor effects.